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1 //===-- SparcInstrInfo.cpp - Sparc Instruction Information ----------------===//
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 contains the Sparc implementation of the TargetInstrInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "SparcInstrInfo.h"
15 #include "Sparc.h"
16 #include "SparcMachineFunctionInfo.h"
17 #include "SparcSubtarget.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/CodeGen/MachineRegisterInfo.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/TargetRegistry.h"
24 
25 #define GET_INSTRINFO_CTOR
26 #include "SparcGenInstrInfo.inc"
27 
28 using namespace llvm;
29 
SparcInstrInfo(SparcSubtarget & ST)30 SparcInstrInfo::SparcInstrInfo(SparcSubtarget &ST)
31   : SparcGenInstrInfo(SP::ADJCALLSTACKDOWN, SP::ADJCALLSTACKUP),
32     RI(ST, *this), Subtarget(ST) {
33 }
34 
35 /// isLoadFromStackSlot - If the specified machine instruction is a direct
36 /// load from a stack slot, return the virtual or physical register number of
37 /// the destination along with the FrameIndex of the loaded stack slot.  If
38 /// not, return 0.  This predicate must return 0 if the instruction has
39 /// any side effects other than loading from the stack slot.
isLoadFromStackSlot(const MachineInstr * MI,int & FrameIndex) const40 unsigned SparcInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
41                                              int &FrameIndex) const {
42   if (MI->getOpcode() == SP::LDri ||
43       MI->getOpcode() == SP::LDFri ||
44       MI->getOpcode() == SP::LDDFri) {
45     if (MI->getOperand(1).isFI() && MI->getOperand(2).isImm() &&
46         MI->getOperand(2).getImm() == 0) {
47       FrameIndex = MI->getOperand(1).getIndex();
48       return MI->getOperand(0).getReg();
49     }
50   }
51   return 0;
52 }
53 
54 /// isStoreToStackSlot - If the specified machine instruction is a direct
55 /// store to a stack slot, return the virtual or physical register number of
56 /// the source reg along with the FrameIndex of the loaded stack slot.  If
57 /// not, return 0.  This predicate must return 0 if the instruction has
58 /// any side effects other than storing to the stack slot.
isStoreToStackSlot(const MachineInstr * MI,int & FrameIndex) const59 unsigned SparcInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
60                                             int &FrameIndex) const {
61   if (MI->getOpcode() == SP::STri ||
62       MI->getOpcode() == SP::STFri ||
63       MI->getOpcode() == SP::STDFri) {
64     if (MI->getOperand(0).isFI() && MI->getOperand(1).isImm() &&
65         MI->getOperand(1).getImm() == 0) {
66       FrameIndex = MI->getOperand(0).getIndex();
67       return MI->getOperand(2).getReg();
68     }
69   }
70   return 0;
71 }
72 
IsIntegerCC(unsigned CC)73 static bool IsIntegerCC(unsigned CC)
74 {
75   return  (CC <= SPCC::ICC_VC);
76 }
77 
78 
GetOppositeBranchCondition(SPCC::CondCodes CC)79 static SPCC::CondCodes GetOppositeBranchCondition(SPCC::CondCodes CC)
80 {
81   switch(CC) {
82   case SPCC::ICC_NE:   return SPCC::ICC_E;
83   case SPCC::ICC_E:    return SPCC::ICC_NE;
84   case SPCC::ICC_G:    return SPCC::ICC_LE;
85   case SPCC::ICC_LE:   return SPCC::ICC_G;
86   case SPCC::ICC_GE:   return SPCC::ICC_L;
87   case SPCC::ICC_L:    return SPCC::ICC_GE;
88   case SPCC::ICC_GU:   return SPCC::ICC_LEU;
89   case SPCC::ICC_LEU:  return SPCC::ICC_GU;
90   case SPCC::ICC_CC:   return SPCC::ICC_CS;
91   case SPCC::ICC_CS:   return SPCC::ICC_CC;
92   case SPCC::ICC_POS:  return SPCC::ICC_NEG;
93   case SPCC::ICC_NEG:  return SPCC::ICC_POS;
