1 //===-- TargetLowering.cpp - Implement the TargetLowering class -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements the TargetLowering class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Target/TargetLowering.h"
15 #include "llvm/ADT/BitVector.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/CodeGen/Analysis.h"
18 #include "llvm/CodeGen/MachineFrameInfo.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/MachineJumpTableInfo.h"
21 #include "llvm/CodeGen/SelectionDAG.h"
22 #include "llvm/IR/DataLayout.h"
23 #include "llvm/IR/DerivedTypes.h"
24 #include "llvm/IR/GlobalVariable.h"
25 #include "llvm/MC/MCAsmInfo.h"
26 #include "llvm/MC/MCExpr.h"
27 #include "llvm/Support/CommandLine.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/MathExtras.h"
30 #include "llvm/Target/TargetLoweringObjectFile.h"
31 #include "llvm/Target/TargetMachine.h"
32 #include "llvm/Target/TargetRegisterInfo.h"
36 /// NOTE: The constructor takes ownership of TLOF.
37 TargetLowering::TargetLowering(const TargetMachine &tm,
38 const TargetLoweringObjectFile *tlof)
39 : TargetLoweringBase(tm, tlof) {}
41 const char *TargetLowering::getTargetNodeName(unsigned Opcode) const {
45 /// Check whether a given call node is in tail position within its function. If
46 /// so, it sets Chain to the input chain of the tail call.
47 bool TargetLowering::isInTailCallPosition(SelectionDAG &DAG, SDNode *Node,
48 SDValue &Chain) const {
49 const Function *F = DAG.getMachineFunction().getFunction();
51 // Conservatively require the attributes of the call to match those of
52 // the return. Ignore noalias because it doesn't affect the call sequence.
53 AttributeSet CallerAttrs = F->getAttributes();
54 if (AttrBuilder(CallerAttrs, AttributeSet::ReturnIndex)
55 .removeAttribute(Attribute::NoAlias).hasAttributes())
58 // It's not safe to eliminate the sign / zero extension of the return value.
59 if (CallerAttrs.hasAttribute(AttributeSet::ReturnIndex, Attribute::ZExt) ||
60 CallerAttrs.hasAttribute(AttributeSet::ReturnIndex, Attribute::SExt))
63 // Check if the only use is a function return node.
64 return isUsedByReturnOnly(Node, Chain);
68 /// Generate a libcall taking the given operands as arguments and returning a
69 /// result of type RetVT.
70 std::pair<SDValue, SDValue>
71 TargetLowering::makeLibCall(SelectionDAG &DAG,
72 RTLIB::Libcall LC, EVT RetVT,
73 const SDValue *Ops, unsigned NumOps,
74 bool isSigned, SDLoc dl,
76 bool isReturnValueUsed) const {
77 TargetLowering::ArgListTy Args;
80 TargetLowering::ArgListEntry Entry;
81 for (unsigned i = 0; i != NumOps; ++i) {
83 Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext());
84 Entry.isSExt = isSigned;
85 Entry.isZExt = !isSigned;
86 Args.push_back(Entry);
88 SDValue Callee = DAG.getExternalSymbol(getLibcallName(LC), getPointerTy());
90 Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
92 CallLoweringInfo CLI(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false,
93 false, 0, getLibcallCallingConv(LC),
95 doesNotReturn, isReturnValueUsed, Callee, Args,
97 return LowerCallTo(CLI);
101 /// SoftenSetCCOperands - Soften the operands of a comparison. This code is
102 /// shared among BR_CC, SELECT_CC, and SETCC handlers.
103 void TargetLowering::softenSetCCOperands(SelectionDAG &DAG, EVT VT,
104 SDValue &NewLHS, SDValue &NewRHS,
105 ISD::CondCode &CCCode,
107 assert((VT == MVT::f32 || VT == MVT::f64 || VT == MVT::f128)
108 && "Unsupported setcc type!");
110 // Expand into one or more soft-fp libcall(s).
111 RTLIB::Libcall LC1 = RTLIB::UNKNOWN_LIBCALL, LC2 = RTLIB::UNKNOWN_LIBCALL;
115 LC1 = (VT == MVT::f32) ? RTLIB::OEQ_F32 :
116 (VT == MVT::f64) ? RTLIB::OEQ_F64 : RTLIB::OEQ_F128;
120 LC1 = (VT == MVT::f32) ? RTLIB::UNE_F32 :
121 (VT == MVT::f64) ? RTLIB::UNE_F64 : RTLIB::UNE_F128;
125 LC1 = (VT == MVT::f32) ? RTLIB::OGE_F32 :
126 (VT == MVT::f64) ? RTLIB::OGE_F64 : RTLIB::OGE_F128;
130 LC1 = (VT == MVT::f32) ? RTLIB::OLT_F32 :
131 (VT == MVT::f64) ? RTLIB::OLT_F64 : RTLIB::OLT_F128;
135 LC1 = (VT == MVT::f32) ? RTLIB::OLE_F32 :
136 (VT == MVT::f64) ? RTLIB::OLE_F64 : RTLIB::OLE_F128;
140 LC1 = (VT == MVT::f32) ? RTLIB::OGT_F32 :
141 (VT == MVT::f64) ? RTLIB::OGT_F64 : RTLIB::OGT_F128;
144 LC1 = (VT == MVT::f32) ? RTLIB::UO_F32 :
145 (VT == MVT::f64) ? RTLIB::UO_F64 : RTLIB::UO_F128;
148 LC1 = (VT == MVT::f32) ? RTLIB::O_F32 :
149 (VT == MVT::f64) ? RTLIB::O_F64 : RTLIB::O_F128;
152 LC1 = (VT == MVT::f32) ? RTLIB::UO_F32 :
153 (VT == MVT::f64) ? RTLIB::UO_F64 : RTLIB::UO_F128;
156 // SETONE = SETOLT | SETOGT
157 LC1 = (VT == MVT::f32) ? RTLIB::OLT_F32 :
158 (VT == MVT::f64) ? RTLIB::OLT_F64 : RTLIB::OLT_F128;
161 LC2 = (VT == MVT::f32) ? RTLIB::OGT_F32 :
162 (VT == MVT::f64) ? RTLIB::OGT_F64 : RTLIB::OGT_F128;
165 LC2 = (VT == MVT::f32) ? RTLIB::OGE_F32 :
166 (VT == MVT::f64) ? RTLIB::OGE_F64 : RTLIB::OGE_F128;
169 LC2 = (VT == MVT::f32) ? RTLIB::OLT_F32 :
170 (VT == MVT::f64) ? RTLIB::OLT_F64 : RTLIB::OLT_F128;
173 LC2 = (VT == MVT::f32) ? RTLIB::OLE_F32 :
174 (VT == MVT::f64) ? RTLIB::OLE_F64 : RTLIB::OLE_F128;
177 LC2 = (VT == MVT::f32) ? RTLIB::OEQ_F32 :
178 (VT == MVT::f64) ? RTLIB::OEQ_F64 : RTLIB::OEQ_F128;
180 default: llvm_unreachable("Do not know how to soften this setcc!");
184 // Use the target specific return value for comparions lib calls.
185 EVT RetVT = getCmpLibcallReturnType();
186 SDValue Ops[2] = { NewLHS, NewRHS };
187 NewLHS = makeLibCall(DAG, LC1, RetVT, Ops, 2, false/*sign irrelevant*/,
189 NewRHS = DAG.getConstant(0, RetVT);
190 CCCode = getCmpLibcallCC(LC1);
191 if (LC2 != RTLIB::UNKNOWN_LIBCALL) {
192 SDValue Tmp = DAG.getNode(ISD::SETCC, dl,
193 getSetCCResultType(*DAG.getContext(), RetVT),
194 NewLHS, NewRHS, DAG.getCondCode(CCCode));
195 NewLHS = makeLibCall(DAG, LC2, RetVT, Ops, 2, false/*sign irrelevant*/,
197 NewLHS = DAG.getNode(ISD::SETCC, dl,
198 getSetCCResultType(*DAG.getContext(), RetVT), NewLHS,
199 NewRHS, DAG.getCondCode(getCmpLibcallCC(LC2)));
200 NewLHS = DAG.getNode(ISD::OR, dl, Tmp.getValueType(), Tmp, NewLHS);
205 /// getJumpTableEncoding - Return the entry encoding for a jump table in the
206 /// current function. The returned value is a member of the
207 /// MachineJumpTableInfo::JTEntryKind enum.
208 unsigned TargetLowering::getJumpTableEncoding() const {
209 // In non-pic modes, just use the address of a block.
210 if (getTargetMachine().getRelocationModel() != Reloc::PIC_)
211 return MachineJumpTableInfo::EK_BlockAddress;
213 // In PIC mode, if the target supports a GPRel32 directive, use it.
214 if (getTargetMachine().getMCAsmInfo()->getGPRel32Directive() != 0)
215 return MachineJumpTableInfo::EK_GPRel32BlockAddress;
217 // Otherwise, use a label difference.
218 return MachineJumpTableInfo::EK_LabelDifference32;
221 SDValue TargetLowering::getPICJumpTableRelocBase(SDValue Table,
222 SelectionDAG &DAG) const {
223 // If our PIC model is GP relative, use the global offset table as the base.
224 unsigned JTEncoding = getJumpTableEncoding();
226 if ((JTEncoding == MachineJumpTableInfo::EK_GPRel64BlockAddress) ||
227 (JTEncoding == MachineJumpTableInfo::EK_GPRel32BlockAddress))
228 return DAG.getGLOBAL_OFFSET_TABLE(getPointerTy(0));
233 /// getPICJumpTableRelocBaseExpr - This returns the relocation base for the
234 /// given PIC jumptable, the same as getPICJumpTableRelocBase, but as an
237 TargetLowering::getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
238 unsigned JTI,MCContext &Ctx) const{
239 // The normal PIC reloc base is the label at the start of the jump table.
240 return MCSymbolRefExpr::Create(MF->getJTISymbol(JTI, Ctx), Ctx);
244 TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
245 // Assume that everything is safe in static mode.
246 if (getTargetMachine().getRelocationModel() == Reloc::Static)
249 // In dynamic-no-pic mode, assume that known defined values are safe.
250 if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC &&
252 !GA->getGlobal()->isDeclaration() &&
253 !GA->getGlobal()->isWeakForLinker())
256 // Otherwise assume nothing is safe.
260 //===----------------------------------------------------------------------===//
261 // Optimization Methods
262 //===----------------------------------------------------------------------===//
264 /// ShrinkDemandedConstant - Check to see if the specified operand of the
265 /// specified instruction is a constant integer. If so, check to see if there
266 /// are any bits set in the constant that are not demanded. If so, shrink the
267 /// constant and return true.
268 bool TargetLowering::TargetLoweringOpt::ShrinkDemandedConstant(SDValue Op,
269 const APInt &Demanded) {
272 // FIXME: ISD::SELECT, ISD::SELECT_CC
273 switch (Op.getOpcode()) {
278 ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
279 if (!C) return false;
281 if (Op.getOpcode() == ISD::XOR &&
282 (C->getAPIntValue() | (~Demanded)).isAllOnesValue())
285 // if we can expand it to have all bits set, do it
286 if (C->getAPIntValue().intersects(~Demanded)) {
287 EVT VT = Op.getValueType();
288 SDValue New = DAG.getNode(Op.getOpcode(), dl, VT, Op.getOperand(0),
289 DAG.getConstant(Demanded &
292 return CombineTo(Op, New);
302 /// ShrinkDemandedOp - Convert x+y to (VT)((SmallVT)x+(SmallVT)y) if the
303 /// casts are free. This uses isZExtFree and ZERO_EXTEND for the widening
304 /// cast, but it could be generalized for targets with other types of
305 /// implicit widening casts.
307 TargetLowering::TargetLoweringOpt::ShrinkDemandedOp(SDValue Op,
309 const APInt &Demanded,
311 assert(Op.getNumOperands() == 2 &&
312 "ShrinkDemandedOp only supports binary operators!");
313 assert(Op.getNode()->getNumValues() == 1 &&
314 "ShrinkDemandedOp only supports nodes with one result!");
316 // Don't do this if the node has another user, which may require the
318 if (!Op.getNode()->hasOneUse())
321 // Search for the smallest integer type with free casts to and from
322 // Op's type. For expedience, just check power-of-2 integer types.
323 const TargetLowering &TLI = DAG.getTargetLoweringInfo();
324 unsigned DemandedSize = BitWidth - Demanded.countLeadingZeros();
325 unsigned SmallVTBits = DemandedSize;
326 if (!isPowerOf2_32(SmallVTBits))
327 SmallVTBits = NextPowerOf2(SmallVTBits);
328 for (; SmallVTBits < BitWidth; SmallVTBits = NextPowerOf2(SmallVTBits)) {
329 EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), SmallVTBits);
330 if (TLI.isTruncateFree(Op.getValueType(), SmallVT) &&
331 TLI.isZExtFree(SmallVT, Op.getValueType())) {
332 // We found a type with free casts.
