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1 //===-- PPCISelDAGToDAG.cpp - PPC --pattern matching inst selector --------===//
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 a pattern matching instruction selector for PowerPC,
11 // converting from a legalized dag to a PPC dag.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "PPC.h"
16 #include "MCTargetDesc/PPCPredicates.h"
17 #include "PPCTargetMachine.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineInstrBuilder.h"
20 #include "llvm/CodeGen/MachineRegisterInfo.h"
21 #include "llvm/CodeGen/SelectionDAG.h"
22 #include "llvm/CodeGen/SelectionDAGISel.h"
23 #include "llvm/IR/Constants.h"
24 #include "llvm/IR/Function.h"
25 #include "llvm/IR/GlobalAlias.h"
26 #include "llvm/IR/GlobalValue.h"
27 #include "llvm/IR/GlobalVariable.h"
28 #include "llvm/IR/Intrinsics.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/Target/TargetOptions.h"
35 using namespace llvm;
36 
37 #define DEBUG_TYPE "ppc-codegen"
38 
39 // FIXME: Remove this once the bug has been fixed!
40 cl::opt<bool> ANDIGlueBug("expose-ppc-andi-glue-bug",
41 cl::desc("expose the ANDI glue bug on PPC"), cl::Hidden);
42 
43 namespace llvm {
44   void initializePPCDAGToDAGISelPass(PassRegistry&);
45 }
46 
47 namespace {
48   //===--------------------------------------------------------------------===//
49   /// PPCDAGToDAGISel - PPC specific code to select PPC machine
50   /// instructions for SelectionDAG operations.
51   ///
52   class PPCDAGToDAGISel : public SelectionDAGISel {
53     const PPCTargetMachine &TM;
54     const PPCTargetLowering *PPCLowering;
55     const PPCSubtarget *PPCSubTarget;
56     unsigned GlobalBaseReg;
57   public:
PPCDAGToDAGISel(PPCTargetMachine & tm)58     explicit PPCDAGToDAGISel(PPCTargetMachine &tm)
59       : SelectionDAGISel(tm), TM(tm),
60         PPCLowering(TM.getTargetLowering()),
61         PPCSubTarget(TM.getSubtargetImpl()) {
62       initializePPCDAGToDAGISelPass(*PassRegistry::getPassRegistry());
63     }
64 
runOnMachineFunction(MachineFunction & MF)65     bool runOnMachineFunction(MachineFunction &MF) override {
66       // Make sure we re-emit a set of the global base reg if necessary
67       GlobalBaseReg = 0;
68       PPCLowering = TM.getTargetLowering();
69       PPCSubTarget = TM.getSubtargetImpl();
70       SelectionDAGISel::runOnMachineFunction(MF);
71 
72       if (!PPCSubTarget->isSVR4ABI())
73         InsertVRSaveCode(MF);
74 
75       return true;
76     }
77 
78     void PostprocessISelDAG() override;
79 
80     /// getI32Imm - Return a target constant with the specified value, of type
81     /// i32.
getI32Imm(unsigned Imm)82     inline SDValue getI32Imm(unsigned Imm) {
83       return CurDAG->getTargetConstant(Imm, MVT::i32);
84     }
85 
86     /// getI64Imm - Return a target constant with the specified value, of type
87     /// i64.
getI64Imm(uint64_t Imm)88     inline SDValue getI64Imm(uint64_t Imm) {
89       return CurDAG->getTargetConstant(Imm, MVT::i64);
90     }
91 
92     /// getSmallIPtrImm - Return a target constant of pointer type.
getSmallIPtrImm(unsigned Imm)93     inline SDValue getSmallIPtrImm(unsigned Imm) {
94       return CurDAG->getTargetConstant(Imm, PPCLowering->getPointerTy());
95     }
96 
97     /// isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s
98     /// with any number of 0s on either side.  The 1s are allowed to wrap from
99     /// LSB to MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs.
100     /// 0x0F0F0000 is not, since all 1s are not contiguous.
101     static bool isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME);
102 
103 
104     /// isRotateAndMask - Returns true if Mask and Shift can be folded into a
105     /// rotate and mask opcode and mask operation.
106     static bool isRotateAndMask(SDNode *N, unsigned Mask, bool isShiftMask,
107                                 unsigned &SH, unsigned &MB, unsigned &ME);
108 
109     /// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
110     /// base register.  Return the virtual register that holds this value.
111     SDNode *getGlobalBaseReg();
112 
113     // Select - Convert the specified operand from a target-independent to a
114     // target-specific node if it hasn't already been changed.
115     SDNode *Select(SDNode *N) override;
116 
117     SDNode *SelectBitfieldInsert(SDNode *N);
118 
119     /// SelectCC - Select a comparison of the specified values with the
120     /// specified condition code, returning the CR# of the expression.
121     SDValue SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC, SDLoc dl);
122 
123     /// SelectAddrImm - Returns true if the address N can be represented by
124     /// a base register plus a signed 16-bit displacement [r+imm].
SelectAddrImm(SDValue N,SDValue & Disp,SDValue & Base)125     bool SelectAddrImm(SDValue N, SDValue &Disp,
126                        SDValue &Base) {
127       return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, false);
128     }
129 
130     /// SelectAddrImmOffs - Return true if the operand is valid for a preinc
131     /// immediate field.  Note that the operand at this point is already the
132     /// result of a prior SelectAddressRegImm call.
SelectAddrImmOffs(SDValue N,SDValue & Out) const133     bool SelectAddrImmOffs(SDValue N, SDValue &Out) const {
134       if (N.getOpcode() == ISD::TargetConstant ||
135           N.getOpcode() == ISD::TargetGlobalAddress) {
136         Out = N;
137         return true;
138       }
139 
140       return false;
141     }
142 
143     /// SelectAddrIdx - Given the specified addressed, check to see if it can be
144     /// represented as an indexed [r+r] operation.  Returns false if it can
145     /// be represented by [r+imm], which are preferred.
SelectAddrIdx(SDValue N,SDValue & Base,SDValue & Index)146     bool SelectAddrIdx(SDValue N, SDValue &Base, SDValue &Index) {
147       return PPCLowering->SelectAddressRegReg(N, Base, Index, *CurDAG);
148     }
149 
150     /// SelectAddrIdxOnly - Given the specified addressed, force it to be
151     /// represented as an indexed [r+r] operation.
SelectAddrIdxOnly(SDValue N,SDValue & Base,SDValue & Index)152     bool SelectAddrIdxOnly(SDValue N, SDValue &Base, SDValue &Index) {
153       return PPCLowering->SelectAddressRegRegOnly(N, Base, Index, *CurDAG);
154     }
155 
156     /// SelectAddrImmX4 - Returns true if the address N can be represented by
157     /// a base register plus a signed 16-bit displacement that is a multiple of 4.
158     /// Suitable for use by STD and friends.
SelectAddrImmX4(SDValue N,SDValue & Disp,SDValue & Base)159     bool SelectAddrImmX4(SDValue N, SDValue &Disp, SDValue &Base) {
160       return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, true);
161     }
162 
163     // Select an address into a single register.
SelectAddr(SDValue N,SDValue & Base)164     bool SelectAddr(SDValue N, SDValue &Base) {
165       Base = N;
166       return true;
167     }
168 
169     /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
170     /// inline asm expressions.  It is always correct to compute the value into
171     /// a register.  The case of adding a (possibly relocatable) constant to a
172     /// register can be improved, but it is wrong to substitute Reg+Reg for
173     /// Reg in an asm, because the load or store opcode would have to change.
SelectInlineAsmMemoryOperand(const SDValue & Op,char ConstraintCode,std::vector<SDValue> & OutOps)174    bool SelectInlineAsmMemoryOperand(const SDValue &Op,
175                                       char ConstraintCode,
176                                       std::vector<SDValue> &OutOps) override {
177       OutOps.push_back(Op);
178       return false;
179     }
180 
181     void InsertVRSaveCode(MachineFunction &MF);
182 
getPassName() const183     const char *getPassName() const override {
184       return "PowerPC DAG->DAG Pattern Instruction Selection";
185     }
186 
187 // Include the pieces autogenerated from the target description.
188 #include "PPCGenDAGISel.inc"
189 
190 private:
191     SDNode *SelectSETCC(SDNode *N);
192 
193     void PeepholePPC64();
194     void PeepholeCROps();
195 
196     bool AllUsersSelectZero(SDNode *N);
197     void SwapAllSelectUsers(SDNode *N);
198   };
199 }
200 
201 /// InsertVRSaveCode - Once the entire function has been instruction selected,
202 /// all virtual registers are created and all machine instructions are built,
203 /// check to see if we need to save/restore VRSAVE.  If so, do it.
InsertVRSaveCode(MachineFunction & Fn)204 void PPCDAGToDAGISel::InsertVRSaveCode(MachineFunction &Fn) {
205   // Check to see if this function uses vector registers, which means we have to
206   // save and restore the VRSAVE register and update it with the regs we use.
207   //
208   // In this case, there will be virtual registers of vector type created
209   // by the scheduler.  Detect them now.
210   bool HasVectorVReg = false;
211   for (unsigned i = 0, e = RegInfo->getNumVirtRegs(); i != e; ++i) {
212     unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
213     if (RegInfo->getRegClass(Reg) == &PPC::VRRCRegClass) {
214       HasVectorVReg = true;
215       break;
216     }
217   }
218   if (!HasVectorVReg) return;  // nothing to do.
219 
220   // If we have a vector register, we want to emit code into the entry and exit
221   // blocks to save and restore the VRSAVE register.  We do this here (instead
222   // of marking all vector instructions as clobbering VRSAVE) for two reasons:
223   //
224   // 1. This (trivially) reduces the load on the register allocator, by not
225   //    having to represent the live range of the VRSAVE register.
226   // 2. This (more significantly) allows us to create a temporary virtual
227   //    register to hold the saved VRSAVE value, allowing this temporary to be
228   //    register allocated, instead of forcing it to be spilled to the stack.
229 
230   // Create two vregs - one to hold the VRSAVE register that is live-in to the
231   // function and one for the value after having bits or'd into it.
232   unsigned InVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
233   unsigned UpdatedVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
234 
235   const TargetInstrInfo &TII = *TM.getInstrInfo();
236   MachineBasicBlock &EntryBB = *Fn.begin();
237   DebugLoc dl;
238   // Emit the following code into the entry block:
239   // InVRSAVE = MFVRSAVE
240   // UpdatedVRSAVE = UPDATE_VRSAVE InVRSAVE
241   // MTVRSAVE UpdatedVRSAVE
242   MachineBasicBlock::iterator IP = EntryBB.begin();  // Insert Point
243   BuildMI(EntryBB, IP, dl, TII.get(PPC::MFVRSAVE), InVRSAVE);
244   BuildMI(EntryBB, IP, dl, TII.get(PPC::UPDATE_VRSAVE),
245           UpdatedVRSAVE).addReg(InVRSAVE);
246   BuildMI(EntryBB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(UpdatedVRSAVE);
247 
248   // Find all return blocks, outputting a restore in each epilog.
249   for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
250     if (!BB->empty() && BB->back().isReturn()) {
251       IP = BB->end(); --IP;
252 
253       // Skip over all terminator instructions, which are part of the return
254       // sequence.
255       MachineBasicBlock::iterator I2 = IP;
256       while (I2 != BB->begin() && (--I2)->isTerminator())
257         IP = I2;
258 
259       // Emit: MTVRSAVE InVRSave
260       BuildMI(*BB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(InVRSAVE);
261     }
262   }
263 }
264 
265 
266 /// getGlobalBaseReg - Output the instructions required to put the
267 /// base address to use for accessing globals into a register.