94   case SPCC::ICC_VC:   return SPCC::ICC_VS;
95   case SPCC::ICC_VS:   return SPCC::ICC_VC;
96 
97   case SPCC::FCC_U:    return SPCC::FCC_O;
98   case SPCC::FCC_O:    return SPCC::FCC_U;
99   case SPCC::FCC_G:    return SPCC::FCC_LE;
100   case SPCC::FCC_LE:   return SPCC::FCC_G;
101   case SPCC::FCC_UG:   return SPCC::FCC_ULE;
102   case SPCC::FCC_ULE:  return SPCC::FCC_UG;
103   case SPCC::FCC_L:    return SPCC::FCC_GE;
104   case SPCC::FCC_GE:   return SPCC::FCC_L;
105   case SPCC::FCC_UL:   return SPCC::FCC_UGE;
106   case SPCC::FCC_UGE:  return SPCC::FCC_UL;
107   case SPCC::FCC_LG:   return SPCC::FCC_UE;
108   case SPCC::FCC_UE:   return SPCC::FCC_LG;
109   case SPCC::FCC_NE:   return SPCC::FCC_E;
110   case SPCC::FCC_E:    return SPCC::FCC_NE;
111   }
112   llvm_unreachable("Invalid cond code");
113 }
114 
115 MachineInstr *
emitFrameIndexDebugValue(MachineFunction & MF,int FrameIx,uint64_t Offset,const MDNode * MDPtr,DebugLoc dl) const116 SparcInstrInfo::emitFrameIndexDebugValue(MachineFunction &MF,
117                                          int FrameIx,
118                                          uint64_t Offset,
119                                          const MDNode *MDPtr,
120                                          DebugLoc dl) const {
121   MachineInstrBuilder MIB = BuildMI(MF, dl, get(SP::DBG_VALUE))
122     .addFrameIndex(FrameIx).addImm(0).addImm(Offset).addMetadata(MDPtr);
123   return &*MIB;
124 }
125 
126 
AnalyzeBranch(MachineBasicBlock & MBB,MachineBasicBlock * & TBB,MachineBasicBlock * & FBB,SmallVectorImpl<MachineOperand> & Cond,bool AllowModify) const127 bool SparcInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
128                                    MachineBasicBlock *&TBB,
129                                    MachineBasicBlock *&FBB,
130                                    SmallVectorImpl<MachineOperand> &Cond,
131                                    bool AllowModify) const
132 {
133 
134   MachineBasicBlock::iterator I = MBB.end();
135   MachineBasicBlock::iterator UnCondBrIter = MBB.end();
136   while (I != MBB.begin()) {
137     --I;
138 
139     if (I->isDebugValue())
140       continue;
141 
142     //When we see a non-terminator, we are done
143     if (!isUnpredicatedTerminator(I))
144       break;
145 
146     //Terminator is not a branch
147     if (!I->isBranch())
148       return true;
149 
150     //Handle Unconditional branches
151     if (I->getOpcode() == SP::BA) {
152       UnCondBrIter = I;
153 
154       if (!AllowModify) {
155         TBB = I->getOperand(0).getMBB();
156         continue;
157       }
158 
159       while (llvm::next(I) != MBB.end())
160         llvm::next(I)->eraseFromParent();
161 
162       Cond.clear();
163       FBB = 0;
164 
165       if (MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
166         TBB = 0;
167         I->eraseFromParent();
168         I = MBB.end();
169         UnCondBrIter = MBB.end();
170         continue;
171       }
172 
173       TBB = I->getOperand(0).getMBB();
174       continue;
175     }
176 
177     unsigned Opcode = I->getOpcode();
178     if (Opcode != SP::BCOND && Opcode != SP::FBCOND)
179       return true; //Unknown Opcode
180 
181     SPCC::CondCodes BranchCode = (SPCC::CondCodes)I->getOperand(1).getImm();
182 
183     if (Cond.empty()) {
184       MachineBasicBlock *TargetBB = I->getOperand(0).getMBB();
185       if (AllowModify && UnCondBrIter != MBB.end() &&
186           MBB.isLayoutSuccessor(TargetBB)) {
187 
188         //Transform the code
189         //
190         //    brCC L1
191         //    ba L2
192         // L1:
193         //    ..
