diff options
Diffstat (limited to 'contrib/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | contrib/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 983 |
1 files changed, 718 insertions, 265 deletions
diff --git a/contrib/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/contrib/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index d9311a343ead..bfd73f4bbac5 100644 --- a/contrib/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/contrib/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -13,18 +13,19 @@ #include "InstCombineInternal.h" #include "llvm/ADT/APSInt.h" +#include "llvm/ADT/SetVector.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/MemoryBuiltins.h" +#include "llvm/Analysis/TargetLibraryInfo.h" +#include "llvm/Analysis/VectorUtils.h" #include "llvm/IR/ConstantRange.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/GetElementPtrTypeIterator.h" #include "llvm/IR/IntrinsicInst.h" #include "llvm/IR/PatternMatch.h" -#include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" -#include "llvm/Analysis/TargetLibraryInfo.h" using namespace llvm; using namespace PatternMatch; @@ -55,8 +56,8 @@ static bool HasAddOverflow(ConstantInt *Result, return Result->getValue().slt(In1->getValue()); } -/// AddWithOverflow - Compute Result = In1+In2, returning true if the result -/// overflowed for this type. +/// Compute Result = In1+In2, returning true if the result overflowed for this +/// type. static bool AddWithOverflow(Constant *&Result, Constant *In1, Constant *In2, bool IsSigned = false) { Result = ConstantExpr::getAdd(In1, In2); @@ -90,8 +91,8 @@ static bool HasSubOverflow(ConstantInt *Result, return Result->getValue().sgt(In1->getValue()); } -/// SubWithOverflow - Compute Result = In1-In2, returning true if the result -/// overflowed for this type. +/// Compute Result = In1-In2, returning true if the result overflowed for this +/// type. static bool SubWithOverflow(Constant *&Result, Constant *In1, Constant *In2, bool IsSigned = false) { Result = ConstantExpr::getSub(In1, In2); @@ -113,13 +114,21 @@ static bool SubWithOverflow(Constant *&Result, Constant *In1, IsSigned); } -/// isSignBitCheck - Given an exploded icmp instruction, return true if the -/// comparison only checks the sign bit. If it only checks the sign bit, set -/// TrueIfSigned if the result of the comparison is true when the input value is -/// signed. -static bool isSignBitCheck(ICmpInst::Predicate pred, ConstantInt *RHS, +/// Given an icmp instruction, return true if any use of this comparison is a +/// branch on sign bit comparison. +static bool isBranchOnSignBitCheck(ICmpInst &I, bool isSignBit) { + for (auto *U : I.users()) + if (isa<BranchInst>(U)) + return isSignBit; + return false; +} + +/// Given an exploded icmp instruction, return true if the comparison only +/// checks the sign bit. If it only checks the sign bit, set TrueIfSigned if the +/// result of the comparison is true when the input value is signed. +static bool isSignBitCheck(ICmpInst::Predicate Pred, ConstantInt *RHS, bool &TrueIfSigned) { - switch (pred) { + switch (Pred) { case ICmpInst::ICMP_SLT: // True if LHS s< 0 TrueIfSigned = true; return RHS->isZero(); @@ -145,21 +154,21 @@ static bool isSignBitCheck(ICmpInst::Predicate pred, ConstantInt *RHS, /// Returns true if the exploded icmp can be expressed as a signed comparison /// to zero and updates the predicate accordingly. /// The signedness of the comparison is preserved. -static bool isSignTest(ICmpInst::Predicate &pred, const ConstantInt *RHS) { - if (!ICmpInst::isSigned(pred)) +static bool isSignTest(ICmpInst::Predicate &Pred, const ConstantInt *RHS) { + if (!ICmpInst::isSigned(Pred)) return false; if (RHS->isZero()) - return ICmpInst::isRelational(pred); + return ICmpInst::isRelational(Pred); if (RHS->isOne()) { - if (pred == ICmpInst::ICMP_SLT) { - pred = ICmpInst::ICMP_SLE; + if (Pred == ICmpInst::ICMP_SLT) { + Pred = ICmpInst::ICMP_SLE; return true; } } else if (RHS->isAllOnesValue()) { - if (pred == ICmpInst::ICMP_SGT) { - pred = ICmpInst::ICMP_SGE; + if (Pred == ICmpInst::ICMP_SGT) { + Pred = ICmpInst::ICMP_SGE; return true; } } @@ -167,19 +176,18 @@ static bool isSignTest(ICmpInst::Predicate &pred, const ConstantInt *RHS) { return false; } -// isHighOnes - Return true if the constant is of the form 1+0+. -// This is the same as lowones(~X). +/// Return true if the constant is of the form 1+0+. This is the same as +/// lowones(~X). static bool isHighOnes(const ConstantInt *CI) { return (~CI->getValue() + 1).isPowerOf2(); } -/// ComputeSignedMinMaxValuesFromKnownBits - Given a signed integer type and a -/// set of known zero and one bits, compute the maximum and minimum values that -/// could have the specified known zero and known one bits, returning them in -/// min/max. -static void ComputeSignedMinMaxValuesFromKnownBits(const APInt& KnownZero, - const APInt& KnownOne, - APInt& Min, APInt& Max) { +/// Given a signed integer type and a set of known zero and one bits, compute +/// the maximum and minimum values that could have the specified known zero and +/// known one bits, returning them in Min/Max. +static void ComputeSignedMinMaxValuesFromKnownBits(const APInt &KnownZero, + const APInt &KnownOne, + APInt &Min, APInt &Max) { assert(KnownZero.getBitWidth() == KnownOne.getBitWidth() && KnownZero.getBitWidth() == Min.getBitWidth() && KnownZero.getBitWidth() == Max.getBitWidth() && @@ -197,10 +205,9 @@ static void ComputeSignedMinMaxValuesFromKnownBits(const APInt& KnownZero, } } -// ComputeUnsignedMinMaxValuesFromKnownBits - Given an unsigned integer type and -// a set of known zero and one bits, compute the maximum and minimum values that -// could have the specified known zero and known one bits, returning them in -// min/max. +/// Given an unsigned integer type and a set of known zero and one bits, compute +/// the maximum and minimum values that could have the specified known zero and +/// known one bits, returning them in Min/Max. static void ComputeUnsignedMinMaxValuesFromKnownBits(const APInt &KnownZero, const APInt &KnownOne, APInt &Min, APInt &Max) { @@ -216,14 +223,14 @@ static void ComputeUnsignedMinMaxValuesFromKnownBits(const APInt &KnownZero, Max = KnownOne|UnknownBits; } -/// FoldCmpLoadFromIndexedGlobal - Called we see this pattern: +/// This is called when we see this pattern: /// cmp pred (load (gep GV, ...)), cmpcst -/// where GV is a global variable with a constant initializer. Try to simplify -/// this into some simple computation that does not need the load. For example +/// where GV is a global variable with a constant initializer. Try to simplify +/// this into some simple computation that does not need the load. For example /// we can optimize "icmp eq (load (gep "foo", 0, i)), 0" into "icmp eq i, 3". /// /// If AndCst is non-null, then the loaded value is masked with that constant -/// before doing the comparison. This handles cases like "A[i]&4 == 0". +/// before doing the comparison. This handles cases like "A[i]&4 == 0". Instruction *InstCombiner:: FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, CmpInst &ICI, ConstantInt *AndCst) { @@ -401,7 +408,7 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, if (SecondTrueElement != Overdefined) { // None true -> false. if (FirstTrueElement == Undefined) - return ReplaceInstUsesWith(ICI, Builder->getFalse()); + return replaceInstUsesWith(ICI, Builder->getFalse()); Value *FirstTrueIdx = ConstantInt::get(Idx->getType(), FirstTrueElement); @@ -421,7 +428,7 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, if (SecondFalseElement != Overdefined) { // None false -> true. if (FirstFalseElement == Undefined) - return ReplaceInstUsesWith(ICI, Builder->getTrue()); + return replaceInstUsesWith(ICI, Builder->getTrue()); Value *FirstFalseIdx = ConstantInt::get(Idx->getType(), FirstFalseElement); @@ -492,12 +499,12 @@ FoldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP, GlobalVariable *GV, return nullptr; } -/// EvaluateGEPOffsetExpression - Return a value that can be used to compare -/// the *offset* implied by a GEP to zero. For example, if we have &A[i], we -/// want to return 'i' for "icmp ne i, 0". Note that, in general, indices can -/// be complex, and scales are involved. The above