268 ///
getGlobalBaseReg()269 SDNode *PPCDAGToDAGISel::getGlobalBaseReg() {
270   if (!GlobalBaseReg) {
271     const TargetInstrInfo &TII = *TM.getInstrInfo();
272     // Insert the set of GlobalBaseReg into the first MBB of the function
273     MachineBasicBlock &FirstMBB = MF->front();
274     MachineBasicBlock::iterator MBBI = FirstMBB.begin();
275     DebugLoc dl;
276 
277     if (PPCLowering->getPointerTy() == MVT::i32) {
278       GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::GPRC_NOR0RegClass);
279       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
280       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
281     } else {
282       GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::G8RC_NOX0RegClass);
283       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR8));
284       BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR8), GlobalBaseReg);
285     }
286   }
287   return CurDAG->getRegister(GlobalBaseReg,
288                              PPCLowering->getPointerTy()).getNode();
289 }
290 
291 /// isIntS16Immediate - This method tests to see if the node is either a 32-bit
292 /// or 64-bit immediate, and if the value can be accurately represented as a
293 /// sign extension from a 16-bit value.  If so, this returns true and the
294 /// immediate.
isIntS16Immediate(SDNode * N,short & Imm)295 static bool isIntS16Immediate(SDNode *N, short &Imm) {
296   if (N->getOpcode() != ISD::Constant)
297     return false;
298 
299   Imm = (short)cast<ConstantSDNode>(N)->getZExtValue();
300   if (N->getValueType(0) == MVT::i32)
301     return Imm == (int32_t)cast<ConstantSDNode>(N)->getZExtValue();
302   else
303     return Imm == (int64_t)cast<ConstantSDNode>(N)->getZExtValue();
304 }
305 
isIntS16Immediate(SDValue Op,short & Imm)306 static bool isIntS16Immediate(SDValue Op, short &Imm) {
307   return isIntS16Immediate(Op.getNode(), Imm);
308 }
309 
310 
311 /// isInt32Immediate - This method tests to see if the node is a 32-bit constant
312 /// operand. If so Imm will receive the 32-bit value.
isInt32Immediate(SDNode * N,unsigned & Imm)313 static bool isInt32Immediate(SDNode *N, unsigned &Imm) {
314   if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i32) {
315     Imm = cast<ConstantSDNode>(N)->getZExtValue();
316     return true;
317   }
318   return false;
319 }
320 
321 /// isInt64Immediate - This method tests to see if the node is a 64-bit constant
322 /// operand.  If so Imm will receive the 64-bit value.
isInt64Immediate(SDNode * N,uint64_t & Imm)323 static bool isInt64Immediate(SDNode *N, uint64_t &Imm) {
324   if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i64) {
325     Imm = cast<ConstantSDNode>(N)->getZExtValue();
326     return true;
327   }
328   return false;
329 }
330 
331 // isInt32Immediate - This method tests to see if a constant operand.
332 // If so Imm will receive the 32 bit value.
isInt32Immediate(SDValue N,unsigned & Imm)333 static bool isInt32Immediate(SDValue N, unsigned &Imm) {
334   return isInt32Immediate(N.getNode(), Imm);
335 }
336 
337 
338 // isOpcWithIntImmediate - This method tests to see if the node is a specific
339 // opcode and that it has a immediate integer right operand.
340 // If so Imm will receive the 32 bit value.
isOpcWithIntImmediate(SDNode * N,unsigned Opc,unsigned & Imm)341 static bool isOpcWithIntImmediate(SDNode *N, unsigned Opc, unsigned& Imm) {
342   return N->getOpcode() == Opc
343          && isInt32Immediate(N->getOperand(1).getNode(), Imm);
344 }
345 
isRunOfOnes(unsigned Val,unsigned & MB,unsigned & ME)346 bool PPCDAGToDAGISel::isRunOfOnes(unsigned Val, unsigned &MB, unsigned &ME) {
347   if (!Val)
348     return false;
349 
350   if (isShiftedMask_32(Val)) {
351     // look for the first non-zero bit
352     MB = countLeadingZeros(Val);
353     // look for the first zero bit after the run of ones
354     ME = countLeadingZeros((Val - 1) ^ Val);
355     return true;
356   } else {
357     Val = ~Val; // invert mask
358     if (isShiftedMask_32(Val)) {
359       // effectively look for the first zero bit
360       ME = countLeadingZeros(Val) - 1;
361       // effectively look for the first one bit after the run of zeros
362       MB = countLeadingZeros((Val - 1) ^ Val) + 1;
363       return true;
364     }
365   }
366   // no run present
367   return false;
368 }
369 
isRotateAndMask(SDNode * N,unsigned Mask,bool isShiftMask,unsigned & SH,unsigned & MB,unsigned & ME)370 bool PPCDAGToDAGISel::isRotateAndMask(SDNode *N, unsigned Mask,
371                                       bool isShiftMask, unsigned &SH,
372                                       unsigned &MB, unsigned &ME) {
373   // Don't even go down this path for i64, since different logic will be
374   // necessary for rldicl/rldicr/rldimi.
375   if (N->getValueType(0) != MVT::i32)
376     return false;
377 
378   unsigned Shift  = 32;
379   unsigned Indeterminant = ~0;  // bit mask marking indeterminant results
380   unsigned Opcode = N->getOpcode();
381   if (N->getNumOperands() != 2 ||
382       !isInt32Immediate(N->getOperand(1).getNode(), Shift) || (Shift > 31))
383     return false;
384 
385   if (Opcode == ISD::SHL) {
386     // apply shift left to mask if it comes first
387     if (isShiftMask) Mask = Mask << Shift;
388     // determine which bits are made indeterminant by shift
389     Indeterminant = ~(0xFFFFFFFFu << Shift);
390   } else if (Opcode == ISD::SRL) {
391     // apply shift right to mask if it comes first
392     if (isShiftMask) Mask = Mask >> Shift;
393     // determine which bits are made indeterminant by shift
394     Indeterminant = ~(0xFFFFFFFFu >> Shift);
395     // adjust for the left rotate
396     Shift = 32 - Shift;
397   } else if (Opcode == ISD::ROTL) {
398     Indeterminant = 0;
399   } else {
400     return false;
401   }
402 
403   // if the mask doesn't intersect any Indeterminant bits
404   if (Mask && !(Mask & Indeterminant)) {
405     SH = Shift & 31;
406     // make sure the mask is still a mask (wrap arounds may not be)
407     return isRunOfOnes(Mask, MB, ME);
408   }
409   return false;
410 }
411 
412 /// SelectBitfieldInsert - turn an or of two masked values into
413 /// the rotate left word immediate then mask insert (rlwimi) instruction.
SelectBitfieldInsert(SDNode * N)414 SDNode *PPCDAGToDAGISel::SelectBitfieldInsert(SDNode *N) {
415   SDValue Op0 = N->getOperand(0);
416   SDValue Op1 = N->getOperand(1);
417   SDLoc dl(N);
418 
419   APInt LKZ, LKO, RKZ, RKO;
420   CurDAG->computeKnownBits(Op0, LKZ, LKO);
421   CurDAG->computeKnownBits(Op1, RKZ, RKO);
422 
423   unsigned TargetMask = LKZ.getZExtValue();
424   unsigned InsertMask = RKZ.getZExtValue();
425 
426   if ((TargetMask | InsertMask) == 0xFFFFFFFF) {
427     unsigned Op0Opc = Op0.getOpcode();
428     unsigned Op1Opc = Op1.getOpcode();
429     unsigned Value, SH = 0;
430     TargetMask = ~TargetMask;
431     InsertMask = ~InsertMask;
432 
433     // If the LHS has a foldable shift and the RHS does not, then swap it to the
434     // RHS so that we can fold the shift into the insert.
435     if (Op0Opc == ISD::AND && Op1Opc == ISD::AND) {
436       if (Op0.getOperand(0).getOpcode() == ISD::SHL ||
437           Op0.getOperand(0).getOpcode() == ISD::SRL) {
438         if (Op1.getOperand(0).getOpcode() != ISD::SHL &&
439             Op1.getOperand(0).getOpcode() != ISD::SRL) {
440           std::swap(Op0, Op1);
441           std::swap(Op0Opc, Op1Opc);
442           std::swap(TargetMask, InsertMask);
443         }
444       }
445     } else if (Op0Opc == ISD::SHL || Op0Opc == ISD::SRL) {
446       if (Op1Opc == ISD::AND && Op1.getOperand(0).getOpcode() != ISD::SHL &&
447           Op1.getOperand(0).getOpcode() != ISD::SRL) {
448         std::swap(Op0, Op1);
449         std::swap(Op0Opc, Op1Opc);
450         std::swap(TargetMask, InsertMask);
451       }
452     }
453 
454     unsigned MB, ME;
455     if (isRunOfOnes(InsertMask, MB, ME)) {
456       SDValue Tmp1, Tmp2;
457 
458       if ((Op1Opc == ISD::SHL || Op1Opc == ISD::SRL) &&
459           isInt32Immediate(Op1.getOperand(1), Value)) {
460         Op1 = Op1.getOperand(0);
461         SH  = (Op1Opc == ISD::SHL) ? Value : 32 - Value;
462       }
463       if (Op1Opc == ISD::AND) {
464        // The AND mask might not be a constant, and we need to make sure that
465        // if we're going to fold the masking with the insert, all bits not
466        // know to be zero in the mask are known to be one.
467         APInt MKZ, MKO;
468         CurDAG->computeKnownBits(Op1.getOperand(1), MKZ, MKO);
469         bool CanFoldMask = InsertMask == MKO.getZExtValue();
470 
471         unsigned SHOpc = Op1.getOperand(0).getOpcode();
472         if ((SHOpc == ISD::SHL || SHOpc == ISD::SRL) && CanFoldMask &&
473             isInt32Immediate(Op1.getOperand(0).getOperand(1), Value)) {
474           // Note that Value must be in range here (less than 32) because
475           // otherwise there would not be any bits set in InsertMask.
476           Op1 = Op1.getOperand(0).getOperand(0);
477           SH  = (SHOpc == ISD::SHL) ? Value : 32 - Value;
478         }
479       }
480 
481       SH &= 31;
482       SDValue Ops[] = { Op0, Op1, getI32Imm(SH), getI32Imm(MB),
483                           getI32Imm(ME) };
484       return CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops);
485     }
486   }
487   return nullptr;
488 }
489 
490 /// SelectCC - Select a comparison of the specified values with the specified
491 /// condition code, returning the CR# of the expression.
SelectCC(SDValue LHS,SDValue RHS,ISD::CondCode CC,SDLoc dl)492 SDValue PPCDAGToDAGISel::SelectCC(SDValue LHS, SDValue RHS,
493                                     ISD::CondCode CC, SDLoc dl) {
494   // Always select the LHS.
495   unsigned Opc;
496 
497   if (LHS.getValueType() == MVT::i32) {
498     unsigned Imm;
499     if (CC == ISD::SETEQ || CC == ISD::SETNE) {
500       if (isInt32Immediate(RHS, Imm)) {
501         // SETEQ/SETNE comparison with 16-bit immediate, fold it.
502         if (isUInt<16>(Imm))
503           return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
504                                                 getI32Imm(Imm & 0xFFFF)), 0);
505         // If this is a 16-bit signed immediate, fold it.
506         if (isInt<16>((int)Imm))
507           return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
508                                                 getI32Imm(Imm & 0xFFFF)), 0);
509 
510         // For non-equality comparisons, the default code would materialize the
511         // constant, then compare against it, like this:
512         //   lis r2, 4660
513         //   ori r2, r2, 22136
514         //   cmpw cr0, r3, r2
515         // Since we are just comparing for equality, we can emit this instead:
516         //   xoris r0,r3,0x1234
517         //   cmplwi cr0,r0,0x5678
518         //   beq cr0,L6
519         SDValue Xor(CurDAG->getMachineNode(PPC::XORIS, dl, MVT::i32, LHS,
520                                            getI32Imm(Imm >> 16)), 0);
521         return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, Xor,
522                                               getI32Imm(Imm & 0xFFFF)), 0);
523       }
524       Opc = PPC::CMPLW;
525     } else if (ISD::isUnsignedIntSetCC(CC)) {
526       if (isInt32Immediate(RHS, Imm) && isUInt<16>(Imm))
527         return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
528                                               getI32Imm(Imm & 0xFFFF)), 0);
529       Opc = PPC::CMPLW;
530     } else {
531       short SImm;
532       if (isIntS16Immediate(RHS, SImm))
533         return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
534                                               getI32Imm((int)SImm & 0xFFFF)),
535                          0);
536       Opc = PPC::CMPW;
537     }
538   } else if (LHS.getValueType() == MVT::i64) {
539     uint64_t Imm;
540     if (CC == ISD::SETEQ || CC == ISD::SETNE) {
541       if (isInt64Immediate(RHS.getNode(), Imm)) {
542         // SETEQ/SETNE comparison with 16-bit immediate, fold it.