194         // L2:
195         //
196         // into
197         //
198         //   brnCC L2
199         // L1:
200         //   ...
201         // L2:
202         //
203         BranchCode = GetOppositeBranchCondition(BranchCode);
204         MachineBasicBlock::iterator OldInst = I;
205         BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(Opcode))
206           .addMBB(UnCondBrIter->getOperand(0).getMBB()).addImm(BranchCode);
207         BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(SP::BA))
208           .addMBB(TargetBB);
209 
210         OldInst->eraseFromParent();
211         UnCondBrIter->eraseFromParent();
212 
213         UnCondBrIter = MBB.end();
214         I = MBB.end();
215         continue;
216       }
217       FBB = TBB;
218       TBB = I->getOperand(0).getMBB();
219       Cond.push_back(MachineOperand::CreateImm(BranchCode));
220       continue;
221     }
222     //FIXME: Handle subsequent conditional branches
223     //For now, we can't handle multiple conditional branches
224     return true;
225   }
226   return false;
227 }
228 
229 unsigned
InsertBranch(MachineBasicBlock & MBB,MachineBasicBlock * TBB,MachineBasicBlock * FBB,const SmallVectorImpl<MachineOperand> & Cond,DebugLoc DL) const230 SparcInstrInfo::InsertBranch(MachineBasicBlock &MBB,MachineBasicBlock *TBB,
231                              MachineBasicBlock *FBB,
232                              const SmallVectorImpl<MachineOperand> &Cond,
233                              DebugLoc DL) const {
234   assert(TBB && "InsertBranch must not be told to insert a fallthrough");
235   assert((Cond.size() == 1 || Cond.size() == 0) &&
236          "Sparc branch conditions should have one component!");
237 
238   if (Cond.empty()) {
239     assert(!FBB && "Unconditional branch with multiple successors!");
240     BuildMI(&MBB, DL, get(SP::BA)).addMBB(TBB);
241     return 1;
242   }
243 
244   //Conditional branch
245   unsigned CC = Cond[0].getImm();
246 
247   if (IsIntegerCC(CC))
248     BuildMI(&MBB, DL, get(SP::BCOND)).addMBB(TBB).addImm(CC);
249   else
250     BuildMI(&MBB, DL, get(SP::FBCOND)).addMBB(TBB).addImm(CC);
251   if (!FBB)
252     return 1;
253 
254   BuildMI(&MBB, DL, get(SP::BA)).addMBB(FBB);
255   return 2;
256 }
257 
RemoveBranch(MachineBasicBlock & MBB) const258 unsigned SparcInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const
259 {
260   MachineBasicBlock::iterator I = MBB.end();
261   unsigned Count = 0;
262   while (I != MBB.begin()) {
263     --I;
264 
265     if (I->isDebugValue())
266       continue;
267 
268     if (I->getOpcode() != SP::BA
269         && I->getOpcode() != SP::BCOND
270         && I->getOpcode() != SP::FBCOND)
271       break; // Not a branch
272 
273     I->eraseFromParent();
274     I = MBB.end();
275     ++Count;
276   }
277   return Count;
278 }
279 
copyPhysReg(MachineBasicBlock & MBB,MachineBasicBlock::iterator I,DebugLoc DL,unsigned DestReg,unsigned SrcReg,bool KillSrc) const280 void SparcInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
281                                  MachineBasicBlock::iterator I, DebugLoc DL,
282                                  unsigned DestReg, unsigned SrcReg,
283                                  bool KillSrc) const {
284   if (SP::IntRegsRegClass.contains(DestReg, SrcReg))
285     BuildMI(MBB, I, DL, get(SP::ORrr), DestReg).addReg(SP::G0)
286       .addReg(SrcReg, getKillRegState(KillSrc));
287   else if (SP::FPRegsRegClass.contains(DestReg, SrcReg))
288     BuildMI(MBB, I, DL, get(SP::FMOVS), DestReg)
289       .addReg(SrcReg, getKillRegState(KillSrc));
290   else if (SP::DFPRegsRegClass.contains(DestReg, SrcReg))
291     BuildMI(MBB, I, DL, get(Subtarget.isV9() ? SP::FMOVD : SP::FpMOVD), DestReg)
292       .addReg(SrcReg, getKillRegState(KillSrc));
293   else
294     llvm_unreachable("Impossible reg-to-reg copy");
295 }
296 
297 void SparcInstrInfo::
storeRegToStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator I,unsigned SrcReg,bool isKill,int FI,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI) const298 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
299                     unsigned SrcReg, bool isKill, int FI,
300                     const TargetRegisterClass *RC,
301                     const TargetRegisterInfo *TRI) const {
302   DebugLoc DL;
303   if (I != MBB.end()) DL = I->getDebugLoc();
304 
305   // On the order of operands here: think "[FrameIdx + 0] = SrcReg".