333 SDValue X = DAG.getNode(Op.getOpcode(), dl, SmallVT,
334 DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
335 Op.getNode()->getOperand(0)),
336 DAG.getNode(ISD::TRUNCATE, dl, SmallVT,
337 Op.getNode()->getOperand(1)));
338 bool NeedZext = DemandedSize > SmallVTBits;
339 SDValue Z = DAG.getNode(NeedZext ? ISD::ZERO_EXTEND : ISD::ANY_EXTEND,
340 dl, Op.getValueType(), X);
341 return CombineTo(Op, Z);
347 /// SimplifyDemandedBits - Look at Op. At this point, we know that only the
348 /// DemandedMask bits of the result of Op are ever used downstream. If we can
349 /// use this information to simplify Op, create a new simplified DAG node and
350 /// return true, returning the original and new nodes in Old and New. Otherwise,
351 /// analyze the expression and return a mask of KnownOne and KnownZero bits for
352 /// the expression (used to simplify the caller). The KnownZero/One bits may
353 /// only be accurate for those bits in the DemandedMask.
354 bool TargetLowering::SimplifyDemandedBits(SDValue Op,
355 const APInt &DemandedMask,
358 TargetLoweringOpt &TLO,
359 unsigned Depth) const {
360 unsigned BitWidth = DemandedMask.getBitWidth();
361 assert(Op.getValueType().getScalarType().getSizeInBits() == BitWidth &&
362 "Mask size mismatches value type size!");
363 APInt NewMask = DemandedMask;
366 // Don't know anything.
367 KnownZero = KnownOne = APInt(BitWidth, 0);
369 // Other users may use these bits.
370 if (!Op.getNode()->hasOneUse()) {
372 // If not at the root, Just compute the KnownZero/KnownOne bits to
373 // simplify things downstream.
374 TLO.DAG.ComputeMaskedBits(Op, KnownZero, KnownOne, Depth);
377 // If this is the root being simplified, allow it to have multiple uses,
378 // just set the NewMask to all bits.
379 NewMask = APInt::getAllOnesValue(BitWidth);
380 } else if (DemandedMask == 0) {
381 // Not demanding any bits from Op.
382 if (Op.getOpcode() != ISD::UNDEF)
383 return TLO.CombineTo(Op, TLO.DAG.getUNDEF(Op.getValueType()));
385 } else if (Depth == 6) { // Limit search depth.
389 APInt KnownZero2, KnownOne2, KnownZeroOut, KnownOneOut;
390 switch (Op.getOpcode()) {
392 // We know all of the bits for a constant!
393 KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue();
394 KnownZero = ~KnownOne;
395 return false; // Don't fall through, will infinitely loop.
397 // If the RHS is a constant, check to see if the LHS would be zero without
398 // using the bits from the RHS. Below, we use knowledge about the RHS to
399 // simplify the LHS, here we're using information from the LHS to simplify
401 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
402 APInt LHSZero, LHSOne;
403 // Do not increment Depth here; that can cause an infinite loop.
404 TLO.DAG.ComputeMaskedBits(Op.getOperand(0), LHSZero, LHSOne, Depth);
405 // If the LHS already has zeros where RHSC does, this and is dead.
406 if ((LHSZero & NewMask) == (~RHSC->getAPIntValue() & NewMask))
407 return TLO.CombineTo(Op, Op.getOperand(0));
408 // If any of the set bits in the RHS are known zero on the LHS, shrink
410 if (TLO.ShrinkDemandedConstant(Op, ~LHSZero & NewMask))
414 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
415 KnownOne, TLO, Depth+1))
417 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
418 if (SimplifyDemandedBits(Op.getOperand(0), ~KnownZero & NewMask,
419 KnownZero2, KnownOne2, TLO, Depth+1))
421 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
423 // If all of the demanded bits are known one on one side, return the other.
424 // These bits cannot contribute to the result of the 'and'.
425 if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
426 return TLO.CombineTo(Op, Op.getOperand(0));
427 if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
428 return TLO.CombineTo(Op, Op.getOperand(1));
429 // If all of the demanded bits in the inputs are known zeros, return zero.
430 if ((NewMask & (KnownZero|KnownZero2)) == NewMask)
431 return TLO.CombineTo(Op, TLO.DAG.getConstant(0, Op.getValueType()));
432 // If the RHS is a constant, see if we can simplify it.
433 if (TLO.ShrinkDemandedConstant(Op, ~KnownZero2 & NewMask))
435 // If the operation can be done in a smaller type, do so.
436 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
439 // Output known-1 bits are only known if set in both the LHS & RHS.
440 KnownOne &= KnownOne2;
441 // Output known-0 are known to be clear if zero in either the LHS | RHS.
442 KnownZero |= KnownZero2;
445 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
446 KnownOne, TLO, Depth+1))
448 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
449 if (SimplifyDemandedBits(Op.getOperand(0), ~KnownOne & NewMask,
450 KnownZero2, KnownOne2, TLO, Depth+1))
452 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
454 // If all of the demanded bits are known zero on one side, return the other.
455 // These bits cannot contribute to the result of the 'or'.
456 if ((NewMask & ~KnownOne2 & KnownZero) == (~KnownOne2 & NewMask))
457 return TLO.CombineTo(Op, Op.getOperand(0));
458 if ((NewMask & ~KnownOne & KnownZero2) == (~KnownOne & NewMask))
459 return TLO.CombineTo(Op, Op.getOperand(1));
460 // If all of the potentially set bits on one side are known to be set on
461 // the other side, just use the 'other' side.
462 if ((NewMask & ~KnownZero & KnownOne2) == (~KnownZero & NewMask))
463 return TLO.CombineTo(Op, Op.getOperand(0));
464 if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
465 return TLO.CombineTo(Op, Op.getOperand(1));
466 // If the RHS is a constant, see if we can simplify it.
467 if (TLO.ShrinkDemandedConstant(Op, NewMask))
469 // If the operation can be done in a smaller type, do so.
470 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
473 // Output known-0 bits are only known if clear in both the LHS & RHS.
474 KnownZero &= KnownZero2;
475 // Output known-1 are known to be set if set in either the LHS | RHS.
476 KnownOne |= KnownOne2;
479 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero,
480 KnownOne, TLO, Depth+1))
482 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
483 if (SimplifyDemandedBits(Op.getOperand(0), NewMask, KnownZero2,
484 KnownOne2, TLO, Depth+1))
486 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
488 // If all of the demanded bits are known zero on one side, return the other.
489 // These bits cannot contribute to the result of the 'xor'.
490 if ((KnownZero & NewMask) == NewMask)
491 return TLO.CombineTo(Op, Op.getOperand(0));
492 if ((KnownZero2 & NewMask) == NewMask)
493 return TLO.CombineTo(Op, Op.getOperand(1));
494 // If the operation can be done in a smaller type, do so.
495 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
498 // If all of the unknown bits are known to be zero on one side or the other
499 // (but not both) turn this into an *inclusive* or.
500 // e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
501 if ((NewMask & ~KnownZero & ~KnownZero2) == 0)
502 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::OR, dl, Op.getValueType(),
506 // Output known-0 bits are known if clear or set in both the LHS & RHS.
507 KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
508 // Output known-1 are known to be set if set in only one of the LHS, RHS.
509 KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
511 // If all of the demanded bits on one side are known, and all of the set
512 // bits on that side are also known to be set on the other side, turn this
513 // into an AND, as we know the bits will be cleared.
514 // e.g. (X | C1) ^ C2 --> (X | C1) & ~C2 iff (C1&C2) == C2
515 // NB: it is okay if more bits are known than are requested
516 if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known on one side
517 if (KnownOne == KnownOne2) { // set bits are the same on both sides
518 EVT VT = Op.getValueType();
519 SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT);
520 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::AND, dl, VT,
521 Op.getOperand(0), ANDC));
525 // If the RHS is a constant, see if we can simplify it.
526 // for XOR, we prefer to force bits to 1 if they will make a -1.
527 // if we can't force bits, try to shrink constant
528 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
529 APInt Expanded = C->getAPIntValue() | (~NewMask);
530 // if we can expand it to have all bits set, do it
531 if (Expanded.isAllOnesValue()) {
532 if (Expanded != C->getAPIntValue()) {
533 EVT VT = Op.getValueType();
534 SDValue New = TLO.DAG.getNode(Op.getOpcode(), dl,VT, Op.getOperand(0),
535 TLO.DAG.getConstant(Expanded, VT));
536 return TLO.CombineTo(Op, New);
538 // if it already has all the bits set, nothing to change
539 // but don't shrink either!
540 } else if (TLO.ShrinkDemandedConstant(Op, NewMask)) {
545 KnownZero = KnownZeroOut;
546 KnownOne = KnownOneOut;
549 if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero,
550 KnownOne, TLO, Depth+1))
552 if (SimplifyDemandedBits(Op.getOperand(1), NewMask, KnownZero2,
553 KnownOne2, TLO, Depth+1))
555 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
556 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
558 // If the operands are constants, see if we can simplify them.
559 if (TLO.ShrinkDemandedConstant(Op, NewMask))
562 // Only known if known in both the LHS and RHS.
563 KnownOne &= KnownOne2;
564 KnownZero &= KnownZero2;
567 if (SimplifyDemandedBits(Op.getOperand(3), NewMask, KnownZero,
568 KnownOne, TLO, Depth+1))
570 if (SimplifyDemandedBits(Op.getOperand(2), NewMask, KnownZero2,
571 KnownOne2, TLO, Depth+1))
573 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
574 assert((KnownZero2 & KnownOne2) == 0 && "Bits known to be one AND zero?");
576 // If the operands are constants, see if we can simplify them.
577 if (TLO.ShrinkDemandedConstant(Op, NewMask))
580 // Only known if known in both the LHS and RHS.
581 KnownOne &= KnownOne2;
582 KnownZero &= KnownZero2;
585 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
586 unsigned ShAmt = SA->getZExtValue();
587 SDValue InOp = Op.getOperand(0);
589 // If the shift count is an invalid immediate, don't do anything.
590 if (ShAmt >= BitWidth)
593 // If this is ((X >>u C1) << ShAmt), see if we can simplify this into a
594 // single shift. We can do this if the bottom bits (which are shifted
595 // out) are never demanded.
596 if (InOp.getOpcode() == ISD::SRL &&
597 isa<ConstantSDNode>(InOp.getOperand(1))) {
598 if (ShAmt && (NewMask & APInt::getLowBitsSet(BitWidth, ShAmt)) == 0) {
599 unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
600 unsigned Opc = ISD::SHL;
608 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
609 EVT VT = Op.getValueType();
610 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
611 InOp.getOperand(0), NewSA));
615 if (SimplifyDemandedBits(InOp, NewMask.lshr(ShAmt),
616 KnownZero, KnownOne, TLO, Depth+1))
619 // Convert (shl (anyext x, c)) to (anyext (shl x, c)) if the high bits
620 // are not demanded. This will likely allow the anyext to be folded away.
621 if (InOp.getNode()->getOpcode() == ISD::ANY_EXTEND) {
622 SDValue InnerOp = InOp.getNode()->getOperand(0);
623 EVT InnerVT = InnerOp.getValueType();
624 unsigned InnerBits = InnerVT.getSizeInBits();
625 if (ShAmt < InnerBits && NewMask.lshr(InnerBits) == 0 &&
626 isTypeDesirableForOp(ISD::SHL, InnerVT)) {
627 EVT ShTy = getShiftAmountTy(InnerVT);
628 if (!APInt(BitWidth, ShAmt).isIntN(ShTy.getSizeInBits()))
631 TLO.DAG.getNode(ISD::SHL, dl, InnerVT, InnerOp,
632 TLO.DAG.getConstant(ShAmt, ShTy));
635 TLO.DAG.getNode(ISD::ANY_EXTEND, dl, Op.getValueType(),
640 KnownZero <<= SA->getZExtValue();
641 KnownOne <<= SA->getZExtValue();
642 // low bits known zero.
643 KnownZero |= APInt::getLowBitsSet(BitWidth, SA->getZExtValue());
647 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
648 EVT VT = Op.getValueType();
649 unsigned ShAmt = SA->getZExtValue();
650 unsigned VTSize = VT.getSizeInBits();
651 SDValue InOp = Op.getOperand(0);
653 // If the shift count is an invalid immediate, don't do anything.
654 if (ShAmt >= BitWidth)
657 // If this is ((X << C1) >>u ShAmt), see if we can simplify this into a
658 // single shift. We can do this if the top bits (which are shifted out)
659 // are never demanded.
660 if (InOp.getOpcode() == ISD::SHL &&
661 isa<ConstantSDNode>(InOp.getOperand(1))) {
662 if (ShAmt && (NewMask & APInt::getHighBitsSet(VTSize, ShAmt)) == 0) {
663 unsigned C1= cast<ConstantSDNode>(InOp.getOperand(1))->getZExtValue();
664 unsigned Opc = ISD::SRL;
672 TLO.DAG.getConstant(Diff, Op.getOperand(1).getValueType());
673 return TLO.CombineTo(Op, TLO.DAG.getNode(Opc, dl, VT,
674 InOp.getOperand(0), NewSA));
678 // Compute the new bits that are at the top now.
