diff options
Diffstat (limited to 'contrib/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp')
-rw-r--r-- | contrib/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp | 118 |
1 files changed, 58 insertions, 60 deletions
diff --git a/contrib/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp b/contrib/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp index 4c6d0c4..46f7b8a 100644 --- a/contrib/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp +++ b/contrib/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp @@ -18,6 +18,8 @@ #include "llvm/IR/DataLayout.h" using namespace llvm; +#define DEBUG_TYPE "instcombine" + /// FoldPHIArgBinOpIntoPHI - If we have something like phi [add (a,b), add(a,c)] /// and if a/b/c and the add's all have a single use, turn this into a phi /// and a single binop. @@ -48,12 +50,12 @@ Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) { // types. I->getOperand(0)->getType() != LHSType || I->getOperand(1)->getType() != RHSType) - return 0; + return nullptr; // If they are CmpInst instructions, check their predicates if (CmpInst *CI = dyn_cast<CmpInst>(I)) if (CI->getPredicate() != cast<CmpInst>(FirstInst)->getPredicate()) - return 0; + return nullptr; if (isNUW) isNUW = cast<OverflowingBinaryOperator>(I)->hasNoUnsignedWrap(); @@ -63,8 +65,8 @@ Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) { isExact = cast<PossiblyExactOperator>(I)->isExact(); // Keep track of which operand needs a phi node. - if (I->getOperand(0) != LHSVal) LHSVal = 0; - if (I->getOperand(1) != RHSVal) RHSVal = 0; + if (I->getOperand(0) != LHSVal) LHSVal = nullptr; + if (I->getOperand(1) != RHSVal) RHSVal = nullptr; } // If both LHS and RHS would need a PHI, don't do this transformation, @@ -72,14 +74,14 @@ Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) { // which leads to higher register pressure. This is especially // bad when the PHIs are in the header of a loop. if (!LHSVal && !RHSVal) - return 0; + return nullptr; // Otherwise, this is safe to transform! Value *InLHS = FirstInst->getOperand(0); Value *InRHS = FirstInst->getOperand(1); - PHINode *NewLHS = 0, *NewRHS = 0; - if (LHSVal == 0) { + PHINode *NewLHS = nullptr, *NewRHS = nullptr; + if (!LHSVal) { NewLHS = PHINode::Create(LHSType, PN.getNumIncomingValues(), FirstInst->getOperand(0)->getName() + ".pn"); NewLHS->addIncoming(InLHS, PN.getIncomingBlock(0)); @@ -87,7 +89,7 @@ Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) { LHSVal = NewLHS; } - if (RHSVal == 0) { + if (!RHSVal) { NewRHS = PHINode::Create(RHSType, PN.getNumIncomingValues(), FirstInst->getOperand(1)->getName() + ".pn"); NewRHS->addIncoming(InRHS, PN.getIncomingBlock(0)); @@ -148,7 +150,7 @@ Instruction *InstCombiner::FoldPHIArgGEPIntoPHI(PHINode &PN) { GetElementPtrInst *GEP= dyn_cast<GetElementPtrInst>(PN.getIncomingValue(i)); if (!GEP || !GEP->hasOneUse() || GEP->getType() != FirstInst->getType() || GEP->getNumOperands() != FirstInst->getNumOperands()) - return 0; + return nullptr; AllInBounds &= GEP->isInBounds(); @@ -170,19 +172,19 @@ Instruction *InstCombiner::FoldPHIArgGEPIntoPHI(PHINode &PN) { // for struct indices, which must always be constant. if (isa<ConstantInt>(FirstInst->getOperand(op)) || isa<ConstantInt>(GEP->getOperand(op))) - return 0; + return nullptr; if (FirstInst->getOperand(op)->getType() !