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1 //===-- MipsISelLowering.cpp - Mips DAG Lowering Implementation -----------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the interfaces that Mips uses to lower LLVM code into a
11 // selection DAG.
12 //
13 //===----------------------------------------------------------------------===//
14 #include "MipsISelLowering.h"
15 #include "InstPrinter/MipsInstPrinter.h"
16 #include "MCTargetDesc/MipsBaseInfo.h"
17 #include "MipsCCState.h"
18 #include "MipsMachineFunction.h"
19 #include "MipsSubtarget.h"
20 #include "MipsTargetMachine.h"
21 #include "MipsTargetObjectFile.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringSwitch.h"
24 #include "llvm/CodeGen/CallingConvLower.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineInstrBuilder.h"
28 #include "llvm/CodeGen/MachineJumpTableInfo.h"
29 #include "llvm/CodeGen/MachineRegisterInfo.h"
30 #include "llvm/CodeGen/FunctionLoweringInfo.h"
31 #include "llvm/CodeGen/SelectionDAGISel.h"
32 #include "llvm/CodeGen/ValueTypes.h"
33 #include "llvm/IR/CallingConv.h"
34 #include "llvm/IR/DerivedTypes.h"
35 #include "llvm/IR/GlobalVariable.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/raw_ostream.h"
40 #include <cctype>
41 
42 using namespace llvm;
43 
44 #define DEBUG_TYPE "mips-lower"
45 
46 STATISTIC(NumTailCalls, "Number of tail calls");
47 
48 static cl::opt<bool>
49 LargeGOT("mxgot", cl::Hidden,
50          cl::desc("MIPS: Enable GOT larger than 64k."), cl::init(false));
51 
52 static cl::opt<bool>
53 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
54                cl::desc("MIPS: Don't trap on integer division by zero."),
55                cl::init(false));
56 
57 static const MCPhysReg Mips64DPRegs[8] = {
58   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
59   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
60 };
61 
62 // If I is a shifted mask, set the size (Size) and the first bit of the
63 // mask (Pos), and return true.
64 // For example, if I is 0x003ff800, (Pos, Size) = (11, 11).
isShiftedMask(uint64_t I,uint64_t & Pos,uint64_t & Size)65 static bool isShiftedMask(uint64_t I, uint64_t &Pos, uint64_t &Size) {
66   if (!isShiftedMask_64(I))
67     return false;
68 
69   Size = countPopulation(I);
70   Pos = countTrailingZeros(I);
71   return true;
72 }
73 
getGlobalReg(SelectionDAG & DAG,EVT Ty) const74 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
75   MipsFunctionInfo *FI = DAG.getMachineFunction().getInfo<MipsFunctionInfo>();
76   return DAG.getRegister(FI->getGlobalBaseReg(), Ty);
77 }
78 
getTargetNode(GlobalAddressSDNode * N,EVT Ty,SelectionDAG & DAG,unsigned Flag) const79 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
80                                           SelectionDAG &DAG,
81                                           unsigned Flag) const {
82   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
83 }
84 
getTargetNode(ExternalSymbolSDNode * N,EVT Ty,SelectionDAG & DAG,unsigned Flag) const85 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
86                                           SelectionDAG &DAG,
87                                           unsigned Flag) const {
88   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
89 }
90 
getTargetNode(BlockAddressSDNode * N,EVT Ty,SelectionDAG & DAG,unsigned Flag) const91 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
92                                           SelectionDAG &DAG,
93                                           unsigned Flag) const {
94   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
95 }
96 
getTargetNode(JumpTableSDNode * N,EVT Ty,SelectionDAG & DAG,unsigned Flag) const97 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
98                                           SelectionDAG &DAG,
99                                           unsigned Flag) const {
100   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
101 }
102 
getTargetNode(ConstantPoolSDNode * N,EVT Ty,SelectionDAG & DAG,unsigned Flag) const103 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
104                                           SelectionDAG &DAG,
105                                           unsigned Flag) const {
106   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlignment(),
107                                    N->getOffset(), Flag);
108 }
109 
getTargetNodeName(unsigned Opcode) const110 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
111   switch ((MipsISD::NodeType)Opcode) {
112   case MipsISD::FIRST_NUMBER:      break;
113   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
114   case MipsISD::TailCall:          return "MipsISD::TailCall";
115   case MipsISD::Hi:                return "MipsISD::Hi";
116   case MipsISD::Lo:                return "MipsISD::Lo";
117   case MipsISD::GPRel:             return "MipsISD::GPRel";
118   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
119   case MipsISD::Ret:               return "MipsISD::Ret";
120   case MipsISD::ERet:              return "MipsISD::ERet";
121   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
122   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
123   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
124   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
125   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
126   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
127   case MipsISD::MFHI:              return "MipsISD::MFHI";
128   case MipsISD::MFLO:              return "MipsISD::MFLO";
129   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
130   case MipsISD::Mult:              return "MipsISD::Mult";
131   case MipsISD::Multu:             return "MipsISD::Multu";
132   case MipsISD::MAdd:              return "MipsISD::MAdd";
133   case MipsISD::MAddu:             return "MipsISD::MAddu";
134   case MipsISD::MSub:              return "MipsISD::MSub";
135   case MipsISD::MSubu:             return "MipsISD::MSubu";
136   case MipsISD::DivRem:            return "MipsISD::DivRem";
137   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
138   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
139   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
140   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
141   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
142   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
143   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
144   case MipsISD::Sync:              return "MipsISD::Sync";
145   case MipsISD::Ext:               return "MipsISD::Ext";
146   case MipsISD::Ins:               return "MipsISD::Ins";
147   case MipsISD::LWL:               return "MipsISD::LWL";
148   case MipsISD::LWR:               return "MipsISD::LWR";
149   case MipsISD::SWL:               return "MipsISD::SWL";
150   case MipsISD::SWR:               return "MipsISD::SWR";
151   case MipsISD::LDL:               return "MipsISD::LDL";
152   case MipsISD::LDR:               return "MipsISD::LDR";
153   case MipsISD::SDL:               return "MipsISD::SDL";
154   case MipsISD::SDR:               return "MipsISD::SDR";
155   case MipsISD::EXTP:              return "MipsISD::EXTP";
156   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
157   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
158   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
159   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
160   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
161   case MipsISD::SHILO:             return "MipsISD::SHILO";
162   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
163   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
164   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
165   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
166   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
167   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
168   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
169   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
170   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
171   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
172   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
173   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
174   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
175   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
176   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
177   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
178   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
179   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
180   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
181   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
182   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
183   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
184   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
185   case MipsISD::MULT:              return "MipsISD::MULT";
186   case MipsISD::MULTU:             return "MipsISD::MULTU";
187   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
188   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
189   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
190   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
191   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
192   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
193   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
194   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
195   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
196   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
197   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
198   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
199   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
200   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
201   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
202   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
203   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
204   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
205   case MipsISD::VSMAX:             return "MipsISD::VSMAX";
206   case MipsISD::VSMIN:             return "MipsISD::VSMIN";
207   case MipsISD::VUMAX:             return "MipsISD::VUMAX";
208   case MipsISD::VUMIN:             return "MipsISD::VUMIN";
209   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
210   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
211   case MipsISD::VNOR:              return "MipsISD::VNOR";
212   case MipsISD::VSHF:              return "MipsISD::VSHF";
213   case MipsISD::SHF:               return "MipsISD::SHF";
214   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
215   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
216   case MipsISD::ILVL:              return "MipsISD::ILVL";
217   case MipsISD::ILVR:              return "MipsISD::ILVR";
218   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
219   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
220   case MipsISD::INSVE:             return "MipsISD::INSVE";
221   }
222   return nullptr;
223 }
224 
MipsTargetLowering(const MipsTargetMachine & TM,const MipsSubtarget & STI)225 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
226                                        const MipsSubtarget &STI)
227     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
228   // Mips does not have i1 type, so use i32 for
229   // setcc operations results (slt, sgt, ...).
230   setBooleanContents(ZeroOrOneBooleanContent);
231   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
232   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
233   // does. Integer booleans still use 0 and 1.
234   if (Subtarget.hasMips32r6())
235     setBooleanContents(ZeroOrOneBooleanContent,
236                        ZeroOrNegativeOneBooleanContent);
237 
238   // Load extented operations for i1 types must be promoted
239   for (MVT VT : MVT::integer_valuetypes()) {
240     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
241     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
242     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
243   }
244 
245   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
246   // for f32, f16
247   for (MVT VT : MVT::fp_valuetypes()) {
248     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
249     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
250   }
251 
252   // Set LoadExtAction for f16 vectors to Expand
253   for (MVT VT : MVT::fp_vector_valuetypes()) {
254     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
255     if (F16VT.isValid())
256       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
257   }
258 
259   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
260   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
261 
262   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
263 
264   // Used by legalize types to correctly generate the setcc result.
265   // Without this, every float setcc comes with a AND/OR with the result,
266   // we don't want this, since the fpcmp result goes to a flag register,
267   // which is used implicitly by brcond and select operations.
268   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
269 
270   // Mips Custom Operations
271   setOperationAction(ISD::BR_JT,              MVT::Other, Custom);
272   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
273   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
274   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
275   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
276   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
277   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
278   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
279   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
280   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
281   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
282   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
283   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
284   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
285   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
286 
287   if (Subtarget.isGP64bit()) {
288     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
289     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
290     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
291     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
292     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
293     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
294     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
295     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
296     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
297     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
298     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
299     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
300   }
301 
302   if (!Subtarget.isGP64bit()) {
303     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
304     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
305     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
306   }
307 
308   setOperationAction(ISD::ADD,                MVT::i32,   Custom);
309   if (Subtarget.isGP64bit())
310     setOperationAction(ISD::ADD,                MVT::i64,   Custom);
311 
312   setOperationAction(ISD::SDIV, MVT::i32, Expand);
313   setOperationAction(ISD::SREM, MVT::i32, Expand);
314   setOperationAction(ISD::UDIV, MVT::i32, Expand);
315   setOperationAction(ISD::UREM, MVT::i32, Expand);
316   setOperationAction(ISD::SDIV, MVT::i64, Expand);
317   setOperationAction(ISD::SREM, MVT::i64, Expand);
318   setOperationAction(ISD::UDIV, MVT::i64, Expand);
319   setOperationAction(ISD::UREM, MVT::i64, Expand);
320 
321   // Operations not directly supported by Mips.
322   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
323   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
324   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
325   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
326   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
327   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
328   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
329   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
330   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
331   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
332   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
333   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
334   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
335   if (Subtarget.hasCnMips()) {
336     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
337     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
338   } else {
339     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
340     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
341   }
342   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
343   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
344   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
345   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
346   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
347   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
348 
349   if (!Subtarget.hasMips32r2())
350     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
351 
352   if (!Subtarget.hasMips64r2())
353     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
354 
355   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
356   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
357   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
358   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
359   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
360   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
361   setOperationAction(ISD::FPOWI,             MVT::f32,   Expand);
362   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
363   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
364   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
365   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
366   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
367   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
368   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
369   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
370   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
371   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
372 
373   // Lower f16 conversion operations into library calls
374   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
375   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
376   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
377   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
378 
379   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
380 
381   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
382   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
383   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
384   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
385 
386   // Use the default for now
387   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
388   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
389 
390   if (!Subtarget.isGP64bit()) {
391     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
392     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
393   }
394 
395 
396   if (!Subtarget.hasMips32r2()) {
397     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
398     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
399   }
400 
401   // MIPS16 lacks MIPS32's clz and clo instructions.
402   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
403     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
404   if (!Subtarget.hasMips64())
405     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
406 
407   if (!Subtarget.hasMips32r2())
408     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
409   if (!Subtarget.hasMips64r2())
410     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
411 
412   if (Subtarget.isGP64bit()) {
413     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
414     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
415     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
416     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
417   }
418 
419   setOperationAction(ISD::TRAP, MVT::Other, Legal);
420 
421   setTargetDAGCombine(ISD::SDIVREM);
422   setTargetDAGCombine(ISD::UDIVREM);
423   setTargetDAGCombine(ISD::SELECT);
424   setTargetDAGCombine(ISD::AND);
425   setTargetDAGCombine(ISD::OR);
426   setTargetDAGCombine(ISD::ADD);
427   setTargetDAGCombine(ISD::AssertZext);
428 
429   setMinFunctionAlignment(Subtarget.isGP64bit() ? 3 : 2);
430 
431   // The arguments on the stack are defined in terms of 4-byte slots on O32
432   // and 8-byte slots on N32/N64.
433   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? 8 : 4);
434 
435   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
436 
437   MaxStoresPerMemcpy = 16;
438 
439   isMicroMips = Subtarget.inMicroMipsMode();
440 }
441 
create(const MipsTargetMachine & TM,const MipsSubtarget & STI)442 const MipsTargetLowering *MipsTargetLowering::create(const MipsTargetMachine &TM,
443                                                      const MipsSubtarget &STI) {
444   if (STI.inMips16Mode())
445     return llvm::createMips16TargetLowering(TM, STI);
446 
447   return llvm::createMipsSETargetLowering(TM, STI);
448 }
449 
450 // Create a fast isel object.
451 FastISel *
createFastISel(FunctionLoweringInfo & funcInfo,const TargetLibraryInfo * libInfo) const452 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
453                                   const TargetLibraryInfo *libInfo) const {
454   if (!funcInfo.MF->getTarget().Options.EnableFastISel)
455     return TargetLowering::createFastISel(funcInfo, libInfo);
456   return Mips::createFastISel(funcInfo, libInfo);
457 }
458 
getSetCCResultType(const DataLayout &,LLVMContext &,EVT VT) const459 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
460                                            EVT VT) const {
461   if (!VT.isVector())
462     return MVT::i32;
463   return VT.changeVectorElementTypeToInteger();
464 }
465 
performDivRemCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const MipsSubtarget & Subtarget)466 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
467                                     TargetLowering::DAGCombinerInfo &DCI,
468                                     const MipsSubtarget &Subtarget) {
469   if (DCI.isBeforeLegalizeOps())
470     return SDValue();
471 
472   EVT Ty = N->getValueType(0);
473   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
474   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
475   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
476                                                   MipsISD::DivRemU16;
477   SDLoc DL(N);
478 
479   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
480                                N->getOperand(0), N->getOperand(1));
481   SDValue InChain = DAG.getEntryNode();
482   SDValue InGlue = DivRem;
483 
484   // insert MFLO
485   if (N->hasAnyUseOfValue(0)) {
486     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
487                                             InGlue);
488     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
489     InChain = CopyFromLo.getValue(1);
490     InGlue = CopyFromLo.getValue(2);
491   }
492 
493   // insert MFHI
494   if (N->hasAnyUseOfValue(1)) {
495     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
496                                             HI, Ty, InGlue);
497     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
498   }
499 
500   return SDValue();
501 }
502 
condCodeToFCC(ISD::CondCode CC)503 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
504   switch (CC) {
505   default: llvm_unreachable("Unknown fp condition code!");
506   case ISD::SETEQ:
507   case ISD::SETOEQ: return Mips::FCOND_OEQ;
508   case ISD::SETUNE: return Mips::FCOND_UNE;
509   case ISD::SETLT:
510   case ISD::SETOLT: return Mips::FCOND_OLT;
511   case ISD::SETGT:
512   case ISD::SETOGT: return Mips::FCOND_OGT;
513   case ISD::SETLE:
514   case ISD::SETOLE: return Mips::FCOND_OLE;
515   case ISD::SETGE:
516   case ISD::SETOGE: return Mips::FCOND_OGE;
517   case ISD::SETULT: return Mips::FCOND_ULT;
518   case ISD::SETULE: return Mips::FCOND_ULE;
519   case ISD::SETUGT: return Mips::FCOND_UGT;
520   case ISD::SETUGE: return Mips::FCOND_UGE;
521   case ISD::SETUO:  return Mips::FCOND_UN;
522   case ISD::SETO:   return Mips::FCOND_OR;
523   case ISD::SETNE:
524   case ISD::SETONE: return Mips::FCOND_ONE;
525   case ISD::SETUEQ: return Mips::FCOND_UEQ;
526   }
527 }
528 
529 
530 /// This function returns true if the floating point conditional branches and
531 /// conditional moves which use condition code CC should be inverted.
invertFPCondCodeUser(Mips::CondCode CC)532 static bool invertFPCondCodeUser(Mips::CondCode CC) {
533   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
534     return false;
535 
536   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
537          "Illegal Condition Code");
538 
539   return true;
540 }
541 
542 // Creates and returns an FPCmp node from a setcc node.
543 // Returns Op if setcc is not a floating point comparison.
createFPCmp(SelectionDAG & DAG,const SDValue & Op)544 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
545   // must be a SETCC node
546   if (Op.getOpcode() != ISD::SETCC)
547     return Op;
548 
549   SDValue LHS = Op.getOperand(0);
550 
551   if (!LHS.getValueType().isFloatingPoint())
552     return Op;
553 
554   SDValue RHS = Op.getOperand(1);
555   SDLoc DL(Op);
556 
557   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
558   // node if necessary.
559   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
560 
561   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
562                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
563 }
564 
565 // Creates and returns a CMovFPT/F node.
createCMovFP(SelectionDAG & DAG,SDValue Cond,SDValue True,SDValue False,const SDLoc & DL)566 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
567                             SDValue False, const SDLoc &DL) {
568   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
569   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
570   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
571 
572   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
573                      True.getValueType(), True, FCC0, False, Cond);
574 }
575 
performSELECTCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const MipsSubtarget & Subtarget)576 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
577                                     TargetLowering::DAGCombinerInfo &DCI,
578                                     const MipsSubtarget &Subtarget) {
579   if (DCI.isBeforeLegalizeOps())
580     return SDValue();
581 
582   SDValue SetCC = N->getOperand(0);
583 
584   if ((SetCC.getOpcode() != ISD::SETCC) ||
585       !SetCC.getOperand(0).getValueType().isInteger())
586     return SDValue();
587 
588   SDValue False = N->getOperand(2);
589   EVT FalseTy = False.getValueType();
590 
591   if (!FalseTy.isInteger())
592     return SDValue();
593 
594   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
595 
596   // If the RHS (False) is 0, we swap the order of the operands
597   // of ISD::SELECT (obviously also inverting the condition) so that we can
598   // take advantage of conditional moves using the $0 register.