679 if (SimplifyDemandedBits(InOp, (NewMask << ShAmt),
680 KnownZero, KnownOne, TLO, Depth+1))
682 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
683 KnownZero = KnownZero.lshr(ShAmt);
684 KnownOne = KnownOne.lshr(ShAmt);
686 APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
687 KnownZero |= HighBits; // High bits known zero.
691 // If this is an arithmetic shift right and only the low-bit is set, we can
692 // always convert this into a logical shr, even if the shift amount is
693 // variable. The low bit of the shift cannot be an input sign bit unless
694 // the shift amount is >= the size of the datatype, which is undefined.
696 return TLO.CombineTo(Op,
697 TLO.DAG.getNode(ISD::SRL, dl, Op.getValueType(),
698 Op.getOperand(0), Op.getOperand(1)));
700 if (ConstantSDNode *SA = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
701 EVT VT = Op.getValueType();
702 unsigned ShAmt = SA->getZExtValue();
704 // If the shift count is an invalid immediate, don't do anything.
705 if (ShAmt >= BitWidth)
708 APInt InDemandedMask = (NewMask << ShAmt);
710 // If any of the demanded bits are produced by the sign extension, we also
711 // demand the input sign bit.
712 APInt HighBits = APInt::getHighBitsSet(BitWidth, ShAmt);
713 if (HighBits.intersects(NewMask))
714 InDemandedMask |= APInt::getSignBit(VT.getScalarType().getSizeInBits());
716 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedMask,
717 KnownZero, KnownOne, TLO, Depth+1))
719 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
720 KnownZero = KnownZero.lshr(ShAmt);
721 KnownOne = KnownOne.lshr(ShAmt);
723 // Handle the sign bit, adjusted to where it is now in the mask.
724 APInt SignBit = APInt::getSignBit(BitWidth).lshr(ShAmt);
726 // If the input sign bit is known to be zero, or if none of the top bits
727 // are demanded, turn this into an unsigned shift right.
728 if (KnownZero.intersects(SignBit) || (HighBits & ~NewMask) == HighBits) {
729 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl, VT,
732 } else if (KnownOne.intersects(SignBit)) { // New bits are known one.
733 KnownOne |= HighBits;
737 case ISD::SIGN_EXTEND_INREG: {
738 EVT ExVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
740 APInt MsbMask = APInt::getHighBitsSet(BitWidth, 1);
741 // If we only care about the highest bit, don't bother shifting right.
742 if (MsbMask == DemandedMask) {
743 unsigned ShAmt = ExVT.getScalarType().getSizeInBits();
744 SDValue InOp = Op.getOperand(0);
746 // Compute the correct shift amount type, which must be getShiftAmountTy
747 // for scalar types after legalization.
748 EVT ShiftAmtTy = Op.getValueType();
749 if (TLO.LegalTypes() && !ShiftAmtTy.isVector())
750 ShiftAmtTy = getShiftAmountTy(ShiftAmtTy);
752 SDValue ShiftAmt = TLO.DAG.getConstant(BitWidth - ShAmt, ShiftAmtTy);
753 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, dl,
754 Op.getValueType(), InOp, ShiftAmt));
757 // Sign extension. Compute the demanded bits in the result that are not
758 // present in the input.
760 APInt::getHighBitsSet(BitWidth,
761 BitWidth - ExVT.getScalarType().getSizeInBits());
763 // If none of the extended bits are demanded, eliminate the sextinreg.
764 if ((NewBits & NewMask) == 0)
765 return TLO.CombineTo(Op, Op.getOperand(0));
768 APInt::getSignBit(ExVT.getScalarType().getSizeInBits()).zext(BitWidth);
769 APInt InputDemandedBits =
770 APInt::getLowBitsSet(BitWidth,
771 ExVT.getScalarType().getSizeInBits()) &
774 // Since the sign extended bits are demanded, we know that the sign
776 InputDemandedBits |= InSignBit;
778 if (SimplifyDemandedBits(Op.getOperand(0), InputDemandedBits,
779 KnownZero, KnownOne, TLO, Depth+1))
781 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
783 // If the sign bit of the input is known set or clear, then we know the
784 // top bits of the result.
786 // If the input sign bit is known zero, convert this into a zero extension.
787 if (KnownZero.intersects(InSignBit))
788 return TLO.CombineTo(Op,
789 TLO.DAG.getZeroExtendInReg(Op.getOperand(0),dl,ExVT));
791 if (KnownOne.intersects(InSignBit)) { // Input sign bit known set
793 KnownZero &= ~NewBits;
794 } else { // Input sign bit unknown
795 KnownZero &= ~NewBits;
796 KnownOne &= ~NewBits;
800 case ISD::ZERO_EXTEND: {
801 unsigned OperandBitWidth =
802 Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
803 APInt InMask = NewMask.trunc(OperandBitWidth);
805 // If none of the top bits are demanded, convert this into an any_extend.
807 APInt::getHighBitsSet(BitWidth, BitWidth - OperandBitWidth) & NewMask;
808 if (!NewBits.intersects(NewMask))
809 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
813 if (SimplifyDemandedBits(Op.getOperand(0), InMask,
814 KnownZero, KnownOne, TLO, Depth+1))
816 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
817 KnownZero = KnownZero.zext(BitWidth);
818 KnownOne = KnownOne.zext(BitWidth);
819 KnownZero |= NewBits;
822 case ISD::SIGN_EXTEND: {
823 EVT InVT = Op.getOperand(0).getValueType();
824 unsigned InBits = InVT.getScalarType().getSizeInBits();
825 APInt InMask = APInt::getLowBitsSet(BitWidth, InBits);
826 APInt InSignBit = APInt::getBitsSet(BitWidth, InBits - 1, InBits);
827 APInt NewBits = ~InMask & NewMask;
829 // If none of the top bits are demanded, convert this into an any_extend.
831 return TLO.CombineTo(Op,TLO.DAG.getNode(ISD::ANY_EXTEND, dl,
835 // Since some of the sign extended bits are demanded, we know that the sign
837 APInt InDemandedBits = InMask & NewMask;
838 InDemandedBits |= InSignBit;
839 InDemandedBits = InDemandedBits.trunc(InBits);
841 if (SimplifyDemandedBits(Op.getOperand(0), InDemandedBits, KnownZero,
842 KnownOne, TLO, Depth+1))
844 KnownZero = KnownZero.zext(BitWidth);
845 KnownOne = KnownOne.zext(BitWidth);
847 // If the sign bit is known zero, convert this to a zero extend.
848 if (KnownZero.intersects(InSignBit))
849 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::ZERO_EXTEND, dl,
853 // If the sign bit is known one, the top bits match.
854 if (KnownOne.intersects(InSignBit)) {
856 assert((KnownZero & NewBits) == 0);
857 } else { // Otherwise, top bits aren't known.
858 assert((KnownOne & NewBits) == 0);
859 assert((KnownZero & NewBits) == 0);
863 case ISD::ANY_EXTEND: {
864 unsigned OperandBitWidth =
865 Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
866 APInt InMask = NewMask.trunc(OperandBitWidth);
867 if (SimplifyDemandedBits(Op.getOperand(0), InMask,
868 KnownZero, KnownOne, TLO, Depth+1))
870 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
871 KnownZero = KnownZero.zext(BitWidth);
872 KnownOne = KnownOne.zext(BitWidth);
875 case ISD::TRUNCATE: {
876 // Simplify the input, using demanded bit information, and compute the known
877 // zero/one bits live out.
878 unsigned OperandBitWidth =
879 Op.getOperand(0).getValueType().getScalarType().getSizeInBits();
880 APInt TruncMask = NewMask.zext(OperandBitWidth);
881 if (SimplifyDemandedBits(Op.getOperand(0), TruncMask,
882 KnownZero, KnownOne, TLO, Depth+1))
884 KnownZero = KnownZero.trunc(BitWidth);
885 KnownOne = KnownOne.trunc(BitWidth);
887 // If the input is only used by this truncate, see if we can shrink it based
888 // on the known demanded bits.
889 if (Op.getOperand(0).getNode()->hasOneUse()) {
890 SDValue In = Op.getOperand(0);
891 switch (In.getOpcode()) {
894 // Shrink SRL by a constant if none of the high bits shifted in are
896 if (TLO.LegalTypes() &&
897 !isTypeDesirableForOp(ISD::SRL, Op.getValueType()))
898 // Do not turn (vt1 truncate (vt2 srl)) into (vt1 srl) if vt1 is
901 ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(In.getOperand(1));
904 SDValue Shift = In.getOperand(1);
905 if (TLO.LegalTypes()) {
906 uint64_t ShVal = ShAmt->getZExtValue();
908 TLO.DAG.getConstant(ShVal, getShiftAmountTy(Op.getValueType()));
911 APInt HighBits = APInt::getHighBitsSet(OperandBitWidth,
912 OperandBitWidth - BitWidth);
913 HighBits = HighBits.lshr(ShAmt->getZExtValue()).trunc(BitWidth);
915 if (ShAmt->getZExtValue() < BitWidth && !(HighBits & NewMask)) {
916 // None of the shifted in bits are needed. Add a truncate of the
917 // shift input, then shift it.
918 SDValue NewTrunc = TLO.DAG.getNode(ISD::TRUNCATE, dl,
921 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SRL, dl,
930 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
933 case ISD::AssertZext: {
934 // AssertZext demands all of the high bits, plus any of the low bits
935 // demanded by its users.
936 EVT VT = cast<VTSDNode>(Op.getOperand(1))->getVT();
937 APInt InMask = APInt::getLowBitsSet(BitWidth,
939 if (SimplifyDemandedBits(Op.getOperand(0), ~InMask | NewMask,
940 KnownZero, KnownOne, TLO, Depth+1))
942 assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
944 KnownZero |= ~InMask & NewMask;
948 // If this is an FP->Int bitcast and if the sign bit is the only
949 // thing demanded, turn this into a FGETSIGN.
950 if (!TLO.LegalOperations() &&
951 !Op.getValueType().isVector() &&
952 !Op.getOperand(0).getValueType().isVector() &&
953 NewMask == APInt::getSignBit(Op.getValueType().getSizeInBits()) &&
954 Op.getOperand(0).getValueType().isFloatingPoint()) {
955 bool OpVTLegal = isOperationLegalOrCustom(ISD::FGETSIGN, Op.getValueType());
956 bool i32Legal = isOperationLegalOrCustom(ISD::FGETSIGN, MVT::i32);
957 if ((OpVTLegal || i32Legal) && Op.getValueType().isSimple()) {
958 EVT Ty = OpVTLegal ? Op.getValueType() : MVT::i32;
959 // Make a FGETSIGN + SHL to move the sign bit into the appropriate
960 // place. We expect the SHL to be eliminated by other optimizations.
961 SDValue Sign = TLO.DAG.getNode(ISD::FGETSIGN, dl, Ty, Op.getOperand(0));
962 unsigned OpVTSizeInBits = Op.getValueType().getSizeInBits();
963 if (!OpVTLegal && OpVTSizeInBits > 32)
964 Sign = TLO.DAG.getNode(ISD::ZERO_EXTEND, dl, Op.getValueType(), Sign);
965 unsigned ShVal = Op.getValueType().getSizeInBits()-1;
966 SDValue ShAmt = TLO.DAG.getConstant(ShVal, Op.getValueType());
967 return TLO.CombineTo(Op, TLO.DAG.getNode(ISD::SHL, dl,
976 // Add, Sub, and Mul don't demand any bits in positions beyond that
977 // of the highest bit demanded of them.
978 APInt LoMask = APInt::getLowBitsSet(BitWidth,
979 BitWidth - NewMask.countLeadingZeros());
980 if (SimplifyDemandedBits(Op.getOperand(0), LoMask, KnownZero2,
981 KnownOne2, TLO, Depth+1))
983 if (SimplifyDemandedBits(Op.getOperand(1), LoMask, KnownZero2,
984 KnownOne2, TLO, Depth+1))
986 // See if the operation should be performed at a smaller bit width.
987 if (TLO.ShrinkDemandedOp(Op, BitWidth, NewMask, dl))
992 // Just use ComputeMaskedBits to compute output bits.
993 TLO.DAG.ComputeMaskedBits(Op, KnownZero, KnownOne, Depth);
997 // If we know the value of all of the demanded bits, return this as a
999 if ((NewMask & (KnownZero|KnownOne)) == NewMask)
1000 return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
1005 /// computeMaskedBitsForTargetNode - Determine which of the bits specified
1006 /// in Mask are known to be either zero or one and return them in the
1007 /// KnownZero/KnownOne bitsets.