=GEP->getOperand(op)->getType()) - return 0; + return nullptr; // If we already needed a PHI for an earlier operand, and another operand // also requires a PHI, we'd be introducing more PHIs than we're // eliminating, which increases register pressure on entry to the PHI's // block. if (NeededPhi) - return 0; + return nullptr; - FixedOperands[op] = 0; // Needs a PHI. + FixedOperands[op] = nullptr; // Needs a PHI. NeededPhi = true; } } @@ -194,7 +196,7 @@ Instruction *InstCombiner::FoldPHIArgGEPIntoPHI(PHINode &PN) { // load up into the predecessors so that we have a load of a gep of an alloca, // which can usually all be folded into the load. if (AllBasePointersAreAllocas) - return 0; + return nullptr; // Otherwise, this is safe to transform. Insert PHI nodes for each operand // that is variable. @@ -255,9 +257,7 @@ static bool isSafeAndProfitableToSinkLoad(LoadInst *L) { // profitable to do this xform. if (AllocaInst *AI = dyn_cast<AllocaInst>(L->getOperand(0))) { bool isAddressTaken = false; - for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end(); - UI != E; ++UI) { - User *U = *UI; + for (User *U : AI->users()) { if (isa<LoadInst>(U)) continue; if (StoreInst *SI = dyn_cast<StoreInst>(U)) { // If storing TO the alloca, then the address isn't taken. @@ -290,7 +290,7 @@ Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) { // FIXME: This is overconservative; this transform is allowed in some cases // for atomic operations. if (FirstLI->isAtomic()) - return 0; + return nullptr; // When processing loads, we need to propagate two bits of information to the // sunk load: whether it is volatile, and what its alignment is. We currently @@ -305,20 +305,20 @@ Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) { // load and the PHI. if (FirstLI->getParent() != PN.getIncomingBlock(0) || !isSafeAndProfitableToSinkLoad(FirstLI)) - return 0; + return nullptr; // If the PHI is of volatile loads and the load block has multiple // successors, sinking it would remove a load of the volatile value from // the path through the other successor. if (isVolatile && FirstLI->getParent()->getTerminator()->getNumSuccessors() != 1) - return 0; + return nullptr; // Check to see if all arguments are the same operation. for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i) { LoadInst *LI = dyn_cast<LoadInst>(PN.getIncomingValue(i)); if (!LI || !LI->hasOneUse()) - return 0; + return nullptr; // We can't sink the load if the loaded value could be modified between // the load and the PHI. @@ -326,12 +326,12 @@ Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) { LI->getParent() != PN.getIncomingBlock(i) || LI->getPointerAddressSpace() != LoadAddrSpace || !isSafeAndProfitableToSinkLoad(LI)) - return 0; + return nullptr; // If some of the loads have an alignment specified but not all of them, // we can't do the transformation. if ((LoadAlignment != 0) != (LI->getAlignment() != 0)) - return 0; + return nullptr; LoadAlignment = std::min(LoadAlignment, LI->getAlignment()); @@ -340,7 +340,7 @@ Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) { // the path through the other successor. if (isVolatile && LI->getParent()->getTerminator()->getNumSuccessors() != 1) - return 0; + return nullptr; } // Okay, they are all the same operation. Create a new PHI node of the @@ -356,7 +356,7 @@ Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) { for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i) { Value *NewInVal = cast<LoadInst>(PN.getIncomingValue(i))->getOperand(0); if (NewInVal != InVal) - InVal = 0; + InVal = nullptr; NewPN->addIncoming(NewInVal, PN.getIncomingBlock(i)); } @@ -400,8 +400,8 @@ Instruction *InstCombiner::FoldPHIArgOpIntoPHI(PHINode &PN) { // If all