expression would also be -/// legal to codegen as "icmp ne (i*4), 0" (assuming A is a pointer to i32). -/// This later form is less amenable to optimization though, and we are allowed +/// Return a value that can be used to compare the *offset* implied by a GEP to +/// zero. For example, if we have &A[i], we want to return 'i' for +/// "icmp ne i, 0". Note that, in general, indices can be complex, and scales +/// are involved. The above expression would also be legal to codegen as +/// "icmp ne (i*4), 0" (assuming A is a pointer to i32). +/// This latter form is less amenable to optimization though, and we are allowed /// to generate the first by knowing that pointer arithmetic doesn't overflow. /// /// If we can't emit an optimized form for this expression, this returns null. @@ -595,8 +602,323 @@ static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC, return IC.Builder->CreateAdd(VariableIdx, OffsetVal, "offset"); } -/// FoldGEPICmp - Fold comparisons between a GEP instruction and something -/// else. At this point we know that the GEP is on the LHS of the comparison. +/// Returns true if we can rewrite Start as a GEP with pointer Base +/// and some integer offset. The nodes that need to be re-written +/// for this transformation will be added to Explored. +static bool canRewriteGEPAsOffset(Value *Start, Value *Base, + const DataLayout &DL, + SetVector<Value *> &Explored) { + SmallVector<Value *, 16> WorkList(1, Start); + Explored.insert(Base); + + // The following traversal gives us an order which can be used + // when doing the final transformation. Since in the final + // transformation we create the PHI replacement instructions first, + // we don't have to get them in any particular order. + // + // However, for other instructions we will have to traverse the + // operands of an instruction first, which means that we have to + // do a post-order traversal. + while (!WorkList.empty()) { + SetVector<PHINode *> PHIs; + + while (!WorkList.empty()) { + if (Explored.size() >= 100) + return false; + + Value *V = WorkList.back(); + + if (Explored.count(V) != 0) { + WorkList.pop_back(); + continue; + } + + if (!isa<IntToPtrInst>(V) && !isa<PtrToIntInst>(V) && + !isa<GEPOperator>(V) && !isa<PHINode>(V)) + // We've found some value that we can't explore which is different from + // the base. Therefore we can't do this transformation. + return false; + + if (isa<IntToPtrInst>(V) || isa<PtrToIntInst>(V)) { + auto *CI = dyn_cast<CastInst>(V); + if (!CI->isNoopCast(DL)) + return false; + + if (Explored.count(CI->getOperand(0)) == 0) + WorkList.push_back(CI->getOperand(0)); + } + + if (auto *GEP = dyn_cast<GEPOperator>(V)) { + // We're limiting the GEP to having one index. This will preserve + // the original pointer type. We could handle more cases in the + // future. + if (GEP->getNumIndices() != 1 || !GEP->isInBounds() || + GEP->getType() != Start->getType()) + return false; + + if (Explored.count(GEP->getOperand(0)) == 0) + WorkList.push_back(GEP->getOperand(0)); + } + + if (WorkList.back() == V) { + WorkList.pop_back(); + // We've finished visiting this node, mark it as such. + Explored.insert(V); + } + + if (auto *PN = dyn_cast<PHINode>(V)) { + // We cannot transform PHIs on unsplittable basic blocks. + if (isa<CatchSwitchInst>(PN->getParent()->getTerminator())) + return false; + Explored.insert(PN); + PHIs.insert(PN); + } + } + + // Explore the PHI nodes further. + for (auto *PN : PHIs) + for (Value *Op : PN->incoming_values()) + if (Explored.count(Op) == 0) + WorkList.push_back(Op); + } + + // Make sure that we can do this. Since we can't insert GEPs in a basic + // block before a PHI node, we can't easily do this transformation if + // we have PHI node users of transformed instructions. + for (Value *Val : Explored) { + for (Value *Use : Val->uses()) { + + auto *PHI = dyn_cast<PHINode>(Use); + auto *Inst = dyn_cast<Instruction>(Val); + + if (Inst == Base || Inst == PHI || !Inst || !PHI || + Explored.count(PHI) == 0) + continue; + + if (PHI->getParent() == Inst->getParent()) + return false; + } + } + return true; +} + +// Sets the appropriate insert point on Builder where we can add +// a replacement Instruction for V (if that is possible). +static void setInsertionPoint(IRBuilder<> &Builder, Value *V, + bool Before = true) { + if (auto *PHI = dyn_cast<PHINode>(V)) { + Builder.SetInsertPoint(&*PHI->getParent()->getFirstInsertionPt()); + return; + } + if (auto *I = dyn_cast<Instruction>(V)) { + if (!Before) + I = &*std::next(I->getIterator()); + Builder.SetInsertPoint(I); + return; + } + if (auto *A = dyn_cast<Argument>(V)) { + // Set the insertion point in the entry block. + BasicBlock &Entry = A->getParent()->getEntryBlock(); + Builder.SetInsertPoint(&*Entry.getFirstInsertionPt()); + return; + } + // Otherwise, this is a constant and we don't need to set a new + // insertion point. + assert(isa<Constant>(V) && "Setting insertion point for unknown value!"); +} + +/// Returns a re-written value of Start as an indexed GEP using Base as a +/// pointer. +static Value *rewriteGEPAsOffset(Value *Start, Value *Base, + const DataLayout &DL, + SetVector<Value *> &Explored) { + // Perform all the substitutions. This is a bit tricky because we can + // have cycles in our use-def chains. + // 1. Create the PHI nodes without any incoming values. + // 2. Create all the other values. + // 3. Add the edges for the PHI nodes. + // 4. Emit GEPs to get the original pointers. + // 5. Remove the original instructions. + Type *IndexType = IntegerType::get( + Base->getContext(), DL.getPointerTypeSizeInBits(Start->getType())); + + DenseMap<Value *, Value *> NewInsts; + NewInsts[Base] = ConstantInt::getNullValue(IndexType); + + // Create the new PHI nodes, without adding any incoming values. + for (Value *Val : Explored) { + if (Val == Base) + continue; + // Create empty phi nodes. This avoids cyclic dependencies when creating + // the remaining instructions. + if (auto *PHI = dyn_cast<PHINode>(Val)) + NewInsts[PHI] = PHINode::Create(IndexType, PHI->getNumIncomingValues(), + PHI->getName() + ".idx", PHI); + } + IRBuilder<> Builder(Base->getContext()); + + // Create all the other instructions. + for (Value *Val : Explored) { + + if (NewInsts.find(Val) != NewInsts.end()) + continue; + + if (auto *CI = dyn_cast<CastInst>(Val)) { + NewInsts[CI] = NewInsts[CI->getOperand(0)]; + continue; + } + if (auto *GEP = dyn_cast<GEPOperator>(Val)) { + Value *Index = NewInsts[GEP->getOperand(1)] ? NewInsts[GEP->getOperand(1)] + : GEP->getOperand(1); + setInsertionPoint(Builder, GEP); + // Indices might need to be sign extended. GEPs will magically do + // this, but we need to do it ourselves here. + if (Index->getType()->getScalarSizeInBits() != + NewInsts[GEP->getOperand(0)]->getType()->getScalarSizeInBits()) { + Index = Builder.CreateSExtOrTrunc( + Index, NewInsts[GEP->getOperand(0)]->getType(), + GEP->getOperand(0)->getName() + ".sext"); + } + + auto *Op = NewInsts[GEP->getOperand(0)]; + if (isa<ConstantInt>(Op) && dyn_cast<ConstantInt>(Op)->isZero()) + NewInsts[GEP] = Index; + else + NewInsts[GEP] = Builder.CreateNSWAdd( + Op, Index, GEP->getOperand(0)->getName() + ".add"); + continue; + } + if (isa<PHINode>(Val)) + continue; + + llvm_unreachable("Unexpected instruction type"); + } + + // Add the incoming values to the PHI nodes. + for (Value *Val : Explored) { + if (Val == Base) + continue; + // All the instructions have been created, we can now add edges to the + // phi nodes. + if (auto *PHI = dyn_cast<PHINode>(Val)) { + PHINode *NewPhi = static_cast<PHINode *>(NewInsts[PHI]); + for (unsigned I = 0, E = PHI->getNumIncomingValues(); I < E; ++I) { + Value *NewIncoming = PHI->getIncomingValue(I); + + if (NewInsts.find(NewIncoming) != NewInsts.end()) + NewIncoming = NewInsts[NewIncoming]; + + NewPhi->addIncoming(NewIncoming, PHI->getIncomingBlock(I)); + } + } + } + + for (Value *Val : Explored) { + if (Val == Base) + continue; + + // Depending on the type, for external users we have to emit + // a GEP or a GEP + ptrtoint. + setInsertionPoint(Builder, Val, false); + + // If required, create an inttoptr instruction for Base. + Value *NewBase = Base; + if (!Base->getType()->isPointerTy()) + NewBase = Builder.CreateBitOrPointerCast(Base, Start->getType(), + Start->getName() + "to.ptr"); + + Value *GEP = Builder.CreateInBoundsGEP( + Start->getType()->getPointerElementType(), NewBase, + makeArrayRef(NewInsts[Val]), Val->getName() + ".ptr"); + + if (!Val->getType()->isPointerTy()) { + Value *Cast = Builder.CreatePointerCast(GEP, Val->getType(), + Val->getName() + ".conv"); + GEP = Cast; + } + Val->replaceAllUsesWith(GEP); + } + + return NewInsts[Start]; +} + +/// Looks through GEPs, IntToPtrInsts and PtrToIntInsts in order to express +/// the input Value as a constant indexed GEP. Returns a pair containing +/// the GEPs Pointer and Index. +static std::pair<Value *, Value *> +getAsConstantIndexedAddress(Value *V, const DataLayout &DL) { + Type *IndexType = IntegerType::get(V->getContext(), + DL.getPointerTypeSizeInBits(V->getType())); + + Constant *Index = ConstantInt::getNullValue(IndexType); + while (true) { + if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) { + // We accept only inbouds GEPs here to exclude the possibility of + // overflow. + if (!GEP->isInBounds()) + break; + if (GEP->hasAllConstantIndices() && GEP->getNumIndices() == 1 && + GEP->getType() == V->getType()) { + V = GEP->getOperand(0); + Constant *GEPIndex = static_cast<Constant *>(GEP->getOperand(1)); + Index = ConstantExpr::getAdd( + Index, ConstantExpr::getSExtOrBitCast(GEPIndex, IndexType)); + continue; + } + break; + } + if (auto *CI = dyn_cast<IntToPtrInst>(V)) { + if (!CI->isNoopCast(DL)) + break; + V = CI->getOperand(0); + continue; + } + if (auto *CI = dyn_cast<PtrToIntInst>(V)) { + if (!CI->isNoopCast(DL)) + break; + V = CI->getOperand(0); + continue; + } + break; + } + return {V, Index}; +} + +/// Converts (CMP GEPLHS, RHS) if this change would make RHS a constant. +/// We can look through PHIs, GEPs and casts in order to determine a common base +/// between GEPLHS and RHS. +static Instruction *transformToIndexedCompare(GEPOperator *GEPLHS, Value *RHS, + ICmpInst::Predicate Cond, + const DataLayout &DL) { + if (!GEPLHS->hasAllConstantIndices()) + return nullptr; + + Value *PtrBase, *Index; + std::tie(PtrBase, Index) = getAsConstantIndexedAddress(GEPLHS, DL); + + // The set of nodes that will take part in this transformation. + SetVector<Value *> Nodes; + + if (!canRewriteGEPAsOffset(RHS, PtrBase, DL, Nodes)) + return nullptr; + + // We know we can re-write this as + // ((gep Ptr, OFFSET1) cmp (gep Ptr, OFFSET2) + // Since we've only looked through inbouds GEPs we know that we + // can't have overflow on either side. We can therefore re-write + // this as: + // OFFSET1 cmp OFFSET2 + Value *NewRHS = rewriteGEPAsOffset(RHS, PtrBase, DL, Nodes); + + // RewriteGEPAsOffset has replaced RHS and all of its uses with a re-written + // GEP having PtrBase as the pointer base, and has returned in NewRHS the + // offset. Since Index is the offset of LHS to the base pointer, we will now + // compare the offsets instead of comparing the pointers. + return new ICmpInst(ICmpInst::getSignedPredicate(Cond), Index, NewRHS); +} + +/// Fold comparisons between a GEP instruction and something else. At this point +/// we know that the GEP is on the LHS of the comparison. Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, ICmpInst::Predicate Cond, Instruction &I) { @@ -670,12 +992,13 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, Value *Cmp = Builder->CreateICmp(ICmpInst::getSignedPredicate(Cond), LOffset, ROffset); - return ReplaceInstUsesWith(I, Cmp); + return replaceInstUsesWith(I, Cmp); } // Otherwise, the base pointers are different and the indices are - // different, bail out. - return nullptr; + // different. Try convert this to an indexed compare by looking through + // PHIs/casts. + return transformToIndexedCompare(GEPLHS, RHS, Cond, DL); } // If one of the GEPs has all zero indices, recurse. @@ -706,7 +1029,7 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, } if (NumDifferences == 0) // SAME GEP? - return ReplaceInstUsesWith(I, // No comparison is needed here. + return replaceInstUsesWith(I, // No comparison is needed here. Builder->getInt1(ICmpInst::isTrueWhenEqual(Cond))); else if (NumDifferences == 1 && GEPsInBounds) { @@ -727,7 +1050,10 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, return new ICmpInst(ICmpInst::getSignedPredicate(Cond), L, R); } } - return nullptr; + + // Try convert this to an indexed compare by looking through PHIs/casts as a + // last resort. + return transformToIndexedCompare(GEPLHS, RHS, Cond, DL); } Instruction *InstCombiner::FoldAllocaCmp(ICmpInst &ICI, AllocaInst *Alloca, @@ -802,12 +1128,12 @@ Instruction *InstCombiner::FoldAllocaCmp(ICmpInst &ICI, AllocaInst *Alloca, } Type *CmpTy = CmpInst::makeCmpResultType(Other->getType()); - return ReplaceInstUsesWith( + return replaceInstUsesWith( ICI, ConstantInt::get(CmpTy, !CmpInst::isTrueWhenEqual(ICI.getPredicate()))); } -/// FoldICmpAddOpCst - Fold "icmp pred (X+CI), X". +/// Fold "icmp pred (X+CI), X". Instruction *InstCombiner::FoldICmpAddOpCst(Instruction &ICI, Value *X, ConstantInt *CI, ICmpInst::Predicate Pred) { @@ -855,8 +1181,8 @@ Instruction *InstCombiner::FoldICmpAddOpCst(Instruction &ICI, return new ICmpInst(ICmpInst::ICMP_SLT, X, ConstantExpr::getSub(SMax, C)); } -/// FoldICmpDivCst - Fold "icmp pred, ([su]div X, DivRHS), CmpRHS" where DivRHS -/// and CmpRHS are both known to be integer constants. +/// Fold "icmp pred, ([su]div X, DivRHS), CmpRHS" where DivRHS and CmpRHS are +/// both known to be integer constants. Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, ConstantInt *DivRHS) { ConstantInt *CmpRHS = cast<ConstantInt>(ICI.getOperand(1)); @@ -898,8 +1224,8 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, // Get the ICmp opcode ICmpInst::Predicate Pred = ICI.getPredicate(); - /// If the division is known to be exact, then there is no remainder from the - /// divide, so the covered range size is unit, otherwise it is the divisor. + // If the division is known to be exact, then there is no remainder from the + // divide, so the covered range size is unit, otherwise it is the divisor. ConstantInt *RangeSize = DivI->isExact() ? getOne(Prod) : DivRHS; // Figure out the interval that is being checked. For example, a comparison @@ -973,46 +1299,46 @@ Instruction *InstCombiner::FoldICmpDivCst(ICmpInst &ICI, BinaryOperator *DivI, default: llvm_unreachable("Unhandled icmp opcode!"); case ICmpInst::ICMP_EQ: if (LoOverflow && HiOverflow) - return ReplaceInstUsesWith(ICI, Builder->getFalse()); + return replaceInstUsesWith(ICI, Builder->getFalse()); if (HiOverflow) return new ICmpInst(DivIsSigned ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE, X, LoBound); if (LoOverflow) return new ICmpInst(DivIsSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT, X, HiBound); - return ReplaceInstUsesWith(ICI, InsertRangeTest(X, LoBound, HiBound, + return replaceInstUsesWith(ICI, InsertRangeTest(X, LoBound, HiBound, DivIsSigned, true)); case ICmpInst::ICMP_NE: if (LoOverflow && HiOverflow) - return ReplaceInstUsesWith(ICI, Builder->getTrue()); + return replaceInstUsesWith(ICI, Builder->getTrue()); if (HiOverflow) return new ICmpInst(DivIsSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT, X, LoBound); if (LoOverflow) return new ICmpInst(DivIsSigned ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE, X, HiBound); - return ReplaceInstUsesWith(ICI, InsertRangeTest(X, LoBound, HiBound, + return replaceInstUsesWith(ICI, InsertRangeTest(X, LoBound, HiBound, DivIsSigned, false)); case ICmpInst::ICMP_ULT: case ICmpInst::ICMP_SLT: if (LoOverflow == +1) // Low bound is greater than input range. - return ReplaceInstUsesWith(ICI, Builder->getTrue()); + return replaceInstUsesWith(ICI, Builder->getTrue()); if (LoOverflow == -1) // Low bound is less than input range. - return ReplaceInstUsesWith(ICI, Builder->getFalse()); + return replaceInstUsesWith(ICI, Builder->getFalse()); return new ICmpInst(Pred, X, LoBound); case ICmpInst::ICMP_UGT: case ICmpInst::ICMP_SGT: if (HiOverflow == +1) // High bound greater than input range. - return ReplaceInstUsesWith(ICI, Builder->getFalse()); + return replaceInstUsesWith(ICI, Builder->getFalse()); if (HiOverflow == -1) // High bound less than input range. - return ReplaceInstUsesWith(ICI, Builder->getTrue()); + return