1008 void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
1011 const SelectionDAG &DAG,
1012 unsigned Depth) const {
1013 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
1014 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
1015 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
1016 Op.getOpcode() == ISD::INTRINSIC_VOID) &&
1017 "Should use MaskedValueIsZero if you don't know whether Op"
1018 " is a target node!");
1019 KnownZero = KnownOne = APInt(KnownOne.getBitWidth(), 0);
1022 /// ComputeNumSignBitsForTargetNode - This method can be implemented by
1023 /// targets that want to expose additional information about sign bits to the
1025 unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op,
1026 unsigned Depth) const {
1027 assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
1028 Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||
1029 Op.getOpcode() == ISD::INTRINSIC_W_CHAIN ||
1030 Op.getOpcode() == ISD::INTRINSIC_VOID) &&
1031 "Should use ComputeNumSignBits if you don't know whether Op"
1032 " is a target node!");
1036 /// ValueHasExactlyOneBitSet - Test if the given value is known to have exactly
1037 /// one bit set. This differs from ComputeMaskedBits in that it doesn't need to
1038 /// determine which bit is set.
1040 static bool ValueHasExactlyOneBitSet(SDValue Val, const SelectionDAG &DAG) {
1041 // A left-shift of a constant one will have exactly one bit set, because
1042 // shifting the bit off the end is undefined.
1043 if (Val.getOpcode() == ISD::SHL)
1044 if (ConstantSDNode *C =
1045 dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
1046 if (C->getAPIntValue() == 1)
1049 // Similarly, a right-shift of a constant sign-bit will have exactly
1051 if (Val.getOpcode() == ISD::SRL)
1052 if (ConstantSDNode *C =
1053 dyn_cast<ConstantSDNode>(Val.getNode()->getOperand(0)))
1054 if (C->getAPIntValue().isSignBit())
1057 // More could be done here, though the above checks are enough
1058 // to handle some common cases.
1060 // Fall back to ComputeMaskedBits to catch other known cases.
1061 EVT OpVT = Val.getValueType();
1062 unsigned BitWidth = OpVT.getScalarType().getSizeInBits();
1063 APInt KnownZero, KnownOne;
1064 DAG.ComputeMaskedBits(Val, KnownZero, KnownOne);
1065 return (KnownZero.countPopulation() == BitWidth - 1) &&
1066 (KnownOne.countPopulation() == 1);
1069 /// SimplifySetCC - Try to simplify a setcc built with the specified operands
1070 /// and cc. If it is unable to simplify it, return a null SDValue.
1072 TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
1073 ISD::CondCode Cond, bool foldBooleans,
1074 DAGCombinerInfo &DCI, SDLoc dl) const {
1075 SelectionDAG &DAG = DCI.DAG;
1077 // These setcc operations always fold.
1081 case ISD::SETFALSE2: return DAG.getConstant(0, VT);
1083 case ISD::SETTRUE2: {
1084 TargetLowering::BooleanContent Cnt = getBooleanContents(VT.isVector());
1085 return DAG.getConstant(
1086 Cnt == TargetLowering::ZeroOrNegativeOneBooleanContent ? -1ULL : 1, VT);
1090 // Ensure that the constant occurs on the RHS, and fold constant
1092 if (isa<ConstantSDNode>(N0.getNode()))
1093 return DAG.getSetCC(dl, VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
1095 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode())) {
1096 const APInt &C1 = N1C->getAPIntValue();
1098 // If the LHS is '(srl (ctlz x), 5)', the RHS is 0/1, and this is an
1099 // equality comparison, then we're just comparing whether X itself is
1101 if (N0.getOpcode() == ISD::SRL && (C1 == 0 || C1 == 1) &&
1102 N0.getOperand(0).getOpcode() == ISD::CTLZ &&
1103 N0.getOperand(1).getOpcode() == ISD::Constant) {
1105 = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
1106 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1107 ShAmt == Log2_32(N0.getValueType().getSizeInBits())) {
1108 if ((C1 == 0) == (Cond == ISD::SETEQ)) {
1109 // (srl (ctlz x), 5) == 0 -> X != 0
1110 // (srl (ctlz x), 5) != 1 -> X != 0
1113 // (srl (ctlz x), 5) != 0 -> X == 0
1114 // (srl (ctlz x), 5) == 1 -> X == 0
1117 SDValue Zero = DAG.getConstant(0, N0.getValueType());
1118 return DAG.getSetCC(dl, VT, N0.getOperand(0).getOperand(0),
1124 // Look through truncs that don't change the value of a ctpop.
1125 if (N0.hasOneUse() && N0.getOpcode() == ISD::TRUNCATE)
1126 CTPOP = N0.getOperand(0);
1128 if (CTPOP.hasOneUse() && CTPOP.getOpcode() == ISD::CTPOP &&
1129 (N0 == CTPOP || N0.getValueType().getSizeInBits() >
1130 Log2_32_Ceil(CTPOP.getValueType().getSizeInBits()))) {
1131 EVT CTVT = CTPOP.getValueType();
1132 SDValue CTOp = CTPOP.getOperand(0);
1134 // (ctpop x) u< 2 -> (x & x-1) == 0
1135 // (ctpop x) u> 1 -> (x & x-1) != 0
1136 if ((Cond == ISD::SETULT && C1 == 2) || (Cond == ISD::SETUGT && C1 == 1)){
1137 SDValue Sub = DAG.getNode(ISD::SUB, dl, CTVT, CTOp,
1138 DAG.getConstant(1, CTVT));
1139 SDValue And = DAG.getNode(ISD::AND, dl, CTVT, CTOp, Sub);
1140 ISD::CondCode CC = Cond == ISD::SETULT ? ISD::SETEQ : ISD::SETNE;
1141 return DAG.getSetCC(dl, VT, And, DAG.getConstant(0, CTVT), CC);
1144 // TODO: (ctpop x) == 1 -> x && (x & x-1) == 0 iff ctpop is illegal.
1147 // (zext x) == C --> x == (trunc C)
1148 if (DCI.isBeforeLegalize() && N0->hasOneUse() &&
1149 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
1150 unsigned MinBits = N0.getValueSizeInBits();
1152 if (N0->getOpcode() == ISD::ZERO_EXTEND) {
1154 MinBits = N0->getOperand(0).getValueSizeInBits();
1155 PreZExt = N0->getOperand(0);
1156 } else if (N0->getOpcode() == ISD::AND) {
1157 // DAGCombine turns costly ZExts into ANDs
1158 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0->getOperand(1)))
1159 if ((C->getAPIntValue()+1).isPowerOf2()) {
1160 MinBits = C->getAPIntValue().countTrailingOnes();
1161 PreZExt = N0->getOperand(0);
1163 } else if (LoadSDNode *LN0 = dyn_cast<LoadSDNode>(N0)) {
1165 if (LN0->getExtensionType() == ISD::ZEXTLOAD) {
1166 MinBits = LN0->getMemoryVT().getSizeInBits();
1171 // Make sure we're not losing bits from the constant.
1173 MinBits < C1.getBitWidth() && MinBits >= C1.getActiveBits()) {
1174 EVT MinVT = EVT::getIntegerVT(*DAG.getContext(), MinBits);
1175 if (isTypeDesirableForOp(ISD::SETCC, MinVT)) {
1176 // Will get folded away.
1177 SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, MinVT, PreZExt);
1178 SDValue C = DAG.getConstant(C1.trunc(MinBits), MinVT);
1179 return DAG.getSetCC(dl, VT, Trunc, C, Cond);
1184 // If the LHS is '(and load, const)', the RHS is 0,
1185 // the test is for equality or unsigned, and all 1 bits of the const are
1186 // in the same partial word, see if we can shorten the load.
1187 if (DCI.isBeforeLegalize() &&
1188 N0.getOpcode() == ISD::AND && C1 == 0 &&
1189 N0.getNode()->hasOneUse() &&
1190 isa<LoadSDNode>(N0.getOperand(0)) &&
1191 N0.getOperand(0).getNode()->hasOneUse() &&
1192 isa<ConstantSDNode>(N0.getOperand(1))) {
1193 LoadSDNode *Lod = cast<LoadSDNode>(N0.getOperand(0));
1195 unsigned bestWidth = 0, bestOffset = 0;
1196 if (!Lod->isVolatile() && Lod->isUnindexed()) {
1197 unsigned origWidth = N0.getValueType().getSizeInBits();
1198 unsigned maskWidth = origWidth;
1199 // We can narrow (e.g.) 16-bit extending loads on 32-bit target to
1200 // 8 bits, but have to be careful...
1201 if (Lod->getExtensionType() != ISD::NON_EXTLOAD)
1202 origWidth = Lod->getMemoryVT().getSizeInBits();
1204 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
1205 for (unsigned width = origWidth / 2; width>=8; width /= 2) {
1206 APInt newMask = APInt::getLowBitsSet(maskWidth, width);
1207 for (unsigned offset=0; offset<origWidth/width; offset++) {
1208 if ((newMask & Mask) == Mask) {
1209 if (!getDataLayout()->isLittleEndian())
1210 bestOffset = (origWidth/width - offset - 1) * (width/8);
1212 bestOffset = (uint64_t)offset * (width/8);
1213 bestMask = Mask.lshr(offset * (width/8) * 8);
1217 newMask = newMask << width;
1222 EVT newVT = EVT::getIntegerVT(*DAG.getContext(), bestWidth);
1223 if (newVT.isRound()) {
1224 EVT PtrType = Lod->getOperand(1).getValueType();
1225 SDValue Ptr = Lod->getBasePtr();
1226 if (bestOffset != 0)
1227 Ptr = DAG.getNode(ISD::ADD, dl, PtrType, Lod->getBasePtr(),
1228 DAG.getConstant(bestOffset, PtrType));
1229 unsigned NewAlign = MinAlign(Lod->getAlignment(), bestOffset);
1230 SDValue NewLoad = DAG.getLoad(newVT, dl, Lod->getChain(), Ptr,
1231 Lod->getPointerInfo().getWithOffset(bestOffset),
1232 false, false, false, NewAlign);
1233 return DAG.getSetCC(dl, VT,
1234 DAG.getNode(ISD::AND, dl, newVT, NewLoad,
1235 DAG.getConstant(bestMask.trunc(bestWidth),
1237 DAG.getConstant(0LL, newVT), Cond);
1242 // If the LHS is a ZERO_EXTEND, perform the comparison on the input.
1243 if (N0.getOpcode() == ISD::ZERO_EXTEND) {
1244 unsigned InSize = N0.getOperand(0).getValueType().getSizeInBits();
1246 // If the comparison constant has bits in the upper part, the
1247 // zero-extended value could never match.
1248 if (C1.intersects(APInt::getHighBitsSet(C1.getBitWidth(),
1249 C1.getBitWidth() - InSize))) {
1253 case ISD::SETEQ: return DAG.getConstant(0, VT);
1256 case ISD::SETNE: return DAG.getConstant(1, VT);
1259 // True if the sign bit of C1 is set.
1260 return DAG.getConstant(C1.isNegative(), VT);
1263 // True if the sign bit of C1 isn't set.
1264 return DAG.getConstant(C1.isNonNegative(), VT);
1270 // Otherwise, we can perform the comparison with the low bits.
1278 EVT newVT = N0.getOperand(0).getValueType();
1279 if (DCI.isBeforeLegalizeOps() ||
1280 (isOperationLegal(ISD::SETCC, newVT) &&
1281 getCondCodeAction(Cond, newVT.getSimpleVT())==Legal))
1282 return DAG.getSetCC(dl, VT, N0.getOperand(0),
1283 DAG.getConstant(C1.trunc(InSize), newVT),
1288 break; // todo, be more careful with signed comparisons
1290 } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
1291 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
1292 EVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
1293 unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits();
1294 EVT ExtDstTy = N0.getValueType();
1295 unsigned ExtDstTyBits = ExtDstTy.getSizeInBits();
1297 // If the constant doesn't fit into the number of bits for the source of
1298 // the sign extension, it is impossible for both sides to be equal.
1299 if (C1.getMinSignedBits() > ExtSrcTyBits)
1300 return DAG.getConstant(Cond == ISD::SETNE, VT);
1303 EVT Op0Ty = N0.getOperand(0).getValueType();
1304 if (Op0Ty == ExtSrcTy) {
1305 ZextOp = N0.getOperand(0);
1307 APInt Imm = APInt::getLowBitsSet(ExtDstTyBits, ExtSrcTyBits);
1308 ZextOp = DAG.getNode(ISD::AND, dl, Op0Ty, N0.getOperand(0),
1309 DAG.getConstant(Imm, Op0Ty));
1311 if (!DCI.isCalledByLegalizer())
1312 DCI.AddToWorklist(ZextOp.getNode());
1313 // Otherwise, make this a use of a zext.
1314 return DAG.getSetCC(dl, VT, ZextOp,
1315 DAG.getConstant(C1 & APInt::getLowBitsSet(
1320 } else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) &&
1321 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
1322 // SETCC (SETCC), [0|1], [EQ|NE] -> SETCC
1323 if (N0.getOpcode() == ISD::SETCC &&
1324 isTypeLegal(VT) && VT.bitsLE(N0.getValueType())) {
1325 bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getAPIntValue() != 1);
1327 return DAG.getNode(ISD::TRUNCATE, dl, VT, N0);
1328 // Invert the condition.