543         if (isUInt<16>(Imm))
544           return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
545                                                 getI32Imm(Imm & 0xFFFF)), 0);
546         // If this is a 16-bit signed immediate, fold it.
547         if (isInt<16>(Imm))
548           return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
549                                                 getI32Imm(Imm & 0xFFFF)), 0);
550 
551         // For non-equality comparisons, the default code would materialize the
552         // constant, then compare against it, like this:
553         //   lis r2, 4660
554         //   ori r2, r2, 22136
555         //   cmpd cr0, r3, r2
556         // Since we are just comparing for equality, we can emit this instead:
557         //   xoris r0,r3,0x1234
558         //   cmpldi cr0,r0,0x5678
559         //   beq cr0,L6
560         if (isUInt<32>(Imm)) {
561           SDValue Xor(CurDAG->getMachineNode(PPC::XORIS8, dl, MVT::i64, LHS,
562                                              getI64Imm(Imm >> 16)), 0);
563           return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, Xor,
564                                                 getI64Imm(Imm & 0xFFFF)), 0);
565         }
566       }
567       Opc = PPC::CMPLD;
568     } else if (ISD::isUnsignedIntSetCC(CC)) {
569       if (isInt64Immediate(RHS.getNode(), Imm) && isUInt<16>(Imm))
570         return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
571                                               getI64Imm(Imm & 0xFFFF)), 0);
572       Opc = PPC::CMPLD;
573     } else {
574       short SImm;
575       if (isIntS16Immediate(RHS, SImm))
576         return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
577                                               getI64Imm(SImm & 0xFFFF)),
578                          0);
579       Opc = PPC::CMPD;
580     }
581   } else if (LHS.getValueType() == MVT::f32) {
582     Opc = PPC::FCMPUS;
583   } else {
584     assert(LHS.getValueType() == MVT::f64 && "Unknown vt!");
585     Opc = PPCSubTarget->hasVSX() ? PPC::XSCMPUDP : PPC::FCMPUD;
586   }
587   return SDValue(CurDAG->getMachineNode(Opc, dl, MVT::i32, LHS, RHS), 0);
588 }
589 
getPredicateForSetCC(ISD::CondCode CC)590 static PPC::Predicate getPredicateForSetCC(ISD::CondCode CC) {
591   switch (CC) {
592   case ISD::SETUEQ:
593   case ISD::SETONE:
594   case ISD::SETOLE:
595   case ISD::SETOGE:
596     llvm_unreachable("Should be lowered by legalize!");
597   default: llvm_unreachable("Unknown condition!");
598   case ISD::SETOEQ:
599   case ISD::SETEQ:  return PPC::PRED_EQ;
600   case ISD::SETUNE:
601   case ISD::SETNE:  return PPC::PRED_NE;
602   case ISD::SETOLT:
603   case ISD::SETLT:  return PPC::PRED_LT;
604   case ISD::SETULE:
605   case ISD::SETLE:  return PPC::PRED_LE;
606   case ISD::SETOGT:
607   case ISD::SETGT:  return PPC::PRED_GT;
608   case ISD::SETUGE:
609   case ISD::SETGE:  return PPC::PRED_GE;
610   case ISD::SETO:   return PPC::PRED_NU;
611   case ISD::SETUO:  return PPC::PRED_UN;
612     // These two are invalid for floating point.  Assume we have int.
613   case ISD::SETULT: return PPC::PRED_LT;
614   case ISD::SETUGT: return PPC::PRED_GT;
615   }
616 }
617 
618 /// getCRIdxForSetCC - Return the index of the condition register field
619 /// associated with the SetCC condition, and whether or not the field is
620 /// treated as inverted.  That is, lt = 0; ge = 0 inverted.
getCRIdxForSetCC(ISD::CondCode CC,bool & Invert)621 static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool &Invert) {
622   Invert = false;
623   switch (CC) {
624   default: llvm_unreachable("Unknown condition!");
625   case ISD::SETOLT:
626   case ISD::SETLT:  return 0;                  // Bit #0 = SETOLT
627   case ISD::SETOGT:
628   case ISD::SETGT:  return 1;                  // Bit #1 = SETOGT
629   case ISD::SETOEQ:
630   case ISD::SETEQ:  return 2;                  // Bit #2 = SETOEQ
631   case ISD::SETUO:  return 3;                  // Bit #3 = SETUO
632   case ISD::SETUGE:
633   case ISD::SETGE:  Invert = true; return 0;   // !Bit #0 = SETUGE
634   case ISD::SETULE:
635   case ISD::SETLE:  Invert = true; return 1;   // !Bit #1 = SETULE
636   case ISD::SETUNE:
637   case ISD::SETNE:  Invert = true; return 2;   // !Bit #2 = SETUNE
638   case ISD::SETO:   Invert = true; return 3;   // !Bit #3 = SETO
639   case ISD::SETUEQ:
640   case ISD::SETOGE:
641   case ISD::SETOLE:
642   case ISD::SETONE:
643     llvm_unreachable("Invalid branch code: should be expanded by legalize");
644   // These are invalid for floating point.  Assume integer.
645   case ISD::SETULT: return 0;
646   case ISD::SETUGT: return 1;
647   }
648 }
649 
650 // getVCmpInst: return the vector compare instruction for the specified
651 // vector type and condition code. Since this is for altivec specific code,
652 // only support the altivec types (v16i8, v8i16, v4i32, and v4f32).
getVCmpInst(MVT::SimpleValueType VecVT,ISD::CondCode CC,bool HasVSX)653 static unsigned int getVCmpInst(MVT::SimpleValueType VecVT, ISD::CondCode CC,
654                                 bool HasVSX) {
655   switch (CC) {
656     case ISD::SETEQ:
657     case ISD::SETUEQ:
658     case ISD::SETNE:
659     case ISD::SETUNE:
660       if (VecVT == MVT::v16i8)
661         return PPC::VCMPEQUB;
662       else if (VecVT == MVT::v8i16)
663         return PPC::VCMPEQUH;
664       else if (VecVT == MVT::v4i32)
665         return PPC::VCMPEQUW;
666       // v4f32 != v4f32 could be translate to unordered not equal
667       else if (VecVT == MVT::v4f32)
668         return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
669       else if (VecVT == MVT::v2f64)
670         return PPC::XVCMPEQDP;
671       break;
672     case ISD::SETLT:
673     case ISD::SETGT:
674     case ISD::SETLE:
675     case ISD::SETGE:
676       if (VecVT == MVT::v16i8)
677         return PPC::VCMPGTSB;
678       else if (VecVT == MVT::v8i16)
679         return PPC::VCMPGTSH;
680       else if (VecVT == MVT::v4i32)
681         return PPC::VCMPGTSW;
682       else if (VecVT == MVT::v4f32)
683         return HasVSX ? PPC::XVCMPGTSP : PPC::VCMPGTFP;
684       else if (VecVT == MVT::v2f64)
685         return PPC::XVCMPGTDP;
686       break;
687     case ISD::SETULT:
688     case ISD::SETUGT:
689     case ISD::SETUGE:
690     case ISD::SETULE:
691       if (VecVT == MVT::v16i8)
692         return PPC::VCMPGTUB;
693       else if (VecVT == MVT::v8i16)
694         return PPC::VCMPGTUH;
695       else if (VecVT == MVT::v4i32)
696         return PPC::VCMPGTUW;
697       break;
698     case ISD::SETOEQ:
699       if (VecVT == MVT::v4f32)
700         return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
701       else if (VecVT == MVT::v2f64)
702         return PPC::XVCMPEQDP;
703       break;
704     case ISD::SETOLT:
705     case ISD::SETOGT:
706     case ISD::SETOLE:
707       if (VecVT == MVT::v4f32)
708         return HasVSX ? PPC::XVCMPGTSP : PPC::VCMPGTFP;
709       else if (VecVT == MVT::v2f64)
710         return PPC::XVCMPGTDP;
711       break;
712     case ISD::SETOGE:
713       if (VecVT == MVT::v4f32)
714         return HasVSX ? PPC::XVCMPGESP : PPC::VCMPGEFP;
715       else if (VecVT == MVT::v2f64)
716         return PPC::XVCMPGEDP;
717       break;
718     default:
719       break;
720   }
721   llvm_unreachable("Invalid integer vector compare condition");
722 }
723 
724 // getVCmpEQInst: return the equal compare instruction for the specified vector
725 // type. Since this is for altivec specific code, only support the altivec
726 // types (v16i8, v8i16, v4i32, and v4f32).
getVCmpEQInst(MVT::SimpleValueType VecVT,bool HasVSX)727 static unsigned int getVCmpEQInst(MVT::SimpleValueType VecVT, bool HasVSX) {
728   switch (VecVT) {
729     case MVT::v16i8:
730       return PPC::VCMPEQUB;
731     case MVT::v8i16:
732       return PPC::VCMPEQUH;
733     case MVT::v4i32:
734       return PPC::VCMPEQUW;
735     case MVT::v4f32:
736       return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
737     case MVT::v2f64:
738       return PPC::XVCMPEQDP;
739     default:
740       llvm_unreachable("Invalid integer vector compare condition");
741   }
742 }
743 
SelectSETCC(SDNode * N)744 SDNode *PPCDAGToDAGISel::SelectSETCC(SDNode *N) {
745   SDLoc dl(N);
746   unsigned Imm;
747   ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
748   EVT PtrVT = CurDAG->getTargetLoweringInfo().getPointerTy();
749   bool isPPC64 = (PtrVT == MVT::i64);
750 
751   if (!PPCSubTarget->useCRBits() &&
752       isInt32Immediate(N->getOperand(1), Imm)) {
753     // We can codegen setcc op, imm very efficiently compared to a brcond.
754     // Check for those cases here.
755     // setcc op, 0
756     if (Imm == 0) {
757       SDValue Op = N->getOperand(0);
758       switch (CC) {
759       default: break;
760       case ISD::SETEQ: {
761         Op = SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Op), 0);
762         SDValue Ops[] = { Op, getI32Imm(27), getI32Imm(5), getI32Imm(31) };
763         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
764       }
765       case ISD::SETNE: {
766         if (isPPC64) break;
767         SDValue AD =
768           SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
769                                          Op, getI32Imm(~0U)), 0);
770         return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op,
771                                     AD.getValue(1));
772       }
773       case ISD::SETLT: {
774         SDValue Ops[] = { Op, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
775         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
776       }
777       case ISD::SETGT: {
778         SDValue T =
779           SDValue(CurDAG->getMachineNode(PPC::NEG, dl, MVT::i32, Op), 0);
780         T = SDValue(CurDAG->getMachineNode(PPC::ANDC, dl, MVT::i32, T, Op), 0);
781         SDValue Ops[] = { T, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
782         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
783       }
784       }
785     } else if (Imm == ~0U) {        // setcc op, -1
786       SDValue Op = N->getOperand(0);
787       switch (CC) {
788       default: break;
789       case ISD::SETEQ:
790         if (isPPC64) break;
791         Op = SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
792                                             Op, getI32Imm(1)), 0);
793         return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
794                               SDValue(CurDAG->getMachineNode(PPC::LI, dl,
795                                                              MVT::i32,
796                                                              getI32Imm(0)), 0),
797                                       Op.getValue(1));
798       case ISD::SETNE: {
799         if (isPPC64) break;
800         Op = SDValue(CurDAG->getMachineNode(PPC::NOR, dl, MVT::i32, Op, Op), 0);
801         SDNode *AD = CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
802                                             Op, getI32Imm(~0U));
803         return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, SDValue(AD, 0),
804                                     Op, SDValue(AD, 1));
805       }
806       case ISD::SETLT: {
807         SDValue AD = SDValue(CurDAG->getMachineNode(PPC::ADDI, dl, MVT::i32, Op,
808                                                     getI32Imm(1)), 0);
809         SDValue AN = SDValue(CurDAG->getMachineNode(PPC::AND, dl, MVT::i32, AD,
810                                                     Op), 0);
811         SDValue Ops[] = { AN, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
812         return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
813       }
814       case ISD::SETGT: {
815         SDValue Ops[] = { Op, getI32Imm(1), getI32Imm(31), getI32Imm(31) };
816         Op = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops),
817                      0);
818         return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Op,
819                                     getI32Imm(1));
820       }
821       }
822     }
823   }
824 
825   SDValue LHS = N->getOperand(0);
826   SDValue RHS = N->getOperand(1);
827 
828   // Altivec Vector compare instructions do not set any CR register by default and
829   // vector compare operations return the same type as the operands.