599   // Example:
600   //   return (a != 0) ? x : 0;
601   //     load $reg, x
602   //     movz $reg, $0, a
603   if (!FalseC)
604     return SDValue();
605 
606   const SDLoc DL(N);
607 
608   if (!FalseC->getZExtValue()) {
609     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
610     SDValue True = N->getOperand(1);
611 
612     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
613                          SetCC.getOperand(1), ISD::getSetCCInverse(CC, true));
614 
615     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
616   }
617 
618   // If both operands are integer constants there's a possibility that we
619   // can do some interesting optimizations.
620   SDValue True = N->getOperand(1);
621   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
622 
623   if (!TrueC || !True.getValueType().isInteger())
624     return SDValue();
625 
626   // We'll also ignore MVT::i64 operands as this optimizations proves
627   // to be ineffective because of the required sign extensions as the result
628   // of a SETCC operator is always MVT::i32 for non-vector types.
629   if (True.getValueType() == MVT::i64)
630     return SDValue();
631 
632   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
633 
634   // 1)  (a < x) ? y : y-1
635   //  slti $reg1, a, x
636   //  addiu $reg2, $reg1, y-1
637   if (Diff == 1)
638     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
639 
640   // 2)  (a < x) ? y-1 : y
641   //  slti $reg1, a, x
642   //  xor $reg1, $reg1, 1
643   //  addiu $reg2, $reg1, y-1
644   if (Diff == -1) {
645     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
646     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
647                          SetCC.getOperand(1), ISD::getSetCCInverse(CC, true));
648     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
649   }
650 
651   // Couldn't optimize.
652   return SDValue();
653 }
654 
performCMovFPCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const MipsSubtarget & Subtarget)655 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
656                                     TargetLowering::DAGCombinerInfo &DCI,
657                                     const MipsSubtarget &Subtarget) {
658   if (DCI.isBeforeLegalizeOps())
659     return SDValue();
660 
661   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
662 
663   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
664   if (!FalseC || FalseC->getZExtValue())
665     return SDValue();
666 
667   // Since RHS (False) is 0, we swap the order of the True/False operands
668   // (obviously also inverting the condition) so that we can
669   // take advantage of conditional moves using the $0 register.
670   // Example:
671   //   return (a != 0) ? x : 0;
672   //     load $reg, x
673   //     movz $reg, $0, a
674   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
675                                                          MipsISD::CMovFP_T;
676 
677   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
678   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
679                      ValueIfFalse, FCC, ValueIfTrue, Glue);
680 }
681 
performANDCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const MipsSubtarget & Subtarget)682 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
683                                  TargetLowering::DAGCombinerInfo &DCI,
684                                  const MipsSubtarget &Subtarget) {
685   // Pattern match EXT.
686   //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
687   //  => ext $dst, $src, size, pos
688   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
689     return SDValue();
690 
691   SDValue ShiftRight = N->getOperand(0), Mask = N->getOperand(1);
692   unsigned ShiftRightOpc = ShiftRight.getOpcode();
693 
694   // Op's first operand must be a shift right.
695   if (ShiftRightOpc != ISD::SRA && ShiftRightOpc != ISD::SRL)
696     return SDValue();
697 
698   // The second operand of the shift must be an immediate.
699   ConstantSDNode *CN;
700   if (!(CN = dyn_cast<ConstantSDNode>(ShiftRight.getOperand(1))))
701     return SDValue();
702 
703   uint64_t Pos = CN->getZExtValue();
704   uint64_t SMPos, SMSize;
705 
706   // Op's second operand must be a shifted mask.
707   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
708       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
709     return SDValue();
710 
711   // Return if the shifted mask does not start at bit 0 or the sum of its size
712   // and Pos exceeds the word's size.
713   EVT ValTy = N->getValueType(0);
714   if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
715     return SDValue();
716 
717   SDLoc DL(N);
718   return DAG.getNode(MipsISD::Ext, DL, ValTy,
719                      ShiftRight.getOperand(0),
720                      DAG.getConstant(Pos, DL, MVT::i32),
721                      DAG.getConstant(SMSize, DL, MVT::i32));
722 }
723 
performORCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const MipsSubtarget & Subtarget)724 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
725                                 TargetLowering::DAGCombinerInfo &DCI,
726                                 const MipsSubtarget &Subtarget) {
727   // Pattern match INS.
728   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
729   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
730   //  => ins $dst, $src, size, pos, $src1
731   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
732     return SDValue();
733 
734   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
735   uint64_t SMPos0, SMSize0, SMPos1, SMSize1;
736   ConstantSDNode *CN;
737 
738   // See if Op's first operand matches (and $src1 , mask0).
739   if (And0.getOpcode() != ISD::AND)
740     return SDValue();
741 
742   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
743       !isShiftedMask(~CN->getSExtValue(), SMPos0, SMSize0))
744     return SDValue();
745 
746   // See if Op's second operand matches (and (shl $src, pos), mask1).
747   if (And1.getOpcode() != ISD::AND)
748     return SDValue();
749 
750   if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
751       !isShiftedMask(CN->getZExtValue(), SMPos1, SMSize1))
752     return SDValue();
753 
754   // The shift masks must have the same position and size.
755   if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
756     return SDValue();
757 
758   SDValue Shl = And1.getOperand(0);
759   if (Shl.getOpcode() != ISD::SHL)
760     return SDValue();
761 
762   if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
763     return SDValue();
764 
765   unsigned Shamt = CN->getZExtValue();
766 
767   // Return if the shift amount and the first bit position of mask are not the
768   // same.
769   EVT ValTy = N->getValueType(0);
770   if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
771     return SDValue();
772 
773   SDLoc DL(N);
774   return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
775                      DAG.getConstant(SMPos0, DL, MVT::i32),
776                      DAG.getConstant(SMSize0, DL, MVT::i32),
777                      And0.getOperand(0));
778 }
779 
performADDCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const MipsSubtarget & Subtarget)780 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
781                                  TargetLowering::DAGCombinerInfo &DCI,
782                                  const MipsSubtarget &Subtarget) {
783   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
784 
785   if (DCI.isBeforeLegalizeOps())
786     return SDValue();
787 
788   SDValue Add = N->getOperand(1);
789 
790   if (Add.getOpcode() != ISD::ADD)
791     return SDValue();
792 
793   SDValue Lo = Add.getOperand(1);
794 
795   if ((Lo.getOpcode() != MipsISD::Lo) ||
796       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
797     return SDValue();
798 
799   EVT ValTy = N->getValueType(0);
800   SDLoc DL(N);
801 
802   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
803                              Add.getOperand(0));
804   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
805 }
806 
performAssertZextCombine(SDNode * N,SelectionDAG & DAG,TargetLowering::DAGCombinerInfo & DCI,const MipsSubtarget & Subtarget)807 static SDValue performAssertZextCombine(SDNode *N, SelectionDAG &DAG,
808                                         TargetLowering::DAGCombinerInfo &DCI,
809                                         const MipsSubtarget &Subtarget) {
810   SDValue N0 = N->getOperand(0);
811   EVT NarrowerVT = cast<VTSDNode>(N->getOperand(1))->getVT();
812 
813   if (N0.getOpcode() != ISD::TRUNCATE)
814     return SDValue();
815 
816   if (N0.getOperand(0).getOpcode() != ISD::AssertZext)
817     return SDValue();
818 
819   // fold (AssertZext (trunc (AssertZext x))) -> (trunc (AssertZext x))
820   // if the type of the extension of the innermost AssertZext node is
821   // smaller from that of the outermost node, eg:
822   // (AssertZext:i32 (trunc:i32 (AssertZext:i64 X, i32)), i8)
823   //   -> (trunc:i32 (AssertZext X, i8))
824   SDValue WiderAssertZext = N0.getOperand(0);
825   EVT WiderVT = cast<VTSDNode>(WiderAssertZext->getOperand(1))->getVT();
826 
827   if (NarrowerVT.bitsLT(WiderVT)) {
828     SDValue NewAssertZext = DAG.getNode(
829         ISD::AssertZext, SDLoc(N), WiderAssertZext.getValueType(),
830         WiderAssertZext.getOperand(0), DAG.getValueType(NarrowerVT));
831     return DAG.getNode(ISD::TRUNCATE, SDLoc(N), N->getValueType(0),
832                        NewAssertZext);
833   }
834 
835   return SDValue();
836 }
837 
PerformDAGCombine(SDNode * N,DAGCombinerInfo & DCI) const838 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
839   const {
840   SelectionDAG &DAG = DCI.DAG;
841   unsigned Opc = N->getOpcode();
842 
843   switch (Opc) {
844   default: break;
845   case ISD::SDIVREM:
846   case ISD::UDIVREM:
847     return performDivRemCombine(N, DAG, DCI, Subtarget);
848   case ISD::SELECT:
849     return performSELECTCombine(N, DAG, DCI, Subtarget);
850   case MipsISD::CMovFP_F:
851   case MipsISD::CMovFP_T:
852     return performCMovFPCombine(N, DAG, DCI, Subtarget);
853   case ISD::AND:
854     return performANDCombine(N, DAG, DCI, Subtarget);
855   case ISD::OR:
856     return performORCombine(N, DAG, DCI, Subtarget);
857   case ISD::ADD:
858     return performADDCombine(N, DAG, DCI, Subtarget);
859   case ISD::AssertZext:
860     return performAssertZextCombine(N, DAG, DCI, Subtarget);
861   }
862 
863   return SDValue();
864 }
865 
isCheapToSpeculateCttz() const866 bool MipsTargetLowering::isCheapToSpeculateCttz() const {
867   return Subtarget.hasMips32();
868 }
869 
isCheapToSpeculateCtlz() const870 bool MipsTargetLowering::isCheapToSpeculateCtlz() const {
871   return Subtarget.hasMips32();
872 }
873 
874 void
LowerOperationWrapper(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const875 MipsTargetLowering::LowerOperationWrapper(SDNode *N,
876                                           SmallVectorImpl<SDValue> &Results,
877                                           SelectionDAG &DAG) const {
878   SDValue Res = LowerOperation(SDValue(N, 0), DAG);
879 
880   for (unsigned I = 0, E = Res->getNumValues(); I != E; ++I)
881     Results.push_back(Res.getValue(I));
882 }
883 
884 void
ReplaceNodeResults(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const885 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
886                                        SmallVectorImpl<SDValue> &Results,
887                                        SelectionDAG &DAG) const {
888   return LowerOperationWrapper(N, Results, DAG);
889 }
890 
891 SDValue MipsTargetLowering::
LowerOperation(SDValue Op,SelectionDAG & DAG) const892 LowerOperation(SDValue Op, SelectionDAG &DAG) const
893 {
894   switch (Op.getOpcode())
895   {
896   case ISD::BR_JT:              return lowerBR_JT(Op, DAG);
897   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
898   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
899   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
900   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
901   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
902   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
903   case ISD::SELECT:             return lowerSELECT(Op, DAG);
904   case ISD::SETCC:              return lowerSETCC(Op, DAG);
905   case ISD::VASTART:            return lowerVASTART(Op, DAG);
906   case ISD::VAARG:              return lowerVAARG(Op, DAG);
907   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
908   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
909   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
910   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
911   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
912   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
913   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
914   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
915   case ISD::LOAD:               return lowerLOAD(Op, DAG);
916   case ISD::STORE:              return lowerSTORE(Op, DAG);
917   case ISD::ADD:                return lowerADD(Op, DAG);
918   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
919   }
920   return SDValue();
921 }
922 
923 //===----------------------------------------------------------------------===//
924 //  Lower helper functions
925 //===----------------------------------------------------------------------===//
926 
927 // addLiveIn - This helper function adds the specified physical register to the
928 // MachineFunction as a live in value.  It also creates a corresponding
929 // virtual register for it.
930 static unsigned
addLiveIn(MachineFunction & MF,unsigned PReg,const TargetRegisterClass * RC)931 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
932 {
933   unsigned VReg = MF.getRegInfo().createVirtualRegister(RC);
934   MF.getRegInfo().addLiveIn(PReg, VReg);
935   return VReg;
936 }
937 
insertDivByZeroTrap(MachineInstr & MI,MachineBasicBlock & MBB,const TargetInstrInfo & TII,bool Is64Bit,bool IsMicroMips)938 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
939                                               MachineBasicBlock &MBB,
940                                               const TargetInstrInfo &TII,
941                                               bool Is64Bit, bool IsMicroMips) {
942   if (NoZeroDivCheck)
943     return &MBB;
944 
945   // Insert instruction "teq $divisor_reg, $zero, 7".
946   MachineBasicBlock::iterator I(MI);
947   MachineInstrBuilder MIB;
948   MachineOperand &Divisor = MI.getOperand(2);
949   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
950                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
951             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
952             .addReg(Mips::ZERO)
953             .addImm(7);
954 
955   // Use the 32-bit sub-register if this is a 64-bit division.
956   if (Is64Bit)
957     MIB->getOperand(0).setSubReg(Mips::sub_32);
958 
959   // Clear Divisor's kill flag.
960   Divisor.setIsKill(false);
961 
962   // We would normally delete the original instruction here but in this case
963   // we only needed to inject an additional instruction rather than replace it.
964 
965   return &MBB;
966 }
967 
968 MachineBasicBlock *
EmitInstrWithCustomInserter(MachineInstr & MI,MachineBasicBlock * BB) const969 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
970                                                 MachineBasicBlock *BB) const {
971   switch (MI.getOpcode()) {
972   default:
973     llvm_unreachable("Unexpected instr type to insert");
974   case Mips::ATOMIC_LOAD_ADD_I8:
975     return emitAtomicBinaryPartword(MI, BB, 1, Mips::ADDu);
976   case Mips::ATOMIC_LOAD_ADD_I16:
977     return emitAtomicBinaryPartword(MI, BB, 2, Mips::ADDu);
978   case Mips::ATOMIC_LOAD_ADD_I32:
979     return emitAtomicBinary(MI, BB, 4, Mips::ADDu);
980   case Mips::ATOMIC_LOAD_ADD_I64:
981     return emitAtomicBinary(MI, BB, 8, Mips::DADDu);
982 
983   case Mips::ATOMIC_LOAD_AND_I8:
984     return emitAtomicBinaryPartword(MI, BB, 1, Mips::AND);
985   case Mips::ATOMIC_LOAD_AND_I16:
986     return emitAtomicBinaryPartword(MI, BB, 2, Mips::AND);
987   case Mips::ATOMIC_LOAD_AND_I32:
988     return emitAtomicBinary(MI, BB, 4, Mips::AND);
989   case Mips::ATOMIC_LOAD_AND_I64:
990     return emitAtomicBinary(MI, BB, 8, Mips::AND64);
991 
992   case Mips::ATOMIC_LOAD_OR_I8:
993     return emitAtomicBinaryPartword(MI, BB, 1, Mips::OR);
994   case Mips::ATOMIC_LOAD_OR_I16:
995     return emitAtomicBinaryPartword(MI, BB, 2, Mips::OR);
996   case Mips::ATOMIC_LOAD_OR_I32:
997     return emitAtomicBinary(MI, BB, 4, Mips::OR);
998   case Mips::ATOMIC_LOAD_OR_I64:
999     return emitAtomicBinary(MI, BB, 8, Mips::OR64);
1000 
1001   case Mips::ATOMIC_LOAD_XOR_I8:
1002     return emitAtomicBinaryPartword(MI, BB, 1, Mips::XOR);
1003   case Mips::ATOMIC_LOAD_XOR_I16:
1004     return emitAtomicBinaryPartword(MI, BB, 2, Mips::XOR);
1005   case Mips::ATOMIC_LOAD_XOR_I32:
1006     return emitAtomicBinary(MI, BB, 4, Mips::XOR);
1007   case Mips::ATOMIC_LOAD_XOR_I64:
1008     return emitAtomicBinary(MI, BB, 8, Mips::XOR64);
1009 
1010   case Mips::ATOMIC_LOAD_NAND_I8:
1011     return emitAtomicBinaryPartword(MI, BB, 1, 0, true);
1012   case Mips::ATOMIC_LOAD_NAND_I16:
1013     return emitAtomicBinaryPartword(MI, BB, 2, 0, true);
1014   case Mips::ATOMIC_LOAD_NAND_I32:
1015     return emitAtomicBinary(MI, BB, 4, 0, true);
1016   case Mips::ATOMIC_LOAD_NAND_I64:
1017     return emitAtomicBinary(MI, BB, 8, 0, true);
1018 
1019   case Mips::ATOMIC_LOAD_SUB_I8:
1020     return emitAtomicBinaryPartword(MI, BB, 1, Mips::SUBu);
1021   case Mips::ATOMIC_LOAD_SUB_I16:
1022     return emitAtomicBinaryPartword(MI, BB, 2, Mips::SUBu);
1023   case Mips::ATOMIC_LOAD_SUB_I32:
1024     return emitAtomicBinary(MI, BB, 4, Mips::SUBu);
1025   case Mips::ATOMIC_LOAD_SUB_I64:
1026     return emitAtomicBinary(MI, BB, 8, Mips::DSUBu);
1027 
1028   case Mips::ATOMIC_SWAP_I8:
1029     return emitAtomicBinaryPartword(MI, BB, 1, 0);
1030   case Mips::ATOMIC_SWAP_I16:
1031     return emitAtomicBinaryPartword(MI, BB, 2, 0);
1032   case Mips::ATOMIC_SWAP_I32:
1033     return emitAtomicBinary(MI, BB, 4, 0);
1034   case Mips::ATOMIC_SWAP_I64:
1035     return emitAtomicBinary(MI, BB, 8, 0);
1036 
1037   case Mips::ATOMIC_CMP_SWAP_I8:
1038     return emitAtomicCmpSwapPartword(MI, BB, 1);
1039   case Mips::ATOMIC_CMP_SWAP_I16:
1040     return emitAtomicCmpSwapPartword(MI, BB, 2);
1041   case Mips::ATOMIC_CMP_SWAP_I32:
1042     return emitAtomicCmpSwap(MI, BB, 4);
1043   case Mips::ATOMIC_CMP_SWAP_I64:
1044     return emitAtomicCmpSwap(MI, BB, 8);
1045   case Mips::PseudoSDIV:
1046   case Mips::PseudoUDIV:
1047   case Mips::DIV:
1048   case Mips::DIVU:
1049   case Mips::MOD:
1050   case Mips::MODU:
1051     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1052                                false);
1053   case Mips::SDIV_MM_Pseudo:
1054   case Mips::UDIV_MM_Pseudo:
1055   case Mips::SDIV_MM:
1056   case Mips::UDIV_MM:
1057   case Mips::DIV_MMR6:
1058   case Mips::DIVU_MMR6:
1059   case Mips::MOD_MMR6:
1060   case Mips::MODU_MMR6:
1061     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1062   case Mips::PseudoDSDIV:
1063   case Mips::PseudoDUDIV:
1064   case Mips::DDIV:
1065   case Mips::DDIVU:
1066   case Mips::DMOD:
1067   case Mips::DMODU:
1068     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1069   case Mips::DDIV_MM64R6:
1070   case Mips::DDIVU_MM64R6:
1071   case Mips::DMOD_MM64R6:
1072   case Mips::DMODU_MM64R6:
1073     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, true);
1074   case Mips::SEL_D:
1075   case Mips::SEL_D_MMR6:
1076     return emitSEL_D(MI, BB);
1077 
1078   case Mips::PseudoSELECT_I:
1079   case Mips::PseudoSELECT_I64:
1080   case Mips::PseudoSELECT_S:
1081   case Mips::PseudoSELECT_D32:
1082   case Mips::PseudoSELECT_D64:
1083     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1084   case Mips::PseudoSELECTFP_F_I:
1085   case Mips::PseudoSELECTFP_F_I64:
1086   case Mips::PseudoSELECTFP_F_S:
1087   case Mips::PseudoSELECTFP_F_D32:
1088   case Mips::PseudoSELECTFP_F_D64:
1089     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1090   case Mips::PseudoSELECTFP_T_I:
1091   case Mips::PseudoSELECTFP_T_I64:
1092   case Mips::PseudoSELECTFP_T_S:
1093   case Mips::PseudoSELECTFP_T_D32:
1094   case Mips::PseudoSELECTFP_T_D64:
1095     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1096   }
1097 }
1098 
1099 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1100 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
emitAtomicBinary(MachineInstr & MI,MachineBasicBlock * BB,unsigned Size,unsigned BinOpcode,bool Nand) const1101 MachineBasicBlock *MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1102                                                         MachineBasicBlock *BB,
1103                                                         unsigned Size,
1104                                                         unsigned BinOpcode,
1105                                                         bool Nand) const {
1106   assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicBinary.");
1107 
1108   MachineFunction *MF = BB->getParent();
1109   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1110   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1111   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1112   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1113   DebugLoc DL = MI.getDebugLoc();
1114   unsigned LL, SC, AND, NOR, ZERO, BEQ;
1115 
1116   if (Size == 4) {
1117     if (isMicroMips) {
1118       LL = Mips::LL_MM;
1119       SC = Mips::SC_MM;
1120     } else {
1121       LL = Subtarget.hasMips32r6()
1122                ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1123                : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1124       SC = Subtarget.hasMips32r6()
1125                ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1126                : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1127     }
1128 
1129     AND = Mips::AND;
1130     NOR = Mips::NOR;
1131     ZERO = Mips::ZERO;
1132     BEQ = Mips::BEQ;
1133   } else {
1134     LL = Subtarget.hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
1135     SC = Subtarget.hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
1136     AND = Mips::AND64;
1137     NOR = Mips::NOR64;
1138     ZERO = Mips::ZERO_64;
1139     BEQ = Mips::BEQ64;
1140   }
1141 
1142   unsigned OldVal = MI.getOperand(0).getReg();
1143   unsigned Ptr = MI.getOperand(1).getReg();
1144   unsigned Incr = MI.getOperand(2).getReg();
1145 
1146   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1147   unsigned AndRes = RegInfo.createVirtualRegister(RC);
1148   unsigned Success = RegInfo.createVirtualRegister(RC);
1149 
1150   // insert new blocks after the current block
1151   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1152   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1153   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1154   MachineFunction::iterator It = ++BB->getIterator();
1155   MF->insert(It, loopMBB);
1156   MF->insert(It, exitMBB);
1157 
1158   // Transfer the remainder of BB and its successor edges to exitMBB.
