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-rw-r--r--llvm/lib/CodeGen/CodeGenPrepare.cpp254
1 files changed, 143 insertions, 111 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 60539a9..7afa2a0 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -92,7 +92,12 @@ static cl::opt<bool> StressStoreExtract(
namespace {
typedef SmallPtrSet<Instruction *, 16> SetOfInstrs;
-typedef DenseMap<Instruction *, Type *> InstrToOrigTy;
+struct TypeIsSExt {
+ Type *Ty;
+ bool IsSExt;
+ TypeIsSExt(Type *Ty, bool IsSExt) : Ty(Ty), IsSExt(IsSExt) {}
+};
+typedef DenseMap<Instruction *, TypeIsSExt> InstrToOrigTy;
class CodeGenPrepare : public FunctionPass {
/// TLI - Keep a pointer of a TargetLowering to consult for determining
@@ -1715,58 +1720,75 @@ static bool MightBeFoldableInst(Instruction *I) {
/// \brief Hepler class to perform type promotion.
class TypePromotionHelper {
- /// \brief Utility function to check whether or not a sign extension of
- /// \p Inst with \p ConsideredSExtType can be moved through \p Inst by either
- /// using the operands of \p Inst or promoting \p Inst.
+ /// \brief Utility function to check whether or not a sign or zero extension
+ /// of \p Inst with \p ConsideredExtType can be moved through \p Inst by
+ /// either using the operands of \p Inst or promoting \p Inst.
+ /// The type of the extension is defined by \p IsSExt.
/// In other words, check if:
- /// sext (Ty Inst opnd1 opnd2 ... opndN) to ConsideredSExtType.
+ /// ext (Ty Inst opnd1 opnd2 ... opndN) to ConsideredExtType.
/// #1 Promotion applies:
- /// ConsideredSExtType Inst (sext opnd1 to ConsideredSExtType, ...).
+ /// ConsideredExtType Inst (ext opnd1 to ConsideredExtType, ...).
/// #2 Operand reuses:
- /// sext opnd1 to ConsideredSExtType.
+ /// ext opnd1 to ConsideredExtType.
/// \p PromotedInsts maps the instructions to their type before promotion.
- static bool canGetThrough(const Instruction *Inst, Type *ConsideredSExtType,
- const InstrToOrigTy &PromotedInsts);
+ static bool canGetThrough(const Instruction *Inst, Type *ConsideredExtType,
+ const InstrToOrigTy &PromotedInsts, bool IsSExt);
/// \brief Utility function to determine if \p OpIdx should be promoted when
/// promoting \p Inst.
- static bool shouldSExtOperand(const Instruction *Inst, int OpIdx) {
+ static bool shouldExtOperand(const Instruction *Inst, int OpIdx) {
if (isa<SelectInst>(Inst) && OpIdx == 0)
return false;
return true;
}
- /// \brief Utility function to promote the operand of \p SExt when this
+ /// \brief Utility function to promote the operand of \p Ext when this
/// operand is a promotable trunc or sext or zext.
/// \p PromotedInsts maps the instructions to their type before promotion.
/// \p CreatedInsts[out] contains how many non-free instructions have been
- /// created to promote the operand of SExt.
+ /// created to promote the operand of Ext.
/// Should never be called directly.
- /// \return The promoted value which is used instead of SExt.
- static Value *promoteOperandForTruncAndAnyExt(Instruction *SExt,
+ /// \return The promoted value which is used instead of Ext.
+ static Value *promoteOperandForTruncAndAnyExt(Instruction *Ext,
TypePromotionTransaction &TPT,
InstrToOrigTy &PromotedInsts,
unsigned &CreatedInsts);
- /// \brief Utility function to promote the operand of \p SExt when this
+ /// \brief Utility function to promote the operand of \p Ext when this
/// operand is promotable and is not a supported trunc or sext.
/// \p PromotedInsts maps the instructions to their type before promotion.
/// \p CreatedInsts[out] contains how many non-free instructions have been
- /// created to promote the operand of SExt.
+ /// created to promote the operand of Ext.
/// Should never be called directly.
- /// \return The promoted value which is used instead of SExt.
- static Value *promoteOperandForOther(Instruction *SExt,
+ /// \return The promoted value which is used instead of Ext.
+ static Value *promoteOperandForOther(Instruction *Ext,
TypePromotionTransaction &TPT,
InstrToOrigTy &PromotedInsts,
- unsigned &CreatedInsts);
+ unsigned &CreatedInsts, bool IsSExt);
+
+ /// \see promoteOperandForOther.