830   if (LHS.getValueType().isVector()) {
831     EVT VecVT = LHS.getValueType();
832     MVT::SimpleValueType VT = VecVT.getSimpleVT().SimpleTy;
833     unsigned int VCmpInst = getVCmpInst(VT, CC, PPCSubTarget->hasVSX());
834 
835     switch (CC) {
836       case ISD::SETEQ:
837       case ISD::SETOEQ:
838       case ISD::SETUEQ:
839         return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, LHS, RHS);
840       case ISD::SETNE:
841       case ISD::SETONE:
842       case ISD::SETUNE: {
843         SDValue VCmp(CurDAG->getMachineNode(VCmpInst, dl, VecVT, LHS, RHS), 0);
844         return CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLNOR :
845                                                                PPC::VNOR,
846                                     VecVT, VCmp, VCmp);
847       }
848       case ISD::SETLT:
849       case ISD::SETOLT:
850       case ISD::SETULT:
851         return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, RHS, LHS);
852       case ISD::SETGT:
853       case ISD::SETOGT:
854       case ISD::SETUGT:
855         return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, LHS, RHS);
856       case ISD::SETGE:
857       case ISD::SETOGE:
858       case ISD::SETUGE: {
859         // Small optimization: Altivec provides a 'Vector Compare Greater Than
860         // or Equal To' instruction (vcmpgefp), so in this case there is no
861         // need for extra logic for the equal compare.
862         if (VecVT.getSimpleVT().isFloatingPoint()) {
863           return CurDAG->SelectNodeTo(N, VCmpInst, VecVT, LHS, RHS);
864         } else {
865           SDValue VCmpGT(CurDAG->getMachineNode(VCmpInst, dl, VecVT, LHS, RHS), 0);
866           unsigned int VCmpEQInst = getVCmpEQInst(VT, PPCSubTarget->hasVSX());
867           SDValue VCmpEQ(CurDAG->getMachineNode(VCmpEQInst, dl, VecVT, LHS, RHS), 0);
868           return CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLOR :
869                                                                  PPC::VOR,
870                                       VecVT, VCmpGT, VCmpEQ);
871         }
872       }
873       case ISD::SETLE:
874       case ISD::SETOLE:
875       case ISD::SETULE: {
876         SDValue VCmpLE(CurDAG->getMachineNode(VCmpInst, dl, VecVT, RHS, LHS), 0);
877         unsigned int VCmpEQInst = getVCmpEQInst(VT, PPCSubTarget->hasVSX());
878         SDValue VCmpEQ(CurDAG->getMachineNode(VCmpEQInst, dl, VecVT, LHS, RHS), 0);
879         return CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLOR :
880                                                                PPC::VOR,
881                                     VecVT, VCmpLE, VCmpEQ);
882       }
883       default:
884         llvm_unreachable("Invalid vector compare type: should be expanded by legalize");
885     }
886   }
887 
888   if (PPCSubTarget->useCRBits())
889     return nullptr;
890 
891   bool Inv;
892   unsigned Idx = getCRIdxForSetCC(CC, Inv);
893   SDValue CCReg = SelectCC(LHS, RHS, CC, dl);
894   SDValue IntCR;
895 
896   // Force the ccreg into CR7.
897   SDValue CR7Reg = CurDAG->getRegister(PPC::CR7, MVT::i32);
898 
899   SDValue InFlag(nullptr, 0);  // Null incoming flag value.
900   CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, CR7Reg, CCReg,
901                                InFlag).getValue(1);
902 
903   IntCR = SDValue(CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32, CR7Reg,
904                                          CCReg), 0);
905 
906   SDValue Ops[] = { IntCR, getI32Imm((32-(3-Idx)) & 31),
907                       getI32Imm(31), getI32Imm(31) };
908   if (!Inv)
909     return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
910 
911   // Get the specified bit.
912   SDValue Tmp =
913     SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
914   return CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1));
915 }
916 
917 
918 // Select - Convert the specified operand from a target-independent to a
919 // target-specific node if it hasn't already been changed.
Select(SDNode * N)920 SDNode *PPCDAGToDAGISel::Select(SDNode *N) {
921   SDLoc dl(N);
922   if (N->isMachineOpcode()) {
923     N->setNodeId(-1);
924     return nullptr;   // Already selected.
925   }
926 
927   switch (N->getOpcode()) {
928   default: break;
929 
930   case ISD::Constant: {
931     if (N->getValueType(0) == MVT::i64) {
932       // Get 64 bit value.
933       int64_t Imm = cast<ConstantSDNode>(N)->getZExtValue();
934       // Assume no remaining bits.
935       unsigned Remainder = 0;
936       // Assume no shift required.
937       unsigned Shift = 0;
938 
939       // If it can't be represented as a 32 bit value.
940       if (!isInt<32>(Imm)) {
941         Shift = countTrailingZeros<uint64_t>(Imm);
942         int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
943 
944         // If the shifted value fits 32 bits.
945         if (isInt<32>(ImmSh)) {
946           // Go with the shifted value.
947           Imm = ImmSh;
948         } else {
949           // Still stuck with a 64 bit value.
950           Remainder = Imm;
951           Shift = 32;
952           Imm >>= 32;
953         }
954       }
955 
956       // Intermediate operand.
957       SDNode *Result;
958 
959       // Handle first 32 bits.
960       unsigned Lo = Imm & 0xFFFF;
961       unsigned Hi = (Imm >> 16) & 0xFFFF;
962 
963       // Simple value.
964       if (isInt<16>(Imm)) {
965        // Just the Lo bits.
966         Result = CurDAG->getMachineNode(PPC::LI8, dl, MVT::i64, getI32Imm(Lo));
967       } else if (Lo) {
968         // Handle the Hi bits.
969         unsigned OpC = Hi ? PPC::LIS8 : PPC::LI8;
970         Result = CurDAG->getMachineNode(OpC, dl, MVT::i64, getI32Imm(Hi));
971         // And Lo bits.
972         Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
973                                         SDValue(Result, 0), getI32Imm(Lo));
974       } else {
975        // Just the Hi bits.
976         Result = CurDAG->getMachineNode(PPC::LIS8, dl, MVT::i64, getI32Imm(Hi));
977       }
978 
979       // If no shift, we're done.
980       if (!Shift) return Result;
981 
982       // Shift for next step if the upper 32-bits were not zero.
983       if (Imm) {
984         Result = CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64,
985                                         SDValue(Result, 0),
986                                         getI32Imm(Shift),
987                                         getI32Imm(63 - Shift));
988       }
989 
990       // Add in the last bits as required.
991       if ((Hi = (Remainder >> 16) & 0xFFFF)) {
992         Result = CurDAG->getMachineNode(PPC::ORIS8, dl, MVT::i64,
993                                         SDValue(Result, 0), getI32Imm(Hi));
994       }
995       if ((Lo = Remainder & 0xFFFF)) {
996         Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
997                                         SDValue(Result, 0), getI32Imm(Lo));
998       }
999 
1000       return Result;
1001     }
1002     break;
1003   }
1004 
1005   case ISD::SETCC: {
1006     SDNode *SN = SelectSETCC(N);
1007     if (SN)
1008       return SN;
1009     break;
1010   }
1011   case PPCISD::GlobalBaseReg:
1012     return getGlobalBaseReg();
1013 
1014   case ISD::FrameIndex: {
1015     int FI = cast<FrameIndexSDNode>(N)->getIndex();
1016     SDValue TFI = CurDAG->getTargetFrameIndex(FI, N->getValueType(0));
1017     unsigned Opc = N->getValueType(0) == MVT::i32 ? PPC::ADDI : PPC::ADDI8;
1018     if (N->hasOneUse())
1019       return CurDAG->SelectNodeTo(N, Opc, N->getValueType(0), TFI,
1020                                   getSmallIPtrImm(0));
1021     return CurDAG->getMachineNode(Opc, dl, N->getValueType(0), TFI,
1022                                   getSmallIPtrImm(0));
1023   }
1024 
1025   case PPCISD::MFOCRF: {
1026     SDValue InFlag = N->getOperand(1);
1027     return CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32,
1028                                   N->getOperand(0), InFlag);
1029   }
1030 
1031   case ISD::SDIV: {
1032     // FIXME: since this depends on the setting of the carry flag from the srawi
1033     //        we should really be making notes about that for the scheduler.
1034     // FIXME: It sure would be nice if we could cheaply recognize the
1035     //        srl/add/sra pattern the dag combiner will generate for this as
1036     //        sra/addze rather than having to handle sdiv ourselves.  oh well.
1037     unsigned Imm;
1038     if (isInt32Immediate(N->getOperand(1), Imm)) {
1039       SDValue N0 = N->getOperand(0);
1040       if ((signed)Imm > 0 && isPowerOf2_32(Imm)) {
1041         SDNode *Op =
1042           CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
1043                                  N0, getI32Imm(Log2_32(Imm)));
1044         return CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
1045                                     SDValue(Op, 0), SDValue(Op, 1));
1046       } else if ((signed)Imm < 0 && isPowerOf2_32(-Imm)) {
1047         SDNode *Op =
1048           CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
1049                                  N0, getI32Imm(Log2_32(-Imm)));
1050         SDValue PT =
1051           SDValue(CurDAG->getMachineNode(PPC::ADDZE, dl, MVT::i32,
1052                                          SDValue(Op, 0), SDValue(Op, 1)),
1053                     0);
1054         return CurDAG->SelectNodeTo(N, PPC::NEG, MVT::i32, PT);
1055       }
1056     }
1057 
1058     // Other cases are autogenerated.
1059     break;
1060   }
1061 
1062   case ISD::LOAD: {
1063     // Handle preincrement loads.
1064     LoadSDNode *LD = cast<LoadSDNode>(N);
1065     EVT LoadedVT = LD->getMemoryVT();
1066 
1067     // Normal loads are handled by code generated from the .td file.
1068     if (LD->getAddressingMode() != ISD::PRE_INC)
1069       break;
1070 
1071     SDValue Offset = LD->getOffset();
1072     if (Offset.getOpcode() == ISD::TargetConstant ||
1073         Offset.getOpcode() == ISD::TargetGlobalAddress) {
1074 
1075       unsigned Opcode;
1076       bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
1077       if (LD->getValueType(0) != MVT::i64) {
1078         // Handle PPC32 integer and normal FP loads.
1079         assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
1080         switch (LoadedVT.getSimpleVT().SimpleTy) {
1081           default: llvm_unreachable("Invalid PPC load type!");
1082           case MVT::f64: Opcode = PPC::LFDU; break;
1083           case MVT::f32: Opcode = PPC::LFSU; break;
1084           case MVT::i32: Opcode = PPC::LWZU; break;
1085           case MVT::i16: Opcode = isSExt ? PPC::LHAU : PPC::LHZU; break;
1086           case MVT::i1:
1087           case MVT::i8:  Opcode = PPC::LBZU; break;
1088         }
1089       } else {
1090         assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
1091         assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
1092         switch (LoadedVT.getSimpleVT().SimpleTy) {
1093           default: llvm_unreachable("Invalid PPC load type!");
1094           case MVT::i64: Opcode = PPC::LDU; break;
1095           case MVT::i32: Opcode = PPC::LWZU8; break;
1096           case MVT::i16: Opcode = isSExt ? PPC::LHAU8 : PPC::LHZU8; break;
1097           case MVT::i1:
1098           case MVT::i8:  Opcode = PPC::LBZU8; break;
1099         }
1100       }
1101 
1102       SDValue Chain = LD->getChain();
1103       SDValue Base = LD->getBasePtr();
1104       SDValue Ops[] = { Offset, Base, Chain };
1105       return CurDAG->getMachineNode(Opcode, dl, LD->getValueType(0),
1106                                     PPCLowering->getPointerTy(),
1107                                     MVT::Other, Ops);
1108     } else {
1109       unsigned Opcode;
1110       bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
1111       if (LD->getValueType(0) != MVT::i64) {
1112         // Handle PPC32 integer and normal FP loads.