1159   exitMBB->splice(exitMBB->begin(), BB,
1160                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1161   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1162 
1163   //  thisMBB:
1164   //    ...
1165   //    fallthrough --> loopMBB
1166   BB->addSuccessor(loopMBB);
1167   loopMBB->addSuccessor(loopMBB);
1168   loopMBB->addSuccessor(exitMBB);
1169 
1170   //  loopMBB:
1171   //    ll oldval, 0(ptr)
1172   //    <binop> storeval, oldval, incr
1173   //    sc success, storeval, 0(ptr)
1174   //    beq success, $0, loopMBB
1175   BB = loopMBB;
1176   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(Ptr).addImm(0);
1177   if (Nand) {
1178     //  and andres, oldval, incr
1179     //  nor storeval, $0, andres
1180     BuildMI(BB, DL, TII->get(AND), AndRes).addReg(OldVal).addReg(Incr);
1181     BuildMI(BB, DL, TII->get(NOR), StoreVal).addReg(ZERO).addReg(AndRes);
1182   } else if (BinOpcode) {
1183     //  <binop> storeval, oldval, incr
1184     BuildMI(BB, DL, TII->get(BinOpcode), StoreVal).addReg(OldVal).addReg(Incr);
1185   } else {
1186     StoreVal = Incr;
1187   }
1188   BuildMI(BB, DL, TII->get(SC), Success).addReg(StoreVal).addReg(Ptr).addImm(0);
1189   BuildMI(BB, DL, TII->get(BEQ)).addReg(Success).addReg(ZERO).addMBB(loopMBB);
1190 
1191   MI.eraseFromParent(); // The instruction is gone now.
1192 
1193   return exitMBB;
1194 }
1195 
emitSignExtendToI32InReg(MachineInstr & MI,MachineBasicBlock * BB,unsigned Size,unsigned DstReg,unsigned SrcReg) const1196 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1197     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1198     unsigned SrcReg) const {
1199   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1200   const DebugLoc &DL = MI.getDebugLoc();
1201 
1202   if (Subtarget.hasMips32r2() && Size == 1) {
1203     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1204     return BB;
1205   }
1206 
1207   if (Subtarget.hasMips32r2() && Size == 2) {
1208     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1209     return BB;
1210   }
1211 
1212   MachineFunction *MF = BB->getParent();
1213   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1214   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1215   unsigned ScrReg = RegInfo.createVirtualRegister(RC);
1216 
1217   assert(Size < 32);
1218   int64_t ShiftImm = 32 - (Size * 8);
1219 
1220   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1221   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1222 
1223   return BB;
1224 }
1225 
emitAtomicBinaryPartword(MachineInstr & MI,MachineBasicBlock * BB,unsigned Size,unsigned BinOpcode,bool Nand) const1226 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1227     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned BinOpcode,
1228     bool Nand) const {
1229   assert((Size == 1 || Size == 2) &&
1230          "Unsupported size for EmitAtomicBinaryPartial.");
1231 
1232   MachineFunction *MF = BB->getParent();
1233   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1234   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1235   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1236   const TargetRegisterClass *RCp =
1237     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1238   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1239   DebugLoc DL = MI.getDebugLoc();
1240 
1241   unsigned Dest = MI.getOperand(0).getReg();
1242   unsigned Ptr = MI.getOperand(1).getReg();
1243   unsigned Incr = MI.getOperand(2).getReg();
1244 
1245   unsigned AlignedAddr = RegInfo.createVirtualRegister(RCp);
1246   unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
1247   unsigned Mask = RegInfo.createVirtualRegister(RC);
1248   unsigned Mask2 = RegInfo.createVirtualRegister(RC);
1249   unsigned NewVal = RegInfo.createVirtualRegister(RC);
1250   unsigned OldVal = RegInfo.createVirtualRegister(RC);
1251   unsigned Incr2 = RegInfo.createVirtualRegister(RC);
1252   unsigned MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1253   unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
1254   unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
1255   unsigned AndRes = RegInfo.createVirtualRegister(RC);
1256   unsigned BinOpRes = RegInfo.createVirtualRegister(RC);
1257   unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
1258   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1259   unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
1260   unsigned SrlRes = RegInfo.createVirtualRegister(RC);
1261   unsigned Success = RegInfo.createVirtualRegister(RC);
1262 
1263   unsigned LL, SC;
1264   if (isMicroMips) {
1265     LL = Mips::LL_MM;
1266     SC = Mips::SC_MM;
1267   } else {
1268     LL = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1269                                  : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1270     SC = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1271                                  : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1272   }
1273 
1274   // insert new blocks after the current block
1275   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1276   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1277   MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1278   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1279   MachineFunction::iterator It = ++BB->getIterator();
1280   MF->insert(It, loopMBB);
1281   MF->insert(It, sinkMBB);
1282   MF->insert(It, exitMBB);
1283 
1284   // Transfer the remainder of BB and its successor edges to exitMBB.
1285   exitMBB->splice(exitMBB->begin(), BB,
1286                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1287   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1288 
1289   BB->addSuccessor(loopMBB);
1290   loopMBB->addSuccessor(loopMBB);
1291   loopMBB->addSuccessor(sinkMBB);
1292   sinkMBB->addSuccessor(exitMBB);
1293 
1294   //  thisMBB:
1295   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1296   //    and     alignedaddr,ptr,masklsb2
1297   //    andi    ptrlsb2,ptr,3
1298   //    sll     shiftamt,ptrlsb2,3
1299   //    ori     maskupper,$0,255               # 0xff
1300   //    sll     mask,maskupper,shiftamt
1301   //    nor     mask2,$0,mask
1302   //    sll     incr2,incr,shiftamt
1303 
1304   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1305   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1306     .addReg(ABI.GetNullPtr()).addImm(-4);
1307   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1308     .addReg(Ptr).addReg(MaskLSB2);
1309   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1310       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1311   if (Subtarget.isLittle()) {
1312     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1313   } else {
1314     unsigned Off = RegInfo.createVirtualRegister(RC);
1315     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1316       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1317     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1318   }
1319   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1320     .addReg(Mips::ZERO).addImm(MaskImm);
1321   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1322     .addReg(MaskUpper).addReg(ShiftAmt);
1323   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1324   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1325 
1326   // atomic.load.binop
1327   // loopMBB:
1328   //   ll      oldval,0(alignedaddr)
1329   //   binop   binopres,oldval,incr2
1330   //   and     newval,binopres,mask
1331   //   and     maskedoldval0,oldval,mask2
1332   //   or      storeval,maskedoldval0,newval
1333   //   sc      success,storeval,0(alignedaddr)
1334   //   beq     success,$0,loopMBB
1335 
1336   // atomic.swap
1337   // loopMBB:
1338   //   ll      oldval,0(alignedaddr)
1339   //   and     newval,incr2,mask
1340   //   and     maskedoldval0,oldval,mask2
1341   //   or      storeval,maskedoldval0,newval
1342   //   sc      success,storeval,0(alignedaddr)
1343   //   beq     success,$0,loopMBB
1344 
1345   BB = loopMBB;
1346   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0);
1347   if (Nand) {
1348     //  and andres, oldval, incr2
1349     //  nor binopres, $0, andres
1350     //  and newval, binopres, mask
1351     BuildMI(BB, DL, TII->get(Mips::AND), AndRes).addReg(OldVal).addReg(Incr2);
1352     BuildMI(BB, DL, TII->get(Mips::NOR), BinOpRes)
1353       .addReg(Mips::ZERO).addReg(AndRes);
1354     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
1355   } else if (BinOpcode) {
1356     //  <binop> binopres, oldval, incr2
1357     //  and newval, binopres, mask
1358     BuildMI(BB, DL, TII->get(BinOpcode), BinOpRes).addReg(OldVal).addReg(Incr2);
1359     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
1360   } else { // atomic.swap
1361     //  and newval, incr2, mask
1362     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(Incr2).addReg(Mask);
1363   }
1364 
1365   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal0)
1366     .addReg(OldVal).addReg(Mask2);
1367   BuildMI(BB, DL, TII->get(Mips::OR), StoreVal)
1368     .addReg(MaskedOldVal0).addReg(NewVal);
1369   BuildMI(BB, DL, TII->get(SC), Success)
1370     .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
1371   BuildMI(BB, DL, TII->get(Mips::BEQ))
1372     .addReg(Success).addReg(Mips::ZERO).addMBB(loopMBB);
1373 
1374   //  sinkMBB:
1375   //    and     maskedoldval1,oldval,mask
1376   //    srl     srlres,maskedoldval1,shiftamt
1377   //    sign_extend dest,srlres
1378   BB = sinkMBB;
1379 
1380   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal1)
1381     .addReg(OldVal).addReg(Mask);
1382   BuildMI(BB, DL, TII->get(Mips::SRLV), SrlRes)
1383       .addReg(MaskedOldVal1).addReg(ShiftAmt);
1384   BB = emitSignExtendToI32InReg(MI, BB, Size, Dest, SrlRes);
1385 
1386   MI.eraseFromParent(); // The instruction is gone now.
1387 
1388   return exitMBB;
1389 }
1390 
emitAtomicCmpSwap(MachineInstr & MI,MachineBasicBlock * BB,unsigned Size) const1391 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1392                                                          MachineBasicBlock *BB,
1393                                                          unsigned Size) const {
1394   assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicCmpSwap.");
1395 
1396   MachineFunction *MF = BB->getParent();
1397   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1398   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1399   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1400   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1401   DebugLoc DL = MI.getDebugLoc();
1402   unsigned LL, SC, ZERO, BNE, BEQ;
1403 
1404   if (Size == 4) {
1405     if (isMicroMips) {
1406       LL = Mips::LL_MM;
1407       SC = Mips::SC_MM;
1408     } else {
1409       LL = Subtarget.hasMips32r6()
1410                ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1411                : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1412       SC = Subtarget.hasMips32r6()
1413                ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1414                : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1415     }
1416 
1417     ZERO = Mips::ZERO;
1418     BNE = Mips::BNE;
1419     BEQ = Mips::BEQ;
1420   } else {
1421     LL = Subtarget.hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
1422     SC = Subtarget.hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
1423     ZERO = Mips::ZERO_64;
1424     BNE = Mips::BNE64;
1425     BEQ = Mips::BEQ64;
1426   }
1427 
1428   unsigned Dest = MI.getOperand(0).getReg();
1429   unsigned Ptr = MI.getOperand(1).getReg();
1430   unsigned OldVal = MI.getOperand(2).getReg();
1431   unsigned NewVal = MI.getOperand(3).getReg();
1432 
1433   unsigned Success = RegInfo.createVirtualRegister(RC);
1434 
1435   // insert new blocks after the current block
1436   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1437   MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1438   MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1439   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1440   MachineFunction::iterator It = ++BB->getIterator();
1441   MF->insert(It, loop1MBB);
1442   MF->insert(It, loop2MBB);
1443   MF->insert(It, exitMBB);
1444 
1445   // Transfer the remainder of BB and its successor edges to exitMBB.
1446   exitMBB->splice(exitMBB->begin(), BB,
1447                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1448   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1449 
1450   //  thisMBB:
1451   //    ...
1452   //    fallthrough --> loop1MBB
1453   BB->addSuccessor(loop1MBB);
1454   loop1MBB->addSuccessor(exitMBB);
1455   loop1MBB->addSuccessor(loop2MBB);
1456   loop2MBB->addSuccessor(loop1MBB);
1457   loop2MBB->addSuccessor(exitMBB);
1458 
1459   // loop1MBB:
1460   //   ll dest, 0(ptr)
1461   //   bne dest, oldval, exitMBB
1462   BB = loop1MBB;
1463   BuildMI(BB, DL, TII->get(LL), Dest).addReg(Ptr).addImm(0);
1464   BuildMI(BB, DL, TII->get(BNE))
1465     .addReg(Dest).addReg(OldVal).addMBB(exitMBB);
1466 
1467   // loop2MBB:
1468   //   sc success, newval, 0(ptr)
1469   //   beq success, $0, loop1MBB
1470   BB = loop2MBB;
1471   BuildMI(BB, DL, TII->get(SC), Success)
1472     .addReg(NewVal).addReg(Ptr).addImm(0);
1473   BuildMI(BB, DL, TII->get(BEQ))
1474     .addReg(Success).addReg(ZERO).addMBB(loop1MBB);
1475 
1476   MI.eraseFromParent(); // The instruction is gone now.
1477 
1478   return exitMBB;
1479 }
1480 
emitAtomicCmpSwapPartword(MachineInstr & MI,MachineBasicBlock * BB,unsigned Size) const1481 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1482     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1483   assert((Size == 1 || Size == 2) &&
1484       "Unsupported size for EmitAtomicCmpSwapPartial.");
1485 
1486   MachineFunction *MF = BB->getParent();
1487   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1488   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1489   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1490   const TargetRegisterClass *RCp =
1491     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1492   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1493   DebugLoc DL = MI.getDebugLoc();
1494 
1495   unsigned Dest = MI.getOperand(0).getReg();
1496   unsigned Ptr = MI.getOperand(1).getReg();
1497   unsigned CmpVal = MI.getOperand(2).getReg();
1498   unsigned NewVal = MI.getOperand(3).getReg();
1499 
1500   unsigned AlignedAddr = RegInfo.createVirtualRegister(RCp);
1501   unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
1502   unsigned Mask = RegInfo.createVirtualRegister(RC);
1503   unsigned Mask2 = RegInfo.createVirtualRegister(RC);
1504   unsigned ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1505   unsigned OldVal = RegInfo.createVirtualRegister(RC);
1506   unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
1507   unsigned ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1508   unsigned MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1509   unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
1510   unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
1511   unsigned MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1512   unsigned MaskedNewVal = RegInfo.createVirtualRegister(RC);
1513   unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
1514   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1515   unsigned SrlRes = RegInfo.createVirtualRegister(RC);
1516   unsigned Success = RegInfo.createVirtualRegister(RC);
1517   unsigned LL, SC;
1518 
1519   if (isMicroMips) {
1520     LL = Mips::LL_MM;
1521     SC = Mips::SC_MM;
1522   } else {
1523     LL = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1524                                  : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1525     SC = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1526                                  : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1527   }
1528 
1529   // insert new blocks after the current block
1530   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1531   MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1532   MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1533   MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1534   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1535   MachineFunction::iterator It = ++BB->getIterator();
1536   MF->insert(It, loop1MBB);
1537   MF->insert(It, loop2MBB);
1538   MF->insert(It, sinkMBB);
1539   MF->insert(It, exitMBB);
1540 
1541   // Transfer the remainder of BB and its successor edges to exitMBB.