+ static Value *signExtendOperandForOther(Instruction *Ext,
+ TypePromotionTransaction &TPT,
+ InstrToOrigTy &PromotedInsts,
+ unsigned &CreatedInsts) {
+ return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInsts, true);
+ }
+
+ /// \see promoteOperandForOther.
+ static Value *zeroExtendOperandForOther(Instruction *Ext,
+ TypePromotionTransaction &TPT,
+ InstrToOrigTy &PromotedInsts,
+ unsigned &CreatedInsts) {
+ return promoteOperandForOther(Ext, TPT, PromotedInsts, CreatedInsts, false);
+ }
public:
- /// Type for the utility function that promotes the operand of SExt.
- typedef Value *(*Action)(Instruction *SExt, TypePromotionTransaction &TPT,
+ /// Type for the utility function that promotes the operand of Ext.
+ typedef Value *(*Action)(Instruction *Ext, TypePromotionTransaction &TPT,
InstrToOrigTy &PromotedInsts,
unsigned &CreatedInsts);
- /// \brief Given a sign extend instruction \p SExt, return the approriate
- /// action to promote the operand of \p SExt instead of using SExt.
+ /// \brief Given a sign/zero extend instruction \p Ext, return the approriate
+ /// action to promote the operand of \p Ext instead of using Ext.
/// \return NULL if no promotable action is possible with the current
/// sign extension.
/// \p InsertedTruncs keeps track of all the truncate instructions inserted by
@@ -1774,36 +1796,42 @@ public:
/// because we do not want to promote these instructions as CodeGenPrepare
/// will reinsert them later. Thus creating an infinite loop: create/remove.
/// \p PromotedInsts maps the instructions to their type before promotion.
- static Action getAction(Instruction *SExt, const SetOfInstrs &InsertedTruncs,
+ static Action getAction(Instruction *Ext, const SetOfInstrs &InsertedTruncs,
const TargetLowering &TLI,
const InstrToOrigTy &PromotedInsts);
};
bool TypePromotionHelper::canGetThrough(const Instruction *Inst,
- Type *ConsideredSExtType,
- const InstrToOrigTy &PromotedInsts) {
- // We can always get through sext or zext.
- if (isa<SExtInst>(Inst) || isa<ZExtInst>(Inst))
+ Type *ConsideredExtType,
+ const InstrToOrigTy &PromotedInsts,
+ bool IsSExt) {
+ // We can always get through zext.
+ if (isa<ZExtInst>(Inst))
+ return true;
+
+ // sext(sext) is ok too.
+ if (IsSExt && isa<SExtInst>(Inst))
return true;
// We can get through binary operator, if it is legal. In other words, the
// binary operator must have a nuw or nsw flag.
const BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Inst);
if (BinOp && isa<OverflowingBinaryOperator>(BinOp) &&
- (BinOp->hasNoUnsignedWrap() || BinOp->hasNoSignedWrap()))
+ ((!IsSExt && BinOp->hasNoUnsignedWrap()) ||
+ (IsSExt && BinOp->hasNoSignedWrap())))
return true;
// Check if we can do the following simplification.
- // sext(trunc(sext)) --> sext
+ // ext(trunc(opnd)) --> ext(opnd)
if (!isa<TruncInst>(Inst))
return false;
Value *OpndVal = Inst->getOperand(0);
- // Check if we can use this operand in the sext.
- // If the type is larger than the result type of the sign extension,
+ // Check if we can use this operand in the extension.
+ // If the type is larger than the result type of the extension,
// we cannot.
if (OpndVal->getType()->getIntegerBitWidth() >
- ConsideredSExtType->getIntegerBitWidth())
+ ConsideredExtType->getIntegerBitWidth())
return false;
// If the operand of the truncate is not an instruction, we will not have
@@ -1814,18 +1842,19 @@ bool TypePromotionHelper::canGetThrough(const Instruction *Inst,
return false;
// Check if the source of the type is narrow enough.
- // I.e., check that trunc just drops sign extended bits.
- // #1 get the type of the operand.
+ // I.e., check that trunc just drops extended bits of the same kind of
+ // the extension.
+ // #1 get the type of the operand and check the kind of the extended bits.
const Type *OpndType;
InstrToOrigTy::const_iterator It = PromotedInsts.find(Opnd);
- if (It != PromotedInsts.end())
- OpndType = It->second;
- else if (isa<SExtInst>(Opnd))
- OpndType = cast<Instruction>(Opnd)->getOperand(0)->getType();
+ if (It != PromotedInsts.end() && It->second.IsSExt == IsSExt)
+ OpndType = It->second.Ty;
+ else if ((IsSExt && isa<SExtInst>(Opnd)) || (!IsSExt && isa<ZExtInst>(Opnd)))
+ OpndType = Opnd->getOperand(0)->getType();
else
return false;
- // #2 check that the truncate just drop sign extended bits.