306   if (RC == &SP::IntRegsRegClass)
307     BuildMI(MBB, I, DL, get(SP::STri)).addFrameIndex(FI).addImm(0)
308       .addReg(SrcReg, getKillRegState(isKill));
309   else if (RC == &SP::FPRegsRegClass)
310     BuildMI(MBB, I, DL, get(SP::STFri)).addFrameIndex(FI).addImm(0)
311       .addReg(SrcReg,  getKillRegState(isKill));
312   else if (RC == &SP::DFPRegsRegClass)
313     BuildMI(MBB, I, DL, get(SP::STDFri)).addFrameIndex(FI).addImm(0)
314       .addReg(SrcReg,  getKillRegState(isKill));
315   else
316     llvm_unreachable("Can't store this register to stack slot");
317 }
318 
319 void SparcInstrInfo::
loadRegFromStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator I,unsigned DestReg,int FI,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI) const320 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
321                      unsigned DestReg, int FI,
322                      const TargetRegisterClass *RC,
323                      const TargetRegisterInfo *TRI) const {
324   DebugLoc DL;
325   if (I != MBB.end()) DL = I->getDebugLoc();
326 
327   if (RC == &SP::IntRegsRegClass)
328     BuildMI(MBB, I, DL, get(SP::LDri), DestReg).addFrameIndex(FI).addImm(0);
329   else if (RC == &SP::FPRegsRegClass)
330     BuildMI(MBB, I, DL, get(SP::LDFri), DestReg).addFrameIndex(FI).addImm(0);
331   else if (RC == &SP::DFPRegsRegClass)
332     BuildMI(MBB, I, DL, get(SP::LDDFri), DestReg).addFrameIndex(FI).addImm(0);
333   else
334     llvm_unreachable("Can't load this register from stack slot");
335 }
336 
getGlobalBaseReg(MachineFunction * MF) const337 unsigned SparcInstrInfo::getGlobalBaseReg(MachineFunction *MF) const
338 {
339   SparcMachineFunctionInfo *SparcFI = MF->getInfo<SparcMachineFunctionInfo>();
340   unsigned GlobalBaseReg = SparcFI->getGlobalBaseReg();
341   if (GlobalBaseReg != 0)
342     return GlobalBaseReg;
343 
344   // Insert the set of GlobalBaseReg into the first MBB of the function
345   MachineBasicBlock &FirstMBB = MF->front();
346   MachineBasicBlock::iterator MBBI = FirstMBB.begin();
347   MachineRegisterInfo &RegInfo = MF->getRegInfo();
348 
349   GlobalBaseReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
350 
351 
352   DebugLoc dl;
353 
354   BuildMI(FirstMBB, MBBI, dl, get(SP::GETPCX), GlobalBaseReg);
355   SparcFI->setGlobalBaseReg(GlobalBaseReg);
356   return GlobalBaseReg;
357 }
358