1113         assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
1114         switch (LoadedVT.getSimpleVT().SimpleTy) {
1115           default: llvm_unreachable("Invalid PPC load type!");
1116           case MVT::f64: Opcode = PPC::LFDUX; break;
1117           case MVT::f32: Opcode = PPC::LFSUX; break;
1118           case MVT::i32: Opcode = PPC::LWZUX; break;
1119           case MVT::i16: Opcode = isSExt ? PPC::LHAUX : PPC::LHZUX; break;
1120           case MVT::i1:
1121           case MVT::i8:  Opcode = PPC::LBZUX; break;
1122         }
1123       } else {
1124         assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
1125         assert((!isSExt || LoadedVT == MVT::i16 || LoadedVT == MVT::i32) &&
1126                "Invalid sext update load");
1127         switch (LoadedVT.getSimpleVT().SimpleTy) {
1128           default: llvm_unreachable("Invalid PPC load type!");
1129           case MVT::i64: Opcode = PPC::LDUX; break;
1130           case MVT::i32: Opcode = isSExt ? PPC::LWAUX  : PPC::LWZUX8; break;
1131           case MVT::i16: Opcode = isSExt ? PPC::LHAUX8 : PPC::LHZUX8; break;
1132           case MVT::i1:
1133           case MVT::i8:  Opcode = PPC::LBZUX8; break;
1134         }
1135       }
1136 
1137       SDValue Chain = LD->getChain();
1138       SDValue Base = LD->getBasePtr();
1139       SDValue Ops[] = { Base, Offset, Chain };
1140       return CurDAG->getMachineNode(Opcode, dl, LD->getValueType(0),
1141                                     PPCLowering->getPointerTy(),
1142                                     MVT::Other, Ops);
1143     }
1144   }
1145 
1146   case ISD::AND: {
1147     unsigned Imm, Imm2, SH, MB, ME;
1148     uint64_t Imm64;
1149 
1150     // If this is an and of a value rotated between 0 and 31 bits and then and'd
1151     // with a mask, emit rlwinm
1152     if (isInt32Immediate(N->getOperand(1), Imm) &&
1153         isRotateAndMask(N->getOperand(0).getNode(), Imm, false, SH, MB, ME)) {
1154       SDValue Val = N->getOperand(0).getOperand(0);
1155       SDValue Ops[] = { Val, getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
1156       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
1157     }
1158     // If this is just a masked value where the input is not handled above, and
1159     // is not a rotate-left (handled by a pattern in the .td file), emit rlwinm
1160     if (isInt32Immediate(N->getOperand(1), Imm) &&
1161         isRunOfOnes(Imm, MB, ME) &&
1162         N->getOperand(0).getOpcode() != ISD::ROTL) {
1163       SDValue Val = N->getOperand(0);
1164       SDValue Ops[] = { Val, getI32Imm(0), getI32Imm(MB), getI32Imm(ME) };
1165       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
1166     }
1167     // If this is a 64-bit zero-extension mask, emit rldicl.
1168     if (isInt64Immediate(N->getOperand(1).getNode(), Imm64) &&
1169         isMask_64(Imm64)) {
1170       SDValue Val = N->getOperand(0);
1171       MB = 64 - CountTrailingOnes_64(Imm64);
1172       SH = 0;
1173 
1174       // If the operand is a logical right shift, we can fold it into this
1175       // instruction: rldicl(rldicl(x, 64-n, n), 0, mb) -> rldicl(x, 64-n, mb)
1176       // for n <= mb. The right shift is really a left rotate followed by a
1177       // mask, and this mask is a more-restrictive sub-mask of the mask implied
1178       // by the shift.
1179       if (Val.getOpcode() == ISD::SRL &&
1180           isInt32Immediate(Val.getOperand(1).getNode(), Imm) && Imm <= MB) {
1181         assert(Imm < 64 && "Illegal shift amount");
1182         Val = Val.getOperand(0);
1183         SH = 64 - Imm;
1184       }
1185 
1186       SDValue Ops[] = { Val, getI32Imm(SH), getI32Imm(MB) };
1187       return CurDAG->SelectNodeTo(N, PPC::RLDICL, MVT::i64, Ops);
1188     }
1189     // AND X, 0 -> 0, not "rlwinm 32".
1190     if (isInt32Immediate(N->getOperand(1), Imm) && (Imm == 0)) {
1191       ReplaceUses(SDValue(N, 0), N->getOperand(1));
1192       return nullptr;
1193     }
1194     // ISD::OR doesn't get all the bitfield insertion fun.
1195     // (and (or x, c1), c2) where isRunOfOnes(~(c1^c2)) is a bitfield insert
1196     if (isInt32Immediate(N->getOperand(1), Imm) &&
1197         N->getOperand(0).getOpcode() == ISD::OR &&
1198         isInt32Immediate(N->getOperand(0).getOperand(1), Imm2)) {
1199       unsigned MB, ME;
1200       Imm = ~(Imm^Imm2);
1201       if (isRunOfOnes(Imm, MB, ME)) {
1202         SDValue Ops[] = { N->getOperand(0).getOperand(0),
1203                             N->getOperand(0).getOperand(1),
1204                             getI32Imm(0), getI32Imm(MB),getI32Imm(ME) };
1205         return CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops);
1206       }
1207     }
1208 
1209     // Other cases are autogenerated.
1210     break;
1211   }
1212   case ISD::OR:
1213     if (N->getValueType(0) == MVT::i32)
1214       if (SDNode *I = SelectBitfieldInsert(N))
1215         return I;
1216 
1217     // Other cases are autogenerated.
1218     break;
1219   case ISD::SHL: {
1220     unsigned Imm, SH, MB, ME;
1221     if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
1222         isRotateAndMask(N, Imm, true, SH, MB, ME)) {
1223       SDValue Ops[] = { N->getOperand(0).getOperand(0),
1224                           getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
1225       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
1226     }
1227 
1228     // Other cases are autogenerated.
1229     break;
1230   }
1231   case ISD::SRL: {
1232     unsigned Imm, SH, MB, ME;
1233     if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
1234         isRotateAndMask(N, Imm, true, SH, MB, ME)) {
1235       SDValue Ops[] = { N->getOperand(0).getOperand(0),
1236                           getI32Imm(SH), getI32Imm(MB), getI32Imm(ME) };
1237       return CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
1238     }
1239 
1240     // Other cases are autogenerated.
1241     break;
1242   }
1243   // FIXME: Remove this once the ANDI glue bug is fixed:
1244   case PPCISD::ANDIo_1_EQ_BIT:
1245   case PPCISD::ANDIo_1_GT_BIT: {
1246     if (!ANDIGlueBug)
1247       break;
1248 
1249     EVT InVT = N->getOperand(0).getValueType();
1250     assert((InVT == MVT::i64 || InVT == MVT::i32) &&
1251            "Invalid input type for ANDIo_1_EQ_BIT");
1252 
1253     unsigned Opcode = (InVT == MVT::i64) ? PPC::ANDIo8 : PPC::ANDIo;
1254     SDValue AndI(CurDAG->getMachineNode(Opcode, dl, InVT, MVT::Glue,
1255                                         N->getOperand(0),
1256                                         CurDAG->getTargetConstant(1, InVT)), 0);
1257     SDValue CR0Reg = CurDAG->getRegister(PPC::CR0, MVT::i32);
1258     SDValue SRIdxVal =
1259       CurDAG->getTargetConstant(N->getOpcode() == PPCISD::ANDIo_1_EQ_BIT ?
1260                                 PPC::sub_eq : PPC::sub_gt, MVT::i32);
1261 
1262     return CurDAG->SelectNodeTo(N, TargetOpcode::EXTRACT_SUBREG, MVT::i1,
1263                                 CR0Reg, SRIdxVal,
1264                                 SDValue(AndI.getNode(), 1) /* glue */);
1265   }
1266   case ISD::SELECT_CC: {
1267     ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
1268     EVT PtrVT = CurDAG->getTargetLoweringInfo().getPointerTy();
1269     bool isPPC64 = (PtrVT == MVT::i64);
1270 
1271     // If this is a select of i1 operands, we'll pattern match it.
1272     if (PPCSubTarget->useCRBits() &&
1273         N->getOperand(0).getValueType() == MVT::i1)
1274       break;
1275 
1276     // Handle the setcc cases here.  select_cc lhs, 0, 1, 0, cc
1277     if (!isPPC64)
1278       if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
1279         if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N->getOperand(2)))
1280           if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N->getOperand(3)))
1281             if (N1C->isNullValue() && N3C->isNullValue() &&
1282                 N2C->getZExtValue() == 1ULL && CC == ISD::SETNE &&
1283                 // FIXME: Implement this optzn for PPC64.
1284                 N->getValueType(0) == MVT::i32) {
1285               SDNode *Tmp =
1286                 CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
1287                                        N->getOperand(0), getI32Imm(~0U));
1288               return CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32,
1289                                           SDValue(Tmp, 0), N->getOperand(0),
1290                                           SDValue(Tmp, 1));
1291             }
1292 
1293     SDValue CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC, dl);
1294 
1295     if (N->getValueType(0) == MVT::i1) {
1296       // An i1 select is: (c & t) | (!c & f).
1297       bool Inv;
1298       unsigned Idx = getCRIdxForSetCC(CC, Inv);
1299 
1300       unsigned SRI;
1301       switch (Idx) {
1302       default: llvm_unreachable("Invalid CC index");
1303       case 0: SRI = PPC::sub_lt; break;
1304       case 1: SRI = PPC::sub_gt; break;
1305       case 2: SRI = PPC::sub_eq; break;
1306       case 3: SRI = PPC::sub_un; break;
1307       }
1308 
1309       SDValue CCBit = CurDAG->getTargetExtractSubreg(SRI, dl, MVT::i1, CCReg);
1310 
1311       SDValue NotCCBit(CurDAG->getMachineNode(PPC::CRNOR, dl, MVT::i1,
1312                                               CCBit, CCBit), 0);
1313       SDValue C =    Inv ? NotCCBit : CCBit,
1314               NotC = Inv ? CCBit    : NotCCBit;
1315 
1316       SDValue CAndT(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
1317                                            C, N->getOperand(2)), 0);
1318       SDValue NotCAndF(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
1319                                               NotC, N->getOperand(3)), 0);
1320 
1321       return CurDAG->SelectNodeTo(N, PPC::CROR, MVT::i1, CAndT, NotCAndF);
1322     }
1323 
1324     unsigned BROpc = getPredicateForSetCC(CC);
1325 
1326     unsigned SelectCCOp;
1327     if (N->getValueType(0) == MVT::i32)
1328       SelectCCOp = PPC::SELECT_CC_I4;
1329     else if (N->getValueType(0) == MVT::i64)
1330       SelectCCOp = PPC::SELECT_CC_I8;
1331     else if (N->getValueType(0) == MVT::f32)
1332       SelectCCOp = PPC::SELECT_CC_F4;
1333     else if (N->getValueType(0) == MVT::f64)
1334       SelectCCOp = PPC::SELECT_CC_F8;
1335     else
1336       SelectCCOp = PPC::SELECT_CC_VRRC;
1337 
1338     SDValue Ops[] = { CCReg, N->getOperand(2), N->getOperand(3),
1339                         getI32Imm(BROpc) };
1340     return CurDAG->SelectNodeTo(N, SelectCCOp, N->getValueType(0), Ops);
1341   }
1342   case ISD::VSELECT:
1343     if (PPCSubTarget->hasVSX()) {
1344       SDValue Ops[] = { N->getOperand(2), N->getOperand(1), N->getOperand(0) };
1345       return CurDAG->SelectNodeTo(N, PPC::XXSEL, N->getValueType(0), Ops);
1346     }
1347 
1348     break;
1349   case ISD::VECTOR_SHUFFLE:
1350     if (PPCSubTarget->hasVSX() && (N->getValueType(0) == MVT::v2f64 ||
1351                                   N->getValueType(0) == MVT::v2i64)) {
1352       ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
1353 
1354       SDValue Op1 = N->getOperand(SVN->getMaskElt(0) < 2 ? 0 : 1),
1355               Op2 = N->getOperand(SVN->getMaskElt(1) < 2 ? 0 : 1);
1356       unsigned DM[2];
1357 
1358       for (int i = 0; i < 2; ++i)
1359         if (SVN->getMaskElt(i) <= 0 || SVN->getMaskElt(i) == 2)
1360           DM[i] = 0;
1361         else
1362           DM[i] = 1;
1363 
1364       SDValue DMV = CurDAG->getTargetConstant(DM[1] | (DM[0] << 1), MVT::i32);
1365 
1366       if (Op1 == Op2 && DM[0] == 0 && DM[1] == 0 &&
1367           Op1.getOpcode() == ISD::SCALAR_TO_VECTOR &&
1368           isa<LoadSDNode>(Op1.getOperand(0))) {
1369         LoadSDNode *LD = cast<LoadSDNode>(Op1.getOperand(0));
1370         SDValue Base, Offset;
1371 
1372         if (LD->isUnindexed() &&
1373             SelectAddrIdxOnly(LD->getBasePtr(), Base, Offset)) {
1374           SDValue Chain = LD->getChain();
1375           SDValue Ops[] = { Base, Offset, Chain };
1376           return CurDAG->SelectNodeTo(N, PPC::LXVDSX,
1377                                       N->getValueType(0), Ops);
1378         }
1379       }
1380 
1381       SDValue Ops[] = { Op1, Op2, DMV };
1382       return CurDAG->SelectNodeTo(N, PPC::XXPERMDI, N->getValueType(0), Ops);
1383     }
1384 
1385     break;
1386   case PPCISD::BDNZ:
1387   case PPCISD::BDZ: {
1388     bool IsPPC64 = PPCSubTarget->isPPC64();
1389     SDValue Ops[] = { N->getOperand(1), N->getOperand(0) };
1390     return CurDAG->SelectNodeTo(N, N->getOpcode() == PPCISD::BDNZ ?