1542   exitMBB->splice(exitMBB->begin(), BB,
1543                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1544   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1545 
1546   BB->addSuccessor(loop1MBB);
1547   loop1MBB->addSuccessor(sinkMBB);
1548   loop1MBB->addSuccessor(loop2MBB);
1549   loop2MBB->addSuccessor(loop1MBB);
1550   loop2MBB->addSuccessor(sinkMBB);
1551   sinkMBB->addSuccessor(exitMBB);
1552 
1553   // FIXME: computation of newval2 can be moved to loop2MBB.
1554   //  thisMBB:
1555   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1556   //    and     alignedaddr,ptr,masklsb2
1557   //    andi    ptrlsb2,ptr,3
1558   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1559   //    sll     shiftamt,ptrlsb2,3
1560   //    ori     maskupper,$0,255               # 0xff
1561   //    sll     mask,maskupper,shiftamt
1562   //    nor     mask2,$0,mask
1563   //    andi    maskedcmpval,cmpval,255
1564   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1565   //    andi    maskednewval,newval,255
1566   //    sll     shiftednewval,maskednewval,shiftamt
1567   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1568   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1569     .addReg(ABI.GetNullPtr()).addImm(-4);
1570   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1571     .addReg(Ptr).addReg(MaskLSB2);
1572   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1573       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1574   if (Subtarget.isLittle()) {
1575     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1576   } else {
1577     unsigned Off = RegInfo.createVirtualRegister(RC);
1578     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1579       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1580     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1581   }
1582   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1583     .addReg(Mips::ZERO).addImm(MaskImm);
1584   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1585     .addReg(MaskUpper).addReg(ShiftAmt);
1586   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1587   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
1588     .addReg(CmpVal).addImm(MaskImm);
1589   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
1590     .addReg(MaskedCmpVal).addReg(ShiftAmt);
1591   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
1592     .addReg(NewVal).addImm(MaskImm);
1593   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
1594     .addReg(MaskedNewVal).addReg(ShiftAmt);
1595 
1596   //  loop1MBB:
1597   //    ll      oldval,0(alginedaddr)
1598   //    and     maskedoldval0,oldval,mask
1599   //    bne     maskedoldval0,shiftedcmpval,sinkMBB
1600   BB = loop1MBB;
1601   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0);
1602   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal0)
1603     .addReg(OldVal).addReg(Mask);
1604   BuildMI(BB, DL, TII->get(Mips::BNE))
1605     .addReg(MaskedOldVal0).addReg(ShiftedCmpVal).addMBB(sinkMBB);
1606 
1607   //  loop2MBB:
1608   //    and     maskedoldval1,oldval,mask2
1609   //    or      storeval,maskedoldval1,shiftednewval
1610   //    sc      success,storeval,0(alignedaddr)
1611   //    beq     success,$0,loop1MBB
1612   BB = loop2MBB;
1613   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal1)
1614     .addReg(OldVal).addReg(Mask2);
1615   BuildMI(BB, DL, TII->get(Mips::OR), StoreVal)
1616     .addReg(MaskedOldVal1).addReg(ShiftedNewVal);
1617   BuildMI(BB, DL, TII->get(SC), Success)
1618       .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
1619   BuildMI(BB, DL, TII->get(Mips::BEQ))
1620       .addReg(Success).addReg(Mips::ZERO).addMBB(loop1MBB);
1621 
1622   //  sinkMBB:
1623   //    srl     srlres,maskedoldval0,shiftamt
1624   //    sign_extend dest,srlres
1625   BB = sinkMBB;
1626 
1627   BuildMI(BB, DL, TII->get(Mips::SRLV), SrlRes)
1628       .addReg(MaskedOldVal0).addReg(ShiftAmt);
1629   BB = emitSignExtendToI32InReg(MI, BB, Size, Dest, SrlRes);
1630 
1631   MI.eraseFromParent(); // The instruction is gone now.
1632 
1633   return exitMBB;
1634 }
1635 
emitSEL_D(MachineInstr & MI,MachineBasicBlock * BB) const1636 MachineBasicBlock *MipsTargetLowering::emitSEL_D(MachineInstr &MI,
1637                                                  MachineBasicBlock *BB) const {
1638   MachineFunction *MF = BB->getParent();
1639   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
1640   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1641   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1642   DebugLoc DL = MI.getDebugLoc();
1643   MachineBasicBlock::iterator II(MI);
1644 
1645   unsigned Fc = MI.getOperand(1).getReg();
1646   const auto &FGR64RegClass = TRI->getRegClass(Mips::FGR64RegClassID);
1647 
1648   unsigned Fc2 = RegInfo.createVirtualRegister(FGR64RegClass);
1649 
1650   BuildMI(*BB, II, DL, TII->get(Mips::SUBREG_TO_REG), Fc2)
1651       .addImm(0)
1652       .addReg(Fc)
1653       .addImm(Mips::sub_lo);
1654 
1655   // We don't erase the original instruction, we just replace the condition
1656   // register with the 64-bit super-register.
1657   MI.getOperand(1).setReg(Fc2);
1658 
1659   return BB;
1660 }
1661 
1662 //===----------------------------------------------------------------------===//
1663 //  Misc Lower Operation implementation
1664 //===----------------------------------------------------------------------===//
lowerBR_JT(SDValue Op,SelectionDAG & DAG) const1665 SDValue MipsTargetLowering::lowerBR_JT(SDValue Op, SelectionDAG &DAG) const {
1666   SDValue Chain = Op.getOperand(0);
1667   SDValue Table = Op.getOperand(1);
1668   SDValue Index = Op.getOperand(2);
1669   SDLoc DL(Op);
1670   auto &TD = DAG.getDataLayout();
1671   EVT PTy = getPointerTy(TD);
1672   unsigned EntrySize =
1673       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
1674 
1675   Index = DAG.getNode(ISD::MUL, DL, PTy, Index,
1676                       DAG.getConstant(EntrySize, DL, PTy));
1677   SDValue Addr = DAG.getNode(ISD::ADD, DL, PTy, Index, Table);
1678 
1679   EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
1680   Addr =
1681       DAG.getExtLoad(ISD::SEXTLOAD, DL, PTy, Chain, Addr,
1682                      MachinePointerInfo::getJumpTable(DAG.getMachineFunction()),
1683                      MemVT, false, false, false, 0);
1684   Chain = Addr.getValue(1);
1685 
1686   if (isPositionIndependent() || ABI.IsN64()) {
1687     // For PIC, the sequence is:
1688     // BRIND(load(Jumptable + index) + RelocBase)
1689     // RelocBase can be JumpTable, GOT or some sort of global base.
1690     Addr = DAG.getNode(ISD::ADD, DL, PTy, Addr,
1691                        getPICJumpTableRelocBase(Table, DAG));
1692   }
1693 
1694   return DAG.getNode(ISD::BRIND, DL, MVT::Other, Chain, Addr);
1695 }
1696 
lowerBRCOND(SDValue Op,SelectionDAG & DAG) const1697 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
1698   // The first operand is the chain, the second is the condition, the third is
1699   // the block to branch to if the condition is true.
1700   SDValue Chain = Op.getOperand(0);
1701   SDValue Dest = Op.getOperand(2);
1702   SDLoc DL(Op);
1703 
1704   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1705   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
1706 
1707   // Return if flag is not set by a floating point comparison.
1708   if (CondRes.getOpcode() != MipsISD::FPCmp)
1709     return Op;
1710 
1711   SDValue CCNode  = CondRes.getOperand(2);
1712   Mips::CondCode CC =
1713     (Mips::CondCode)cast<ConstantSDNode>(CCNode)->getZExtValue();
1714   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
1715   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
1716   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
1717   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
1718                      FCC0, Dest, CondRes);
1719 }
1720 
1721 SDValue MipsTargetLowering::
lowerSELECT(SDValue Op,SelectionDAG & DAG) const1722 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
1723 {
1724   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1725   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
1726 
1727   // Return if flag is not set by a floating point comparison.
1728   if (Cond.getOpcode() != MipsISD::FPCmp)
1729     return Op;
1730 
1731   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
1732                       SDLoc(Op));
1733 }
1734 
lowerSETCC(SDValue Op,SelectionDAG & DAG) const1735 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
1736   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1737   SDValue Cond = createFPCmp(DAG, Op);
1738 
1739   assert(Cond.getOpcode() == MipsISD::FPCmp &&
1740          "Floating point operand expected.");
1741 
1742   SDLoc DL(Op);
1743   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
1744   SDValue False = DAG.getConstant(0, DL, MVT::i32);
1745 
1746   return createCMovFP(DAG, Cond, True, False, DL);
1747 }
1748 
lowerGlobalAddress(SDValue Op,SelectionDAG & DAG) const1749 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
1750                                                SelectionDAG &DAG) const {
1751   EVT Ty = Op.getValueType();
1752   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
1753   const GlobalValue *GV = N->getGlobal();
1754 
1755   if (!isPositionIndependent() && !ABI.IsN64()) {
1756     const MipsTargetObjectFile *TLOF =
1757         static_cast<const MipsTargetObjectFile *>(
1758             getTargetMachine().getObjFileLowering());
1759     if (TLOF->IsGlobalInSmallSection(GV, getTargetMachine()))
1760       // %gp_rel relocation
1761       return getAddrGPRel(N, SDLoc(N), Ty, DAG);
1762 
1763     // %hi/%lo relocation
1764     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1765   }
1766 
1767   // Every other architecture would use shouldAssumeDSOLocal in here, but
1768   // mips is special.
1769   // * In PIC code mips requires got loads even for local statics!
1770   // * To save on got entries, for local statics the got entry contains the
1771   //   page and an additional add instruction takes care of the low bits.
1772   // * It is legal to access a hidden symbol with a non hidden undefined,
1773   //   so one cannot guarantee that all access to a hidden symbol will know
1774   //   it is hidden.
1775   // * Mips linkers don't support creating a page and a full got entry for
1776   //   the same symbol.
1777   // * Given all that, we have to use a full got entry for hidden symbols :-(
1778   if (GV->hasLocalLinkage())
1779     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1780 
1781   if (LargeGOT)
1782     return getAddrGlobalLargeGOT(
1783         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
1784         DAG.getEntryNode(),
1785         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
1786 
1787   return getAddrGlobal(
1788       N, SDLoc(N), Ty, DAG,
1789       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
1790       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
1791 }
1792 
lowerBlockAddress(SDValue Op,SelectionDAG & DAG) const1793 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
1794                                               SelectionDAG &DAG) const {
1795   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
1796   EVT Ty = Op.getValueType();
1797 
1798   if (!isPositionIndependent() && !ABI.IsN64())
1799     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1800 
1801   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1802 }
1803 
1804 SDValue MipsTargetLowering::
lowerGlobalTLSAddress(SDValue Op,SelectionDAG & DAG) const1805 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
1806 {
1807   // If the relocation model is PIC, use the General Dynamic TLS Model or
1808   // Local Dynamic TLS model, otherwise use the Initial Exec or
1809   // Local Exec TLS Model.
1810 
1811   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
1812   if (DAG.getTarget().Options.EmulatedTLS)
1813     return LowerToTLSEmulatedModel(GA, DAG);
1814 
1815   SDLoc DL(GA);
1816   const GlobalValue *GV = GA->getGlobal();
1817   EVT PtrVT = getPointerTy(DAG.getDataLayout());
1818 
1819   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
1820 
1821   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
1822     // General Dynamic and Local Dynamic TLS Model.
1823     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
1824                                                       : MipsII::MO_TLSGD;
1825 
1826     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
1827     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
1828                                    getGlobalReg(DAG, PtrVT), TGA);
1829     unsigned PtrSize = PtrVT.getSizeInBits();
1830     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
1831 
1832     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
1833 
1834     ArgListTy Args;
1835     ArgListEntry Entry;
1836     Entry.Node = Argument;
1837     Entry.Ty = PtrTy;
1838     Args.push_back(Entry);
1839 
1840     TargetLowering::CallLoweringInfo CLI(DAG);
1841     CLI.setDebugLoc(DL).setChain(DAG.getEntryNode())
1842       .setCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
1843     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
1844 
1845     SDValue Ret = CallResult.first;
1846 
1847     if (model != TLSModel::LocalDynamic)
1848       return Ret;
1849 
1850     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1851                                                MipsII::MO_DTPREL_HI);
1852     SDValue Hi = DAG.getNode(MipsISD::Hi, DL, PtrVT, TGAHi);
1853     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1854                                                MipsII::MO_DTPREL_LO);
1855     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
1856     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
1857     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
1858   }
1859 
1860   SDValue Offset;
1861   if (model == TLSModel::InitialExec) {
1862     // Initial Exec TLS Model
1863     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1864                                              MipsII::MO_GOTTPREL);
1865     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
1866                       TGA);
1867     Offset = DAG.getLoad(PtrVT, DL,
1868                          DAG.getEntryNode(), TGA, MachinePointerInfo(),
1869                          false, false, false, 0);
1870   } else {
1871     // Local Exec TLS Model
1872     assert(model == TLSModel::LocalExec);
1873     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1874                                                MipsII::MO_TPREL_HI);
1875     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1876                                                MipsII::MO_TPREL_LO);
1877     SDValue Hi = DAG.getNode(MipsISD::Hi, DL, PtrVT, TGAHi);
1878     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
1879     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
1880   }
1881 
1882   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
1883   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
1884 }
1885 
1886 SDValue MipsTargetLowering::
lowerJumpTable(SDValue Op,SelectionDAG & DAG) const1887 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
1888 {
1889   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
1890   EVT Ty = Op.getValueType();
1891 
1892   if (!isPositionIndependent() && !ABI.IsN64())
1893     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1894 
1895   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1896 }
1897 
1898 SDValue MipsTargetLowering::
lowerConstantPool(SDValue Op,SelectionDAG & DAG) const1899 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
1900 {
1901   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
1902   EVT Ty = Op.getValueType();
1903 
1904   if (!isPositionIndependent() && !ABI.IsN64()) {
1905     const MipsTargetObjectFile *TLOF =
1906         static_cast<const MipsTargetObjectFile *>(
1907             getTargetMachine().getObjFileLowering());
1908 
1909     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
1910                                        getTargetMachine()))
1911       // %gp_rel relocation
1912       return getAddrGPRel(N, SDLoc(N), Ty, DAG);
1913 
1914     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1915   }
1916 
1917   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1918 }
1919 
lowerVASTART(SDValue Op,SelectionDAG & DAG) const1920 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
1921   MachineFunction &MF = DAG.getMachineFunction();
1922   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
1923 
1924   SDLoc DL(Op);
1925   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
1926                                  getPointerTy(MF.getDataLayout()));
1927 
1928   // vastart just stores the address of the VarArgsFrameIndex slot into the
1929   // memory location argument.
1930   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
1931   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
1932                       MachinePointerInfo(SV), false, false, 0);
1933 }
1934 
lowerVAARG(SDValue Op,SelectionDAG & DAG) const1935 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
1936   SDNode *Node = Op.getNode();
1937   EVT VT = Node->getValueType(0);
1938   SDValue Chain = Node->getOperand(0);
1939   SDValue VAListPtr = Node->getOperand(1);
1940   unsigned Align = Node->getConstantOperandVal(3);
1941   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
1942   SDLoc DL(Node);
1943   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
1944 
1945   SDValue VAListLoad =
1946       DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain, VAListPtr,
1947                   MachinePointerInfo(SV), false, false, false, 0);
1948   SDValue VAList = VAListLoad;
1949 
1950   // Re-align the pointer if necessary.
1951   // It should only ever be necessary for 64-bit types on O32 since the minimum
1952   // argument alignment is the same as the maximum type alignment for N32/N64.
1953   //
1954   // FIXME: We currently align too often. The code generator doesn't notice
1955   //        when the pointer is still aligned from the last va_arg (or pair of
1956   //        va_args for the i64 on O32 case).
1957   if (Align > getMinStackArgumentAlignment()) {
1958     assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2");
1959 
1960     VAList = DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
1961                          DAG.getConstant(Align - 1, DL, VAList.getValueType()));
1962 
1963     VAList = DAG.getNode(ISD::AND, DL, VAList.getValueType(), VAList,
1964                          DAG.getConstant(-(int64_t)Align, DL,
1965                                          VAList.getValueType()));
1966   }
1967 
1968   // Increment the pointer, VAList, to the next vaarg.
1969   auto &TD = DAG.getDataLayout();
1970   unsigned ArgSizeInBytes =
1971       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
1972   SDValue Tmp3 =
1973       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
1974                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
1975                                   DL, VAList.getValueType()));
1976   // Store the incremented VAList to the legalized pointer
1977   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
1978                       MachinePointerInfo(SV), false, false, 0);
1979 
1980   // In big-endian mode we must adjust the pointer when the load size is smaller
1981   // than the argument slot size. We must also reduce the known alignment to
1982   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
1983   // the correct half of the slot, and reduce the alignment from 8 (slot
1984   // alignment) down to 4 (type alignment).
1985   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
1986     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
1987     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
1988                          DAG.getIntPtrConstant(Adjustment, DL));
1989   }
1990   // Load the actual argument out of the pointer VAList
1991   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo(), false, false,
1992                      false, 0);
1993 }
1994 
lowerFCOPYSIGN32(SDValue Op,SelectionDAG & DAG,bool HasExtractInsert)1995 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
1996                                 bool HasExtractInsert) {
1997   EVT TyX = Op.getOperand(0).getValueType();
1998   EVT TyY = Op.getOperand(1).getValueType();
1999   SDLoc DL(Op);
2000   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2001   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2002   SDValue Res;
2003 
2004   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2005   // to i32.