replaceInstUsesWith(ICI, Builder->getTrue()); if (Pred == ICmpInst::ICMP_UGT) return new ICmpInst(ICmpInst::ICMP_UGE, X, HiBound); return new ICmpInst(ICmpInst::ICMP_SGE, X, HiBound); } } -/// FoldICmpShrCst - Handle "icmp(([al]shr X, cst1), cst2)". +/// Handle "icmp(([al]shr X, cst1), cst2)". Instruction *InstCombiner::FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *Shr, ConstantInt *ShAmt) { const APInt &CmpRHSV = cast<ConstantInt>(ICI.getOperand(1))->getValue(); @@ -1077,7 +1403,7 @@ Instruction *InstCombiner::FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *Shr, if (Comp != CmpRHSV) { // Comparing against a bit that we know is zero. bool IsICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE; Constant *Cst = Builder->getInt1(IsICMP_NE); - return ReplaceInstUsesWith(ICI, Cst); + return replaceInstUsesWith(ICI, Cst); } // Otherwise, check to see if the bits shifted out are known to be zero. @@ -1098,7 +1424,7 @@ Instruction *InstCombiner::FoldICmpShrCst(ICmpInst &ICI, BinaryOperator *Shr, return nullptr; } -/// FoldICmpCstShrCst - Handle "(icmp eq/ne (ashr/lshr const2, A), const1)" -> +/// Handle "(icmp eq/ne (ashr/lshr const2, A), const1)" -> /// (icmp eq/ne A, Log2(const2/const1)) -> /// (icmp eq/ne A, Log2(const2) - Log2(const1)). Instruction *InstCombiner::FoldICmpCstShrCst(ICmpInst &I, Value *Op, Value *A, @@ -1109,7 +1435,7 @@ Instruction *InstCombiner::FoldICmpCstShrCst(ICmpInst &I, Value *Op, Value *A, auto getConstant = [&I, this](bool IsTrue) { if (I.getPredicate() == I.ICMP_NE) IsTrue = !IsTrue; - return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), IsTrue)); + return replaceInstUsesWith(I, ConstantInt::get(I.getType(), IsTrue)); }; auto getICmp = [&I](CmpInst::Predicate Pred, Value *LHS, Value *RHS) { @@ -1118,8 +1444,8 @@ Instruction *InstCombiner::FoldICmpCstShrCst(ICmpInst &I, Value *Op, Value *A, return new ICmpInst(Pred, LHS, RHS); }; - APInt AP1 = CI1->getValue(); - APInt AP2 = CI2->getValue(); + const APInt &AP1 = CI1->getValue(); + const APInt &AP2 = CI2->getValue(); // Don't bother doing any work for cases which InstSimplify handles. if (AP2 == 0) @@ -1163,7 +1489,7 @@ Instruction *InstCombiner::FoldICmpCstShrCst(ICmpInst &I, Value *Op, Value *A, return getConstant(false); } -/// FoldICmpCstShlCst - Handle "(icmp eq/ne (shl const2, A), const1)" -> +/// Handle "(icmp eq/ne (shl const2, A), const1)" -> /// (icmp eq/ne A, TrailingZeros(const1) - TrailingZeros(const2)). Instruction *InstCombiner::FoldICmpCstShlCst(ICmpInst &I, Value *Op, Value *A, ConstantInt *CI1, @@ -1173,7 +1499,7 @@ Instruction *InstCombiner::FoldICmpCstShlCst(ICmpInst &I, Value *Op, Value *A, auto getConstant = [&I, this](bool IsTrue) { if (I.getPredicate() == I.ICMP_NE) IsTrue = !IsTrue; - return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), IsTrue)); + return replaceInstUsesWith(I, ConstantInt::get(I.getType(), IsTrue)); }; auto getICmp = [&I](CmpInst::Predicate Pred, Value *LHS, Value *RHS) { @@ -1182,8 +1508,8 @@ Instruction *InstCombiner::FoldICmpCstShlCst(ICmpInst &I, Value *Op, Value *A, return new ICmpInst(Pred, LHS, RHS); }; - APInt AP1 = CI1->getValue(); - APInt AP2 = CI2->getValue(); + const APInt &AP1 = CI1->getValue(); + const APInt &AP2 = CI2->getValue(); // Don't bother doing any work for cases which InstSimplify handles. if (AP2 == 0) @@ -1208,8 +1534,7 @@ Instruction *InstCombiner::FoldICmpCstShlCst(ICmpInst &I, Value *Op, Value *A, return getConstant(false); } -/// visitICmpInstWithInstAndIntCst - Handle "icmp (instr, intcst)". -/// +/// Handle "icmp (instr, intcst)". Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, Instruction *LHSI, ConstantInt *RHS) { @@ -1412,9 +1737,9 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, // As a special case, check to see if this means that the // result is always true or false now. if (ICI.getPredicate() == ICmpInst::ICMP_EQ) - return ReplaceInstUsesWith(ICI, Builder->getFalse()); + return replaceInstUsesWith(ICI, Builder->getFalse()); if (ICI.getPredicate() == ICmpInst::ICMP_NE) - return ReplaceInstUsesWith(ICI, Builder->getTrue()); + return replaceInstUsesWith(ICI, Builder->getTrue()); } else { ICI.setOperand(1, NewCst); Constant *NewAndCst; @@ -1674,7 +1999,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, if (Comp != RHS) {// Comparing against a bit that we know is zero. bool IsICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE; Constant *Cst = Builder->getInt1(IsICMP_NE); - return ReplaceInstUsesWith(ICI, Cst); + return replaceInstUsesWith(ICI, Cst); } // If the shift is NUW, then it is just shifting out zeros, no need for an @@ -1764,8 +2089,28 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, break; } - case Instruction::SDiv: case Instruction::UDiv: + if (ConstantInt *DivLHS = dyn_cast<ConstantInt>(LHSI->getOperand(0))) { + Value *X = LHSI->getOperand(1); + const APInt &C1 = RHS->getValue(); + const APInt &C2 = DivLHS->getValue(); + assert(C2 != 0 && "udiv 0, X should have been simplified already."); + // (icmp ugt (udiv C2, X), C1) -> (icmp ule X, C2/(C1+1)) + if (ICI.getPredicate() == ICmpInst::ICMP_UGT) { + assert(!C1.isMaxValue() && + "icmp ugt X, UINT_MAX should have been simplified already."); + return new ICmpInst(ICmpInst::ICMP_ULE, X, + ConstantInt::get(X->getType(), C2.udiv(C1 + 1))); + } + // (icmp ult (udiv C2, X), C1) -> (icmp ugt X, C2/C1) + if (ICI.getPredicate() == ICmpInst::ICMP_ULT) { + assert(C1 != 0 && "icmp ult X, 0 should have been simplified already."); + return new ICmpInst(ICmpInst::ICMP_UGT, X, + ConstantInt::get(X->getType(), C2.udiv(C1))); + } + } + // fall-through + case Instruction::SDiv: // Fold: icmp pred ([us]div X, C1), C2 -> range test // Fold this div into the comparison, producing a range check. // Determine, based on the divide type, what the range is being @@ -1895,27 +2240,30 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } break; case Instruction::Xor: - // For the xor case, we can xor two constants together, eliminating - // the explicit xor. - if (Constant *BOC = dyn_cast<Constant>(BO->getOperand(1))) { - return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), - ConstantExpr::getXor(RHS, BOC)); - } else if (RHSV == 0) { - // Replace ((xor A, B) != 0) with (A != B) - return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), - BO->getOperand(1)); + if (BO->hasOneUse()) { + if (Constant *BOC = dyn_cast<Constant>(BO->getOperand(1))) { + // For the xor case, we can xor two constants together, eliminating + // the explicit xor. + return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), + ConstantExpr::getXor(RHS, BOC)); + } else if (RHSV == 0) { + // Replace ((xor A, B) != 0) with (A != B) + return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), + BO->getOperand(1)); + } } break; case Instruction::Sub: - // Replace ((sub A, B) != C) with (B != A-C) if A & C are constants. - if (ConstantInt *BOp0C = dyn_cast<ConstantInt>(BO->getOperand(0))) { - if (BO->hasOneUse()) + if (BO->hasOneUse()) { + if (ConstantInt *BOp0C = dyn_cast<ConstantInt>(BO->getOperand(0))) { + // Replace ((sub A, B) != C) with (B != A-C) if A & C are constants. return new ICmpInst(ICI.getPredicate(), BO->getOperand(1), - ConstantExpr::getSub(BOp0C, RHS)); - } else if (RHSV == 0) { - // Replace ((sub A, B) != 0) with (A != B) - return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), - BO->getOperand(1)); + ConstantExpr::getSub(BOp0C, RHS)); + } else if (RHSV == 0) { + // Replace ((sub A, B) != 0) with (A != B) + return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), + BO->getOperand(1)); + } } break; case Instruction::Or: @@ -1924,7 +2272,16 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, if (ConstantInt *BOC = dyn_cast<ConstantInt>(BO->getOperand(1))) { Constant *NotCI = ConstantExpr::getNot(RHS); if (!ConstantExpr::getAnd(BOC, NotCI)->isNullValue()) - return ReplaceInstUsesWith(ICI, Builder->getInt1(isICMP_NE)); + return replaceInstUsesWith(ICI, Builder->getInt1(isICMP_NE)); + + // Comparing if all bits outside of a constant mask are set? + // Replace (X | C) == -1 with (X & ~C) == ~C. + // This removes the -1 constant. + if (BO->hasOneUse() && RHS->isAllOnesValue()) { + Constant *NotBOC = ConstantExpr::getNot(BOC); + Value *And = Builder->CreateAnd(BO->getOperand(0), NotBOC); + return