1329 ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
1330 CC = ISD::getSetCCInverse(CC,
1331 N0.getOperand(0).getValueType().isInteger());
1332 return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
1335 if ((N0.getOpcode() == ISD::XOR ||
1336 (N0.getOpcode() == ISD::AND &&
1337 N0.getOperand(0).getOpcode() == ISD::XOR &&
1338 N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
1339 isa<ConstantSDNode>(N0.getOperand(1)) &&
1340 cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue() == 1) {
1341 // If this is (X^1) == 0/1, swap the RHS and eliminate the xor. We
1342 // can only do this if the top bits are known zero.
1343 unsigned BitWidth = N0.getValueSizeInBits();
1344 if (DAG.MaskedValueIsZero(N0,
1345 APInt::getHighBitsSet(BitWidth,
1347 // Okay, get the un-inverted input value.
1349 if (N0.getOpcode() == ISD::XOR)
1350 Val = N0.getOperand(0);
1352 assert(N0.getOpcode() == ISD::AND &&
1353 N0.getOperand(0).getOpcode() == ISD::XOR);
1354 // ((X^1)&1)^1 -> X & 1
1355 Val = DAG.getNode(ISD::AND, dl, N0.getValueType(),
1356 N0.getOperand(0).getOperand(0),
1360 return DAG.getSetCC(dl, VT, Val, N1,
1361 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
1363 } else if (N1C->getAPIntValue() == 1 &&
1365 getBooleanContents(false) == ZeroOrOneBooleanContent)) {
1367 if (Op0.getOpcode() == ISD::TRUNCATE)
1368 Op0 = Op0.getOperand(0);
1370 if ((Op0.getOpcode() == ISD::XOR) &&
1371 Op0.getOperand(0).getOpcode() == ISD::SETCC &&
1372 Op0.getOperand(1).getOpcode() == ISD::SETCC) {
1373 // (xor (setcc), (setcc)) == / != 1 -> (setcc) != / == (setcc)
1374 Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ;
1375 return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1),
1378 if (Op0.getOpcode() == ISD::AND &&
1379 isa<ConstantSDNode>(Op0.getOperand(1)) &&
1380 cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
1381 // If this is (X&1) == / != 1, normalize it to (X&1) != / == 0.
1382 if (Op0.getValueType().bitsGT(VT))
1383 Op0 = DAG.getNode(ISD::AND, dl, VT,
1384 DAG.getNode(ISD::TRUNCATE, dl, VT, Op0.getOperand(0)),
1385 DAG.getConstant(1, VT));
1386 else if (Op0.getValueType().bitsLT(VT))
1387 Op0 = DAG.getNode(ISD::AND, dl, VT,
1388 DAG.getNode(ISD::ANY_EXTEND, dl, VT, Op0.getOperand(0)),
1389 DAG.getConstant(1, VT));
1391 return DAG.getSetCC(dl, VT, Op0,
1392 DAG.getConstant(0, Op0.getValueType()),
1393 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
1395 if (Op0.getOpcode() == ISD::AssertZext &&
1396 cast<VTSDNode>(Op0.getOperand(1))->getVT() == MVT::i1)
1397 return DAG.getSetCC(dl, VT, Op0,
1398 DAG.getConstant(0, Op0.getValueType()),
1399 Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
1403 APInt MinVal, MaxVal;
1404 unsigned OperandBitSize = N1C->getValueType(0).getSizeInBits();
1405 if (ISD::isSignedIntSetCC(Cond)) {
1406 MinVal = APInt::getSignedMinValue(OperandBitSize);
1407 MaxVal = APInt::getSignedMaxValue(OperandBitSize);
1409 MinVal = APInt::getMinValue(OperandBitSize);
1410 MaxVal = APInt::getMaxValue(OperandBitSize);
1413 // Canonicalize GE/LE comparisons to use GT/LT comparisons.
1414 if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
1415 if (C1 == MinVal) return DAG.getConstant(1, VT); // X >= MIN --> true
1416 // X >= C0 --> X > (C0-1)
1417 return DAG.getSetCC(dl, VT, N0,
1418 DAG.getConstant(C1-1, N1.getValueType()),
1419 (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT);
1422 if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
1423 if (C1 == MaxVal) return DAG.getConstant(1, VT); // X <= MAX --> true
1424 // X <= C0 --> X < (C0+1)
1425 return DAG.getSetCC(dl, VT, N0,
1426 DAG.getConstant(C1+1, N1.getValueType()),
1427 (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT);
1430 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal)
1431 return DAG.getConstant(0, VT); // X < MIN --> false
1432 if ((Cond == ISD::SETGE || Cond == ISD::SETUGE) && C1 == MinVal)
1433 return DAG.getConstant(1, VT); // X >= MIN --> true
1434 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal)
1435 return DAG.getConstant(0, VT); // X > MAX --> false
1436 if ((Cond == ISD::SETLE || Cond == ISD::SETULE) && C1 == MaxVal)
1437 return DAG.getConstant(1, VT); // X <= MAX --> true
1439 // Canonicalize setgt X, Min --> setne X, Min
1440 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MinVal)
1441 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
1442 // Canonicalize setlt X, Max --> setne X, Max
1443 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MaxVal)
1444 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETNE);
1446 // If we have setult X, 1, turn it into seteq X, 0
1447 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C1 == MinVal+1)
1448 return DAG.getSetCC(dl, VT, N0,
1449 DAG.getConstant(MinVal, N0.getValueType()),
1451 // If we have setugt X, Max-1, turn it into seteq X, Max
1452 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C1 == MaxVal-1)
1453 return DAG.getSetCC(dl, VT, N0,
1454 DAG.getConstant(MaxVal, N0.getValueType()),
1457 // If we have "setcc X, C0", check to see if we can shrink the immediate
1460 // SETUGT X, SINTMAX -> SETLT X, 0
1461 if (Cond == ISD::SETUGT &&
1462 C1 == APInt::getSignedMaxValue(OperandBitSize))
1463 return DAG.getSetCC(dl, VT, N0,
1464 DAG.getConstant(0, N1.getValueType()),
1467 // SETULT X, SINTMIN -> SETGT X, -1
1468 if (Cond == ISD::SETULT &&
1469 C1 == APInt::getSignedMinValue(OperandBitSize)) {
1470 SDValue ConstMinusOne =
1471 DAG.getConstant(APInt::getAllOnesValue(OperandBitSize),
1473 return DAG.getSetCC(dl, VT, N0, ConstMinusOne, ISD::SETGT);
1476 // Fold bit comparisons when we can.
1477 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1478 (VT == N0.getValueType() ||
1479 (isTypeLegal(VT) && VT.bitsLE(N0.getValueType()))) &&
1480 N0.getOpcode() == ISD::AND)
1481 if (ConstantSDNode *AndRHS =
1482 dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1483 EVT ShiftTy = DCI.isBeforeLegalizeOps() ?
1484 getPointerTy() : getShiftAmountTy(N0.getValueType());
1485 if (Cond == ISD::SETNE && C1 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
1486 // Perform the xform if the AND RHS is a single bit.
1487 if (AndRHS->getAPIntValue().isPowerOf2()) {
1488 return DAG.getNode(ISD::TRUNCATE, dl, VT,
1489 DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0,
1490 DAG.getConstant(AndRHS->getAPIntValue().logBase2(), ShiftTy)));
1492 } else if (Cond == ISD::SETEQ && C1 == AndRHS->getAPIntValue()) {
1493 // (X & 8) == 8 --> (X & 8) >> 3
1494 // Perform the xform if C1 is a single bit.
1495 if (C1.isPowerOf2()) {
1496 return DAG.getNode(ISD::TRUNCATE, dl, VT,
1497 DAG.getNode(ISD::SRL, dl, N0.getValueType(), N0,
1498 DAG.getConstant(C1.logBase2(), ShiftTy)));
1503 if (C1.getMinSignedBits() <= 64 &&
1504 !isLegalICmpImmediate(C1.getSExtValue())) {
1505 // (X & -256) == 256 -> (X >> 8) == 1
1506 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1507 N0.getOpcode() == ISD::AND && N0.hasOneUse()) {
1508 if (ConstantSDNode *AndRHS =
1509 dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1510 const APInt &AndRHSC = AndRHS->getAPIntValue();
1511 if ((-AndRHSC).isPowerOf2() && (AndRHSC & C1) == C1) {
1512 unsigned ShiftBits = AndRHSC.countTrailingZeros();
1513 EVT ShiftTy = DCI.isBeforeLegalizeOps() ?
1514 getPointerTy() : getShiftAmountTy(N0.getValueType());
1515 EVT CmpTy = N0.getValueType();
1516 SDValue Shift = DAG.getNode(ISD::SRL, dl, CmpTy, N0.getOperand(0),
1517 DAG.getConstant(ShiftBits, ShiftTy));
1518 SDValue CmpRHS = DAG.getConstant(C1.lshr(ShiftBits), CmpTy);
1519 return DAG.getSetCC(dl, VT, Shift, CmpRHS, Cond);
1522 } else if (Cond == ISD::SETULT || Cond == ISD::SETUGE ||
1523 Cond == ISD::SETULE || Cond == ISD::SETUGT) {
1524 bool AdjOne = (Cond == ISD::SETULE || Cond == ISD::SETUGT);
1525 // X < 0x100000000 -> (X >> 32) < 1
1526 // X >= 0x100000000 -> (X >> 32) >= 1
1527 // X <= 0x0ffffffff -> (X >> 32) < 1
1528 // X > 0x0ffffffff -> (X >> 32) >= 1
1531 ISD::CondCode NewCond = Cond;
1533 ShiftBits = C1.countTrailingOnes();
1535 NewCond = (Cond == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
1537 ShiftBits = C1.countTrailingZeros();
1539 NewC = NewC.lshr(ShiftBits);
1540 if (ShiftBits && isLegalICmpImmediate(NewC.getSExtValue())) {
1541 EVT ShiftTy = DCI.isBeforeLegalizeOps() ?
1542 getPointerTy() : getShiftAmountTy(N0.getValueType());
1543 EVT CmpTy = N0.getValueType();
1544 SDValue Shift = DAG.getNode(ISD::SRL, dl, CmpTy, N0,
1545 DAG.getConstant(ShiftBits, ShiftTy));
1546 SDValue CmpRHS = DAG.getConstant(NewC, CmpTy);
1547 return DAG.getSetCC(dl, VT, Shift, CmpRHS, NewCond);
1553 if (isa<ConstantFPSDNode>(N0.getNode())) {
1554 // Constant fold or commute setcc.
1555 SDValue O = DAG.FoldSetCC(VT, N0, N1, Cond, dl);
1556 if (O.getNode()) return O;
1557 } else if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1.getNode())) {
1558 // If the RHS of an FP comparison is a constant, simplify it away in
1560 if (CFP->getValueAPF().isNaN()) {
1561 // If an operand is known to be a nan, we can fold it.
1562 switch (ISD::getUnorderedFlavor(Cond)) {
1563 default: llvm_unreachable("Unknown flavor!");
1564 case 0: // Known false.
1565 return DAG.getConstant(0, VT);
1566 case 1: // Known true.
1567 return DAG.getConstant(1, VT);
1568 case 2: // Undefined.
1569 return DAG.getUNDEF(VT);
1573 // Otherwise, we know the RHS is not a NaN. Simplify the node to drop the
1574 // constant if knowing that the operand is non-nan is enough. We prefer to
1575 // have SETO(x,x) instead of SETO(x, 0.0) because this avoids having to
1577 if (Cond == ISD::SETO || Cond == ISD::SETUO)
1578 return DAG.getSetCC(dl, VT, N0, N0, Cond);
1580 // If the condition is not legal, see if we can find an equivalent one
1582 if (!isCondCodeLegal(Cond, N0.getSimpleValueType())) {
1583 // If the comparison was an awkward floating-point == or != and one of
1584 // the comparison operands is infinity or negative infinity, convert the
1585 // condition to a less-awkward <= or >=.