2006   SDValue X = (TyX == MVT::f32) ?
2007     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2008     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2009                 Const1);
2010   SDValue Y = (TyY == MVT::f32) ?
2011     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2012     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2013                 Const1);
2014 
2015   if (HasExtractInsert) {
2016     // ext  E, Y, 31, 1  ; extract bit31 of Y
2017     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2018     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2019     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2020   } else {
2021     // sll SllX, X, 1
2022     // srl SrlX, SllX, 1
2023     // srl SrlY, Y, 31
2024     // sll SllY, SrlX, 31
2025     // or  Or, SrlX, SllY
2026     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2027     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2028     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2029     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2030     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2031   }
2032 
2033   if (TyX == MVT::f32)
2034     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2035 
2036   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2037                              Op.getOperand(0),
2038                              DAG.getConstant(0, DL, MVT::i32));
2039   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2040 }
2041 
lowerFCOPYSIGN64(SDValue Op,SelectionDAG & DAG,bool HasExtractInsert)2042 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2043                                 bool HasExtractInsert) {
2044   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2045   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2046   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2047   SDLoc DL(Op);
2048   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2049 
2050   // Bitcast to integer nodes.
2051   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2052   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2053 
2054   if (HasExtractInsert) {
2055     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2056     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2057     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2058                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2059 
2060     if (WidthX > WidthY)
2061       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2062     else if (WidthY > WidthX)
2063       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2064 
2065     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2066                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2067                             X);
2068     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2069   }
2070 
2071   // (d)sll SllX, X, 1
2072   // (d)srl SrlX, SllX, 1
2073   // (d)srl SrlY, Y, width(Y)-1
2074   // (d)sll SllY, SrlX, width(Y)-1
2075   // or     Or, SrlX, SllY
2076   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2077   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2078   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2079                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2080 
2081   if (WidthX > WidthY)
2082     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2083   else if (WidthY > WidthX)
2084     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2085 
2086   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2087                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2088   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2089   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2090 }
2091 
2092 SDValue
lowerFCOPYSIGN(SDValue Op,SelectionDAG & DAG) const2093 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2094   if (Subtarget.isGP64bit())
2095     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2096 
2097   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2098 }
2099 
2100 SDValue MipsTargetLowering::
lowerFRAMEADDR(SDValue Op,SelectionDAG & DAG) const2101 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2102   // check the depth
2103   assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
2104          "Frame address can only be determined for current frame.");
2105 
2106   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
2107   MFI->setFrameAddressIsTaken(true);
2108   EVT VT = Op.getValueType();
2109   SDLoc DL(Op);
2110   SDValue FrameAddr = DAG.getCopyFromReg(
2111       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2112   return FrameAddr;
2113 }
2114 
lowerRETURNADDR(SDValue Op,SelectionDAG & DAG) const2115 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2116                                             SelectionDAG &DAG) const {
2117   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2118     return SDValue();
2119 
2120   // check the depth
2121   assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
2122          "Return address can be determined only for current frame.");
2123 
2124   MachineFunction &MF = DAG.getMachineFunction();
2125   MachineFrameInfo *MFI = MF.getFrameInfo();
2126   MVT VT = Op.getSimpleValueType();
2127   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2128   MFI->setReturnAddressIsTaken(true);
2129 
2130   // Return RA, which contains the return address. Mark it an implicit live-in.
2131   unsigned Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2132   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2133 }
2134 
2135 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2136 // generated from __builtin_eh_return (offset, handler)
2137 // The effect of this is to adjust the stack pointer by "offset"
2138 // and then branch to "handler".
lowerEH_RETURN(SDValue Op,SelectionDAG & DAG) const2139 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2140                                                                      const {
2141   MachineFunction &MF = DAG.getMachineFunction();
2142   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2143 
2144   MipsFI->setCallsEhReturn();
2145   SDValue Chain     = Op.getOperand(0);
2146   SDValue Offset    = Op.getOperand(1);
2147   SDValue Handler   = Op.getOperand(2);
2148   SDLoc DL(Op);
2149   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2150 
2151   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2152   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2153   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2154   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2155   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2156   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2157   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2158                      DAG.getRegister(OffsetReg, Ty),
2159                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2160                      Chain.getValue(1));
2161 }
2162 
lowerATOMIC_FENCE(SDValue Op,SelectionDAG & DAG) const2163 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2164                                               SelectionDAG &DAG) const {
2165   // FIXME: Need pseudo-fence for 'singlethread' fences
2166   // FIXME: Set SType for weaker fences where supported/appropriate.
2167   unsigned SType = 0;
2168   SDLoc DL(Op);
2169   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2170                      DAG.getConstant(SType, DL, MVT::i32));
2171 }
2172 
lowerShiftLeftParts(SDValue Op,SelectionDAG & DAG) const2173 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2174                                                 SelectionDAG &DAG) const {
2175   SDLoc DL(Op);
2176   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2177 
2178   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2179   SDValue Shamt = Op.getOperand(2);
2180   // if shamt < (VT.bits):
2181   //  lo = (shl lo, shamt)
2182   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), ~shamt))
2183   // else:
2184   //  lo = 0
2185   //  hi = (shl lo, shamt[4:0])
2186   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2187                             DAG.getConstant(-1, DL, MVT::i32));
2188   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2189                                       DAG.getConstant(1, DL, VT));
2190   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2191   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2192   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2193   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2194   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2195                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2196   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2197                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2198   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2199 
2200   SDValue Ops[2] = {Lo, Hi};
2201   return DAG.getMergeValues(Ops, DL);
2202 }
2203 
lowerShiftRightParts(SDValue Op,SelectionDAG & DAG,bool IsSRA) const2204 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2205                                                  bool IsSRA) const {
2206   SDLoc DL(Op);
2207   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2208   SDValue Shamt = Op.getOperand(2);
2209   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2210 
2211   // if shamt < (VT.bits):
2212   //  lo = (or (shl (shl hi, 1), ~shamt) (srl lo, shamt))
2213   //  if isSRA:
2214   //    hi = (sra hi, shamt)
2215   //  else:
2216   //    hi = (srl hi, shamt)
2217   // else:
2218   //  if isSRA:
2219   //   lo = (sra hi, shamt[4:0])
2220   //   hi = (sra hi, 31)
2221   //  else:
2222   //   lo = (srl hi, shamt[4:0])
2223   //   hi = 0
2224   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2225                             DAG.getConstant(-1, DL, MVT::i32));
2226   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2227                                      DAG.getConstant(1, DL, VT));
2228   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2229   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2230   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2231   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2232                                      DL, VT, Hi, Shamt);
2233   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2234                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2235   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2236                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2237   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2238   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2239                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2240 
2241   SDValue Ops[2] = {Lo, Hi};
2242   return DAG.getMergeValues(Ops, DL);
2243 }
2244 
createLoadLR(unsigned Opc,SelectionDAG & DAG,LoadSDNode * LD,SDValue Chain,SDValue Src,unsigned Offset)2245 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2246                             SDValue Chain, SDValue Src, unsigned Offset) {
2247   SDValue Ptr = LD->getBasePtr();
2248   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2249   EVT BasePtrVT = Ptr.getValueType();
2250   SDLoc DL(LD);
2251   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2252 
2253   if (Offset)
2254     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2255                       DAG.getConstant(Offset, DL, BasePtrVT));
2256 
2257   SDValue Ops[] = { Chain, Ptr, Src };
2258   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2259                                  LD->getMemOperand());
2260 }
2261 
2262 // Expand an unaligned 32 or 64-bit integer load node.
lowerLOAD(SDValue Op,SelectionDAG & DAG) const2263 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2264   LoadSDNode *LD = cast<LoadSDNode>(Op);
2265   EVT MemVT = LD->getMemoryVT();
2266 
2267   if (Subtarget.systemSupportsUnalignedAccess())
2268     return Op;
2269 
2270   // Return if load is aligned or if MemVT is neither i32 nor i64.
2271   if ((LD->getAlignment() >= MemVT.getSizeInBits() / 8) ||
2272       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2273     return SDValue();
2274 
2275   bool IsLittle = Subtarget.isLittle();
2276   EVT VT = Op.getValueType();
2277   ISD::LoadExtType ExtType = LD->getExtensionType();
2278   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2279 
2280   assert((VT == MVT::i32) || (VT == MVT::i64));
2281 
2282   // Expand
2283   //  (set dst, (i64 (load baseptr)))
2284   // to
2285   //  (set tmp, (ldl (add baseptr, 7), undef))
2286   //  (set dst, (ldr baseptr, tmp))
2287   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2288     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2289                                IsLittle ? 7 : 0);
2290     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2291                         IsLittle ? 0 : 7);
2292   }
2293 
2294   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2295                              IsLittle ? 3 : 0);
2296   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2297                              IsLittle ? 0 : 3);
2298 
2299   // Expand
2300   //  (set dst, (i32 (load baseptr))) or
2301   //  (set dst, (i64 (sextload baseptr))) or
2302   //  (set dst, (i64 (extload baseptr)))
2303   // to
2304   //  (set tmp, (lwl (add baseptr, 3), undef))
2305   //  (set dst, (lwr baseptr, tmp))
2306   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2307       (ExtType == ISD::EXTLOAD))
2308     return LWR;
2309 
2310   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2311 
2312   // Expand
2313   //  (set dst, (i64 (zextload baseptr)))
2314   // to
2315   //  (set tmp0, (lwl (add baseptr, 3), undef))
2316   //  (set tmp1, (lwr baseptr, tmp0))
2317   //  (set tmp2, (shl tmp1, 32))
2318   //  (set dst, (srl tmp2, 32))
2319   SDLoc DL(LD);
2320   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2321   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2322   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2323   SDValue Ops[] = { SRL, LWR.getValue(1) };
2324   return DAG.getMergeValues(Ops, DL);
2325 }
2326 
createStoreLR(unsigned Opc,SelectionDAG & DAG,StoreSDNode * SD,SDValue Chain,unsigned Offset)2327 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2328                              SDValue Chain, unsigned Offset) {
2329   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2330   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2331   SDLoc DL(SD);
2332   SDVTList VTList = DAG.getVTList(MVT::Other);
2333 
2334   if (Offset)
2335     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2336                       DAG.getConstant(Offset, DL, BasePtrVT));
2337 
2338   SDValue Ops[] = { Chain, Value, Ptr };
2339   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2340                                  SD->getMemOperand());
2341 }
2342 
2343 // Expand an unaligned 32 or 64-bit integer store node.
lowerUnalignedIntStore(StoreSDNode * SD,SelectionDAG & DAG,bool IsLittle)2344 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2345                                       bool IsLittle) {
2346   SDValue Value = SD->getValue(), Chain = SD->getChain();
2347   EVT VT = Value.getValueType();
2348 
2349   // Expand
2350   //  (store val, baseptr) or
2351   //  (truncstore val, baseptr)
2352   // to
2353   //  (swl val, (add baseptr, 3))
2354   //  (swr val, baseptr)
2355   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2356     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2357                                 IsLittle ? 3 : 0);
2358     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2359   }
2360 
2361   assert(VT == MVT::i64);
2362 
2363   // Expand
2364   //  (store val, baseptr)
2365   // to
2366   //  (sdl val, (add baseptr, 7))
2367   //  (sdr val, baseptr)
2368   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2369   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2370 }
2371 
2372 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
lowerFP_TO_SINT_STORE(StoreSDNode * SD,SelectionDAG & DAG)2373 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG) {
2374   SDValue Val = SD->getValue();
2375 
2376   if (Val.getOpcode() != ISD::FP_TO_SINT)
2377     return SDValue();
2378 
2379   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2380   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2381                            Val.getOperand(0));
2382 
2383   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2384                       SD->getPointerInfo(), SD->isVolatile(),
2385                       SD->isNonTemporal(), SD->getAlignment());
2386 }
2387 
lowerSTORE(SDValue Op,SelectionDAG & DAG) const2388 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2389   StoreSDNode *SD = cast<StoreSDNode>(Op);
2390   EVT MemVT = SD->getMemoryVT();
2391 
2392   // Lower unaligned integer stores.
2393   if (!Subtarget.systemSupportsUnalignedAccess() &&
2394       (SD->getAlignment() < MemVT.getSizeInBits() / 8) &&
2395       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2396     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2397 
2398   return lowerFP_TO_SINT_STORE(SD, DAG);
2399 }
2400 
lowerADD(SDValue Op,SelectionDAG & DAG) const2401 SDValue MipsTargetLowering::lowerADD(SDValue Op, SelectionDAG &DAG) const {
2402   if (Op->getOperand(0).getOpcode() != ISD::FRAMEADDR
2403       || cast<ConstantSDNode>
2404         (Op->getOperand(0).getOperand(0))->getZExtValue() != 0
2405       || Op->getOperand(1).getOpcode() != ISD::FRAME_TO_ARGS_OFFSET)
2406     return SDValue();
2407 
2408   // The pattern
2409   //   (add (frameaddr 0), (frame_to_args_offset))
2410   // results from lowering llvm.eh.dwarf.cfa intrinsic. Transform it to
2411   //   (add FrameObject, 0)
2412   // where FrameObject is a fixed StackObject with offset 0 which points to
2413   // the old stack pointer.
2414   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
2415   EVT ValTy = Op->getValueType(0);
2416   int FI = MFI->CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2417   SDValue InArgsAddr = DAG.getFrameIndex(FI, ValTy);
2418   SDLoc DL(Op);
2419   return DAG.getNode(ISD::ADD, DL, ValTy, InArgsAddr,
2420                      DAG.getConstant(0, DL, ValTy));
2421 }
2422 
lowerFP_TO_SINT(SDValue Op,SelectionDAG & DAG) const2423 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2424                                             SelectionDAG &DAG) const {
2425   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2426   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2427                               Op.getOperand(0));
2428   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2429 }
2430 
2431 //===----------------------------------------------------------------------===//
2432 //                      Calling Convention Implementation
2433 //===----------------------------------------------------------------------===//
2434 
2435 //===----------------------------------------------------------------------===//
2436 // TODO: Implement a generic logic using tblgen that can support this.
2437 // Mips O32 ABI rules:
2438 // ---
2439 // i32 - Passed in A0, A1, A2, A3 and stack
2440 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2441 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2442 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2443 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2444 //       not used, it must be shadowed. If only A3 is available, shadow it and
2445 //       go to stack.
2446 //
2447 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2448 //===----------------------------------------------------------------------===//
2449 
CC_MipsO32(unsigned ValNo,MVT ValVT,MVT LocVT,CCValAssign::LocInfo LocInfo,ISD::ArgFlagsTy ArgFlags,CCState & State,ArrayRef<MCPhysReg> F64Regs)2450 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2451                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2452                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2453   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2454       State.getMachineFunction().getSubtarget());
2455 
2456   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2457   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2458 
2459   // Do not process byval args here.
2460   if (ArgFlags.isByVal())
2461     return true;
2462 
2463   // Promote i8 and i16
2464   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2465     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2466       LocVT = MVT::i32;
2467       if (ArgFlags.isSExt())
2468         LocInfo = CCValAssign::SExtUpper;
2469       else if (ArgFlags.isZExt())
2470         LocInfo = CCValAssign::ZExtUpper;
2471       else
2472         LocInfo = CCValAssign::AExtUpper;
2473     }
2474   }
2475 
2476   // Promote i8 and i16
2477   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2478     LocVT = MVT::i32;
2479     if (ArgFlags.isSExt())
2480       LocInfo = CCValAssign::SExt;
2481     else if (ArgFlags.isZExt())
2482       LocInfo = CCValAssign::ZExt;
2483     else
2484       LocInfo = CCValAssign::AExt;
2485   }
2486 
2487   unsigned Reg;
2488 
2489   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2490   // is true: function is vararg, argument is 3rd or higher, there is previous
2491   // argument which is not f32 or f64.
2492   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2493                                 State.getFirstUnallocated(F32Regs) != ValNo;
2494   unsigned OrigAlign = ArgFlags.getOrigAlign();
2495   bool isI64 = (ValVT == MVT::i32 && OrigAlign == 8);
2496 
2497   if (ValVT == MVT::i32 || (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2498     Reg = State.AllocateReg(IntRegs);
2499     // If this is the first part of an i64 arg,
2500     // the allocated register must be either A0 or A2.
2501     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2502       Reg = State.AllocateReg(IntRegs);
2503     LocVT = MVT::i32;
2504   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2505     // Allocate int register and shadow next int register. If first
2506     // available register is Mips::A1 or Mips::A3, shadow it too.