1391                                    (IsPPC64 ? PPC::BDNZ8 : PPC::BDNZ) :
1392                                    (IsPPC64 ? PPC::BDZ8 : PPC::BDZ),
1393                                 MVT::Other, Ops);
1394   }
1395   case PPCISD::COND_BRANCH: {
1396     // Op #0 is the Chain.
1397     // Op #1 is the PPC::PRED_* number.
1398     // Op #2 is the CR#
1399     // Op #3 is the Dest MBB
1400     // Op #4 is the Flag.
1401     // Prevent PPC::PRED_* from being selected into LI.
1402     SDValue Pred =
1403       getI32Imm(cast<ConstantSDNode>(N->getOperand(1))->getZExtValue());
1404     SDValue Ops[] = { Pred, N->getOperand(2), N->getOperand(3),
1405       N->getOperand(0), N->getOperand(4) };
1406     return CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
1407   }
1408   case ISD::BR_CC: {
1409     ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
1410     unsigned PCC = getPredicateForSetCC(CC);
1411 
1412     if (N->getOperand(2).getValueType() == MVT::i1) {
1413       unsigned Opc;
1414       bool Swap;
1415       switch (PCC) {
1416       default: llvm_unreachable("Unexpected Boolean-operand predicate");
1417       case PPC::PRED_LT: Opc = PPC::CRANDC; Swap = true;  break;
1418       case PPC::PRED_LE: Opc = PPC::CRORC;  Swap = true;  break;
1419       case PPC::PRED_EQ: Opc = PPC::CREQV;  Swap = false; break;
1420       case PPC::PRED_GE: Opc = PPC::CRORC;  Swap = false; break;
1421       case PPC::PRED_GT: Opc = PPC::CRANDC; Swap = false; break;
1422       case PPC::PRED_NE: Opc = PPC::CRXOR;  Swap = false; break;
1423       }
1424 
1425       SDValue BitComp(CurDAG->getMachineNode(Opc, dl, MVT::i1,
1426                                              N->getOperand(Swap ? 3 : 2),
1427                                              N->getOperand(Swap ? 2 : 3)), 0);
1428       return CurDAG->SelectNodeTo(N, PPC::BC, MVT::Other,
1429                                   BitComp, N->getOperand(4), N->getOperand(0));
1430     }
1431 
1432     SDValue CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC, dl);
1433     SDValue Ops[] = { getI32Imm(PCC), CondCode,
1434                         N->getOperand(4), N->getOperand(0) };
1435     return CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
1436   }
1437   case ISD::BRIND: {
1438     // FIXME: Should custom lower this.
1439     SDValue Chain = N->getOperand(0);
1440     SDValue Target = N->getOperand(1);
1441     unsigned Opc = Target.getValueType() == MVT::i32 ? PPC::MTCTR : PPC::MTCTR8;
1442     unsigned Reg = Target.getValueType() == MVT::i32 ? PPC::BCTR : PPC::BCTR8;
1443     Chain = SDValue(CurDAG->getMachineNode(Opc, dl, MVT::Glue, Target,
1444                                            Chain), 0);
1445     return CurDAG->SelectNodeTo(N, Reg, MVT::Other, Chain);
1446   }
1447   case PPCISD::TOC_ENTRY: {
1448     assert (PPCSubTarget->isPPC64() && "Only supported for 64-bit ABI");
1449 
1450     // For medium and large code model, we generate two instructions as
1451     // described below.  Otherwise we allow SelectCodeCommon to handle this,
1452     // selecting one of LDtoc, LDtocJTI, and LDtocCPT.
1453     CodeModel::Model CModel = TM.getCodeModel();
1454     if (CModel != CodeModel::Medium && CModel != CodeModel::Large)
1455       break;
1456 
1457     // The first source operand is a TargetGlobalAddress or a TargetJumpTable.
1458     // If it is an externally defined symbol, a symbol with common linkage,
1459     // a non-local function address, or a jump table address, or if we are
1460     // generating code for large code model, we generate:
1461     //   LDtocL(<ga:@sym>, ADDIStocHA(%X2, <ga:@sym>))
1462     // Otherwise we generate:
1463     //   ADDItocL(ADDIStocHA(%X2, <ga:@sym>), <ga:@sym>)
1464     SDValue GA = N->getOperand(0);
1465     SDValue TOCbase = N->getOperand(1);
1466     SDNode *Tmp = CurDAG->getMachineNode(PPC::ADDIStocHA, dl, MVT::i64,
1467                                         TOCbase, GA);
1468 
1469     if (isa<JumpTableSDNode>(GA) || CModel == CodeModel::Large)
1470       return CurDAG->getMachineNode(PPC::LDtocL, dl, MVT::i64, GA,
1471                                     SDValue(Tmp, 0));
1472 
1473     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(GA)) {
1474       const GlobalValue *GValue = G->getGlobal();
1475       if ((GValue->getType()->getElementType()->isFunctionTy() &&
1476            (GValue->isDeclaration() || GValue->isWeakForLinker())) ||
1477           GValue->isDeclaration() || GValue->hasCommonLinkage() ||
1478           GValue->hasAvailableExternallyLinkage())
1479         return CurDAG->getMachineNode(PPC::LDtocL, dl, MVT::i64, GA,
1480                                       SDValue(Tmp, 0));
1481     }
1482 
1483     return CurDAG->getMachineNode(PPC::ADDItocL, dl, MVT::i64,
1484                                   SDValue(Tmp, 0), GA);
1485   }
1486   case PPCISD::VADD_SPLAT: {
1487     // This expands into one of three sequences, depending on whether
1488     // the first operand is odd or even, positive or negative.
1489     assert(isa<ConstantSDNode>(N->getOperand(0)) &&
1490            isa<ConstantSDNode>(N->getOperand(1)) &&
1491            "Invalid operand on VADD_SPLAT!");
1492 
1493     int Elt     = N->getConstantOperandVal(0);
1494     int EltSize = N->getConstantOperandVal(1);
1495     unsigned Opc1, Opc2, Opc3;
1496     EVT VT;
1497 
1498     if (EltSize == 1) {
1499       Opc1 = PPC::VSPLTISB;
1500       Opc2 = PPC::VADDUBM;
1501       Opc3 = PPC::VSUBUBM;
1502       VT = MVT::v16i8;
1503     } else if (EltSize == 2) {
1504       Opc1 = PPC::VSPLTISH;
1505       Opc2 = PPC::VADDUHM;
1506       Opc3 = PPC::VSUBUHM;
1507       VT = MVT::v8i16;
1508     } else {
1509       assert(EltSize == 4 && "Invalid element size on VADD_SPLAT!");
1510       Opc1 = PPC::VSPLTISW;
1511       Opc2 = PPC::VADDUWM;
1512       Opc3 = PPC::VSUBUWM;
1513       VT = MVT::v4i32;
1514     }
1515 
1516     if ((Elt & 1) == 0) {
1517       // Elt is even, in the range [-32,-18] + [16,30].
1518       //
1519       // Convert: VADD_SPLAT elt, size
1520       // Into:    tmp = VSPLTIS[BHW] elt
1521       //          VADDU[BHW]M tmp, tmp
1522       // Where:   [BHW] = B for size = 1, H for size = 2, W for size = 4
1523       SDValue EltVal = getI32Imm(Elt >> 1);
1524       SDNode *Tmp = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
1525       SDValue TmpVal = SDValue(Tmp, 0);
1526       return CurDAG->getMachineNode(Opc2, dl, VT, TmpVal, TmpVal);
1527 
1528     } else if (Elt > 0) {
1529       // Elt is odd and positive, in the range [17,31].
1530       //
1531       // Convert: VADD_SPLAT elt, size
1532       // Into:    tmp1 = VSPLTIS[BHW] elt-16
1533       //          tmp2 = VSPLTIS[BHW] -16
1534       //          VSUBU[BHW]M tmp1, tmp2
1535       SDValue EltVal = getI32Imm(Elt - 16);
1536       SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
1537       EltVal = getI32Imm(-16);
1538       SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
1539       return CurDAG->getMachineNode(Opc3, dl, VT, SDValue(Tmp1, 0),
1540                                     SDValue(Tmp2, 0));
1541 
1542     } else {
1543       // Elt is odd and negative, in the range [-31,-17].
1544       //
1545       // Convert: VADD_SPLAT elt, size
1546       // Into:    tmp1 = VSPLTIS[BHW] elt+16
1547       //          tmp2 = VSPLTIS[BHW] -16
1548       //          VADDU[BHW]M tmp1, tmp2
1549       SDValue EltVal = getI32Imm(Elt + 16);
1550       SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
1551       EltVal = getI32Imm(-16);
1552       SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
1553       return CurDAG->getMachineNode(Opc2, dl, VT, SDValue(Tmp1, 0),
1554                                     SDValue(Tmp2, 0));
1555     }
1556   }
1557   }
1558 
1559   return SelectCode(N);
1560 }
1561 
1562 /// PostprocessISelDAG - Perform some late peephole optimizations
1563 /// on the DAG representation.
PostprocessISelDAG()1564 void PPCDAGToDAGISel::PostprocessISelDAG() {
1565 
1566   // Skip peepholes at -O0.
1567   if (TM.getOptLevel() == CodeGenOpt::None)
1568     return;
1569 
1570   PeepholePPC64();
1571   PeepholeCROps();
1572 }
1573 
1574 // Check if all users of this node will become isel where the second operand
1575 // is the constant zero. If this is so, and if we can negate the condition,
1576 // then we can flip the true and false operands. This will allow the zero to
1577 // be folded with the isel so that we don't need to materialize a register
1578 // containing zero.
AllUsersSelectZero(SDNode * N)1579 bool PPCDAGToDAGISel::AllUsersSelectZero(SDNode *N) {
1580   // If we're not using isel, then this does not matter.