1586 if (CFP->getValueAPF().isInfinity()) {
1587 if (CFP->getValueAPF().isNegative()) {
1588 if (Cond == ISD::SETOEQ &&
1589 isCondCodeLegal(ISD::SETOLE, N0.getSimpleValueType()))
1590 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLE);
1591 if (Cond == ISD::SETUEQ &&
1592 isCondCodeLegal(ISD::SETOLE, N0.getSimpleValueType()))
1593 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULE);
1594 if (Cond == ISD::SETUNE &&
1595 isCondCodeLegal(ISD::SETUGT, N0.getSimpleValueType()))
1596 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGT);
1597 if (Cond == ISD::SETONE &&
1598 isCondCodeLegal(ISD::SETUGT, N0.getSimpleValueType()))
1599 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGT);
1601 if (Cond == ISD::SETOEQ &&
1602 isCondCodeLegal(ISD::SETOGE, N0.getSimpleValueType()))
1603 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOGE);
1604 if (Cond == ISD::SETUEQ &&
1605 isCondCodeLegal(ISD::SETOGE, N0.getSimpleValueType()))
1606 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETUGE);
1607 if (Cond == ISD::SETUNE &&
1608 isCondCodeLegal(ISD::SETULT, N0.getSimpleValueType()))
1609 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETULT);
1610 if (Cond == ISD::SETONE &&
1611 isCondCodeLegal(ISD::SETULT, N0.getSimpleValueType()))
1612 return DAG.getSetCC(dl, VT, N0, N1, ISD::SETOLT);
1619 // The sext(setcc()) => setcc() optimization relies on the appropriate
1620 // constant being emitted.
1622 switch (getBooleanContents(N0.getValueType().isVector())) {
1623 case UndefinedBooleanContent:
1624 case ZeroOrOneBooleanContent:
1625 EqVal = ISD::isTrueWhenEqual(Cond);
1627 case ZeroOrNegativeOneBooleanContent:
1628 EqVal = ISD::isTrueWhenEqual(Cond) ? -1 : 0;
1632 // We can always fold X == X for integer setcc's.
1633 if (N0.getValueType().isInteger()) {
1634 return DAG.getConstant(EqVal, VT);
1636 unsigned UOF = ISD::getUnorderedFlavor(Cond);
1637 if (UOF == 2) // FP operators that are undefined on NaNs.
1638 return DAG.getConstant(EqVal, VT);
1639 if (UOF == unsigned(ISD::isTrueWhenEqual(Cond)))
1640 return DAG.getConstant(EqVal, VT);
1641 // Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
1642 // if it is not already.
1643 ISD::CondCode NewCond = UOF == 0 ? ISD::SETO : ISD::SETUO;
1644 if (NewCond != Cond && (DCI.isBeforeLegalizeOps() ||
1645 getCondCodeAction(NewCond, N0.getSimpleValueType()) == Legal))
1646 return DAG.getSetCC(dl, VT, N0, N1, NewCond);
1649 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
1650 N0.getValueType().isInteger()) {
1651 if (N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::SUB ||
1652 N0.getOpcode() == ISD::XOR) {
1653 // Simplify (X+Y) == (X+Z) --> Y == Z
1654 if (N0.getOpcode() == N1.getOpcode()) {
1655 if (N0.getOperand(0) == N1.getOperand(0))
1656 return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(1), Cond);
1657 if (N0.getOperand(1) == N1.getOperand(1))
1658 return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(0), Cond);
1659 if (DAG.isCommutativeBinOp(N0.getOpcode())) {
1660 // If X op Y == Y op X, try other combinations.
1661 if (N0.getOperand(0) == N1.getOperand(1))
1662 return DAG.getSetCC(dl, VT, N0.getOperand(1), N1.getOperand(0),
1664 if (N0.getOperand(1) == N1.getOperand(0))
1665 return DAG.getSetCC(dl, VT, N0.getOperand(0), N1.getOperand(1),
1670 // If RHS is a legal immediate value for a compare instruction, we need
1671 // to be careful about increasing register pressure needlessly.
1672 bool LegalRHSImm = false;
1674 if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(N1)) {
1675 if (ConstantSDNode *LHSR = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
1676 // Turn (X+C1) == C2 --> X == C2-C1
1677 if (N0.getOpcode() == ISD::ADD && N0.getNode()->hasOneUse()) {
1678 return DAG.getSetCC(dl, VT, N0.getOperand(0),
1679 DAG.getConstant(RHSC->getAPIntValue()-
1680 LHSR->getAPIntValue(),
1681 N0.getValueType()), Cond);
1684 // Turn (X^C1) == C2 into X == C1^C2 iff X&~C1 = 0.
1685 if (N0.getOpcode() == ISD::XOR)
1686 // If we know that all of the inverted bits are zero, don't bother
1687 // performing the inversion.
1688 if (DAG.MaskedValueIsZero(N0.getOperand(0), ~LHSR->getAPIntValue()))
1690 DAG.getSetCC(dl, VT, N0.getOperand(0),
1691 DAG.getConstant(LHSR->getAPIntValue() ^
1692 RHSC->getAPIntValue(),
1697 // Turn (C1-X) == C2 --> X == C1-C2
1698 if (ConstantSDNode *SUBC = dyn_cast<ConstantSDNode>(N0.getOperand(0))) {
1699 if (N0.getOpcode() == ISD::SUB && N0.getNode()->hasOneUse()) {
1701 DAG.getSetCC(dl, VT, N0.getOperand(1),
1702 DAG.getConstant(SUBC->getAPIntValue() -
1703 RHSC->getAPIntValue(),
1709 // Could RHSC fold directly into a compare?
1710 if (RHSC->getValueType(0).getSizeInBits() <= 64)
1711 LegalRHSImm = isLegalICmpImmediate(RHSC->getSExtValue());
1714 // Simplify (X+Z) == X --> Z == 0
1715 // Don't do this if X is an immediate that can fold into a cmp
1716 // instruction and X+Z has other uses. It could be an induction variable
1717 // chain, and the transform would increase register pressure.
1718 if (!LegalRHSImm || N0.getNode()->hasOneUse()) {
1719 if (N0.getOperand(0) == N1)
1720 return DAG.getSetCC(dl, VT, N0.getOperand(1),
1721 DAG.getConstant(0, N0.getValueType()), Cond);
1722 if (N0.getOperand(1) == N1) {
1723 if (DAG.isCommutativeBinOp(N0.getOpcode()))
1724 return DAG.getSetCC(dl, VT, N0.getOperand(0),
1725 DAG.getConstant(0, N0.getValueType()), Cond);
1726 if (N0.getNode()->hasOneUse()) {
1727 assert(N0.getOpcode() == ISD::SUB && "Unexpected operation!");
1728 // (Z-X) == X --> Z == X<<1
1729 SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N1,
1730 DAG.getConstant(1, getShiftAmountTy(N1.getValueType())));
1731 if (!DCI.isCalledByLegalizer())
1732 DCI.AddToWorklist(SH.getNode());
1733 return DAG.getSetCC(dl, VT, N0.getOperand(0), SH, Cond);
1739 if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
1740 N1.getOpcode() == ISD::XOR) {
1741 // Simplify X == (X+Z) --> Z == 0
1742 if (N1.getOperand(0) == N0)
1743 return DAG.getSetCC(dl, VT, N1.getOperand(1),
1744 DAG.getConstant(0, N1.getValueType()), Cond);
1745 if (N1.getOperand(1) == N0) {
1746 if (DAG.isCommutativeBinOp(N1.getOpcode()))
1747 return DAG.getSetCC(dl, VT, N1.getOperand(0),
1748 DAG.getConstant(0, N1.getValueType()), Cond);
1749 if (N1.getNode()->hasOneUse()) {
1750 assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
1751 // X == (Z-X) --> X<<1 == Z
1752 SDValue SH = DAG.getNode(ISD::SHL, dl, N1.getValueType(), N0,
1753 DAG.getConstant(1, getShiftAmountTy(N0.getValueType())));
1754 if (!DCI.isCalledByLegalizer())
1755 DCI.AddToWorklist(SH.getNode());
1756 return DAG.getSetCC(dl, VT, SH, N1.getOperand(0), Cond);
1761 // Simplify x&y == y to x&y != 0 if y has exactly one bit set.
1762 // Note that where y is variable and is known to have at most
1763 // one bit set (for example, if it is z&1) we cannot do this;
1764 // the expressions are not equivalent when y==0.
1765 if (N0.getOpcode() == ISD::AND)
1766 if (N0.getOperand(0) == N1 || N0.getOperand(1) == N1) {
1767 if (ValueHasExactlyOneBitSet(N1, DAG)) {
1768 Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
1769 SDValue Zero = DAG.getConstant(0, N1.getValueType());
1770 return DAG.getSetCC(dl, VT, N0, Zero, Cond);
1773 if (N1.getOpcode() == ISD::AND)
1774 if (N1.getOperand(0) == N0 || N1.getOperand(1) == N0) {
1775 if (ValueHasExactlyOneBitSet(N0, DAG)) {
1776 Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
1777 SDValue Zero = DAG.getConstant(0, N0.getValueType());
1778 return DAG.getSetCC(dl, VT, N1, Zero, Cond);
1783 // Fold away ALL boolean setcc's.
1785 if (N0.getValueType() == MVT::i1 && foldBooleans) {
1787 default: llvm_unreachable("Unknown integer setcc!");
1788 case ISD::SETEQ: // X == Y -> ~(X^Y)
1789 Temp = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
1790 N0 = DAG.getNOT(dl, Temp, MVT::i1);
1791 if (!DCI.isCalledByLegalizer())
1792 DCI.AddToWorklist(Temp.getNode());
1794 case ISD::SETNE: // X != Y --> (X^Y)
1795 N0 = DAG.getNode(ISD::XOR, dl, MVT::i1, N0, N1);
1797 case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> ~X & Y
1798 case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> ~X & Y
1799 Temp = DAG.getNOT(dl, N0, MVT::i1);
1800 N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N1, Temp);
1801 if (!DCI.isCalledByLegalizer())
1802 DCI.AddToWorklist(Temp.getNode());
1804 case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> ~Y & X
1805 case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> ~Y & X
1806 Temp = DAG.getNOT(dl, N1, MVT::i1);
1807 N0 = DAG.getNode(ISD::AND, dl, MVT::i1, N0, Temp);
1808 if (!DCI.isCalledByLegalizer())
1809 DCI.AddToWorklist(Temp.getNode());
1811 case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> ~X | Y
1812 case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> ~X | Y
1813 Temp = DAG.getNOT(dl, N0, MVT::i1);
1814 N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N1, Temp);
1815 if (!DCI.isCalledByLegalizer())
1816 DCI.AddToWorklist(Temp.getNode());
1818 case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> ~Y | X
1819 case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> ~Y | X
1820 Temp = DAG.getNOT(dl, N1, MVT::i1);
1821 N0 = DAG.getNode(ISD::OR, dl, MVT::i1, N0, Temp);
1824 if (VT != MVT::i1) {
1825 if (!DCI.isCalledByLegalizer())
1826 DCI.AddToWorklist(N0.getNode());
1827 // FIXME: If running after legalize, we probably can't do this.
1828 N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0);
1833 // Could not fold it.
1837 /// isGAPlusOffset - Returns true (and the GlobalValue and the offset) if the
1838 /// node is a GlobalAddress + offset.
1839 bool TargetLowering::isGAPlusOffset(SDNode *N, const GlobalValue *&GA,
1840 int64_t &Offset) const {
1841 if (isa<GlobalAddressSDNode>(N)) {
1842 GlobalAddressSDNode *GASD = cast<GlobalAddressSDNode>(N);
1843 GA = GASD->getGlobal();
1844 Offset += GASD->getOffset();
1848 if (N->getOpcode() == ISD::ADD) {
1849 SDValue N1 = N->getOperand(0);
1850 SDValue N2 = N->getOperand(1);
1851 if (isGAPlusOffset(N1.getNode(), GA, Offset)) {
1852 ConstantSDNode *V = dyn_cast<ConstantSDNode>(N2);
1854 Offset += V->getSExtValue();
1857 } else if (isGAPlusOffset(N2.getNode(), GA, Offset)) {
1858 ConstantSDNode *V = dyn_cast<ConstantSDNode>(N1);
1860 Offset += V->getSExtValue();
1870 SDValue TargetLowering::
1871 PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const {
1872 // Default implementation: no optimization.
1876 //===----------------------------------------------------------------------===//
1877 // Inline Assembler Implementation Methods
1878 //===----------------------------------------------------------------------===//
1881 TargetLowering::ConstraintType
1882 TargetLowering::getConstraintType(const std::string &Constraint) const {
1883 unsigned S = Constraint.size();
1886 switch (Constraint[0]) {
1888 case 'r': return C_RegisterClass;
1890 case 'o': // offsetable
1891 case 'V': // not offsetable
1893 case 'i': // Simple Integer or Relocatable Constant
1894 case 'n': // Simple Integer
1895 case 'E': // Floating Point Constant
1896 case 'F': // Floating Point Constant
1897 case 's': // Relocatable Constant
1898 case 'p': // Address.
1899 case 'X': // Allow ANY value.
1900 case 'I': // Target registers.
1914 if (S > 1 && Constraint[0] == '{' && Constraint[S-1] == '}') {
1915 if (S == 8 && !Constraint.compare(1, 6, "memory", 6)) // "{memory}"
1922 /// LowerXConstraint - try to replace an X constraint, which matches anything,
1923 /// with another that has more specific requirements based on the type of the
1924 /// corresponding operand.