2507     Reg = State.AllocateReg(IntRegs);
2508     if (Reg == Mips::A1 || Reg == Mips::A3)
2509       Reg = State.AllocateReg(IntRegs);
2510     State.AllocateReg(IntRegs);
2511     LocVT = MVT::i32;
2512   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2513     // we are guaranteed to find an available float register
2514     if (ValVT == MVT::f32) {
2515       Reg = State.AllocateReg(F32Regs);
2516       // Shadow int register
2517       State.AllocateReg(IntRegs);
2518     } else {
2519       Reg = State.AllocateReg(F64Regs);
2520       // Shadow int registers
2521       unsigned Reg2 = State.AllocateReg(IntRegs);
2522       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2523         State.AllocateReg(IntRegs);
2524       State.AllocateReg(IntRegs);
2525     }
2526   } else
2527     llvm_unreachable("Cannot handle this ValVT.");
2528 
2529   if (!Reg) {
2530     unsigned Offset = State.AllocateStack(ValVT.getSizeInBits() >> 3,
2531                                           OrigAlign);
2532     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2533   } else
2534     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2535 
2536   return false;
2537 }
2538 
CC_MipsO32_FP32(unsigned ValNo,MVT ValVT,MVT LocVT,CCValAssign::LocInfo LocInfo,ISD::ArgFlagsTy ArgFlags,CCState & State)2539 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2540                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2541                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2542   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2543 
2544   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2545 }
2546 
CC_MipsO32_FP64(unsigned ValNo,MVT ValVT,MVT LocVT,CCValAssign::LocInfo LocInfo,ISD::ArgFlagsTy ArgFlags,CCState & State)2547 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
2548                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2549                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2550   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
2551 
2552   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2553 }
2554 
2555 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2556                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2557                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
2558 
2559 #include "MipsGenCallingConv.inc"
2560 
2561 //===----------------------------------------------------------------------===//
2562 //                  Call Calling Convention Implementation
2563 //===----------------------------------------------------------------------===//
2564 
2565 // Return next O32 integer argument register.
getNextIntArgReg(unsigned Reg)2566 static unsigned getNextIntArgReg(unsigned Reg) {
2567   assert((Reg == Mips::A0) || (Reg == Mips::A2));
2568   return (Reg == Mips::A0) ? Mips::A1 : Mips::A3;
2569 }
2570 
passArgOnStack(SDValue StackPtr,unsigned Offset,SDValue Chain,SDValue Arg,const SDLoc & DL,bool IsTailCall,SelectionDAG & DAG) const2571 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
2572                                            SDValue Chain, SDValue Arg,
2573                                            const SDLoc &DL, bool IsTailCall,
2574                                            SelectionDAG &DAG) const {
2575   if (!IsTailCall) {
2576     SDValue PtrOff =
2577         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
2578                     DAG.getIntPtrConstant(Offset, DL));
2579     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo(), false,
2580                         false, 0);
2581   }
2582 
2583   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
2584   int FI = MFI->CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
2585   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
2586   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(),
2587                       /*isVolatile=*/ true, false, 0);
2588 }
2589 
2590 void MipsTargetLowering::
getOpndList(SmallVectorImpl<SDValue> & Ops,std::deque<std::pair<unsigned,SDValue>> & RegsToPass,bool IsPICCall,bool GlobalOrExternal,bool InternalLinkage,bool IsCallReloc,CallLoweringInfo & CLI,SDValue Callee,SDValue Chain) const2591 getOpndList(SmallVectorImpl<SDValue> &Ops,
2592             std::deque< std::pair<unsigned, SDValue> > &RegsToPass,
2593             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
2594             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
2595             SDValue Chain) const {
2596   // Insert node "GP copy globalreg" before call to function.
2597   //
2598   // R_MIPS_CALL* operators (emitted when non-internal functions are called
2599   // in PIC mode) allow symbols to be resolved via lazy binding.
2600   // The lazy binding stub requires GP to point to the GOT.
2601   // Note that we don't need GP to point to the GOT for indirect calls
2602   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
2603   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
2604   // used for the function (that is, Mips linker doesn't generate lazy binding
2605   // stub for a function whose address is taken in the program).
2606   if (IsPICCall && !InternalLinkage && IsCallReloc) {
2607     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
2608     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2609     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
2610   }
2611 
2612   // Build a sequence of copy-to-reg nodes chained together with token
2613   // chain and flag operands which copy the outgoing args into registers.
2614   // The InFlag in necessary since all emitted instructions must be
2615   // stuck together.
2616   SDValue InFlag;
2617 
2618   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
2619     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, RegsToPass[i].first,
2620                                  RegsToPass[i].second, InFlag);
2621     InFlag = Chain.getValue(1);
2622   }
2623 
2624   // Add argument registers to the end of the list so that they are
2625   // known live into the call.
2626   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
2627     Ops.push_back(CLI.DAG.getRegister(RegsToPass[i].first,
2628                                       RegsToPass[i].second.getValueType()));
2629 
2630   // Add a register mask operand representing the call-preserved registers.
2631   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
2632   const uint32_t *Mask =
2633       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
2634   assert(Mask && "Missing call preserved mask for calling convention");
2635   if (Subtarget.inMips16HardFloat()) {
2636     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
2637       llvm::StringRef Sym = G->getGlobal()->getName();
2638       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
2639       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
2640         Mask = MipsRegisterInfo::getMips16RetHelperMask();
2641       }
2642     }
2643   }
2644   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
2645 
2646   if (InFlag.getNode())
2647     Ops.push_back(InFlag);
2648 }
2649 
2650 /// LowerCall - functions arguments are copied from virtual regs to
2651 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
2652 SDValue
LowerCall(TargetLowering::CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals) const2653 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
2654                               SmallVectorImpl<SDValue> &InVals) const {
2655   SelectionDAG &DAG                     = CLI.DAG;
2656   SDLoc DL                              = CLI.DL;
2657   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
2658   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
2659   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
2660   SDValue Chain                         = CLI.Chain;
2661   SDValue Callee                        = CLI.Callee;
2662   bool &IsTailCall                      = CLI.IsTailCall;
2663   CallingConv::ID CallConv              = CLI.CallConv;
2664   bool IsVarArg                         = CLI.IsVarArg;
2665 
2666   MachineFunction &MF = DAG.getMachineFunction();
2667   MachineFrameInfo *MFI = MF.getFrameInfo();
2668   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
2669   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2670   bool IsPIC = isPositionIndependent();
2671 
2672   // Analyze operands of the call, assigning locations to each operand.
2673   SmallVector<CCValAssign, 16> ArgLocs;
2674   MipsCCState CCInfo(
2675       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
2676       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
2677 
2678   // Allocate the reserved argument area. It seems strange to do this from the
2679   // caller side but removing it breaks the frame size calculation.
2680   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), 1);
2681 
2682   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(), Callee.getNode());
2683 
2684   // Get a count of how many bytes are to be pushed on the stack.
2685   unsigned NextStackOffset = CCInfo.getNextStackOffset();
2686 
2687   // Check if it's really possible to do a tail call.
2688   if (IsTailCall)
2689     IsTailCall = isEligibleForTailCallOptimization(
2690         CCInfo, NextStackOffset, *MF.getInfo<MipsFunctionInfo>());
2691 
2692   if (!IsTailCall && CLI.CS && CLI.CS->isMustTailCall())
2693     report_fatal_error("failed to perform tail call elimination on a call "
2694                        "site marked musttail");
2695 
2696   if (IsTailCall)
2697     ++NumTailCalls;
2698 
2699   // Chain is the output chain of the last Load/Store or CopyToReg node.
2700   // ByValChain is the output chain of the last Memcpy node created for copying
2701   // byval arguments to the stack.
2702   unsigned StackAlignment = TFL->getStackAlignment();
2703   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
2704   SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, DL, true);
2705 
2706   if (!IsTailCall)
2707     Chain = DAG.getCALLSEQ_START(Chain, NextStackOffsetVal, DL);
2708 
2709   SDValue StackPtr =
2710       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
2711                          getPointerTy(DAG.getDataLayout()));
2712 
2713   std::deque< std::pair<unsigned, SDValue> > RegsToPass;
2714   SmallVector<SDValue, 8> MemOpChains;
2715 
2716   CCInfo.rewindByValRegsInfo();
2717 
2718   // Walk the register/memloc assignments, inserting copies/loads.
2719   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
2720     SDValue Arg = OutVals[i];
2721     CCValAssign &VA = ArgLocs[i];
2722     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
2723     ISD::ArgFlagsTy Flags = Outs[i].Flags;
2724     bool UseUpperBits = false;
2725 
2726     // ByVal Arg.
2727     if (Flags.isByVal()) {
2728       unsigned FirstByValReg, LastByValReg;
2729       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
2730       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
2731 
2732       assert(Flags.getByValSize() &&
2733              "ByVal args of size 0 should have been ignored by front-end.");
2734       assert(ByValIdx < CCInfo.getInRegsParamsCount());
2735       assert(!IsTailCall &&
2736              "Do not tail-call optimize if there is a byval argument.");
2737       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
2738                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
2739                    VA);
2740       CCInfo.nextInRegsParam();
2741       continue;
2742     }
2743 
2744     // Promote the value if needed.
2745     switch (VA.getLocInfo()) {
2746     default:
2747       llvm_unreachable("Unknown loc info!");
2748     case CCValAssign::Full:
2749       if (VA.isRegLoc()) {
2750         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
2751             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
2752             (ValVT == MVT::i64 && LocVT == MVT::f64))
2753           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
2754         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
2755           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2756                                    Arg, DAG.getConstant(0, DL, MVT::i32));
2757           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2758                                    Arg, DAG.getConstant(1, DL, MVT::i32));
2759           if (!Subtarget.isLittle())
2760             std::swap(Lo, Hi);
2761           unsigned LocRegLo = VA.getLocReg();
2762           unsigned LocRegHigh = getNextIntArgReg(LocRegLo);
2763           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
2764           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
2765           continue;
2766         }
2767       }
2768       break;
2769     case CCValAssign::BCvt:
2770       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
2771       break;
2772     case CCValAssign::SExtUpper:
2773       UseUpperBits = true;
2774       // Fallthrough
2775     case CCValAssign::SExt:
2776       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
2777       break;
2778     case CCValAssign::ZExtUpper:
2779       UseUpperBits = true;
2780       // Fallthrough
2781     case CCValAssign::ZExt:
2782       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
2783       break;
2784     case CCValAssign::AExtUpper:
2785       UseUpperBits = true;
2786       // Fallthrough
2787     case CCValAssign::AExt:
2788       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
2789       break;
2790     }
2791 
2792     if (UseUpperBits) {
2793       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
2794       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
2795       Arg = DAG.getNode(
2796           ISD::SHL, DL, VA.getLocVT(), Arg,
2797           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
2798     }
2799 
2800     // Arguments that can be passed on register must be kept at
2801     // RegsToPass vector
2802     if (VA.isRegLoc()) {
2803       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
2804       continue;
2805     }
2806 
2807     // Register can't get to this point...
2808     assert(VA.isMemLoc());
2809 
2810     // emit ISD::STORE whichs stores the
2811     // parameter value to a stack Location
2812     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
2813                                          Chain, Arg, DL, IsTailCall, DAG));
2814   }
2815 
2816   // Transform all store nodes into one single node because all store
2817   // nodes are independent of each other.
2818   if (!MemOpChains.empty())
2819     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
2820 
2821   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
2822   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
2823   // node so that legalize doesn't hack it.
2824   bool IsPICCall = (ABI.IsN64() || IsPIC); // true if calls are translated to
2825                                            // jalr $25
2826   bool GlobalOrExternal = false, InternalLinkage = false, IsCallReloc = false;
2827   SDValue CalleeLo;
2828   EVT Ty = Callee.getValueType();
2829 
2830   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
2831     if (IsPICCall) {
2832       const GlobalValue *Val = G->getGlobal();
2833       InternalLinkage = Val->hasInternalLinkage();
2834 
2835       if (InternalLinkage)
2836         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
2837       else if (LargeGOT) {
2838         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
2839                                        MipsII::MO_CALL_LO16, Chain,
2840                                        FuncInfo->callPtrInfo(Val));
2841         IsCallReloc = true;
2842       } else {
2843         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
2844                                FuncInfo->callPtrInfo(Val));
2845         IsCallReloc = true;
2846       }
2847     } else
2848       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
2849                                           getPointerTy(DAG.getDataLayout()), 0,
2850                                           MipsII::MO_NO_FLAG);
2851     GlobalOrExternal = true;
2852   }
2853   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
2854     const char *Sym = S->getSymbol();
2855 
2856     if (!ABI.IsN64() && !IsPIC) // !N64 && static
2857       Callee = DAG.getTargetExternalSymbol(
2858           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
2859     else if (LargeGOT) {
2860       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
2861                                      MipsII::MO_CALL_LO16, Chain,
2862                                      FuncInfo->callPtrInfo(Sym));
2863       IsCallReloc = true;
2864     } else { // N64 || PIC
2865       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
2866                              FuncInfo->callPtrInfo(Sym));
2867       IsCallReloc = true;
2868     }
2869 
2870     GlobalOrExternal = true;
2871   }
2872 
2873   SmallVector<SDValue, 8> Ops(1, Chain);
2874   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
2875 
2876   getOpndList(Ops, RegsToPass, IsPICCall, GlobalOrExternal, InternalLinkage,
2877               IsCallReloc, CLI, Callee, Chain);
2878 
2879   if (IsTailCall)
2880     return DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
2881 
2882   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
2883   SDValue InFlag = Chain.getValue(1);
2884 
2885   // Create the CALLSEQ_END node.
2886   Chain = DAG.getCALLSEQ_END(Chain, NextStackOffsetVal,
2887                              DAG.getIntPtrConstant(0, DL, true), InFlag, DL);
2888   InFlag = Chain.getValue(1);
2889 
2890   // Handle result values, copying them out of physregs into vregs that we
2891   // return.
2892   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
2893                          InVals, CLI);
2894 }
2895 
2896 /// LowerCallResult - Lower the result values of a call into the
2897 /// appropriate copies out of appropriate physical registers.
LowerCallResult(SDValue Chain,SDValue InFlag,CallingConv::ID CallConv,bool IsVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,const SDLoc & DL,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals,TargetLowering::CallLoweringInfo & CLI) const2898 SDValue MipsTargetLowering::LowerCallResult(
2899     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool IsVarArg,
2900     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
2901     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
2902     TargetLowering::CallLoweringInfo &CLI) const {
2903   // Assign locations to each value returned by this call.
2904   SmallVector<CCValAssign, 16> RVLocs;
2905   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
2906                      *DAG.getContext());
2907   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI);
2908 
2909   // Copy all of the result registers out of their specified physreg.
2910   for (unsigned i = 0; i != RVLocs.size(); ++i) {
2911     CCValAssign &VA = RVLocs[i];
2912     assert(VA.isRegLoc() && "Can only return in registers!");
2913 
2914     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
2915                                      RVLocs[i].getLocVT(), InFlag);
2916     Chain = Val.getValue(1);
2917     InFlag = Val.getValue(2);
2918 
2919     if (VA.isUpperBitsInLoc()) {
2920       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
2921       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
2922       unsigned Shift =
2923           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
2924       Val = DAG.getNode(
2925           Shift, DL, VA.getLocVT(), Val,
2926           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
2927     }
2928 
2929     switch (VA.getLocInfo()) {
2930     default:
2931       llvm_unreachable("Unknown loc info!");
2932     case CCValAssign::Full:
2933       break;
2934     case CCValAssign::BCvt:
2935       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
2936       break;
2937     case CCValAssign::AExt:
2938     case CCValAssign::AExtUpper:
2939       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
2940       break;
2941     case CCValAssign::ZExt:
2942     case CCValAssign::ZExtUpper:
2943       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
2944                         DAG.getValueType(VA.getValVT()));
2945       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
2946       break;
2947     case CCValAssign::SExt:
2948     case CCValAssign::SExtUpper:
2949       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
2950                         DAG.getValueType(VA.getValVT()));
2951       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
2952       break;
2953     }
2954 
2955     InVals.push_back(Val);
2956   }
2957 
2958   return Chain;
2959 }
2960 
UnpackFromArgumentSlot(SDValue Val,const CCValAssign & VA,EVT ArgVT,const SDLoc & DL,SelectionDAG & DAG)2961 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
2962                                       EVT ArgVT, const SDLoc &DL,
2963                                       SelectionDAG &DAG) {
2964   MVT LocVT = VA.getLocVT();
2965   EVT ValVT = VA.getValVT();
2966 
2967   // Shift into the upper bits if necessary.
2968   switch (VA.getLocInfo()) {
2969   default:
2970     break;
2971   case CCValAssign::AExtUpper:
2972   case CCValAssign::SExtUpper:
2973   case CCValAssign::ZExtUpper: {
2974     unsigned ValSizeInBits = ArgVT.getSizeInBits();
2975     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
2976     unsigned Opcode =
2977         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
2978     Val = DAG.getNode(
2979         Opcode, DL, VA.getLocVT(), Val,
2980         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
2981     break;
2982   }
2983   }
2984 
2985   // If this is an value smaller than the argument slot size (32-bit for O32,
2986   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
2987   // size. Extract the value and insert any appropriate assertions regarding
2988   // sign/zero extension.
2989   switch (VA.getLocInfo()) {
2990   default:
2991     llvm_unreachable("Unknown loc info!");
2992   case CCValAssign::Full:
2993     break;
2994   case CCValAssign::AExtUpper:
2995   case CCValAssign::AExt:
2996     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
2997     break;
2998   case CCValAssign::SExtUpper:
2999   case CCValAssign::SExt:
3000     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3001     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3002     break;
3003   case CCValAssign::ZExtUpper:
3004   case CCValAssign::ZExt:
3005     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3006     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3007     break;
3008   case CCValAssign::BCvt:
3009     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3010     break;
3011   }
3012 
3013   return Val;
3014 }
3015 
3016 //===----------------------------------------------------------------------===//
3017 //             Formal Arguments Calling Convention Implementation
3018 //===----------------------------------------------------------------------===//
3019 /// LowerFormalArguments - transform physical registers into virtual registers
3020 /// and generate load operations for arguments places on the stack.
LowerFormalArguments(SDValue Chain,CallingConv::ID CallConv,bool IsVarArg,const SmallVectorImpl<ISD::InputArg> & Ins,const SDLoc & DL,SelectionDAG & DAG,SmallVectorImpl<SDValue> & InVals) const3021 SDValue MipsTargetLowering::LowerFormalArguments(
3022     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3023     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3024     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3025   MachineFunction &MF = DAG.getMachineFunction();
3026   MachineFrameInfo *MFI = MF.getFrameInfo();
3027   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3028 
3029   MipsFI->setVarArgsFrameIndex(0);
3030 
3031   // Used with vargs to acumulate store chains.
3032   std::vector<SDValue> OutChains;
3033 
3034   // Assign locations to all of the incoming arguments.