+ // #2 check that the truncate just drop extended bits.
if (Inst->getType()->getIntegerBitWidth() >= OpndType->getIntegerBitWidth())
return true;
@@ -1833,34 +1862,36 @@ bool TypePromotionHelper::canGetThrough(const Instruction *Inst,
}
TypePromotionHelper::Action TypePromotionHelper::getAction(
- Instruction *SExt, const SetOfInstrs &InsertedTruncs,
+ Instruction *Ext, const SetOfInstrs &InsertedTruncs,
const TargetLowering &TLI, const InstrToOrigTy &PromotedInsts) {
- Instruction *SExtOpnd = dyn_cast<Instruction>(SExt->getOperand(0));
- Type *SExtTy = SExt->getType();
- // If the operand of the sign extension is not an instruction, we cannot
+ assert((isa<SExtInst>(Ext) || isa<ZExtInst>(Ext)) &&
+ "Unexpected instruction type");
+ Instruction *ExtOpnd = dyn_cast<Instruction>(Ext->getOperand(0));
+ Type *ExtTy = Ext->getType();
+ bool IsSExt = isa<SExtInst>(Ext);
+ // If the operand of the extension is not an instruction, we cannot
// get through.
// If it, check we can get through.
- if (!SExtOpnd || !canGetThrough(SExtOpnd, SExtTy, PromotedInsts))
+ if (!ExtOpnd || !canGetThrough(ExtOpnd, ExtTy, PromotedInsts, IsSExt))
return nullptr;
// Do not promote if the operand has been added by codegenprepare.
// Otherwise, it means we are undoing an optimization that is likely to be
// redone, thus causing potential infinite loop.
- if (isa<TruncInst>(SExtOpnd) && InsertedTruncs.count(SExtOpnd))
+ if (isa<TruncInst>(ExtOpnd) && InsertedTruncs.count(ExtOpnd))
return nullptr;
// SExt or Trunc instructions.
// Return the related handler.
- if (isa<SExtInst>(SExtOpnd) || isa<TruncInst>(SExtOpnd) ||
- isa<ZExtInst>(SExtOpnd))
+ if (isa<SExtInst>(ExtOpnd) || isa<TruncInst>(ExtOpnd) ||
+ isa<ZExtInst>(ExtOpnd))
return promoteOperandForTruncAndAnyExt;
// Regular instruction.
// Abort early if we will have to insert non-free instructions.
- if (!SExtOpnd->hasOneUse() &&
- !TLI.isTruncateFree(SExtTy, SExtOpnd->getType()))
+ if (!ExtOpnd->hasOneUse() && !TLI.isTruncateFree(ExtTy, ExtOpnd->getType()))
return nullptr;
- return promoteOperandForOther;
+ return IsSExt ? signExtendOperandForOther : zeroExtendOperandForOther;
}
Value *TypePromotionHelper::promoteOperandForTruncAndAnyExt(
@@ -1871,7 +1902,7 @@ Value *TypePromotionHelper::promoteOperandForTruncAndAnyExt(
Instruction *SExtOpnd = cast<Instruction>(SExt->getOperand(0));
Value *ExtVal = SExt;
if (isa<ZExtInst>(SExtOpnd)) {
- // Replace sext(zext(opnd))
+ // Replace s|zext(zext(opnd))
// => zext(opnd).
Value *ZExt =
TPT.createZExt(SExt, SExtOpnd->getOperand(0), SExt->getType());
@@ -1879,8 +1910,8 @@ Value *TypePromotionHelper::promoteOperandForTruncAndAnyExt(
TPT.eraseInstruction(SExt);
ExtVal = ZExt;
} else {
- // Replace sext(trunc(opnd)) or sext(sext(opnd))
- // => sext(opnd).
+ // Replace z|sext(trunc(opnd)) or sext(sext(opnd))
+ // => z|sext(opnd).
TPT.setOperand(SExt, 0, SExtOpnd->getOperand(0));
}
CreatedInsts = 0;
@@ -1901,97 +1932,97 @@ Value *TypePromotionHelper::promoteOperandForTruncAndAnyExt(
return NextVal;
}
-Value *
-TypePromotionHelper::promoteOperandForOther(Instruction *SExt,
- TypePromotionTransaction &TPT,
- InstrToOrigTy &PromotedInsts,
- unsigned &CreatedInsts) {
- // By construction, the operand of SExt is an instruction. Otherwise we cannot
+Value *TypePromotionHelper::promoteOperandForOther(
+ Instruction *Ext, TypePromotionTransaction &TPT,
+ InstrToOrigTy &PromotedInsts, unsigned &CreatedInsts, bool IsSExt) {
+ // By construction, the operand of Ext is an instruction. Otherwise we cannot
// get through it and this method should not be called.