input operands to the phi are the same instruction (e.g. a cast from // the same type or "+42") we can pull the operation through the PHI, reducing // code size and simplifying code. - Constant *ConstantOp = 0; - Type *CastSrcTy = 0; + Constant *ConstantOp = nullptr; + Type *CastSrcTy = nullptr; bool isNUW = false, isNSW = false, isExact = false; if (isa<CastInst>(FirstInst)) { @@ -411,13 +411,13 @@ Instruction *InstCombiner::FoldPHIArgOpIntoPHI(PHINode &PN) { // the code by turning an i32 into an i1293. if (PN.getType()->isIntegerTy() && CastSrcTy->isIntegerTy()) { if (!ShouldChangeType(PN.getType(), CastSrcTy)) - return 0; + return nullptr; } } else if (isa<BinaryOperator>(FirstInst) || isa<CmpInst>(FirstInst)) { // Can fold binop, compare or shift here if the RHS is a constant, // otherwise call FoldPHIArgBinOpIntoPHI. ConstantOp = dyn_cast<Constant>(FirstInst->getOperand(1)); - if (ConstantOp == 0) + if (!ConstantOp) return FoldPHIArgBinOpIntoPHI(PN); if (OverflowingBinaryOperator *BO = @@ -428,19 +428,19 @@ Instruction *InstCombiner::FoldPHIArgOpIntoPHI(PHINode &PN) { dyn_cast<PossiblyExactOperator>(FirstInst)) isExact = PEO->isExact(); } else { - return 0; // Cannot fold this operation. + return nullptr; // Cannot fold this operation. } // Check to see if all arguments are the same operation. for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i) { Instruction *I = dyn_cast<Instruction>(PN.getIncomingValue(i)); - if (I == 0 || !I->hasOneUse() || !I->isSameOperationAs(FirstInst)) - return 0; + if (!I || !I->hasOneUse() || !I->isSameOperationAs(FirstInst)) + return nullptr; if (CastSrcTy) { if (I->getOperand(0)->getType() != CastSrcTy) - return 0; // Cast operation must match. + return nullptr; // Cast operation must match. } else if (I->getOperand(1) != ConstantOp) { - return 0; + return nullptr; } if (isNUW) @@ -464,7 +464,7 @@ Instruction *InstCombiner::FoldPHIArgOpIntoPHI(PHINode &PN) { for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i) { Value *NewInVal = cast<Instruction>(PN.getIncomingValue(i))->getOperand(0); if (NewInVal != InVal) - InVal = 0; + InVal = nullptr; NewPN->addIncoming(NewInVal, PN.getIncomingBlock(i)); } @@ -518,7 +518,7 @@ static bool DeadPHICycle(PHINode *PN, if (PotentiallyDeadPHIs.size() == 16) return false; - if (PHINode *PU = dyn_cast<PHINode>(PN->use_back())) + if (PHINode *PU = dyn_cast<PHINode>(PN->user_back())) return DeadPHICycle(PU, PotentiallyDeadPHIs); return false; @@ -589,10 +589,10 @@ namespace llvm { template<> struct DenseMapInfo<LoweredPHIRecord> { static inline LoweredPHIRecord getEmptyKey() { - return LoweredPHIRecord(0, 0); + return LoweredPHIRecord(nullptr, 0); } static inline LoweredPHIRecord getTombstoneKey() { - return LoweredPHIRecord(0, 1); + return LoweredPHIRecord(nullptr, 1); } static unsigned getHashValue(const LoweredPHIRecord &Val) { return DenseMapInfo<PHINode*>::getHashValue(Val.PN) ^ (Val.Shift>>3) ^ @@ -639,42 +639,40 @@ Instruction *InstCombiner::SliceUpIllegalIntegerPHI(PHINode &FirstPhi) { // bail out. for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { InvokeInst *II = dyn_cast<InvokeInst>(PN->getIncomingValue(i)); - if (II == 0) continue; + if (!II) continue; if (II->getParent() != PN->getIncomingBlock(i)) continue; // If we have a phi, and if it's directly in the predecessor, then we have // a critical edge where we need to put the truncate. Since we can't // split the edge in instcombine, we have to bail out. - return 0; + return nullptr; } - - for (Value::use_iterator UI = PN->use_begin(), E = PN->use_end(); - UI != E; ++UI) { - Instruction *User = cast<Instruction>(*UI); + for (User *U : PN->users()) { + Instruction *UserI = cast<Instruction>(U); // If the user is a PHI, inspect its uses recursively. - if (PHINode *UserPN = dyn_cast<PHINode>(User)) { + if (PHINode *UserPN = dyn_cast<PHINode>(UserI)) { if (PHIsInspected.insert(UserPN)) PHIsToSlice.push_back(UserPN); continue; } // Truncates are always ok. - if (isa<TruncInst>(User)) { - PHIUsers.push_back(PHIUsageRecord(PHIId, 0, User)); + if (isa<TruncInst>(UserI)) { + PHIUsers.push_back(PHIUsageRecord(PHIId, 0, UserI)); continue; } // Otherwise it must be a lshr which can only be used by one trunc. - if (User->getOpcode() != Instruction::LShr || - !User->hasOneUse() || !isa<TruncInst>(User->use_back()) || - !isa<ConstantInt>(User->getOperand(1))) - return 0; + if (UserI->getOpcode() != Instruction::LShr || + !UserI->hasOneUse() || !isa<TruncInst>(UserI->user_back()) || + !isa<ConstantInt>(UserI->getOperand(1))) + return nullptr; - unsigned Shift = cast<ConstantInt>(User->getOperand(1))->getZExtValue(); - PHIUsers.push_back(PHIUsageRecord(PHIId, Shift, User->use_back())); + unsigned Shift = cast<ConstantInt>(UserI->getOperand(1))->getZExtValue(); + PHIUsers.push_back(PHIUsageRecord(PHIId, Shift, UserI->user_back())); } } @@ -709,7 +707,7 @@ Instruction *InstCombiner::SliceUpIllegalIntegerPHI(PHINode &FirstPhi) { // If we've already lowered a user like this, reuse the previously lowered // value. - if ((EltPHI = ExtractedVals[LoweredPHIRecord(PN, Offset, Ty)]) == 0) { + if ((EltPHI = ExtractedVals[LoweredPHIRecord(PN, Offset, Ty)]) == nullptr) { // Otherwise, Create the new PHI node for this user. EltPHI = PHINode::Create(Ty, PN->getNumIncomingValues(), @@ -790,7 +788,7 @@ Instruction *InstCombiner::SliceUpIllegalIntegerPHI(PHINode &FirstPhi) { // PHINode simplification // Instruction *InstCombiner::visitPHINode(PHINode &PN) { - if (Value *V = SimplifyInstruction(&PN, TD, TLI)) + if (Value *V = SimplifyInstruction(&PN, DL, TLI)) return ReplaceInstUsesWith(PN, V); // If all PHI operands are the same operation, pull them through the PHI, @@ -809,7 +807,7 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) { // this PHI only has a single use (a PHI), and if that PHI only has one use (a // PHI)... break the cycle. if (PN.hasOneUse()) { - Instruction *PHIUser = cast<Instruction>(PN.use_back()); + Instruction *PHIUser = cast<Instruction>(PN.user_back()); if (PHINode *PU = dyn_cast<PHINode>(PHIUser)) { SmallPtrSet<PHINode*, 16> PotentiallyDeadPHIs; PotentiallyDeadPHIs.insert(&PN); @@ -825,7 +823,7 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) { // late. if (PHIUser->hasOneUse() && (isa<BinaryOperator>(PHIUser) || isa<GetElementPtrInst>(PHIUser)) && - PHIUser->use_back() == &PN) { + PHIUser->user_back() == &PN) { return ReplaceInstUsesWith(PN, UndefValue::get(PN.getType())); } } @@ -893,10 +891,10 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) { // it is only used by trunc or trunc(lshr) operations. If so, we split the // PHI into the various pieces being extracted. This sort of thing is // introduced when SROA promotes an aggregate to a single large integer type. - if (PN.getType()->isIntegerTy() && TD && - !TD->isLegalInteger(PN.getType()->getPrimitiveSizeInBits())) + if (PN.getType()->isIntegerTy() && DL && + !DL->isLegalInteger(PN.getType()->getPrimitiveSizeInBits())) if (Instruction *Res = SliceUpIllegalIntegerPHI(PN)) return Res; - return 0; + return nullptr; } |