new ICmpInst(ICI.getPredicate(), And, NotBOC); + } } break; @@ -1933,7 +2290,7 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, // If bits are being compared against that are and'd out, then the // comparison can never succeed! if ((RHSV & ~BOC->getValue()) != 0) - return ReplaceInstUsesWith(ICI, Builder->getInt1(isICMP_NE)); + return replaceInstUsesWith(ICI, Builder->getInt1(isICMP_NE)); // If we have ((X & C) == C), turn it into ((X & C) != 0). if (RHS == BOC && RHSV.isPowerOf2()) @@ -2013,11 +2370,10 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, return nullptr; } -/// visitICmpInstWithCastAndCast - Handle icmp (cast x to y), (cast/cst). -/// We only handle extending casts so far. -/// -Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { - const CastInst *LHSCI = cast<CastInst>(ICI.getOperand(0)); +/// Handle icmp (cast x to y), (cast/cst). We only handle extending casts so +/// far. +Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICmp) { + const CastInst *LHSCI = cast<CastInst>(ICmp.getOperand(0)); Value *LHSCIOp = LHSCI->getOperand(0); Type *SrcTy = LHSCIOp->getType(); Type *DestTy = LHSCI->getType(); @@ -2028,7 +2384,7 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { if (LHSCI->getOpcode() == Instruction::PtrToInt && DL.getPointerTypeSizeInBits(SrcTy) == DestTy->getIntegerBitWidth()) { Value *RHSOp = nullptr; - if (PtrToIntOperator *RHSC = dyn_cast<PtrToIntOperator>(ICI.getOperand(1))) { + if (auto *RHSC = dyn_cast<PtrToIntOperator>(ICmp.getOperand(1))) { Value *RHSCIOp = RHSC->getOperand(0); if (RHSCIOp->getType()->getPointerAddressSpace() == LHSCIOp->getType()->getPointerAddressSpace()) { @@ -2037,11 +2393,12 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { if (LHSCIOp->getType() != RHSOp->getType()) RHSOp = Builder->CreateBitCast(RHSOp, LHSCIOp->getType()); } - } else if (Constant *RHSC = dyn_cast<Constant>(ICI.getOperand(1))) + } else if (auto *RHSC = dyn_cast<Constant>(ICmp.getOperand(1))) { RHSOp = ConstantExpr::getIntToPtr(RHSC, SrcTy); + } if (RHSOp) - return new ICmpInst(ICI.getPredicate(), LHSCIOp, RHSOp); + return new ICmpInst(ICmp.getPredicate(), LHSCIOp, RHSOp); } // The code below only handles extension cast instructions, so far. @@ -2051,9 +2408,9 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { return nullptr; bool isSignedExt = LHSCI->getOpcode() == Instruction::SExt; - bool isSignedCmp = ICI.isSigned(); + bool isSignedCmp = ICmp.isSigned(); - if (CastInst *CI = dyn_cast<CastInst>(ICI.getOperand(1))) { + if (auto *CI = dyn_cast<CastInst>(ICmp.getOperand(1))) { // Not an extension from the same type? RHSCIOp = CI->getOperand(0); if (RHSCIOp->getType() != LHSCIOp->getType()) @@ -2065,50 +2422,51 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { return nullptr; // Deal with equality cases early. - if (ICI.isEquality()) - return new ICmpInst(ICI.getPredicate(), LHSCIOp, RHSCIOp); + if (ICmp.isEquality()) + return new ICmpInst(ICmp.getPredicate(), LHSCIOp, RHSCIOp); // A signed comparison of sign extended values simplifies into a // signed comparison. if (isSignedCmp && isSignedExt) - return new ICmpInst(ICI.getPredicate(), LHSCIOp, RHSCIOp); + return new ICmpInst(ICmp.getPredicate(), LHSCIOp, RHSCIOp); // The other three cases all fold into an unsigned comparison. - return new ICmpInst(ICI.getUnsignedPredicate(), LHSCIOp, RHSCIOp); + return new ICmpInst(ICmp.getUnsignedPredicate(), LHSCIOp, RHSCIOp); } - // If we aren't dealing with a constant on the RHS, exit early - ConstantInt *CI = dyn_cast<ConstantInt>(ICI.getOperand(1)); - if (!CI) + // If we aren't dealing with a constant on the RHS, exit early. + auto *C = dyn_cast<Constant>(ICmp.getOperand(1)); + if (!C) return nullptr; // Compute the constant that would happen if we truncated to SrcTy then - // reextended to DestTy. - Constant *Res1 = ConstantExpr::getTrunc(CI, SrcTy); - Constant *Res2 = ConstantExpr::getCast(LHSCI->getOpcode(), - Res1, DestTy); + // re-extended to DestTy. + Constant *Res1 = ConstantExpr::getTrunc(C, SrcTy); + Constant *Res2 = ConstantExpr::getCast(LHSCI->getOpcode(), Res1, DestTy); // If the re-extended constant didn't change... - if (Res2 == CI) { + if (Res2 == C) { // Deal with equality cases early. - if (ICI.isEquality()) - return new ICmpInst(ICI.getPredicate(), LHSCIOp, Res1); + if (ICmp.isEquality()) + return new ICmpInst(ICmp.getPredicate(), LHSCIOp, Res1); // A signed comparison of sign extended values simplifies into a // signed comparison. if (isSignedExt && isSignedCmp) - return new ICmpInst(ICI.getPredicate(), LHSCIOp, Res1); + return new ICmpInst(ICmp.getPredicate(), LHSCIOp, Res1); // The other three cases all fold into an unsigned comparison. - return new ICmpInst(ICI.getUnsignedPredicate(), LHSCIOp, Res1); + return new ICmpInst(ICmp.getUnsignedPredicate(), LHSCIOp, Res1); } - // The re-extended constant changed so the constant cannot be represented - // in the shorter type. Consequently, we cannot emit a simple comparison. + // The re-extended constant changed, partly changed (in the case of a vector), + // or could not be determined to be equal (in the case of a constant + // expression), so the constant cannot be represented in the shorter type. + // Consequently, we cannot emit a simple comparison. // All the cases that fold to true or false will have already been handled // by SimplifyICmpInst, so only deal with the tricky case. - if (isSignedCmp || !isSignedExt) + if (isSignedCmp || !isSignedExt || !isa<ConstantInt>(C)) return nullptr; // Evaluate the comparison for LT (we invert for GT below). LE and GE cases @@ -2117,17 +2475,17 @@ Instruction *InstCombiner::visitICmpInstWithCastAndCast(ICmpInst &ICI) { // We're performing an unsigned comp with a sign extended value. // This is true if the input is >= 0. [aka >s -1] Constant *NegOne = Constant::getAllOnesValue(SrcTy); - Value *Result = Builder->CreateICmpSGT(LHSCIOp, NegOne, ICI.getName()); + Value *Result = Builder->CreateICmpSGT(LHSCIOp, NegOne, ICmp.getName()); // Finally, return the value computed. - if (ICI.getPredicate() == ICmpInst::ICMP_ULT) - return ReplaceInstUsesWith(ICI, Result); + if (ICmp.getPredicate() == ICmpInst::ICMP_ULT) + return replaceInstUsesWith(ICmp, Result); - assert(ICI.getPredicate() == ICmpInst::ICMP_UGT && "ICmp should be folded!"); + assert(ICmp.getPredicate() == ICmpInst::ICMP_UGT && "ICmp should be folded!"); return BinaryOperator::CreateNot(Result); } -/// ProcessUGT_ADDCST_ADD - The caller has matched a pattern of the form: +/// The caller has matched a pattern of the form: /// I = icmp ugt (add (add A, B), CI2), CI1 /// If this is of the form: /// sum = a + b @@ -2207,7 +2565,7 @@ static Instruction *ProcessUGT_ADDCST_ADD(ICmpInst &I, Value *A, Value *B, // The inner add was the result of the narrow add, zero extended to the // wider type. Replace it with the result computed by the intrinsic. - IC.ReplaceInstUsesWith(*OrigAdd, ZExt); + IC.replaceInstUsesWith(*OrigAdd, ZExt); // The original icmp gets replaced with the overflow value. return ExtractValueInst::Create(Call, 1, "sadd.overflow"); @@ -2491,7 +2849,7 @@ static Instruction *ProcessUMulZExtIdiom(ICmpInst &I, Value *MulVal, continue; if (TruncInst *TI = dyn_cast<TruncInst>(U)) { if (TI->getType()->getPrimitiveSizeInBits() == MulWidth) - IC.ReplaceInstUsesWith(*TI, Mul); + IC.replaceInstUsesWith(*TI, Mul); else TI->setOperand(0, Mul); } else if (BinaryOperator *BO = dyn_cast<BinaryOperator>(U)) { @@ -2503,7 +2861,7 @@ static Instruction *ProcessUMulZExtIdiom(ICmpInst &I, Value *MulVal, Instruction *Zext = cast<Instruction>(Builder->CreateZExt(ShortAnd, BO->getType())); IC.Worklist.Add(Zext); - IC.ReplaceInstUsesWith(*BO, Zext); + IC.replaceInstUsesWith(*BO, Zext); } else { llvm_unreachable("Unexpected Binary operation"); } @@ -2545,9 +2903,9 @@ static Instruction *ProcessUMulZExtIdiom(ICmpInst &I, Value *MulVal, return ExtractValueInst::Create(Call, 1); } -// DemandedBitsLHSMask - When performing a comparison against a constant, -// it is possible that not all the bits in the LHS are demanded. This helper -// method computes the mask that IS demanded. +/// When performing a comparison against a constant, it is possible that not all +/// the bits in the LHS are demanded. This