3035   SmallVector<CCValAssign, 16> ArgLocs;
3036   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3037                      *DAG.getContext());
3038   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), 1);
3039   const Function *Func = DAG.getMachineFunction().getFunction();
3040   Function::const_arg_iterator FuncArg = Func->arg_begin();
3041 
3042   if (Func->hasFnAttribute("interrupt") && !Func->arg_empty())
3043     report_fatal_error(
3044         "Functions with the interrupt attribute cannot have arguments!");
3045 
3046   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3047   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
3048                            CCInfo.getInRegsParamsCount() > 0);
3049 
3050   unsigned CurArgIdx = 0;
3051   CCInfo.rewindByValRegsInfo();
3052 
3053   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3054     CCValAssign &VA = ArgLocs[i];
3055     if (Ins[i].isOrigArg()) {
3056       std::advance(FuncArg, Ins[i].getOrigArgIndex() - CurArgIdx);
3057       CurArgIdx = Ins[i].getOrigArgIndex();
3058     }
3059     EVT ValVT = VA.getValVT();
3060     ISD::ArgFlagsTy Flags = Ins[i].Flags;
3061     bool IsRegLoc = VA.isRegLoc();
3062 
3063     if (Flags.isByVal()) {
3064       assert(Ins[i].isOrigArg() && "Byval arguments cannot be implicit");
3065       unsigned FirstByValReg, LastByValReg;
3066       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3067       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3068 
3069       assert(Flags.getByValSize() &&
3070              "ByVal args of size 0 should have been ignored by front-end.");
3071       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3072       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3073                     FirstByValReg, LastByValReg, VA, CCInfo);
3074       CCInfo.nextInRegsParam();
3075       continue;
3076     }
3077 
3078     // Arguments stored on registers
3079     if (IsRegLoc) {
3080       MVT RegVT = VA.getLocVT();
3081       unsigned ArgReg = VA.getLocReg();
3082       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3083 
3084       // Transform the arguments stored on
3085       // physical registers into virtual ones
3086       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3087       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3088 
3089       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3090 
3091       // Handle floating point arguments passed in integer registers and
3092       // long double arguments passed in floating point registers.
3093       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3094           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3095           (RegVT == MVT::f64 && ValVT == MVT::i64))
3096         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3097       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3098                ValVT == MVT::f64) {
3099         unsigned Reg2 = addLiveIn(DAG.getMachineFunction(),
3100                                   getNextIntArgReg(ArgReg), RC);
3101         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3102         if (!Subtarget.isLittle())
3103           std::swap(ArgValue, ArgValue2);
3104         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3105                                ArgValue, ArgValue2);
3106       }
3107 
3108       InVals.push_back(ArgValue);
3109     } else { // VA.isRegLoc()
3110       MVT LocVT = VA.getLocVT();
3111 
3112       if (ABI.IsO32()) {
3113         // We ought to be able to use LocVT directly but O32 sets it to i32
3114         // when allocating floating point values to integer registers.
3115         // This shouldn't influence how we load the value into registers unless
3116         // we are targeting softfloat.
3117         if (VA.getValVT().isFloatingPoint() && !Subtarget.useSoftFloat())
3118           LocVT = VA.getValVT();
3119       }
3120 
3121       // sanity check
3122       assert(VA.isMemLoc());
3123 
3124       // The stack pointer offset is relative to the caller stack frame.
3125       int FI = MFI->CreateFixedObject(LocVT.getSizeInBits() / 8,
3126                                       VA.getLocMemOffset(), true);
3127 
3128       // Create load nodes to retrieve arguments from the stack
3129       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3130       SDValue ArgValue = DAG.getLoad(
3131           LocVT, DL, Chain, FIN,
3132           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI),
3133           false, false, false, 0);
3134       OutChains.push_back(ArgValue.getValue(1));
3135 
3136       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3137 
3138       InVals.push_back(ArgValue);
3139     }
3140   }
3141 
3142   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3143     // The mips ABIs for returning structs by value requires that we copy
3144     // the sret argument into $v0 for the return. Save the argument into
3145     // a virtual register so that we can access it from the return points.
3146     if (Ins[i].Flags.isSRet()) {
3147       unsigned Reg = MipsFI->getSRetReturnReg();
3148       if (!Reg) {
3149         Reg = MF.getRegInfo().createVirtualRegister(
3150             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3151         MipsFI->setSRetReturnReg(Reg);
3152       }
3153       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3154       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3155       break;
3156     }
3157   }
3158 
3159   if (IsVarArg)
3160     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3161 
3162   // All stores are grouped in one node to allow the matching between
3163   // the size of Ins and InVals. This only happens when on varg functions
3164   if (!OutChains.empty()) {
3165     OutChains.push_back(Chain);
3166     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3167   }
3168 
3169   return Chain;
3170 }
3171 
3172 //===----------------------------------------------------------------------===//
3173 //               Return Value Calling Convention Implementation
3174 //===----------------------------------------------------------------------===//
3175 
3176 bool
CanLowerReturn(CallingConv::ID CallConv,MachineFunction & MF,bool IsVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,LLVMContext & Context) const3177 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3178                                    MachineFunction &MF, bool IsVarArg,
3179                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3180                                    LLVMContext &Context) const {
3181   SmallVector<CCValAssign, 16> RVLocs;
3182   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3183   return CCInfo.CheckReturn(Outs, RetCC_Mips);
3184 }
3185 
3186 bool
shouldSignExtendTypeInLibCall(EVT Type,bool IsSigned) const3187 MipsTargetLowering::shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const {
3188   if (Subtarget.hasMips3() && Subtarget.useSoftFloat()) {
3189     if (Type == MVT::i32)
3190       return true;
3191   }
3192   return IsSigned;
3193 }
3194 
3195 SDValue
LowerInterruptReturn(SmallVectorImpl<SDValue> & RetOps,const SDLoc & DL,SelectionDAG & DAG) const3196 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3197                                          const SDLoc &DL,
3198                                          SelectionDAG &DAG) const {
3199 
3200   MachineFunction &MF = DAG.getMachineFunction();
3201   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3202 
3203   MipsFI->setISR();
3204 
3205   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3206 }
3207 
3208 SDValue
LowerReturn(SDValue Chain,CallingConv::ID CallConv,bool IsVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,const SDLoc & DL,SelectionDAG & DAG) const3209 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3210                                 bool IsVarArg,
3211                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3212                                 const SmallVectorImpl<SDValue> &OutVals,
3213                                 const SDLoc &DL, SelectionDAG &DAG) const {
3214   // CCValAssign - represent the assignment of
3215   // the return value to a location
3216   SmallVector<CCValAssign, 16> RVLocs;
3217   MachineFunction &MF = DAG.getMachineFunction();
3218 
3219   // CCState - Info about the registers and stack slot.
3220   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3221 
3222   // Analyze return values.
3223   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3224 
3225   SDValue Flag;
3226   SmallVector<SDValue, 4> RetOps(1, Chain);
3227 
3228   // Copy the result values into the output registers.
3229   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3230     SDValue Val = OutVals[i];
3231     CCValAssign &VA = RVLocs[i];
3232     assert(VA.isRegLoc() && "Can only return in registers!");
3233     bool UseUpperBits = false;
3234 
3235     switch (VA.getLocInfo()) {
3236     default:
3237       llvm_unreachable("Unknown loc info!");
3238     case CCValAssign::Full:
3239       break;
3240     case CCValAssign::BCvt:
3241       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3242       break;
3243     case CCValAssign::AExtUpper:
3244       UseUpperBits = true;
3245       // Fallthrough
3246     case CCValAssign::AExt:
3247       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3248       break;
3249     case CCValAssign::ZExtUpper:
3250       UseUpperBits = true;
3251       // Fallthrough
3252     case CCValAssign::ZExt:
3253       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3254       break;
3255     case CCValAssign::SExtUpper:
3256       UseUpperBits = true;
3257       // Fallthrough
3258     case CCValAssign::SExt:
3259       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3260       break;
3261     }
3262 
3263     if (UseUpperBits) {
3264       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3265       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3266       Val = DAG.getNode(
3267           ISD::SHL, DL, VA.getLocVT(), Val,
3268           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3269     }
3270 
3271     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Flag);
3272 
3273     // Guarantee that all emitted copies are stuck together with flags.
3274     Flag = Chain.getValue(1);
3275     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3276   }
3277 
3278   // The mips ABIs for returning structs by value requires that we copy
3279   // the sret argument into $v0 for the return. We saved the argument into
3280   // a virtual register in the entry block, so now we copy the value out
3281   // and into $v0.
3282   if (MF.getFunction()->hasStructRetAttr()) {
3283     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3284     unsigned Reg = MipsFI->getSRetReturnReg();
3285 
3286     if (!Reg)
3287       llvm_unreachable("sret virtual register not created in the entry block");
3288     SDValue Val =
3289         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3290     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3291 
3292     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Flag);
3293     Flag = Chain.getValue(1);
3294     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3295   }
3296 
3297   RetOps[0] = Chain;  // Update chain.
3298 
3299   // Add the flag if we have it.
3300   if (Flag.getNode())
3301     RetOps.push_back(Flag);
3302 
3303   // ISRs must use "eret".
3304   if (DAG.getMachineFunction().getFunction()->hasFnAttribute("interrupt"))
3305     return LowerInterruptReturn(RetOps, DL, DAG);
3306 
3307   // Standard return on Mips is a "jr $ra"
3308   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
3309 }
3310 
3311 //===----------------------------------------------------------------------===//
3312 //                           Mips Inline Assembly Support
3313 //===----------------------------------------------------------------------===//
3314 
3315 /// getConstraintType - Given a constraint letter, return the type of
3316 /// constraint it is for this target.
3317 MipsTargetLowering::ConstraintType
getConstraintType(StringRef Constraint) const3318 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
3319   // Mips specific constraints
3320   // GCC config/mips/constraints.md
3321   //
3322   // 'd' : An address register. Equivalent to r
3323   //       unless generating MIPS16 code.
3324   // 'y' : Equivalent to r; retained for
3325   //       backwards compatibility.
3326   // 'c' : A register suitable for use in an indirect
3327   //       jump. This will always be $25 for -mabicalls.
3328   // 'l' : The lo register. 1 word storage.
3329   // 'x' : The hilo register pair. Double word storage.
3330   if (Constraint.size() == 1) {
3331     switch (Constraint[0]) {
3332       default : break;
3333       case 'd':
3334       case 'y':
3335       case 'f':
3336       case 'c':
3337       case 'l':
3338       case 'x':
3339         return C_RegisterClass;
3340       case 'R':
3341         return C_Memory;
3342     }
3343   }
3344 
3345   if (Constraint == "ZC")
3346     return C_Memory;
3347 
3348   return TargetLowering::getConstraintType(Constraint);
3349 }
3350 
3351 /// Examine constraint type and operand type and determine a weight value.
3352 /// This object must already have been set up with the operand type
3353 /// and the current alternative constraint selected.
3354 TargetLowering::ConstraintWeight
getSingleConstraintMatchWeight(AsmOperandInfo & info,const char * constraint) const3355 MipsTargetLowering::getSingleConstraintMatchWeight(
3356     AsmOperandInfo &info, const char *constraint) const {
3357   ConstraintWeight weight = CW_Invalid;
3358   Value *CallOperandVal = info.CallOperandVal;
3359     // If we don't have a value, we can't do a match,
3360     // but allow it at the lowest weight.
3361   if (!CallOperandVal)
3362     return CW_Default;
3363   Type *type = CallOperandVal->getType();
3364   // Look at the constraint type.
3365   switch (*constraint) {
3366   default:
3367     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3368     break;
3369   case 'd':
3370   case 'y':
3371     if (type->isIntegerTy())
3372       weight = CW_Register;
3373     break;
3374   case 'f': // FPU or MSA register
3375     if (Subtarget.hasMSA() && type->isVectorTy() &&
3376         cast<VectorType>(type)->getBitWidth() == 128)
3377       weight = CW_Register;
3378     else if (type->isFloatTy())
3379       weight = CW_Register;
3380     break;
3381   case 'c': // $25 for indirect jumps
3382   case 'l': // lo register
3383   case 'x': // hilo register pair
3384     if (type->isIntegerTy())
3385       weight = CW_SpecificReg;
3386     break;
3387   case 'I': // signed 16 bit immediate
3388   case 'J': // integer zero
3389   case 'K': // unsigned 16 bit immediate
3390   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3391   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3392   case 'O': // signed 15 bit immediate (+- 16383)
3393   case 'P': // immediate in the range of 65535 to 1 (inclusive)
3394     if (isa<ConstantInt>(CallOperandVal))
3395       weight = CW_Constant;
3396     break;
3397   case 'R':
3398     weight = CW_Memory;
3399     break;
3400   }
3401   return weight;
3402 }
3403 
3404 /// This is a helper function to parse a physical register string and split it
3405 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
3406 /// that is returned indicates whether parsing was successful. The second flag
3407 /// is true if the numeric part exists.
parsePhysicalReg(StringRef C,StringRef & Prefix,unsigned long long & Reg)3408 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
3409                                               unsigned long long &Reg) {
3410   if (C.front() != '{' || C.back() != '}')
3411     return std::make_pair(false, false);
3412 
3413   // Search for the first numeric character.
3414   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
3415   I = std::find_if(B, E, isdigit);
3416 
3417   Prefix = StringRef(B, I - B);
3418 
3419   // The second flag is set to false if no numeric characters were found.
3420   if (I == E)
3421     return std::make_pair(true, false);
3422 
3423   // Parse the numeric characters.
3424   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
3425                         true);
3426 }
3427 
3428 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
parseRegForInlineAsmConstraint(StringRef C,MVT VT) const3429 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
3430   const TargetRegisterInfo *TRI =
3431       Subtarget.getRegisterInfo();
3432   const TargetRegisterClass *RC;
3433   StringRef Prefix;
3434   unsigned long long Reg;
3435 
3436   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
3437 
3438   if (!R.first)
3439     return std::make_pair(0U, nullptr);
3440 
3441   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
3442     // No numeric characters follow "hi" or "lo".
3443     if (R.second)
3444       return std::make_pair(0U, nullptr);
3445 
3446     RC = TRI->getRegClass(Prefix == "hi" ?
3447                           Mips::HI32RegClassID : Mips::LO32RegClassID);
3448     return std::make_pair(*(RC->begin()), RC);
3449   } else if (Prefix.startswith("$msa")) {
3450     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
3451 
3452     // No numeric characters follow the name.
3453     if (R.second)
3454       return std::make_pair(0U, nullptr);
3455 
3456     Reg = StringSwitch<unsigned long long>(Prefix)
3457               .Case("$msair", Mips::MSAIR)
3458               .Case("$msacsr", Mips::MSACSR)
3459               .Case("$msaaccess", Mips::MSAAccess)
3460               .Case("$msasave", Mips::MSASave)
3461               .Case("$msamodify", Mips::MSAModify)
3462               .Case("$msarequest", Mips::MSARequest)
3463               .Case("$msamap", Mips::MSAMap)
3464               .Case("$msaunmap", Mips::MSAUnmap)
3465               .Default(0);
3466 
3467     if (!Reg)
3468       return std::make_pair(0U, nullptr);
3469 
3470     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
3471     return std::make_pair(Reg, RC);
3472   }
3473 
3474   if (!R.second)
3475     return std::make_pair(0U, nullptr);
3476 
3477   if (Prefix == "$f") { // Parse $f0-$f31.
3478     // If the size of FP registers is 64-bit or Reg is an even number, select
3479     // the 64-bit register class. Otherwise, select the 32-bit register class.
3480     if (VT == MVT::Other)
3481       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
3482 
3483     RC = getRegClassFor(VT);
3484 
3485     if (RC == &Mips::AFGR64RegClass) {
3486       assert(Reg % 2 == 0);
3487       Reg >>= 1;
3488     }
3489   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
3490     RC = TRI->getRegClass(Mips::FCCRegClassID);
3491   else if (Prefix == "$w") { // Parse $w0-$w31.
3492     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
3493   } else { // Parse $0-$31.
3494     assert(Prefix == "$");
3495     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
3496   }
3497 
3498   assert(Reg < RC->getNumRegs());
3499   return std::make_pair(*(RC->begin() + Reg), RC);
3500 }
3501 
3502 /// Given a register class constraint, like 'r', if this corresponds directly
3503 /// to an LLVM register class, return a register of 0 and the register class
3504 /// pointer.
3505 std::pair<unsigned, const TargetRegisterClass *>
getRegForInlineAsmConstraint(const TargetRegisterInfo * TRI,StringRef Constraint,MVT VT) const3506 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
3507                                                  StringRef Constraint,
3508                                                  MVT VT) const {
3509   if (Constraint.size() == 1) {
3510     switch (Constraint[0]) {
3511     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
3512     case 'y': // Same as 'r'. Exists for compatibility.
3513     case 'r':
3514       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8) {
3515         if (Subtarget.inMips16Mode())
3516           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
3517         return std::make_pair(0U, &Mips::GPR32RegClass);
3518       }
3519       if (VT == MVT::i64 && !Subtarget.isGP64bit())
3520         return std::make_pair(0U, &Mips::GPR32RegClass);
3521       if (VT == MVT::i64 && Subtarget.isGP64bit())
3522         return std::make_pair(0U, &Mips::GPR64RegClass);
3523       // This will generate an error message
3524       return std::make_pair(0U, nullptr);
3525     case 'f': // FPU or MSA register
3526       if (VT == MVT::v16i8)
3527         return std::make_pair(0U, &Mips::MSA128BRegClass);
3528       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
3529         return std::make_pair(0U, &Mips::MSA128HRegClass);
3530       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
3531         return std::make_pair(0U, &Mips::MSA128WRegClass);
3532       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
3533         return std::make_pair(0U, &Mips::MSA128DRegClass);
3534       else if (VT == MVT::f32)
3535         return std::make_pair(0U, &Mips::FGR32RegClass);
3536       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
3537         if (Subtarget.isFP64bit())
3538           return std::make_pair(0U, &Mips::FGR64RegClass);
3539         return std::make_pair(0U, &Mips::AFGR64RegClass);
3540       }
3541       break;
3542     case 'c': // register suitable for indirect jump
3543       if (VT == MVT::i32)
3544         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
3545       assert(VT == MVT::i64 && "Unexpected type.");
3546       return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
3547     case 'l': // register suitable for indirect jump
3548       if (VT == MVT::i32)
3549         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
3550       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
3551     case 'x': // register suitable for indirect jump
3552       // Fixme: Not triggering the use of both hi and low
3553       // This will generate an error message
3554       return std::make_pair(0U, nullptr);
3555     }
3556   }
3557 
3558   std::pair<unsigned, const TargetRegisterClass *> R;
3559   R = parseRegForInlineAsmConstraint(Constraint, VT);
3560 
3561   if (R.second)
3562     return R;
3563 
3564   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
3565 }
3566 
3567 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
3568 /// vector.  If it is invalid, don't add anything to Ops.