1925 const char *TargetLowering::LowerXConstraint(EVT ConstraintVT) const{
1926 if (ConstraintVT.isInteger())
1928 if (ConstraintVT.isFloatingPoint())
1929 return "f"; // works for many targets
1933 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
1934 /// vector. If it is invalid, don't add anything to Ops.
1935 void TargetLowering::LowerAsmOperandForConstraint(SDValue Op,
1936 std::string &Constraint,
1937 std::vector<SDValue> &Ops,
1938 SelectionDAG &DAG) const {
1940 if (Constraint.length() > 1) return;
1942 char ConstraintLetter = Constraint[0];
1943 switch (ConstraintLetter) {
1945 case 'X': // Allows any operand; labels (basic block) use this.
1946 if (Op.getOpcode() == ISD::BasicBlock) {
1951 case 'i': // Simple Integer or Relocatable Constant
1952 case 'n': // Simple Integer
1953 case 's': { // Relocatable Constant
1954 // These operands are interested in values of the form (GV+C), where C may
1955 // be folded in as an offset of GV, or it may be explicitly added. Also, it
1956 // is possible and fine if either GV or C are missing.
1957 ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
1958 GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op);
1960 // If we have "(add GV, C)", pull out GV/C
1961 if (Op.getOpcode() == ISD::ADD) {
1962 C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
1963 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(0));
1964 if (C == 0 || GA == 0) {
1965 C = dyn_cast<ConstantSDNode>(Op.getOperand(0));
1966 GA = dyn_cast<GlobalAddressSDNode>(Op.getOperand(1));
1968 if (C == 0 || GA == 0)
1972 // If we find a valid operand, map to the TargetXXX version so that the
1973 // value itself doesn't get selected.
1974 if (GA) { // Either &GV or &GV+C
1975 if (ConstraintLetter != 'n') {
1976 int64_t Offs = GA->getOffset();
1977 if (C) Offs += C->getZExtValue();
1978 Ops.push_back(DAG.getTargetGlobalAddress(GA->getGlobal(),
1979 C ? SDLoc(C) : SDLoc(),
1980 Op.getValueType(), Offs));
1984 if (C) { // just C, no GV.
1985 // Simple constants are not allowed for 's'.
1986 if (ConstraintLetter != 's') {
1987 // gcc prints these as sign extended. Sign extend value to 64 bits
1988 // now; without this it would get ZExt'd later in
1989 // ScheduleDAGSDNodes::EmitNode, which is very generic.
1990 Ops.push_back(DAG.getTargetConstant(C->getAPIntValue().getSExtValue(),
2000 std::pair<unsigned, const TargetRegisterClass*> TargetLowering::
2001 getRegForInlineAsmConstraint(const std::string &Constraint,
2003 if (Constraint[0] != '{')
2004 return std::make_pair(0u, static_cast<TargetRegisterClass*>(0));
2005 assert(*(Constraint.end()-1) == '}' && "Not a brace enclosed constraint?");
2007 // Remove the braces from around the name.
2008 StringRef RegName(Constraint.data()+1, Constraint.size()-2);
2010 std::pair<unsigned, const TargetRegisterClass*> R =
2011 std::make_pair(0u, static_cast<const TargetRegisterClass*>(0));
2013 // Figure out which register class contains this reg.
2014 const TargetRegisterInfo *RI = getTargetMachine().getRegisterInfo();
2015 for (TargetRegisterInfo::regclass_iterator RCI = RI->regclass_begin(),
2016 E = RI->regclass_end(); RCI != E; ++RCI) {
2017 const TargetRegisterClass *RC = *RCI;
2019 // If none of the value types for this register class are valid, we
2020 // can't use it. For example, 64-bit reg classes on 32-bit targets.
2024 for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
2026 if (RegName.equals_lower(RI->getName(*I))) {
2027 std::pair<unsigned, const TargetRegisterClass*> S =
2028 std::make_pair(*I, RC);
2030 // If this register class has the requested value type, return it,
2031 // otherwise keep searching and return the first class found
2032 // if no other is found which explicitly has the requested type.
2033 if (RC->hasType(VT))
2044 //===----------------------------------------------------------------------===//
2045 // Constraint Selection.
2047 /// isMatchingInputConstraint - Return true of this is an input operand that is
2048 /// a matching constraint like "4".
2049 bool TargetLowering::AsmOperandInfo::isMatchingInputConstraint() const {
2050 assert(!ConstraintCode.empty() && "No known constraint!");
2051 return isdigit(static_cast<unsigned char>(ConstraintCode[0]));
2054 /// getMatchedOperand - If this is an input matching constraint, this method
2055 /// returns the output operand it matches.
2056 unsigned TargetLowering::AsmOperandInfo::getMatchedOperand() const {
2057 assert(!ConstraintCode.empty() && "No known constraint!");
2058 return atoi(ConstraintCode.c_str());
2062 /// ParseConstraints - Split up the constraint string from the inline
2063 /// assembly value into the specific constraints and their prefixes,
2064 /// and also tie in the associated operand values.
2065 /// If this returns an empty vector, and if the constraint string itself
2066 /// isn't empty, there was an error parsing.
2067 TargetLowering::AsmOperandInfoVector TargetLowering::ParseConstraints(
2068 ImmutableCallSite CS) const {
2069 /// ConstraintOperands - Information about all of the constraints.
2070 AsmOperandInfoVector ConstraintOperands;
2071 const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
2072 unsigned maCount = 0; // Largest number of multiple alternative constraints.
2074 // Do a prepass over the constraints, canonicalizing them, and building up the
2075 // ConstraintOperands list.
2076 InlineAsm::ConstraintInfoVector
2077 ConstraintInfos = IA->ParseConstraints();
2079 unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
2080 unsigned ResNo = 0; // ResNo - The result number of the next output.
2082 for (unsigned i = 0, e = ConstraintInfos.size(); i != e; ++i) {
2083 ConstraintOperands.push_back(AsmOperandInfo(ConstraintInfos[i]));
2084 AsmOperandInfo &OpInfo = ConstraintOperands.back();
2086 // Update multiple alternative constraint count.
2087 if (OpInfo.multipleAlternatives.size() > maCount)
2088 maCount = OpInfo.multipleAlternatives.size();
2090 OpInfo.ConstraintVT = MVT::Other;
2092 // Compute the value type for each operand.
2093 switch (OpInfo.Type) {
2094 case InlineAsm::isOutput:
2095 // Indirect outputs just consume an argument.
2096 if (OpInfo.isIndirect) {
2097 OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
2101 // The return value of the call is this value. As such, there is no
2102 // corresponding argument.
2103 assert(!CS.getType()->isVoidTy() &&
2105 if (StructType *STy = dyn_cast<StructType>(CS.getType())) {
2106 OpInfo.ConstraintVT = getSimpleValueType(STy->getElementType(ResNo));
2108 assert(ResNo == 0 && "Asm only has one result!");
2109 OpInfo.ConstraintVT = getSimpleValueType(CS.getType());
2113 case InlineAsm::isInput:
2114 OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
2116 case InlineAsm::isClobber:
2121 if (OpInfo.CallOperandVal) {
2122 llvm::Type *OpTy = OpInfo.CallOperandVal->getType();
2123 if (OpInfo.isIndirect) {
2124 llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy);
2126 report_fatal_error("Indirect operand for inline asm not a pointer!");
2127 OpTy = PtrTy->getElementType();
2130 // Look for vector wrapped in a struct. e.g. { <16 x i8> }.
2131 if (StructType *STy = dyn_cast<StructType>(OpTy))
2132 if (STy->getNumElements() == 1)
2133 OpTy = STy->getElementType(0);
2135 // If OpTy is not a single value, it may be a struct/union that we
2136 // can tile with integers.
2137 if (!OpTy->isSingleValueType() && OpTy->isSized()) {
2138 unsigned BitSize = getDataLayout()->getTypeSizeInBits(OpTy);
2147 OpInfo.ConstraintVT =
2148 MVT::getVT(IntegerType::get(OpTy->getContext(), BitSize), true);
2151 } else if (PointerType *PT = dyn_cast<PointerType>(OpTy)) {
2152 OpInfo.ConstraintVT = MVT::getIntegerVT(
2153 8*getDataLayout()->getPointerSize(PT->getAddressSpace()));
2155 OpInfo.ConstraintVT = MVT::getVT(OpTy, true);
2160 // If we have multiple alternative constraints, select the best alternative.
2161 if (ConstraintInfos.size()) {
2163 unsigned bestMAIndex = 0;
2164 int bestWeight = -1;
2165 // weight: -1 = invalid match, and 0 = so-so match to 5 = good match.
2168 // Compute the sums of the weights for each alternative, keeping track
2169 // of the best (highest weight) one so far.
2170 for (maIndex = 0; maIndex < maCount; ++maIndex) {
2172 for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
2173 cIndex != eIndex; ++cIndex) {
2174 AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
2175 if (OpInfo.Type == InlineAsm::isClobber)
2178 // If this is an output operand with a matching input operand,
2179 // look up the matching input. If their types mismatch, e.g. one
2180 // is an integer, the other is floating point, or their sizes are
2181 // different, flag it as an maCantMatch.
2182 if (OpInfo.hasMatchingInput()) {
2183 AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
2184 if (OpInfo.ConstraintVT != Input.ConstraintVT) {
2185 if ((OpInfo.ConstraintVT.isInteger() !=
2186 Input.ConstraintVT.isInteger()) ||
2187 (OpInfo.ConstraintVT.getSizeInBits() !=
2188 Input.ConstraintVT.getSizeInBits())) {
2189 weightSum = -1; // Can't match.
2194 weight = getMultipleConstraintMatchWeight(OpInfo, maIndex);
2199 weightSum += weight;
2202 if (weightSum > bestWeight) {
2203 bestWeight = weightSum;
2204 bestMAIndex = maIndex;
2208 // Now select chosen alternative in each constraint.
2209 for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
2210 cIndex != eIndex; ++cIndex) {
2211 AsmOperandInfo& cInfo = ConstraintOperands[cIndex];
2212 if (cInfo.Type == InlineAsm::isClobber)
2214 cInfo.selectAlternative(bestMAIndex);
2219 // Check and hook up tied operands, choose constraint code to use.
2220 for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
2221 cIndex != eIndex; ++cIndex) {
2222 AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
2224 // If this is an output operand with a matching input operand, look up the
2225 // matching input. If their types mismatch, e.g. one is an integer, the
2226 // other is floating point, or their sizes are different, flag it as an
2228 if (OpInfo.hasMatchingInput()) {
2229 AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
2231 if (OpInfo.ConstraintVT != Input.ConstraintVT) {
2232 std::pair<unsigned, const TargetRegisterClass*> MatchRC =
2233 getRegForInlineAsmConstraint(OpInfo.ConstraintCode,
2234 OpInfo.ConstraintVT);
2235 std::pair<unsigned, const TargetRegisterClass*> InputRC =
2236 getRegForInlineAsmConstraint(Input.ConstraintCode,
2237 Input.ConstraintVT);
2238 if ((OpInfo.ConstraintVT.isInteger() !=
2239 Input.ConstraintVT.isInteger()) ||
2240 (MatchRC.second != InputRC.second)) {
2241 report_fatal_error("Unsupported asm: input constraint"
2242 " with a matching output constraint of"
2243 " incompatible type!");
2250 return ConstraintOperands;
2254 /// getConstraintGenerality - Return an integer indicating how general CT
2256 static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) {
2258 case TargetLowering::C_Other:
2259 case TargetLowering::C_Unknown:
2261 case TargetLowering::C_Register:
2263 case TargetLowering::C_RegisterClass:
2265 case TargetLowering::C_Memory:
2268 llvm_unreachable("Invalid constraint type");
2271 /// Examine constraint type and operand type and determine a weight value.
2272 /// This object must already have been set up with the operand type
2273 /// and the current alternative constraint selected.
2274 TargetLowering::ConstraintWeight
2275 TargetLowering::getMultipleConstraintMatchWeight(
2276 AsmOperandInfo &info, int maIndex) const {
2277 InlineAsm::ConstraintCodeVector *rCodes;
2278 if (maIndex >= (int)info.multipleAlternatives.size())
2279 rCodes = &info.Codes;
2281 rCodes = &info.multipleAlternatives[maIndex].Codes;
2282 ConstraintWeight BestWeight = CW_Invalid;
2284 // Loop over the options, keeping track of the most general one.
2285 for (unsigned i = 0, e = rCodes->size(); i != e; ++i) {
2286 ConstraintWeight weight =
2287 getSingleConstraintMatchWeight(info, (*rCodes)[i].c_str());
2288 if (weight > BestWeight)
2289 BestWeight = weight;
2295 /// Examine constraint type and operand type and determine a weight value.
2296 /// This object must already have been set up with the operand type
2297 /// and the current alternative constraint selected.
2298 TargetLowering::ConstraintWeight
2299 TargetLowering::getSingleConstraintMatchWeight(
2300 AsmOperandInfo &info, const char *constraint) const {
2301 ConstraintWeight weight = CW_Invalid;
2302 Value *CallOperandVal = info.CallOperandVal;
2303 // If we don't have a value, we can't do a match,
2304 // but allow it at the lowest weight.