1581   if (!PPCSubTarget->hasISEL())
1582     return false;
1583 
1584   for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
1585        UI != UE; ++UI) {
1586     SDNode *User = *UI;
1587     if (!User->isMachineOpcode())
1588       return false;
1589     if (User->getMachineOpcode() != PPC::SELECT_I4 &&
1590         User->getMachineOpcode() != PPC::SELECT_I8)
1591       return false;
1592 
1593     SDNode *Op2 = User->getOperand(2).getNode();
1594     if (!Op2->isMachineOpcode())
1595       return false;
1596 
1597     if (Op2->getMachineOpcode() != PPC::LI &&
1598         Op2->getMachineOpcode() != PPC::LI8)
1599       return false;
1600 
1601     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op2->getOperand(0));
1602     if (!C)
1603       return false;
1604 
1605     if (!C->isNullValue())
1606       return false;
1607   }
1608 
1609   return true;
1610 }
1611 
SwapAllSelectUsers(SDNode * N)1612 void PPCDAGToDAGISel::SwapAllSelectUsers(SDNode *N) {
1613   SmallVector<SDNode *, 4> ToReplace;
1614   for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
1615        UI != UE; ++UI) {
1616     SDNode *User = *UI;
1617     assert((User->getMachineOpcode() == PPC::SELECT_I4 ||
1618             User->getMachineOpcode() == PPC::SELECT_I8) &&
1619            "Must have all select users");
1620     ToReplace.push_back(User);
1621   }
1622 
1623   for (SmallVector<SDNode *, 4>::iterator UI = ToReplace.begin(),
1624        UE = ToReplace.end(); UI != UE; ++UI) {
1625     SDNode *User = *UI;
1626     SDNode *ResNode =
1627       CurDAG->getMachineNode(User->getMachineOpcode(), SDLoc(User),
1628                              User->getValueType(0), User->getOperand(0),
1629                              User->getOperand(2),
1630                              User->getOperand(1));
1631 
1632       DEBUG(dbgs() << "CR Peephole replacing:\nOld:    ");
1633       DEBUG(User->dump(CurDAG));
1634       DEBUG(dbgs() << "\nNew: ");
1635       DEBUG(ResNode->dump(CurDAG));
1636       DEBUG(dbgs() << "\n");
1637 
1638       ReplaceUses(User, ResNode);
1639   }
1640 }
1641 
PeepholeCROps()1642 void PPCDAGToDAGISel::PeepholeCROps() {
1643   bool IsModified;
1644   do {
1645     IsModified = false;
1646     for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
1647          E = CurDAG->allnodes_end(); I != E; ++I) {
1648       MachineSDNode *MachineNode = dyn_cast<MachineSDNode>(I);
1649       if (!MachineNode || MachineNode->use_empty())
1650         continue;
1651       SDNode *ResNode = MachineNode;
1652 
1653       bool Op1Set   = false, Op1Unset = false,
1654            Op1Not   = false,
1655            Op2Set   = false, Op2Unset = false,
1656            Op2Not   = false;
1657 
1658       unsigned Opcode = MachineNode->getMachineOpcode();
1659       switch (Opcode) {
1660       default: break;
1661       case PPC::CRAND:
1662       case PPC::CRNAND:
1663       case PPC::CROR:
1664       case PPC::CRXOR:
1665       case PPC::CRNOR:
1666       case PPC::CREQV:
1667       case PPC::CRANDC:
1668       case PPC::CRORC: {
1669         SDValue Op = MachineNode->getOperand(1);
1670         if (Op.isMachineOpcode()) {
1671           if (Op.getMachineOpcode() == PPC::CRSET)
1672             Op2Set = true;
1673           else if (Op.getMachineOpcode() == PPC::CRUNSET)
1674             Op2Unset = true;
1675           else if (Op.getMachineOpcode() == PPC::CRNOR &&
1676                    Op.getOperand(0) == Op.getOperand(1))
1677             Op2Not = true;
1678         }
1679         }  // fallthrough
1680       case PPC::BC:
1681       case PPC::BCn:
1682       case PPC::SELECT_I4:
1683       case PPC::SELECT_I8:
1684       case PPC::SELECT_F4:
1685       case PPC::SELECT_F8:
1686       case PPC::SELECT_VRRC: {
1687         SDValue Op = MachineNode->getOperand(0);
1688         if (Op.isMachineOpcode()) {
1689           if (Op.getMachineOpcode() == PPC::CRSET)
1690             Op1Set = true;
1691           else if (Op.getMachineOpcode() == PPC::CRUNSET)
1692             Op1Unset = true;
1693           else if (Op.getMachineOpcode() == PPC::CRNOR &&
1694                    Op.getOperand(0) == Op.getOperand(1))
1695             Op1Not = true;
1696         }
1697         }
1698         break;
1699       }
1700 
1701       bool SelectSwap = false;
1702       switch (Opcode) {
1703       default: break;
1704       case PPC::CRAND:
1705         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
1706           // x & x = x
1707           ResNode = MachineNode->getOperand(0).getNode();
1708         else if (Op1Set)
1709           // 1 & y = y
1710           ResNode = MachineNode->getOperand(1).getNode();
1711         else if (Op2Set)
1712           // x & 1 = x
1713           ResNode = MachineNode->getOperand(0).getNode();
1714         else if (Op1Unset || Op2Unset)
1715           // x & 0 = 0 & y = 0
1716           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
1717                                            MVT::i1);
1718         else if (Op1Not)
1719           // ~x & y = andc(y, x)
1720           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
1721                                            MVT::i1, MachineNode->getOperand(1),
1722                                            MachineNode->getOperand(0).
1723                                              getOperand(0));
1724         else if (Op2Not)
1725           // x & ~y = andc(x, y)
1726           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
1727                                            MVT::i1, MachineNode->getOperand(0),
1728                                            MachineNode->getOperand(1).
1729                                              getOperand(0));
1730         else if (AllUsersSelectZero(MachineNode))
1731           ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
1732                                            MVT::i1, MachineNode->getOperand(0),
1733                                            MachineNode->getOperand(1)),
1734           SelectSwap = true;
1735         break;
1736       case PPC::CRNAND:
1737         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
1738           // nand(x, x) -> nor(x, x)
1739           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1740                                            MVT::i1, MachineNode->getOperand(0),
1741                                            MachineNode->getOperand(0));
1742         else if (Op1Set)
1743           // nand(1, y) -> nor(y, y)
1744           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1745                                            MVT::i1, MachineNode->getOperand(1),
1746                                            MachineNode->getOperand(1));
1747         else if (Op2Set)
1748           // nand(x, 1) -> nor(x, x)
1749           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1750                                            MVT::i1, MachineNode->getOperand(0),
1751                                            MachineNode->getOperand(0));
1752         else if (Op1Unset || Op2Unset)
1753           // nand(x, 0) = nand(0, y) = 1
1754           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
1755                                            MVT::i1);
1756         else if (Op1Not)
1757           // nand(~x, y) = ~(~x & y) = x | ~y = orc(x, y)
1758           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
1759                                            MVT::i1, MachineNode->getOperand(0).
1760                                                       getOperand(0),
1761                                            MachineNode->getOperand(1));
1762         else if (Op2Not)
1763           // nand(x, ~y) = ~x | y = orc(y, x)
1764           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
1765                                            MVT::i1, MachineNode->getOperand(1).
1766                                                       getOperand(0),
1767                                            MachineNode->getOperand(0));
1768         else if (AllUsersSelectZero(MachineNode))
1769           ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
1770                                            MVT::i1, MachineNode->getOperand(0),
1771                                            MachineNode->getOperand(1)),
1772           SelectSwap = true;
1773         break;
1774       case PPC::CROR:
1775         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
1776           // x | x = x
1777           ResNode = MachineNode->getOperand(0).getNode();
1778         else if (Op1Set || Op2Set)
1779           // x | 1 = 1 | y = 1
1780           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
1781                                            MVT::i1);
1782         else if (Op1Unset)
1783           // 0 | y = y
1784           ResNode = MachineNode->getOperand(1).getNode();
1785         else if (Op2Unset)
1786           // x | 0 = x
1787           ResNode = MachineNode->getOperand(0).getNode();
1788         else if (Op1Not)
1789           // ~x | y = orc(y, x)
1790           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
1791                                            MVT::i1, MachineNode->getOperand(1),
1792                                            MachineNode->getOperand(0).
1793                                              getOperand(0));
1794         else if (Op2Not)
1795           // x | ~y = orc(x, y)
1796           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
1797                                            MVT::i1, MachineNode->getOperand(0),
1798                                            MachineNode->getOperand(1).
1799                                              getOperand(0));
1800         else if (AllUsersSelectZero(MachineNode))
1801           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1802                                            MVT::i1, MachineNode->getOperand(0),
1803                                            MachineNode->getOperand(1)),
1804           SelectSwap = true;
1805         break;
1806       case PPC::CRXOR:
1807         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
1808           // xor(x, x) = 0
1809           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
1810                                            MVT::i1);
1811         else if (Op1Set)
1812           // xor(1, y) -> nor(y, y)
1813           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1814                                            MVT::i1, MachineNode->getOperand(1),
1815                                            MachineNode->getOperand(1));
1816         else if (Op2Set)
1817           // xor(x, 1) -> nor(x, x)
1818           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1819                                            MVT::i1, MachineNode->getOperand(0),
1820                                            MachineNode->getOperand(0));
1821         else if (Op1Unset)
1822           // xor(0, y) = y
1823           ResNode = MachineNode->getOperand(1).getNode();
1824         else if (Op2Unset)
1825           // xor(x, 0) = x
1826           ResNode = MachineNode->getOperand(0).getNode();
1827         else if (Op1Not)
1828           // xor(~x, y) = eqv(x, y)
1829           ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
1830                                            MVT::i1, MachineNode->getOperand(0).
1831                                                       getOperand(0),
1832                                            MachineNode->getOperand(1));
1833         else if (Op2Not)
1834           // xor(x, ~y) = eqv(x, y)
1835           ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
1836                                            MVT::i1, MachineNode->getOperand(0),
1837                                            MachineNode->getOperand(1).
1838                                              getOperand(0));
1839         else if (AllUsersSelectZero(MachineNode))
1840           ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
1841                                            MVT::i1, MachineNode->getOperand(0),
1842                                            MachineNode->getOperand(1)),
1843           SelectSwap = true;
1844         break;
1845       case PPC::CRNOR:
1846         if (Op1Set || Op2Set)
1847           // nor(1, y) -> 0
1848           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
1849                                            MVT::i1);
1850         else if (Op1Unset)
1851           // nor(0, y) = ~y -> nor(y, y)
1852           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1853                                            MVT::i1, MachineNode->getOperand(1),
1854                                            MachineNode->getOperand(1));
1855         else if (Op2Unset)
1856           // nor(x, 0) = ~x
1857           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1858                                            MVT::i1, MachineNode->getOperand(0),
1859                                            MachineNode->getOperand(0));
1860         else if (Op1Not)
1861           // nor(~x, y) = andc(x, y)
1862           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
1863                                            MVT::i1, MachineNode->getOperand(0).
1864                                                       getOperand(0),
1865                                            MachineNode->getOperand(1));
1866         else if (Op2Not)
1867           // nor(x, ~y) = andc(y, x)
1868           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
1869                                            MVT::i1, MachineNode->getOperand(1).
1870                                                       getOperand(0),
1871                                            MachineNode->getOperand(0));
1872         else if (AllUsersSelectZero(MachineNode))
1873           ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
1874                                            MVT::i1, MachineNode->getOperand(0),
1875                                            MachineNode->getOperand(1)),
1876           SelectSwap = true;
1877         break;
1878       case PPC::CREQV:
1879         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
1880           // eqv(x, x) = 1
1881           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
1882                                            MVT::i1);
1883         else if (Op1Set)
1884           // eqv(1, y) = y
1885           ResNode = MachineNode->getOperand(1).getNode();
1886         else if (Op2Set)
1887           // eqv(x, 1) = x
1888           ResNode = MachineNode->getOperand(0).getNode();
1889         else if (Op1Unset)
1890           // eqv(0, y) = ~y -> nor(y, y)
1891           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1892                                            MVT::i1, MachineNode->getOperand(1),
1893                                            MachineNode->getOperand(1));
1894         else if (Op2Unset)
1895           // eqv(x, 0) = ~x
1896           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1897                                            MVT::i1, MachineNode->getOperand(0),
1898                                            MachineNode->getOperand(0));
1899         else if (Op1Not)
1900           // eqv(~x, y) = xor(x, y)
1901           ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
1902                                            MVT::i1, MachineNode->getOperand(0).
1903                                                       getOperand(0),
1904                                            MachineNode->getOperand(1));
1905         else if (Op2Not)
1906           // eqv(x, ~y) = xor(x, y)
1907           ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
1908                                            MVT::i1, MachineNode->getOperand(0),
1909                                            MachineNode->getOperand(1).
1910                                              getOperand(0));
1911         else if (AllUsersSelectZero(MachineNode))
1912           ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
1913                                            MVT::i1, MachineNode->getOperand(0),
1914                                            MachineNode->getOperand(1)),
1915           SelectSwap = true;
1916         break;
1917       case PPC::CRANDC:
1918         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
1919           // andc(x, x) = 0
1920           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
1921                                            MVT::i1);
1922         else if (Op1Set)
1923           // andc(1, y) = ~y
1924           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1925                                            MVT::i1, MachineNode->getOperand(1),
1926                                            MachineNode->getOperand(1));
1927         else if (Op1Unset || Op2Set)
1928           // andc(0, y) = andc(x, 1) = 0
1929           ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
1930                                            MVT::i1);
1931         else if (Op2Unset)
1932           // andc(x, 0) = x
1933           ResNode = MachineNode->getOperand(0).getNode();
1934         else if (Op1Not)
1935           // andc(~x, y) = ~(x | y) = nor(x, y)
1936           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1937                                            MVT::i1, MachineNode->getOperand(0).