LowerAsmOperandForConstraint(SDValue Op,std::string & Constraint,std::vector<SDValue> & Ops,SelectionDAG & DAG) const3569 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
3570                                                      std::string &Constraint,
3571                                                      std::vector<SDValue>&Ops,
3572                                                      SelectionDAG &DAG) const {
3573   SDLoc DL(Op);
3574   SDValue Result;
3575 
3576   // Only support length 1 constraints for now.
3577   if (Constraint.length() > 1) return;
3578 
3579   char ConstraintLetter = Constraint[0];
3580   switch (ConstraintLetter) {
3581   default: break; // This will fall through to the generic implementation
3582   case 'I': // Signed 16 bit constant
3583     // If this fails, the parent routine will give an error
3584     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3585       EVT Type = Op.getValueType();
3586       int64_t Val = C->getSExtValue();
3587       if (isInt<16>(Val)) {
3588         Result = DAG.getTargetConstant(Val, DL, Type);
3589         break;
3590       }
3591     }
3592     return;
3593   case 'J': // integer zero
3594     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3595       EVT Type = Op.getValueType();
3596       int64_t Val = C->getZExtValue();
3597       if (Val == 0) {
3598         Result = DAG.getTargetConstant(0, DL, Type);
3599         break;
3600       }
3601     }
3602     return;
3603   case 'K': // unsigned 16 bit immediate
3604     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3605       EVT Type = Op.getValueType();
3606       uint64_t Val = (uint64_t)C->getZExtValue();
3607       if (isUInt<16>(Val)) {
3608         Result = DAG.getTargetConstant(Val, DL, Type);
3609         break;
3610       }
3611     }
3612     return;
3613   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3614     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3615       EVT Type = Op.getValueType();
3616       int64_t Val = C->getSExtValue();
3617       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
3618         Result = DAG.getTargetConstant(Val, DL, Type);
3619         break;
3620       }
3621     }
3622     return;
3623   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3624     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3625       EVT Type = Op.getValueType();
3626       int64_t Val = C->getSExtValue();
3627       if ((Val >= -65535) && (Val <= -1)) {
3628         Result = DAG.getTargetConstant(Val, DL, Type);
3629         break;
3630       }
3631     }
3632     return;
3633   case 'O': // signed 15 bit immediate
3634     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3635       EVT Type = Op.getValueType();
3636       int64_t Val = C->getSExtValue();
3637       if ((isInt<15>(Val))) {
3638         Result = DAG.getTargetConstant(Val, DL, Type);
3639         break;
3640       }
3641     }
3642     return;
3643   case 'P': // immediate in the range of 1 to 65535 (inclusive)
3644     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3645       EVT Type = Op.getValueType();
3646       int64_t Val = C->getSExtValue();
3647       if ((Val <= 65535) && (Val >= 1)) {
3648         Result = DAG.getTargetConstant(Val, DL, Type);
3649         break;
3650       }
3651     }
3652     return;
3653   }
3654 
3655   if (Result.getNode()) {
3656     Ops.push_back(Result);
3657     return;
3658   }
3659 
3660   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
3661 }
3662 
isLegalAddressingMode(const DataLayout & DL,const AddrMode & AM,Type * Ty,unsigned AS) const3663 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
3664                                                const AddrMode &AM, Type *Ty,
3665                                                unsigned AS) const {
3666   // No global is ever allowed as a base.
3667   if (AM.BaseGV)
3668     return false;
3669 
3670   switch (AM.Scale) {
3671   case 0: // "r+i" or just "i", depending on HasBaseReg.
3672     break;
3673   case 1:
3674     if (!AM.HasBaseReg) // allow "r+i".
3675       break;
3676     return false; // disallow "r+r" or "r+r+i".
3677   default:
3678     return false;
3679   }
3680 
3681   return true;
3682 }
3683 
3684 bool
isOffsetFoldingLegal(const GlobalAddressSDNode * GA) const3685 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
3686   // The Mips target isn't yet aware of offsets.
3687   return false;
3688 }
3689 
getOptimalMemOpType(uint64_t Size,unsigned DstAlign,unsigned SrcAlign,bool IsMemset,bool ZeroMemset,bool MemcpyStrSrc,MachineFunction & MF) const3690 EVT MipsTargetLowering::getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
3691                                             unsigned SrcAlign,
3692                                             bool IsMemset, bool ZeroMemset,
3693                                             bool MemcpyStrSrc,
3694                                             MachineFunction &MF) const {
3695   if (Subtarget.hasMips64())
3696     return MVT::i64;
3697 
3698   return MVT::i32;
3699 }
3700 
isFPImmLegal(const APFloat & Imm,EVT VT) const3701 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
3702   if (VT != MVT::f32 && VT != MVT::f64)
3703     return false;
3704   if (Imm.isNegZero())
3705     return false;
3706   return Imm.isZero();
3707 }
3708 
getJumpTableEncoding() const3709 unsigned MipsTargetLowering::getJumpTableEncoding() const {
3710   if (ABI.IsN64())
3711     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
3712 
3713   return TargetLowering::getJumpTableEncoding();
3714 }
3715 
useSoftFloat() const3716 bool MipsTargetLowering::useSoftFloat() const {
3717   return Subtarget.useSoftFloat();
3718 }
3719 
copyByValRegs(SDValue Chain,const SDLoc & DL,std::vector<SDValue> & OutChains,SelectionDAG & DAG,const ISD::ArgFlagsTy & Flags,SmallVectorImpl<SDValue> & InVals,const Argument * FuncArg,unsigned FirstReg,unsigned LastReg,const CCValAssign & VA,MipsCCState & State) const3720 void MipsTargetLowering::copyByValRegs(
3721     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
3722     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
3723     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
3724     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
3725     MipsCCState &State) const {
3726   MachineFunction &MF = DAG.getMachineFunction();
3727   MachineFrameInfo *MFI = MF.getFrameInfo();
3728   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
3729   unsigned NumRegs = LastReg - FirstReg;
3730   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
3731   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
3732   int FrameObjOffset;
3733   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
3734 
3735   if (RegAreaSize)
3736     FrameObjOffset =
3737         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
3738         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
3739   else
3740     FrameObjOffset = VA.getLocMemOffset();
3741 
3742   // Create frame object.
3743   EVT PtrTy = getPointerTy(DAG.getDataLayout());
3744   int FI = MFI->CreateFixedObject(FrameObjSize, FrameObjOffset, true);
3745   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
3746   InVals.push_back(FIN);
3747 
3748   if (!NumRegs)
3749     return;
3750 
3751   // Copy arg registers.
3752   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
3753   const TargetRegisterClass *RC = getRegClassFor(RegTy);
3754 
3755   for (unsigned I = 0; I < NumRegs; ++I) {
3756     unsigned ArgReg = ByValArgRegs[FirstReg + I];
3757     unsigned VReg = addLiveIn(MF, ArgReg, RC);
3758     unsigned Offset = I * GPRSizeInBytes;
3759     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
3760                                    DAG.getConstant(Offset, DL, PtrTy));
3761     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
3762                                  StorePtr, MachinePointerInfo(FuncArg, Offset),
3763                                  false, false, 0);
3764     OutChains.push_back(Store);
3765   }
3766 }
3767 
3768 // Copy byVal arg to registers and stack.
passByValArg(SDValue Chain,const SDLoc & DL,std::deque<std::pair<unsigned,SDValue>> & RegsToPass,SmallVectorImpl<SDValue> & MemOpChains,SDValue StackPtr,MachineFrameInfo * MFI,SelectionDAG & DAG,SDValue Arg,unsigned FirstReg,unsigned LastReg,const ISD::ArgFlagsTy & Flags,bool isLittle,const CCValAssign & VA) const3769 void MipsTargetLowering::passByValArg(
3770     SDValue Chain, const SDLoc &DL,
3771     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3772     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
3773     MachineFrameInfo *MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
3774     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
3775     const CCValAssign &VA) const {
3776   unsigned ByValSizeInBytes = Flags.getByValSize();
3777   unsigned OffsetInBytes = 0; // From beginning of struct
3778   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
3779   unsigned Alignment = std::min(Flags.getByValAlign(), RegSizeInBytes);
3780   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
3781       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
3782   unsigned NumRegs = LastReg - FirstReg;
3783 
3784   if (NumRegs) {
3785     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
3786     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
3787     unsigned I = 0;
3788 
3789     // Copy words to registers.
3790     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
3791       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
3792                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
3793       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
3794                                     MachinePointerInfo(), false, false, false,
3795                                     Alignment);
3796       MemOpChains.push_back(LoadVal.getValue(1));
3797       unsigned ArgReg = ArgRegs[FirstReg + I];
3798       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
3799     }
3800 
3801     // Return if the struct has been fully copied.
3802     if (ByValSizeInBytes == OffsetInBytes)
3803       return;
3804 
3805     // Copy the remainder of the byval argument with sub-word loads and shifts.
3806     if (LeftoverBytes) {
3807       SDValue Val;
3808 
3809       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
3810            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
3811         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
3812 
3813         if (RemainingSizeInBytes < LoadSizeInBytes)
3814           continue;
3815 
3816         // Load subword.
3817         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
3818                                       DAG.getConstant(OffsetInBytes, DL,
3819                                                       PtrTy));
3820         SDValue LoadVal = DAG.getExtLoad(
3821             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
3822             MVT::getIntegerVT(LoadSizeInBytes * 8), false, false, false,
3823             Alignment);
3824         MemOpChains.push_back(LoadVal.getValue(1));
3825 
3826         // Shift the loaded value.
3827         unsigned Shamt;
3828 
3829         if (isLittle)
3830           Shamt = TotalBytesLoaded * 8;
3831         else
3832           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
3833 
3834         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
3835                                     DAG.getConstant(Shamt, DL, MVT::i32));
3836 
3837         if (Val.getNode())
3838           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
3839         else
3840           Val = Shift;
3841 
3842         OffsetInBytes += LoadSizeInBytes;
3843         TotalBytesLoaded += LoadSizeInBytes;
3844         Alignment = std::min(Alignment, LoadSizeInBytes);
3845       }
3846 
3847       unsigned ArgReg = ArgRegs[FirstReg + I];
3848       RegsToPass.push_back(std::make_pair(ArgReg, Val));
3849       return;
3850     }
3851   }
3852 
3853   // Copy remainder of byval arg to it with memcpy.
3854   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
3855   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
3856                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
3857   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
3858                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
3859   Chain = DAG.getMemcpy(Chain, DL, Dst, Src,
3860                         DAG.getConstant(MemCpySize, DL, PtrTy),
3861                         Alignment, /*isVolatile=*/false, /*AlwaysInline=*/false,
3862                         /*isTailCall=*/false,
3863                         MachinePointerInfo(), MachinePointerInfo());
3864   MemOpChains.push_back(Chain);
3865 }
3866 
writeVarArgRegs(std::vector<SDValue> & OutChains,SDValue Chain,const SDLoc & DL,SelectionDAG & DAG,CCState & State) const3867 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
3868                                          SDValue Chain, const SDLoc &DL,
3869                                          SelectionDAG &DAG,
3870                                          CCState &State) const {
3871   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
3872   unsigned Idx = State.getFirstUnallocated(ArgRegs);
3873   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
3874   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
3875   const TargetRegisterClass *RC = getRegClassFor(RegTy);
3876   MachineFunction &MF = DAG.getMachineFunction();
3877   MachineFrameInfo *MFI = MF.getFrameInfo();
3878   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3879 
3880   // Offset of the first variable argument from stack pointer.
3881   int VaArgOffset;
3882 
3883   if (ArgRegs.size() == Idx)
3884     VaArgOffset = alignTo(State.getNextStackOffset(), RegSizeInBytes);
3885   else {
3886     VaArgOffset =
3887         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
3888         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
3889   }
3890 
3891   // Record the frame index of the first variable argument
3892   // which is a value necessary to VASTART.
3893   int FI = MFI->CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
3894   MipsFI->setVarArgsFrameIndex(FI);
3895 
3896   // Copy the integer registers that have not been used for argument passing
3897   // to the argument register save area. For O32, the save area is allocated
3898   // in the caller's stack frame, while for N32/64, it is allocated in the
3899   // callee's stack frame.
3900   for (unsigned I = Idx; I < ArgRegs.size();
3901        ++I, VaArgOffset += RegSizeInBytes) {
3902     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
3903     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
3904     FI = MFI->CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
3905     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3906     SDValue Store = DAG.getStore(Chain, DL, ArgValue, PtrOff,
3907                                  MachinePointerInfo(), false, false, 0);
3908     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
3909         (Value *)nullptr);
3910     OutChains.push_back(Store);
3911   }
3912 }
3913 
HandleByVal(CCState * State,unsigned & Size,unsigned Align) const3914 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
3915                                      unsigned Align) const {
3916   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3917 
3918   assert(Size && "Byval argument's size shouldn't be 0.");
3919 
3920   Align = std::min(Align, TFL->getStackAlignment());
3921 
3922   unsigned FirstReg = 0;
3923   unsigned NumRegs = 0;
3924 
3925   if (State->getCallingConv() != CallingConv::Fast) {
3926     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
3927     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
3928     // FIXME: The O32 case actually describes no shadow registers.
3929     const MCPhysReg *ShadowRegs =
3930         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
3931 
3932     // We used to check the size as well but we can't do that anymore since
3933     // CCState::HandleByVal() rounds up the size after calling this function.
3934     assert(!(Align % RegSizeInBytes) &&
3935            "Byval argument's alignment should be a multiple of"
3936            "RegSizeInBytes.");
3937 
3938     FirstReg = State->getFirstUnallocated(IntArgRegs);
3939 
3940     // If Align > RegSizeInBytes, the first arg register must be even.
3941     // FIXME: This condition happens to do the right thing but it's not the
3942     //        right way to test it. We want to check that the stack frame offset
3943     //        of the register is aligned.
3944     if ((Align > RegSizeInBytes) && (FirstReg % 2)) {
3945       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
3946       ++FirstReg;
3947     }
3948 
3949     // Mark the registers allocated.
3950     Size = alignTo(Size, RegSizeInBytes);
3951     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
3952          Size -= RegSizeInBytes, ++I, ++NumRegs)
3953       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
3954   }
3955 
3956   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
3957 }
3958 
emitPseudoSELECT(MachineInstr & MI,MachineBasicBlock * BB,bool isFPCmp,unsigned Opc) const3959 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
3960                                                         MachineBasicBlock *BB,
3961                                                         bool isFPCmp,
3962                                                         unsigned Opc) const {
3963   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
3964          "Subtarget already supports SELECT nodes with the use of"
3965          "conditional-move instructions.");
3966 
3967   const TargetInstrInfo *TII =
3968       Subtarget.getInstrInfo();
3969   DebugLoc DL = MI.getDebugLoc();
3970 
3971   // To "insert" a SELECT instruction, we actually have to insert the
3972   // diamond control-flow pattern.  The incoming instruction knows the
3973   // destination vreg to set, the condition code register to branch on, the
3974   // true/false values to select between, and a branch opcode to use.
3975   const BasicBlock *LLVM_BB = BB->getBasicBlock();
3976   MachineFunction::iterator It = ++BB->getIterator();
3977 
3978   //  thisMBB:
3979   //  ...
3980   //   TrueVal = ...
3981   //   setcc r1, r2, r3
3982   //   bNE   r1, r0, copy1MBB
3983   //   fallthrough --> copy0MBB
3984   MachineBasicBlock *thisMBB  = BB;
3985   MachineFunction *F = BB->getParent();
3986   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
3987   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
3988   F->insert(It, copy0MBB);
3989   F->insert(It, sinkMBB);
3990 
3991   // Transfer the remainder of BB and its successor edges to sinkMBB.
3992   sinkMBB->splice(sinkMBB->begin(), BB,
3993                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
3994   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
3995 
3996   // Next, add the true and fallthrough blocks as its successors.
3997   BB->addSuccessor(copy0MBB);
3998   BB->addSuccessor(sinkMBB);
3999 
4000   if (isFPCmp) {
4001     // bc1[tf] cc, sinkMBB
4002     BuildMI(BB, DL, TII->get(Opc))
4003         .addReg(MI.getOperand(1).getReg())
4004         .addMBB(sinkMBB);
4005   } else {
4006     // bne rs, $0, sinkMBB
4007     BuildMI(BB, DL, TII->get(Opc))
4008         .addReg(MI.getOperand(1).getReg())
4009         .addReg(Mips::ZERO)
4010         .addMBB(sinkMBB);
4011   }
4012 
4013   //  copy0MBB:
4014   //   %FalseValue = ...
4015   //   # fallthrough to sinkMBB
4016   BB = copy0MBB;
4017 
4018   // Update machine-CFG edges
4019   BB->addSuccessor(sinkMBB);
4020 
4021   //  sinkMBB:
4022   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4023   //  ...
4024   BB = sinkMBB;
4025 
4026   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4027       .addReg(MI.getOperand(2).getReg())
4028       .addMBB(thisMBB)
4029       .addReg(MI.getOperand(3).getReg())
4030       .addMBB(copy0MBB);
4031 
4032   MI.eraseFromParent(); // The pseudo instruction is gone now.
4033 
4034   return BB;
4035 }
4036 
4037 // FIXME? Maybe this could be a TableGen attribute on some registers and
4038 // this table could be generated automatically from RegInfo.
getRegisterByName(const char * RegName,EVT VT,SelectionDAG & DAG) const4039 unsigned MipsTargetLowering::getRegisterByName(const char* RegName, EVT VT,
4040                                                SelectionDAG &DAG) const {
4041   // Named registers is expected to be fairly rare. For now, just support $28
4042   // since the linux kernel uses it.
4043   if (Subtarget.isGP64bit()) {
4044     unsigned Reg = StringSwitch<unsigned>(RegName)
4045                          .Case("$28", Mips::GP_64)
4046                          .Default(0);
4047     if (Reg)
4048       return Reg;
4049   } else {
4050     unsigned Reg = StringSwitch<unsigned>(RegName)
4051                          .Case("$28", Mips::GP)
4052                          .Default(0);
4053     if (Reg)
4054       return Reg;
4055   }
4056   report_fatal_error("Invalid register name global variable");
4057 }
4058