2305 if (CallOperandVal == NULL)
2307 // Look at the constraint type.
2308 switch (*constraint) {
2309 case 'i': // immediate integer.
2310 case 'n': // immediate integer with a known value.
2311 if (isa<ConstantInt>(CallOperandVal))
2312 weight = CW_Constant;
2314 case 's': // non-explicit intregal immediate.
2315 if (isa<GlobalValue>(CallOperandVal))
2316 weight = CW_Constant;
2318 case 'E': // immediate float if host format.
2319 case 'F': // immediate float.
2320 if (isa<ConstantFP>(CallOperandVal))
2321 weight = CW_Constant;
2323 case '<': // memory operand with autodecrement.
2324 case '>': // memory operand with autoincrement.
2325 case 'm': // memory operand.
2326 case 'o': // offsettable memory operand
2327 case 'V': // non-offsettable memory operand
2330 case 'r': // general register.
2331 case 'g': // general register, memory operand or immediate integer.
2332 // note: Clang converts "g" to "imr".
2333 if (CallOperandVal->getType()->isIntegerTy())
2334 weight = CW_Register;
2336 case 'X': // any operand.
2338 weight = CW_Default;
2344 /// ChooseConstraint - If there are multiple different constraints that we
2345 /// could pick for this operand (e.g. "imr") try to pick the 'best' one.
2346 /// This is somewhat tricky: constraints fall into four classes:
2347 /// Other -> immediates and magic values
2348 /// Register -> one specific register
2349 /// RegisterClass -> a group of regs
2350 /// Memory -> memory
2351 /// Ideally, we would pick the most specific constraint possible: if we have
2352 /// something that fits into a register, we would pick it. The problem here
2353 /// is that if we have something that could either be in a register or in
2354 /// memory that use of the register could cause selection of *other*
2355 /// operands to fail: they might only succeed if we pick memory. Because of
2356 /// this the heuristic we use is:
2358 /// 1) If there is an 'other' constraint, and if the operand is valid for
2359 /// that constraint, use it. This makes us take advantage of 'i'
2360 /// constraints when available.
2361 /// 2) Otherwise, pick the most general constraint present. This prefers
2362 /// 'm' over 'r', for example.
2364 static void ChooseConstraint(TargetLowering::AsmOperandInfo &OpInfo,
2365 const TargetLowering &TLI,
2366 SDValue Op, SelectionDAG *DAG) {
2367 assert(OpInfo.Codes.size() > 1 && "Doesn't have multiple constraint options");
2368 unsigned BestIdx = 0;
2369 TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown;
2370 int BestGenerality = -1;
2372 // Loop over the options, keeping track of the most general one.
2373 for (unsigned i = 0, e = OpInfo.Codes.size(); i != e; ++i) {
2374 TargetLowering::ConstraintType CType =
2375 TLI.getConstraintType(OpInfo.Codes[i]);
2377 // If this is an 'other' constraint, see if the operand is valid for it.
2378 // For example, on X86 we might have an 'rI' constraint. If the operand
2379 // is an integer in the range [0..31] we want to use I (saving a load
2380 // of a register), otherwise we must use 'r'.
2381 if (CType == TargetLowering::C_Other && Op.getNode()) {
2382 assert(OpInfo.Codes[i].size() == 1 &&
2383 "Unhandled multi-letter 'other' constraint");
2384 std::vector<SDValue> ResultOps;
2385 TLI.LowerAsmOperandForConstraint(Op, OpInfo.Codes[i],
2387 if (!ResultOps.empty()) {
2394 // Things with matching constraints can only be registers, per gcc
2395 // documentation. This mainly affects "g" constraints.
2396 if (CType == TargetLowering::C_Memory && OpInfo.hasMatchingInput())
2399 // This constraint letter is more general than the previous one, use it.
2400 int Generality = getConstraintGenerality(CType);
2401 if (Generality > BestGenerality) {
2404 BestGenerality = Generality;
2408 OpInfo.ConstraintCode = OpInfo.Codes[BestIdx];
2409 OpInfo.ConstraintType = BestType;
2412 /// ComputeConstraintToUse - Determines the constraint code and constraint
2413 /// type to use for the specific AsmOperandInfo, setting
2414 /// OpInfo.ConstraintCode and OpInfo.ConstraintType.
2415 void TargetLowering::ComputeConstraintToUse(AsmOperandInfo &OpInfo,
2417 SelectionDAG *DAG) const {
2418 assert(!OpInfo.Codes.empty() && "Must have at least one constraint");
2420 // Single-letter constraints ('r') are very common.
2421 if (OpInfo.Codes.size() == 1) {
2422 OpInfo.ConstraintCode = OpInfo.Codes[0];
2423 OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
2425 ChooseConstraint(OpInfo, *this, Op, DAG);
2428 // 'X' matches anything.
2429 if (OpInfo.ConstraintCode == "X" && OpInfo.CallOperandVal) {
2430 // Labels and constants are handled elsewhere ('X' is the only thing
2431 // that matches labels). For Functions, the type here is the type of
2432 // the result, which is not what we want to look at; leave them alone.
2433 Value *v = OpInfo.CallOperandVal;
2434 if (isa<BasicBlock>(v) || isa<ConstantInt>(v) || isa<Function>(v)) {
2435 OpInfo.CallOperandVal = v;
2439 // Otherwise, try to resolve it to something we know about by looking at
2440 // the actual operand type.
2441 if (const char *Repl = LowerXConstraint(OpInfo.ConstraintVT)) {
2442 OpInfo.ConstraintCode = Repl;
2443 OpInfo.ConstraintType = getConstraintType(OpInfo.ConstraintCode);
2448 /// \brief Given an exact SDIV by a constant, create a multiplication
2449 /// with the multiplicative inverse of the constant.
2450 SDValue TargetLowering::BuildExactSDIV(SDValue Op1, SDValue Op2, SDLoc dl,
2451 SelectionDAG &DAG) const {
2452 ConstantSDNode *C = cast<ConstantSDNode>(Op2);
2453 APInt d = C->getAPIntValue();
2454 assert(d != 0 && "Division by zero!");
2456 // Shift the value upfront if it is even, so the LSB is one.
2457 unsigned ShAmt = d.countTrailingZeros();
2459 // TODO: For UDIV use SRL instead of SRA.
2460 SDValue Amt = DAG.getConstant(ShAmt, getShiftAmountTy(Op1.getValueType()));
2461 Op1 = DAG.getNode(ISD::SRA, dl, Op1.getValueType(), Op1, Amt);
2465 // Calculate the multiplicative inverse, using Newton's method.
2467 while ((t = d*xn) != 1)
2468 xn *= APInt(d.getBitWidth(), 2) - t;
2470 Op2 = DAG.getConstant(xn, Op1.getValueType());
2471 return DAG.getNode(ISD::MUL, dl, Op1.getValueType(), Op1, Op2);
2474 /// \brief Given an ISD::SDIV node expressing a divide by constant,
2475 /// return a DAG expression to select that will generate the same value by
2476 /// multiplying by a magic number. See:
2477 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
2478 SDValue TargetLowering::
2479 BuildSDIV(SDNode *N, SelectionDAG &DAG, bool IsAfterLegalization,
2480 std::vector<SDNode*> *Created) const {
2481 EVT VT = N->getValueType(0);
2484 // Check to see if we can do this.
2485 // FIXME: We should be more aggressive here.
2486 if (!isTypeLegal(VT))
2489 APInt d = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue();
2490 APInt::ms magics = d.magic();
2492 // Multiply the numerator (operand 0) by the magic value
2493 // FIXME: We should support doing a MUL in a wider type
2495 if (IsAfterLegalization ? isOperationLegal(ISD::MULHS, VT) :
2496 isOperationLegalOrCustom(ISD::MULHS, VT))
2497 Q = DAG.getNode(ISD::MULHS, dl, VT, N->getOperand(0),
2498 DAG.getConstant(magics.m, VT));
2499 else if (IsAfterLegalization ? isOperationLegal(ISD::SMUL_LOHI, VT) :
2500 isOperationLegalOrCustom(ISD::SMUL_LOHI, VT))
2501 Q = SDValue(DAG.getNode(ISD::SMUL_LOHI, dl, DAG.getVTList(VT, VT),
2503 DAG.getConstant(magics.m, VT)).getNode(), 1);
2505 return SDValue(); // No mulhs or equvialent
2506 // If d > 0 and m < 0, add the numerator
2507 if (d.isStrictlyPositive() && magics.m.isNegative()) {
2508 Q = DAG.getNode(ISD::ADD, dl, VT, Q, N->getOperand(0));
2510 Created->push_back(Q.getNode());
2512 // If d < 0 and m > 0, subtract the numerator.
2513 if (d.isNegative() && magics.m.isStrictlyPositive()) {
2514 Q = DAG.getNode(ISD::SUB, dl, VT, Q, N->getOperand(0));
2516 Created->push_back(Q.getNode());
2518 // Shift right algebraic if shift value is nonzero
2520 Q = DAG.getNode(ISD::SRA, dl, VT, Q,
2521 DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType())));
2523 Created->push_back(Q.getNode());
2525 // Extract the sign bit and add it to the quotient
2527 DAG.getNode(ISD::SRL, dl, VT, Q, DAG.getConstant(VT.getSizeInBits()-1,
2528 getShiftAmountTy(Q.getValueType())));
2530 Created->push_back(T.getNode());
2531 return DAG.getNode(ISD::ADD, dl, VT, Q, T);
2534 /// \brief Given an ISD::UDIV node expressing a divide by constant,
2535 /// return a DAG expression to select that will generate the same value by
2536 /// multiplying by a magic number. See:
2537 /// <http://the.wall.riscom.net/books/proc/ppc/cwg/code2.html>
2538 SDValue TargetLowering::
2539 BuildUDIV(SDNode *N, SelectionDAG &DAG, bool IsAfterLegalization,
2540 std::vector<SDNode*> *Created) const {
2541 EVT VT = N->getValueType(0);
2544 // Check to see if we can do this.
2545 // FIXME: We should be more aggressive here.
2546 if (!isTypeLegal(VT))
2549 // FIXME: We should use a narrower constant when the upper
2550 // bits are known to be zero.
2551 const APInt &N1C = cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue();
2552 APInt::mu magics = N1C.magicu();
2554 SDValue Q = N->getOperand(0);
2556 // If the divisor is even, we can avoid using the expensive fixup by shifting
2557 // the divided value upfront.
2558 if (magics.a != 0 && !N1C[0]) {
2559 unsigned Shift = N1C.countTrailingZeros();
2560 Q = DAG.getNode(ISD::SRL, dl, VT, Q,
2561 DAG.getConstant(Shift, getShiftAmountTy(Q.getValueType())));
2563 Created->push_back(Q.getNode());
2565 // Get magic number for the shifted divisor.
2566 magics = N1C.lshr(Shift).magicu(Shift);
2567 assert(magics.a == 0 && "Should use cheap fixup now");
2570 // Multiply the numerator (operand 0) by the magic value
2571 // FIXME: We should support doing a MUL in a wider type
2572 if (IsAfterLegalization ? isOperationLegal(ISD::MULHU, VT) :
2573 isOperationLegalOrCustom(ISD::MULHU, VT))
2574 Q = DAG.getNode(ISD::MULHU, dl, VT, Q, DAG.getConstant(magics.m, VT));
2575 else if (IsAfterLegalization ? isOperationLegal(ISD::UMUL_LOHI, VT) :
2576 isOperationLegalOrCustom(ISD::UMUL_LOHI, VT))
2577 Q = SDValue(DAG.getNode(ISD::UMUL_LOHI, dl, DAG.getVTList(VT, VT), Q,
2578 DAG.getConstant(magics.m, VT)).getNode(), 1);
2580 return SDValue(); // No mulhu or equvialent
2582 Created->push_back(Q.getNode());
2584 if (magics.a == 0) {
2585 assert(magics.s < N1C.getBitWidth() &&
2586 "We shouldn't generate an undefined shift!");
2587 return DAG.getNode(ISD::SRL, dl, VT, Q,
2588 DAG.getConstant(magics.s, getShiftAmountTy(Q.getValueType())));
2590 SDValue NPQ = DAG.getNode(ISD::SUB, dl, VT, N->getOperand(0), Q);
2592 Created->push_back(NPQ.getNode());
2593 NPQ = DAG.getNode(ISD::SRL, dl, VT, NPQ,
2594 DAG.getConstant(1, getShiftAmountTy(NPQ.getValueType())));
2596 Created->push_back(NPQ.getNode());
2597 NPQ = DAG.getNode(ISD::ADD, dl, VT, NPQ, Q);
2599 Created->push_back(NPQ.getNode());
2600 return DAG.getNode(ISD::SRL, dl, VT, NPQ,
2601 DAG.getConstant(magics.s-1, getShiftAmountTy(NPQ.getValueType())));