- Instruction *SExtOpnd = cast<Instruction>(SExt->getOperand(0));
+ Instruction *ExtOpnd = cast<Instruction>(Ext->getOperand(0));
CreatedInsts = 0;
- if (!SExtOpnd->hasOneUse()) {
- // SExtOpnd will be promoted.
- // All its uses, but SExt, will need to use a truncated value of the
+ if (!ExtOpnd->hasOneUse()) {
+ // ExtOpnd will be promoted.
+ // All its uses, but Ext, will need to use a truncated value of the
// promoted version.
// Create the truncate now.
- Value *Trunc = TPT.createTrunc(SExt, SExtOpnd->getType());
+ Value *Trunc = TPT.createTrunc(Ext, ExtOpnd->getType());
if (Instruction *ITrunc = dyn_cast<Instruction>(Trunc)) {
ITrunc->removeFromParent();
// Insert it just after the definition.
- ITrunc->insertAfter(SExtOpnd);
+ ITrunc->insertAfter(ExtOpnd);
}
- TPT.replaceAllUsesWith(SExtOpnd, Trunc);
- // Restore the operand of SExt (which has been replace by the previous call
+ TPT.replaceAllUsesWith(ExtOpnd, Trunc);
+ // Restore the operand of Ext (which has been replace by the previous call
// to replaceAllUsesWith) to avoid creating a cycle trunc <-> sext.
- TPT.setOperand(SExt, 0, SExtOpnd);
+ TPT.setOperand(Ext, 0, ExtOpnd);
}
// Get through the Instruction:
// 1. Update its type.
- // 2. Replace the uses of SExt by Inst.
- // 3. Sign extend each operand that needs to be sign extended.
+ // 2. Replace the uses of Ext by Inst.
+ // 3. Extend each operand that needs to be extended.
// Remember the original type of the instruction before promotion.
// This is useful to know that the high bits are sign extended bits.
- PromotedInsts.insert(
- std::pair<Instruction *, Type *>(SExtOpnd, SExtOpnd->getType()));
+ PromotedInsts.insert(std::pair<Instruction *, TypeIsSExt>(
+ ExtOpnd, TypeIsSExt(ExtOpnd->getType(), IsSExt)));
// Step #1.
- TPT.mutateType(SExtOpnd, SExt->getType());
+ TPT.mutateType(ExtOpnd, Ext->getType());
// Step #2.
- TPT.replaceAllUsesWith(SExt, SExtOpnd);
+ TPT.replaceAllUsesWith(Ext, ExtOpnd);
// Step #3.
- Instruction *SExtForOpnd = SExt;
+ Instruction *ExtForOpnd = Ext;
- DEBUG(dbgs() << "Propagate SExt to operands\n");
- for (int OpIdx = 0, EndOpIdx = SExtOpnd->getNumOperands(); OpIdx != EndOpIdx;
+ DEBUG(dbgs() << "Propagate Ext to operands\n");
+ for (int OpIdx = 0, EndOpIdx = ExtOpnd->getNumOperands(); OpIdx != EndOpIdx;
++OpIdx) {
- DEBUG(dbgs() << "Operand:\n" << *(SExtOpnd->getOperand(OpIdx)) << '\n');
- if (SExtOpnd->getOperand(OpIdx)->getType() == SExt->getType() ||
- !shouldSExtOperand(SExtOpnd, OpIdx)) {
+ DEBUG(dbgs() << "Operand:\n" << *(ExtOpnd->getOperand(OpIdx)) << '\n');
+ if (ExtOpnd->getOperand(OpIdx)->getType() == Ext->getType() ||
+ !shouldExtOperand(ExtOpnd, OpIdx)) {
DEBUG(dbgs() << "No need to propagate\n");
continue;
}
- // Check if we can statically sign extend the operand.
- Value *Opnd = SExtOpnd->getOperand(OpIdx);
+ // Check if we can statically extend the operand.