1938                                                       getOperand(0),
1939                                            MachineNode->getOperand(1));
1940         else if (Op2Not)
1941           // andc(x, ~y) = x & y
1942           ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
1943                                            MVT::i1, MachineNode->getOperand(0),
1944                                            MachineNode->getOperand(1).
1945                                              getOperand(0));
1946         else if (AllUsersSelectZero(MachineNode))
1947           ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
1948                                            MVT::i1, MachineNode->getOperand(1),
1949                                            MachineNode->getOperand(0)),
1950           SelectSwap = true;
1951         break;
1952       case PPC::CRORC:
1953         if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
1954           // orc(x, x) = 1
1955           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
1956                                            MVT::i1);
1957         else if (Op1Set || Op2Unset)
1958           // orc(1, y) = orc(x, 0) = 1
1959           ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
1960                                            MVT::i1);
1961         else if (Op2Set)
1962           // orc(x, 1) = x
1963           ResNode = MachineNode->getOperand(0).getNode();
1964         else if (Op1Unset)
1965           // orc(0, y) = ~y
1966           ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
1967                                            MVT::i1, MachineNode->getOperand(1),
1968                                            MachineNode->getOperand(1));
1969         else if (Op1Not)
1970           // orc(~x, y) = ~(x & y) = nand(x, y)
1971           ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
1972                                            MVT::i1, MachineNode->getOperand(0).
1973                                                       getOperand(0),
1974                                            MachineNode->getOperand(1));
1975         else if (Op2Not)
1976           // orc(x, ~y) = x | y
1977           ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
1978                                            MVT::i1, MachineNode->getOperand(0),
1979                                            MachineNode->getOperand(1).
1980                                              getOperand(0));
1981         else if (AllUsersSelectZero(MachineNode))
1982           ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
1983                                            MVT::i1, MachineNode->getOperand(1),
1984                                            MachineNode->getOperand(0)),
1985           SelectSwap = true;
1986         break;
1987       case PPC::SELECT_I4:
1988       case PPC::SELECT_I8:
1989       case PPC::SELECT_F4:
1990       case PPC::SELECT_F8:
1991       case PPC::SELECT_VRRC:
1992         if (Op1Set)
1993           ResNode = MachineNode->getOperand(1).getNode();
1994         else if (Op1Unset)
1995           ResNode = MachineNode->getOperand(2).getNode();
1996         else if (Op1Not)
1997           ResNode = CurDAG->getMachineNode(MachineNode->getMachineOpcode(),
1998                                            SDLoc(MachineNode),
1999                                            MachineNode->getValueType(0),
2000                                            MachineNode->getOperand(0).
2001                                              getOperand(0),
2002                                            MachineNode->getOperand(2),
2003                                            MachineNode->getOperand(1));
2004         break;
2005       case PPC::BC:
2006       case PPC::BCn:
2007         if (Op1Not)
2008           ResNode = CurDAG->getMachineNode(Opcode == PPC::BC ? PPC::BCn :
2009                                                                PPC::BC,
2010                                            SDLoc(MachineNode),
2011                                            MVT::Other,
2012                                            MachineNode->getOperand(0).
2013                                              getOperand(0),
2014                                            MachineNode->getOperand(1),
2015                                            MachineNode->getOperand(2));
2016         // FIXME: Handle Op1Set, Op1Unset here too.
2017         break;
2018       }
2019 
2020       // If we're inverting this node because it is used only by selects that
2021       // we'd like to swap, then swap the selects before the node replacement.
2022       if (SelectSwap)
2023         SwapAllSelectUsers(MachineNode);
2024 
2025       if (ResNode != MachineNode) {
2026         DEBUG(dbgs() << "CR Peephole replacing:\nOld:    ");
2027         DEBUG(MachineNode->dump(CurDAG));
2028         DEBUG(dbgs() << "\nNew: ");
2029         DEBUG(ResNode->dump(CurDAG));
2030         DEBUG(dbgs() << "\n");
2031 
2032         ReplaceUses(MachineNode, ResNode);
2033         IsModified = true;
2034       }
2035     }
2036     if (IsModified)
2037       CurDAG->RemoveDeadNodes();
2038   } while (IsModified);
2039 }
2040 
PeepholePPC64()2041 void PPCDAGToDAGISel::PeepholePPC64() {
2042   // These optimizations are currently supported only for 64-bit SVR4.
2043   if (PPCSubTarget->isDarwin() || !PPCSubTarget->isPPC64())
2044     return;
2045 
2046   SelectionDAG::allnodes_iterator Position(CurDAG->getRoot().getNode());
2047   ++Position;
2048 
2049   while (Position != CurDAG->allnodes_begin()) {
2050     SDNode *N = --Position;
2051     // Skip dead nodes and any non-machine opcodes.
2052     if (N->use_empty() || !N->isMachineOpcode())
2053       continue;
2054 
2055     unsigned FirstOp;
2056     unsigned StorageOpcode = N->getMachineOpcode();
2057 
2058     switch (StorageOpcode) {
2059     default: continue;
2060 
2061     case PPC::LBZ:
2062     case PPC::LBZ8:
2063     case PPC::LD:
2064     case PPC::LFD:
2065     case PPC::LFS:
2066     case PPC::LHA:
2067     case PPC::LHA8:
2068     case PPC::LHZ:
2069     case PPC::LHZ8:
2070     case PPC::LWA:
2071     case PPC::LWZ:
2072     case PPC::LWZ8:
2073       FirstOp = 0;
2074       break;
2075 
2076     case PPC::STB:
2077     case PPC::STB8:
2078     case PPC::STD:
2079     case PPC::STFD:
2080     case PPC::STFS:
2081     case PPC::STH:
2082     case PPC::STH8:
2083     case PPC::STW:
2084     case PPC::STW8:
2085       FirstOp = 1;
2086       break;
2087     }
2088 
2089     // If this is a load or store with a zero offset, we may be able to
2090     // fold an add-immediate into the memory operation.
2091     if (!isa<ConstantSDNode>(N->getOperand(FirstOp)) ||
2092         N->getConstantOperandVal(FirstOp) != 0)
2093       continue;
2094 
2095     SDValue Base = N->getOperand(FirstOp + 1);
2096     if (!Base.isMachineOpcode())
2097       continue;
2098 
2099     unsigned Flags = 0;
2100     bool ReplaceFlags = true;
2101 
2102     // When the feeding operation is an add-immediate of some sort,
2103     // determine whether we need to add relocation information to the
2104     // target flags on the immediate operand when we fold it into the
2105     // load instruction.
2106     //
2107     // For something like ADDItocL, the relocation information is
2108     // inferred from the opcode; when we process it in the AsmPrinter,
2109     // we add the necessary relocation there.  A load, though, can receive
2110     // relocation from various flavors of ADDIxxx, so we need to carry
2111     // the relocation information in the target flags.
2112     switch (Base.getMachineOpcode()) {
2113     default: continue;
2114 
2115     case PPC::ADDI8:
2116     case PPC::ADDI:
2117       // In some cases (such as TLS) the relocation information
2118       // is already in place on the operand, so copying the operand
2119       // is sufficient.
2120       ReplaceFlags = false;
2121       // For these cases, the immediate may not be divisible by 4, in
2122       // which case the fold is illegal for DS-form instructions.  (The
2123       // other cases provide aligned addresses and are always safe.)
2124       if ((StorageOpcode == PPC::LWA ||
2125            StorageOpcode == PPC::LD  ||
2126            StorageOpcode == PPC::STD) &&
2127           (!isa<ConstantSDNode>(Base.getOperand(1)) ||
2128            Base.getConstantOperandVal(1) % 4 != 0))
2129         continue;
2130       break;
2131     case PPC::ADDIdtprelL:
2132       Flags = PPCII::MO_DTPREL_LO;
2133       break;
2134     case PPC::ADDItlsldL:
2135       Flags = PPCII::MO_TLSLD_LO;
2136       break;
2137     case PPC::ADDItocL:
2138       Flags = PPCII::MO_TOC_LO;
2139       break;
2140     }
2141 
2142     // We found an opportunity.  Reverse the operands from the add
2143     // immediate and substitute them into the load or store.  If
2144     // needed, update the target flags for the immediate operand to
2145     // reflect the necessary relocation information.
2146     DEBUG(dbgs() << "Folding add-immediate into mem-op:\nBase:    ");
2147     DEBUG(Base->dump(CurDAG));
2148     DEBUG(dbgs() << "\nN: ");
2149     DEBUG(N->dump(CurDAG));
2150     DEBUG(dbgs() << "\n");
2151 
2152     SDValue ImmOpnd = Base.getOperand(1);
2153 
2154     // If the relocation information isn't already present on the
2155     // immediate operand, add it now.
2156     if (ReplaceFlags) {
2157       if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
2158         SDLoc dl(GA);
2159         const GlobalValue *GV = GA->getGlobal();
2160         // We can't perform this optimization for data whose alignment
2161         // is insufficient for the instruction encoding.
2162         if (GV->getAlignment() < 4 &&
2163             (StorageOpcode == PPC::LD || StorageOpcode == PPC::STD ||
2164              StorageOpcode == PPC::LWA)) {
2165           DEBUG(dbgs() << "Rejected this candidate for alignment.\n\n");
2166           continue;
2167         }
2168         ImmOpnd = CurDAG->getTargetGlobalAddress(GV, dl, MVT::i64, 0, Flags);
2169       } else if (ConstantPoolSDNode *CP =
2170                  dyn_cast<ConstantPoolSDNode>(ImmOpnd)) {
2171         const Constant *C = CP->getConstVal();
2172         ImmOpnd = CurDAG->getTargetConstantPool(C, MVT::i64,
2173                                                 CP->getAlignment(),
2174                                                 0, Flags);
2175       }
2176     }
2177 
2178     if (FirstOp == 1) // Store
2179       (void)CurDAG->UpdateNodeOperands(N, N->getOperand(0), ImmOpnd,
2180                                        Base.getOperand(0), N->getOperand(3));
2181     else // Load
2182       (void)CurDAG->UpdateNodeOperands(N, ImmOpnd, Base.getOperand(0),
2183                                        N->getOperand(2));
2184 
2185     // The add-immediate may now be dead, in which case remove it.
2186     if (Base.getNode()->use_empty())
2187       CurDAG->RemoveDeadNode(Base.getNode());
2188   }
2189 }
2190 
2191 
2192 /// createPPCISelDag - This pass converts a legalized DAG into a
2193 /// PowerPC-specific DAG, ready for instruction scheduling.
2194 ///
createPPCISelDag(PPCTargetMachine & TM)2195 FunctionPass *llvm::createPPCISelDag(PPCTargetMachine &TM) {
2196   return new PPCDAGToDAGISel(TM);
2197 }
2198 
initializePassOnce(PassRegistry & Registry)2199 static void initializePassOnce(PassRegistry &Registry) {
2200   const char *Name = "PowerPC DAG->DAG Pattern Instruction Selection";
2201   PassInfo *PI = new PassInfo(Name, "ppc-codegen", &SelectionDAGISel::ID,
2202                               nullptr, false, false);
2203   Registry.registerPass(*PI, true);
2204 }
2205 
initializePPCDAGToDAGISelPass(PassRegistry & Registry)2206 void llvm::initializePPCDAGToDAGISelPass(PassRegistry &Registry) {
2207   CALL_ONCE_INITIALIZATION(initializePassOnce);
2208 }
2209 
2210