helper method computes the mask that +/// IS demanded. static APInt DemandedBitsLHSMask(ICmpInst &I, unsigned BitWidth, bool isSignCheck) { if (isSignCheck) @@ -2656,9 +3014,7 @@ bool InstCombiner::dominatesAllUses(const Instruction *DI, return true; } -/// -/// true when the instruction sequence within a block is select-cmp-br. -/// +/// Return true when the instruction sequence within a block is select-cmp-br. static bool isChainSelectCmpBranch(const SelectInst *SI) { const BasicBlock *BB = SI->getParent(); if (!BB) @@ -2672,7 +3028,6 @@ static bool isChainSelectCmpBranch(const SelectInst *SI) { return true; } -/// /// \brief True when a select result is replaced by one of its operands /// in select-icmp sequence. This will eventually result in the elimination /// of the select. @@ -2738,6 +3093,63 @@ bool InstCombiner::replacedSelectWithOperand(SelectInst *SI, return false; } +/// If we have an icmp le or icmp ge instruction with a constant operand, turn +/// it into the appropriate icmp lt or icmp gt instruction. This transform +/// allows them to be folded in visitICmpInst. +static ICmpInst *canonicalizeCmpWithConstant(ICmpInst &I) { + ICmpInst::Predicate Pred = I.getPredicate(); + if (Pred != ICmpInst::ICMP_SLE && Pred != ICmpInst::ICMP_SGE && + Pred != ICmpInst::ICMP_ULE && Pred != ICmpInst::ICMP_UGE) + return nullptr; + + Value *Op0 = I.getOperand(0); + Value *Op1 = I.getOperand(1); + auto *Op1C = dyn_cast<Constant>(Op1); + if (!Op1C) + return nullptr; + + // Check if the constant operand can be safely incremented/decremented without + // overflowing/underflowing. For scalars, SimplifyICmpInst has already handled + // the edge cases for us, so we just assert on them. For vectors, we must + // handle the edge cases. + Type *Op1Type = Op1->getType(); + bool IsSigned = I.isSigned(); + bool IsLE = (Pred == ICmpInst::ICMP_SLE || Pred == ICmpInst::ICMP_ULE); + auto *CI = dyn_cast<ConstantInt>(Op1C); + if (CI) { + // A <= MAX -> TRUE ; A >= MIN -> TRUE + assert(IsLE ? !CI->isMaxValue(IsSigned) : !CI->isMinValue(IsSigned)); + } else if (Op1Type->isVectorTy()) { + // TODO? If the edge cases for vectors were guaranteed to be handled as they + // are for scalar, we could remove the min/max checks. However, to do that, + // we would have to use insertelement/shufflevector to replace edge values. + unsigned NumElts = Op1Type->getVectorNumElements(); + for (unsigned i = 0; i != NumElts; ++i) { + Constant *Elt = Op1C->getAggregateElement(i); + if (!Elt) + return nullptr; + + if (isa<UndefValue>(Elt)) + continue; + // Bail out if we can't determine if this constant is min/max or if we + // know that this constant is min/max. + auto *CI = dyn_cast<ConstantInt>(Elt); + if (!CI || (IsLE ? CI->isMaxValue(IsSigned) : CI->isMinValue(IsSigned))) + return nullptr; + } + } else { + // ConstantExpr? + return nullptr; + } + + // Increment or decrement the constant and set the new comparison predicate: + // ULE -> ULT ; UGE -> UGT ; SLE -> SLT ; SGE -> SGT + Constant *OneOrNegOne = ConstantInt::get(Op1Type, IsLE ? 1 : -1, true); + CmpInst::Predicate NewPred = IsLE ? ICmpInst::ICMP_ULT: ICmpInst::ICMP_UGT; + NewPred = IsSigned ? ICmpInst::getSignedPredicate(NewPred) : NewPred; + return new ICmpInst(NewPred, Op0, ConstantExpr::getAdd(Op1C, OneOrNegOne)); +} + Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { bool Changed = false; Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); @@ -2748,8 +3160,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { /// complex to least complex. This puts constants before unary operators, /// before binary operators. if (Op0Cplxity < Op1Cplxity || - (Op0Cplxity == Op1Cplxity && - swapMayExposeCSEOpportunities(Op0, Op1))) { + (Op0Cplxity == Op1Cplxity && swapMayExposeCSEOpportunities(Op0, Op1))) { I.swapOperands(); std::swap(Op0, Op1); Changed = true; @@ -2757,12 +3168,11 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { if (Value *V = SimplifyICmpInst(I.getPredicate(), Op0, Op1, DL, TLI, DT, AC, &I)) - return ReplaceInstUsesWith(I, V); + return replaceInstUsesWith(I, V); // comparing -val or val with non-zero is the same as just comparing val // ie, abs(val) != 0 -> val != 0 - if (I.getPredicate() == ICmpInst::ICMP_NE && match(Op1, m_Zero())) - { + if (I.getPredicate() == ICmpInst::ICMP_NE && match(Op1, m_Zero())) { Value *Cond, *SelectTrue, *SelectFalse; if (match(Op0, m_Select(m_Value(Cond), m_Value(SelectTrue), m_Value(SelectFalse)))) { @@ -2780,47 +3190,50 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { Type *Ty = Op0->getType(); // icmp's with boolean values can always be turned into bitwise operations - if (Ty->isIntegerTy(1)) { + if (Ty->getScalarType()->isIntegerTy(1)) { switch (I.getPredicate()) { default: llvm_unreachable("Invalid icmp instruction!"); - case ICmpInst::ICMP_EQ: { // icmp eq i1 A, B -> ~(A^B) - Value *Xor = Builder->CreateXor(Op0, Op1, I.getName()+"tmp"); + case ICmpInst::ICMP_EQ: { // icmp eq i1 A, B -> ~(A^B) + Value *Xor = Builder->CreateXor(Op0, Op1, I.getName() + "tmp"); return BinaryOperator::CreateNot(Xor); } - case ICmpInst::ICMP_NE: // icmp eq i1 A, B -> A^B + case ICmpInst::ICMP_NE: // icmp ne i1 A, B -> A^B return BinaryOperator::CreateXor(Op0, Op1); case ICmpInst::ICMP_UGT: std::swap(Op0, Op1); // Change icmp ugt -> icmp ult // FALL THROUGH - case ICmpInst::ICMP_ULT:{ // icmp ult i1 A, B -> ~A & B - Value *Not = Builder->CreateNot(Op0, I.getName()+"tmp"); + case ICmpInst::ICMP_ULT:{ // icmp ult i1 A, B -> ~A & B + Value *Not = Builder->CreateNot(Op0, I.getName() + "tmp"); return BinaryOperator::CreateAnd(Not, Op1); } case ICmpInst::ICMP_SGT: std::swap(Op0, Op1); // Change icmp sgt -> icmp slt // FALL THROUGH case ICmpInst::ICMP_SLT: { // icmp slt i1 A, B -> A & ~B - Value *Not = Builder->CreateNot(Op1, I.getName()+"tmp"); + Value *Not = Builder->CreateNot(Op1, I.getName() + "tmp"); return BinaryOperator::CreateAnd(Not, Op0); } case ICmpInst::ICMP_UGE: std::swap(Op0, Op1); // Change icmp uge -> icmp ule // FALL THROUGH - case ICmpInst::ICMP_ULE: { // icmp ule i1 A, B -> ~A | B - Value *Not = Builder->CreateNot(Op0, I.getName()+"tmp"); + case ICmpInst::ICMP_ULE: { // icmp ule i1 A, B -> ~A | B + Value *Not = Builder->CreateNot(Op0, I.getName() + "tmp"); return BinaryOperator::CreateOr(Not, Op1); } case ICmpInst::ICMP_SGE: std::swap(Op0, Op1); // Change icmp sge -> icmp sle // FALL THROUGH - case ICmpInst::ICMP_SLE: { // icmp sle i1 A, B -> A | ~B - Value *Not = Builder->CreateNot(Op1, I.getName()+"tmp"); + case ICmpInst::ICMP_SLE: { // icmp sle i1 A, B -> A | ~B + Value *Not = Builder->CreateNot(Op1, I.getName() + "tmp"); return BinaryOperator::CreateOr(Not, Op0); } } } + if (ICmpInst *NewICmp = canonicalizeCmpWithConstant(I)) + return NewICmp; + unsigned BitWidth = 0; if (Ty->isIntOrIntVectorTy()) BitWidth = Ty->getScalarSizeInBits(); @@ -2853,6 +3266,19 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return Res; } + // (icmp sgt smin(PosA, B) 0) -> (icmp sgt B 0) + if (CI->isZero() && I.getPredicate() == ICmpInst::ICMP_SGT) + if (auto *SI = dyn_cast<SelectInst>(Op0)) { + SelectPatternResult SPR = matchSelectPattern(SI, A, B); + if (SPR.Flavor == SPF_SMIN) { + if (isKnownPositive(A, DL)) + return new ICmpInst(I.getPredicate(), B, CI); + if (isKnownPositive(B, DL)) + return new ICmpInst(I.getPredicate(), A, CI); + } + } + + // The following transforms are only 'worth it' if the only user of the // subtraction is the icmp. if (Op0->hasOneUse()) { @@ -2882,30 +3308,6 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return new ICmpInst(ICmpInst::ICMP_SLE, A, B); } - // If we have an icmp le or icmp ge instruction, turn it into the - // appropriate icmp lt or icmp gt instruction. This allows us to rely on - // them being folded in the code below. The SimplifyICmpInst code has - // already handled the edge cases for us, so we just assert on them. - switch (I.getPredicate()) { - default: break; - case ICmpInst::ICMP_ULE: - assert(!CI->isMaxValue(false)); // A <=u MAX -> TRUE - return new ICmpInst(ICmpInst::ICMP_ULT, Op0, - Builder->getInt(CI->getValue()+1)); - case ICmpInst::ICMP_SLE: - assert(!CI->isMaxValue(true)); // A <=s MAX -> TRUE - return new ICmpInst(ICmpInst::ICMP_SLT, Op0, - Builder->getInt(CI->getValue()+1)); - case ICmpInst::ICMP_UGE: - assert(!CI->isMinValue(false)); // A >=u MIN -> TRUE - return new ICmpInst(ICmpInst::ICMP_UGT, Op0, - Builder->getInt(CI->getValue()-1)); - case ICmpInst::ICMP_SGE: - assert(!CI->isMinValue(true)); // A >=s MIN -> TRUE - return new ICmpInst(ICmpInst::ICMP_SGT, Op0, - Builder->getInt(CI->getValue()-1)); - } - if (I.isEquality()) { ConstantInt *CI2; if (match(Op0, m_AShr(m_ConstantInt(CI2), m_Value(A))) || @@ -2925,6 +3327,42 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // bits, if it is a sign bit comparison, it only demands the sign bit. bool UnusedBit; isSignBit = isSignBitCheck(I.getPredicate(), CI, UnusedBit); + + // Canonicalize icmp instructions based on dominating conditions. + BasicBlock *Parent = I.getParent(); + BasicBlock *Dom = Parent->getSinglePredecessor(); + auto *BI = Dom ? dyn_cast<BranchInst>(Dom->getTerminator()) : nullptr; + ICmpInst::Predicate Pred; + BasicBlock *TrueBB, *FalseBB; + ConstantInt *CI2; + if (BI && match(BI, m_Br(m_ICmp(Pred, m_Specific(Op0), m_ConstantInt(CI2)), + TrueBB, FalseBB)) && + TrueBB != FalseBB) { + ConstantRange CR = ConstantRange::makeAllowedICmpRegion(I.getPredicate(), + CI->getValue()); + ConstantRange DominatingCR = + (Parent == TrueBB) + ? ConstantRange::makeExactICmpRegion(Pred, CI2->getValue()) + : ConstantRange::makeExactICmpRegion( + CmpInst::getInversePredicate(Pred), CI2->getValue()); + ConstantRange Intersection = DominatingCR.intersectWith(CR); + ConstantRange Difference = DominatingCR.difference(CR); + if (Intersection.isEmptySet()) + return replaceInstUsesWith(I, Builder->getFalse()); + if (Difference.isEmptySet()) + return replaceInstUsesWith(I, Builder->getTrue()); + // Canonicalizing a sign bit comparison that gets used in a branch, + // pessimizes codegen by generating branch on zero instruction instead + // of a test and branch. So we avoid canonicalizing in such situations + // because test and branch instruction has better branch displacement + // than compare and branch instruction. + if (!isBranchOnSignBitCheck(I, isSignBit) && !I.isEquality()) { + if (auto *AI = Intersection.getSingleElement()) + return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Builder->getInt(*AI)); + if (auto *AD = Difference.getSingleElement()) + return new ICmpInst(ICmpInst::ICMP_NE, Op0, Builder->getInt(*AD)); + } + } } // See if we can fold the comparison based on range information we can get @@ -2975,7 +3413,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { default: llvm_unreachable("Unknown icmp opcode!"); case ICmpInst::ICMP_EQ: { if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max)) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); // If all bits are known zero except for one, then we know at most one // bit is set. If the comparison is against zero, then this is a check @@ -3019,7 +3457,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } case ICmpInst::ICMP_NE: { if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max)) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); // If all bits are known zero except for one, then we know at most one // bit is set. If the comparison is against zero, then this is a check @@ -3063,9 +3501,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } case ICmpInst::ICMP_ULT: if (Op0Max.ult(Op1Min)) // A <u B -> true if max(A) < min(B) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Min.uge(Op1Max)) // A <u B -> false if min(A) >= max(B) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); if (Op1Min == Op0Max) // A <u B -> A != B if max(A) == min(B) return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1); if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) { @@ -3081,9 +3519,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { break; case ICmpInst::ICMP_UGT: if (Op0Min.ugt(Op1Max)) // A >u B -> true if min(A) > max(B) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Max.ule(Op1Min)) // A >u B -> false if max(A) <= max(B) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); if (Op1Max == Op0Min) // A >u B -> A != B if min(A) == max(B) return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1); @@ -3100,9 +3538,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { break; case ICmpInst::ICMP_SLT: if (Op0Max.slt(Op1Min)) // A <s B -> true if max(A) < min(C) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Min.sge(Op1Max)) // A <s B -> false if min(A) >= max(C) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); if (Op1Min == Op0Max) // A <s B -> A != B if max(A) == min(B) return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1); if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) { @@ -3113,9 +3551,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { break; case ICmpInst::ICMP_SGT: if (Op0Min.sgt(Op1Max)) // A >s B -> true if min(A) > max(B) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Max.sle(Op1Min)) // A >s B -> false if max(A) <= min(B) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); if (Op1Max == Op0Min) // A >s B -> A != B if min(A) == max(B) return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1); @@ -3128,30 +3566,30 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { case ICmpInst::ICMP_SGE: assert(!isa<ConstantInt>(Op1) && "ICMP_SGE with ConstantInt not folded!"); if (Op0Min.sge(Op1Max)) // A >=s B -> true if min(A) >= max(B) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Max.slt(Op1Min)) // A >=s B -> false if max(A) < min(B) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); break; case ICmpInst::ICMP_SLE: assert(!isa<ConstantInt>(Op1) && "ICMP_SLE with ConstantInt not folded!"); if (Op0Max.sle(Op1Min)) // A <=s B -> true if max(A) <= min(B) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Min.sgt(Op1Max)) // A <=s B -> false if min(A) > max(B) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); break; case ICmpInst::ICMP_UGE: assert(!isa<ConstantInt>(Op1) && "ICMP_UGE with ConstantInt not folded!"); if (Op0Min.uge(Op1Max)) // A >=u B -> true if min(A) >= max(B) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Max.ult(Op1Min)) // A >=u B -> false if max(A) < min(B) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); break; case ICmpInst::ICMP_ULE: assert(!isa<ConstantInt>(Op1) && "ICMP_ULE with ConstantInt not folded!"); if (Op0Max.ule(Op1Min)) // A <=u B -> true if max(A) <= min(B) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Min.ugt(Op1Max)) // A <=u B -> false if min(A) > max(B) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); break; } @@ -3179,12 +3617,22 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // See if we are doing a comparison between a constant and an instruction that // can be folded into the comparison. if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) { + Value *A = nullptr, *B = nullptr; // Since the RHS is a ConstantInt (CI), if the left hand side is an // instruction, see if that instruction also has constants so that the // instruction can be folded into the icmp if (Instruction *LHSI = dyn_cast<Instruction>(Op0)) if (Instruction *Res = visitICmpInstWithInstAndIntCst(I, LHSI, CI)) return Res; + + // (icmp eq/ne (udiv A, B), 0) -> (icmp ugt/ule i32 B, A) + if (I.isEquality() && CI->isZero() && + match(Op0, m_UDiv(m_Value(A), m_Value(B)))) { + ICmpInst::Predicate Pred = I.getPredicate() == ICmpInst::ICMP_EQ + ? ICmpInst::ICMP_UGT + : ICmpInst::ICMP_ULE; + return new ICmpInst(Pred, B, A); + } } // Handle icmp with constant (but not simple integer constant) RHS @@ -3354,10 +3802,14 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // Analyze the case when either Op0 or Op1 is an add instruction. // Op0 = A + B (or A and B are null); Op1 = C + D (or C and D are null). Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr; - if (BO0 && BO0->getOpcode() == Instruction::Add) - A = BO0->getOperand(0), B = BO0->getOperand(1); - if (BO1 && BO1->getOpcode() == Instruction::Add) - C = BO1->getOperand(0), D = BO1->getOperand(1); + if (BO0 && BO0->getOpcode() == Instruction::Add) { + A = BO0->getOperand(0); + B = BO0->getOperand(1); + } + if (BO1 && BO1->getOpcode() == Instruction::Add) { + C = BO1->getOperand(0); + D = BO1->getOperand(1); + } // icmp (X+cst) < 0 --> X < -cst if (NoOp0WrapProblem && ICmpInst::isSigned(Pred) && match(Op1, m_Zero())) @@ -3474,11 +3926,18 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // Analyze the case when either Op0 or Op1 is a sub instruction. // Op0 = A - B (or A and B are null); Op1 = C - D (or C and D are null). - A = nullptr; B = nullptr; C = nullptr; D = nullptr; - if (BO0 && BO0->getOpcode() == Instruction::Sub) - A = BO0->getOperand(0), B = BO0->getOperand(1); - if (BO1 && BO1->getOpcode() == Instruction::Sub) - C = BO1->getOperand(0), D = BO1->getOperand(1); + A = nullptr; + B = nullptr; + C = nullptr; + D = nullptr; + if (BO0 && BO0->getOpcode() == Instruction::Sub) { + A = BO0->getOperand(0); + B = BO0->getOperand(1); + } + if (BO1 && BO1->getOpcode() == Instruction::Sub) { + C = BO1->getOperand(0); + D = BO1->getOperand(1); + } // icmp (X-Y), X -> icmp 0, Y for equalities or if there is no overflow. if (A == Op1 && NoOp0WrapProblem) @@ -3525,9 +3984,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { switch (SRem == BO0 ? ICmpInst::getSwappedPredicate(Pred) : Pred) { default: break; case ICmpInst::ICMP_EQ: - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); case ICmpInst::ICMP_NE: - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); case ICmpInst::ICMP_SGT: case ICmpInst::ICMP_SGE: return new ICmpInst(ICmpInst::ICMP_SGT, SRem->getOperand(1), @@ -3654,8 +4113,8 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { Constant *Overflow; if (OptimizeOverflowCheck(OCF_UNSIGNED_ADD, A, B, *AddI, Result, Overflow)) { - ReplaceInstUsesWith(*AddI, Result); - return ReplaceInstUsesWith(I, Overflow); + replaceInstUsesWith(*AddI, Result); + return replaceInstUsesWith(I, Overflow); } } @@ -3834,7 +4293,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return Changed ? &I : nullptr; } -/// FoldFCmp_IntToFP_Cst - Fold fcmp ([us]itofp x, cst) if possible. +/// Fold fcmp ([us]itofp x, cst) if possible. Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, Instruction *LHSI, Constant *RHSC) { @@ -3864,10 +4323,10 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, RHSRoundInt.roundToIntegral(APFloat::rmNearestTiesToEven); if (RHS.compare(RHSRoundInt) != APFloat::cmpEqual) { if (P == FCmpInst::FCMP_OEQ || P == FCmpInst::FCMP_UEQ) - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getFalse()); assert(P == FCmpInst::FCMP_ONE || P == FCmpInst::FCMP_UNE); - return ReplaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getTrue()); } } @@ -3933,9 +4392,9 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, Pred = ICmpInst::ICMP_NE; break; case FCmpInst::FCMP_ORD: - return ReplaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getTrue()); case FCmpInst::FCMP_UNO: - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getFalse()); } // Now we know that the APFloat is a normal number, zero or inf. @@ -3953,8 +4412,8 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, if (SMax.compare(RHS) == APFloat::cmpLessThan) { // smax < 13123.0 if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SLE) - return ReplaceInstUsesWith(I, Builder->getTrue()); - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getFalse()); } } else { // If the RHS value is > UnsignedMax, fold the comparison. This handles @@ -3965,8 +4424,8 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, if (UMax.compare(RHS) == APFloat::cmpLessThan) { // umax < 13123.0 if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_ULT || Pred == ICmpInst::ICMP_ULE) - return ReplaceInstUsesWith(I, Builder->getTrue()); - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getFalse()); } } @@ -3978,8 +4437,8 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, if (SMin.compare(RHS) == APFloat::cmpGreaterThan) { // smin > 12312.0 if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SGE) - return ReplaceInstUsesWith(I, Builder->getTrue()); - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getFalse()); } } else { // See if the RHS value is < UnsignedMin. @@ -3989,8 +4448,8 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, if (SMin.compare(RHS) == APFloat::cmpGreaterThan) { // umin > 12312.0 if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_UGT || Pred == ICmpInst::ICMP_UGE) - return ReplaceInstUsesWith(I, Builder->getTrue()); - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getFalse()); } } @@ -4012,14 +4471,14 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, switch (Pred) { default: llvm_unreachable("Unexpected integer comparison!"); case ICmpInst::ICMP_NE: // (float)int != 4.4 --> true - return ReplaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getTrue()); case ICmpInst::ICMP_EQ: // (float)int == 4.4 --> false - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getFalse()); case ICmpInst::ICMP_ULE: // (float)int <= 4.4 --> int <= 4 // (float)int <= -4.4 --> false if (RHS.isNegative()) - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getFalse()); break; case ICmpInst::ICMP_SLE: // (float)int <= 4.4 --> int <= 4 @@ -4031,7 +4490,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, // (float)int < -4.4 --> false // (float)int < 4.4 --> int <= 4 if (RHS.isNegative()) - return ReplaceInstUsesWith(I, Builder->getFalse()); + return replaceInstUsesWith(I, Builder->getFalse()); Pred = ICmpInst::ICMP_ULE; break; case ICmpInst::ICMP_SLT: @@ -4044,7 +4503,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, // (float)int > 4.4 --> int > 4 // (float)int > -4.4 --> true if (RHS.isNegative()) - return ReplaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getTrue()); break; case ICmpInst::ICMP_SGT: // (float)int > 4.4 --> int > 4 @@ -4056,7 +4515,7 @@ Instruction *InstCombiner::FoldFCmp_IntToFP_Cst(FCmpInst &I, // (float)int >= -4.4 --> true // (float)int >= 4.4 --> int > 4 if (RHS.isNegative()) - return ReplaceInstUsesWith(I, Builder->getTrue()); + return replaceInstUsesWith(I, Builder->getTrue()); Pred = ICmpInst::ICMP_UGT; break; case ICmpInst::ICMP_SGE: @@ -4089,7 +4548,7 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { if (Value *V = SimplifyFCmpInst(I.getPredicate(), Op0, Op1, I.getFastMathFlags(), DL, TLI, DT, AC, &I)) - return ReplaceInstUsesWith(I, V); + return replaceInstUsesWith(I, V); // Simplify 'fcmp pred X, X' if (Op0 == Op1) { @@ -4208,39 +4667,33 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { break; CallInst *CI = cast<CallInst>(LHSI); - const Function *F = CI->getCalledFunction(); - if (!F) + Intrinsic::ID IID = getIntrinsicForCallSite(CI, TLI); + if (IID != Intrinsic::fabs) break; // Various optimization for fabs compared with zero. - LibFunc::Func Func; - if (F->getIntrinsicID() == Intrinsic::fabs || - (TLI->getLibFunc(F->getName(), Func) && TLI->has(Func) && - (Func == LibFunc::fabs || Func == LibFunc::fabsf || - Func == LibFunc::fabsl))) { - switch (I.getPredicate()) { - default: - break; - // fabs(x) < 0 --> false - case FCmpInst::FCMP_OLT: - return ReplaceInstUsesWith(I, Builder->getFalse()); - // fabs(x) > 0 --> x != 0 - case FCmpInst::FCMP_OGT: - return new FCmpInst(FCmpInst::FCMP_ONE, CI->getArgOperand(0), RHSC); - // fabs(x) <= 0 --> x == 0 - case FCmpInst::FCMP_OLE: - return new FCmpInst(FCmpInst::FCMP_OEQ, CI->getArgOperand(0), RHSC); - // fabs(x) >= 0 --> !isnan(x) - case FCmpInst::FCMP_OGE: - return new FCmpInst(FCmpInst::FCMP_ORD, CI->getArgOperand(0), RHSC); - // fabs(x) == 0 --> x == 0 - // fabs(x) != 0 --> x != 0 - case FCmpInst::FCMP_OEQ: - case FCmpInst::FCMP_UEQ: - case FCmpInst::FCMP_ONE: - case FCmpInst::FCMP_UNE: - return new FCmpInst(I.getPredicate(), CI->getArgOperand(0), RHSC); - } + switch (I.getPredicate()) { + default: + break; + // fabs(x) < 0 --> false + case FCmpInst::FCMP_OLT: + llvm_unreachable("handled by SimplifyFCmpInst"); + // fabs(x) > 0 --> x != 0 + case FCmpInst::FCMP_OGT: + return new FCmpInst(FCmpInst::FCMP_ONE, CI->getArgOperand(0), RHSC); + // fabs(x) <= 0 --> x == 0 + case FCmpInst::FCMP_OLE: + return new FCmpInst(FCmpInst::FCMP_OEQ, CI->getArgOperand(0), RHSC); + // fabs(x) >= 0 --> !isnan(x) + case FCmpInst::FCMP_OGE: + return new FCmpInst(FCmpInst::FCMP_ORD, CI->getArgOperand(0), RHSC); + // fabs(x) == 0 --> x == 0 + // fabs(x) != 0 --> x != 0 + case FCmpInst::FCMP_OEQ: + case FCmpInst::FCMP_UEQ: + case FCmpInst::FCMP_ONE: + case FCmpInst::FCMP_UNE: + return new FCmpInst(I.getPredicate(), CI->getArgOperand(0), RHSC); } } } |