+ Value *Opnd = ExtOpnd->getOperand(OpIdx);
if (const ConstantInt *Cst = dyn_cast<ConstantInt>(Opnd)) {
- DEBUG(dbgs() << "Statically sign extend\n");
- TPT.setOperand(
- SExtOpnd, OpIdx,
- ConstantInt::getSigned(SExt->getType(), Cst->getSExtValue()));
+ DEBUG(dbgs() << "Statically extend\n");
+ unsigned BitWidth = Ext->getType()->getIntegerBitWidth();
+ APInt CstVal = IsSExt ? Cst->getValue().sext(BitWidth)
+ : Cst->getValue().zext(BitWidth);
+ TPT.setOperand(ExtOpnd, OpIdx, ConstantInt::get(Ext->getType(), CstVal));
continue;
}
// UndefValue are typed, so we have to statically sign extend them.
if (isa<UndefValue>(Opnd)) {
- DEBUG(dbgs() << "Statically sign extend\n");
- TPT.setOperand(SExtOpnd, OpIdx, UndefValue::get(SExt->getType()));
+ DEBUG(dbgs() << "Statically extend\n");
+ TPT.setOperand(ExtOpnd, OpIdx, UndefValue::get(Ext->getType()));
continue;
}
// Otherwise we have to explicity sign extend the operand.
- // Check if SExt was reused to sign extend an operand.
- if (!SExtForOpnd) {
+ // Check if Ext was reused to extend an operand.
+ if (!ExtForOpnd) {
// If yes, create a new one.
- DEBUG(dbgs() << "More operands to sext\n");
- SExtForOpnd =
- cast<Instruction>(TPT.createSExt(SExt, Opnd, SExt->getType()));
+ DEBUG(dbgs() << "More operands to ext\n");
+ ExtForOpnd =
+ cast<Instruction>(IsSExt ? TPT.createSExt(Ext, Opnd, Ext->getType())
+ : TPT.createZExt(Ext, Opnd, Ext->getType()));
++CreatedInsts;
}
- TPT.setOperand(SExtForOpnd, 0, Opnd);
+ TPT.setOperand(ExtForOpnd, 0, Opnd);
// Move the sign extension before the insertion point.
- TPT.moveBefore(SExtForOpnd, SExtOpnd);
- TPT.setOperand(SExtOpnd, OpIdx, SExtForOpnd);
+ TPT.moveBefore(ExtForOpnd, ExtOpnd);
+ TPT.setOperand(ExtOpnd, OpIdx, ExtForOpnd);
// If more sext are required, new instructions will have to be created.
- SExtForOpnd = nullptr;
+ ExtForOpnd = nullptr;
}
- if (SExtForOpnd == SExt) {
- DEBUG(dbgs() << "Sign extension is useless now\n");
- TPT.eraseInstruction(SExt);
+ if (ExtForOpnd == Ext) {
+ DEBUG(dbgs() << "Extension is useless now\n");
+ TPT.eraseInstruction(Ext);
}
- return SExtOpnd;
+ return ExtOpnd;
}
/// IsPromotionProfitable - Check whether or not promoting an instruction
@@ -2203,31 +2234,32 @@ bool AddressingModeMatcher::MatchOperationAddr(User *AddrInst, unsigned Opcode,
return true;
}
- case Instruction::SExt: {
- Instruction *SExt = dyn_cast<Instruction>(AddrInst);
- if (!SExt)
+ case Instruction::SExt:
+ case Instruction::ZExt: {
+ Instruction *Ext = dyn_cast<Instruction>(AddrInst);
+ if (!Ext)
return false;
- // Try to move this sext out of the way of the addressing mode.
+ // Try to move this ext out of the way of the addressing mode.
// Ask for a method for doing so.
- TypePromotionHelper::Action TPH = TypePromotionHelper::getAction(
- SExt, InsertedTruncs, TLI, PromotedInsts);
+ TypePromotionHelper::Action TPH =
+ TypePromotionHelper::getAction(Ext, InsertedTruncs, TLI, PromotedInsts);
if (!TPH)
return false;
TypePromotionTransaction::ConstRestorationPt LastKnownGood =
TPT.getRestorationPoint();
unsigned CreatedInsts = 0;
- Value *PromotedOperand = TPH(SExt, TPT, PromotedInsts, CreatedInsts);
+ Value *PromotedOperand = TPH(Ext, TPT, PromotedInsts, CreatedInsts);
// SExt has been moved away.
// Thus either it will be rematched later in the recursive calls or it is
// gone. Anyway, we must not fold it into the addressing mode at this point.
// E.g.,
// op = add opnd, 1
- // idx = sext op
+ // idx = ext op
// addr = gep base, idx
// is now:
- // promotedOpnd = sext opnd <- no match here
+ // promotedOpnd = ext opnd <- no match here
// op = promoted_add promotedOpnd, 1 <- match (later in recursive calls)
// addr = gep base, op <- match
if (MovedAway)
generated by cgit v1.1 at 2025-10-18 14:10:30 +0000