diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineCompares.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 82 |
1 files changed, 52 insertions, 30 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index 02e8bf1..5e71c5c 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -612,9 +612,10 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, if (ICmpInst::isSigned(Cond)) return nullptr; - // Look through bitcasts. - if (BitCastInst *BCI = dyn_cast<BitCastInst>(RHS)) - RHS = BCI->getOperand(0); + // Look through bitcasts and addrspacecasts. We do not however want to remove + // 0 GEPs. + if (!isa<GetElementPtrInst>(RHS)) + RHS = RHS->stripPointerCasts(); Value *PtrBase = GEPLHS->getOperand(0); if (DL && PtrBase == RHS && GEPLHS->isInBounds()) { @@ -655,9 +656,24 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, (GEPRHS->hasAllConstantIndices() || GEPRHS->hasOneUse()) && PtrBase->stripPointerCasts() == GEPRHS->getOperand(0)->stripPointerCasts()) { + Value *LOffset = EmitGEPOffset(GEPLHS); + Value *ROffset = EmitGEPOffset(GEPRHS); + + // If we looked through an addrspacecast between different sized address + // spaces, the LHS and RHS pointers are different sized + // integers. Truncate to the smaller one. + Type *LHSIndexTy = LOffset->getType(); + Type *RHSIndexTy = ROffset->getType(); + if (LHSIndexTy != RHSIndexTy) { + if (LHSIndexTy->getPrimitiveSizeInBits() < + RHSIndexTy->getPrimitiveSizeInBits()) { + ROffset = Builder->CreateTrunc(ROffset, LHSIndexTy); + } else + LOffset = Builder->CreateTrunc(LOffset, RHSIndexTy); + } + Value *Cmp = Builder->CreateICmp(ICmpInst::getSignedPredicate(Cond), - EmitGEPOffset(GEPLHS), - EmitGEPOffset(GEPRHS)); + LOffset, ROffset); return ReplaceInstUsesWith(I, Cmp); } @@ -667,26 +683,12 @@ Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS, } // If one of the GEPs has all zero indices, recurse. - bool AllZeros = true; - for (unsigned i = 1, e = GEPLHS->getNumOperands(); i != e; ++i) - if (!isa<Constant>(GEPLHS->getOperand(i)) || - !cast<Constant>(GEPLHS->getOperand(i))->isNullValue()) { - AllZeros = false; - break; - } - if (AllZeros) + if (GEPLHS->hasAllZeroIndices()) return FoldGEPICmp(GEPRHS, GEPLHS->getOperand(0), ICmpInst::getSwappedPredicate(Cond), I); // If the other GEP has all zero indices, recurse. - AllZeros = true; - for (unsigned i = 1, e = GEPRHS->getNumOperands(); i != e; ++i) - if (!isa<Constant>(GEPRHS->getOperand(i)) || - !cast<Constant>(GEPRHS->getOperand(i))->isNullValue()) { - AllZeros = false; - break; - } - if (AllZeros) + if (GEPRHS->hasAllZeroIndices()) return FoldGEPICmp(GEPLHS, GEPRHS->getOperand(0), Cond, I); bool GEPsInBounds = GEPLHS->isInBounds() && GEPRHS->isInBounds(); @@ -2026,9 +2028,13 @@ static Instruction *ProcessUAddIdiom(Instruction &I, Value *OrigAddV, /// replacement required. static Instruction *ProcessUMulZExtIdiom(ICmpInst &I, Value *MulVal, Value *OtherVal, InstCombiner &IC) { + // Don't bother doing this transformation for pointers, don't do it for + // vectors. + if (!isa<IntegerType>(MulVal->getType())) + return nullptr; + assert(I.getOperand(0) == MulVal || I.getOperand(1) == MulVal); assert(I.getOperand(0) == OtherVal || I.getOperand(1) == OtherVal); - assert(isa<IntegerType>(MulVal->getType())); Instruction *MulInstr = cast<Instruction>(MulVal); assert(MulInstr->getOpcode() == Instruction::Mul); @@ -2523,7 +2529,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // bit is set. If the comparison is against zero, then this is a check // to see if *that* bit is set. APInt Op0KnownZeroInverted = ~Op0KnownZero; - if (~Op1KnownZero == 0 && Op0KnownZeroInverted.isPowerOf2()) { + if (~Op1KnownZero == 0) { // If the LHS is an AND with the same constant, look through it. Value *LHS = nullptr; ConstantInt *LHSC = nullptr; @@ -2533,11 +2539,19 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // If the LHS is 1 << x, and we know the result is a power of 2 like 8, // then turn "((1 << x)&8) == 0" into "x != 3". + // or turn "((1 << x)&7) == 0" into "x > 2". Value *X = nullptr; if (match(LHS, m_Shl(m_One(), m_Value(X)))) { - unsigned CmpVal = Op0KnownZeroInverted.countTrailingZeros(); - return new ICmpInst(ICmpInst::ICMP_NE, X, - ConstantInt::get(X->getType(), CmpVal)); + APInt ValToCheck = Op0KnownZeroInverted; + if (ValToCheck.isPowerOf2()) { + unsigned CmpVal = ValToCheck.countTrailingZeros(); + return new ICmpInst(ICmpInst::ICMP_NE, X, + ConstantInt::get(X->getType(), CmpVal)); + } else if ((++ValToCheck).isPowerOf2()) { + unsigned CmpVal = ValToCheck.countTrailingZeros() - 1; + return new ICmpInst(ICmpInst::ICMP_UGT, X, + ConstantInt::get(X->getType(), CmpVal)); + } } // If the LHS is 8 >>u x, and we know the result is a power of 2 like 1, @@ -2560,7 +2574,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // bit is set. If the comparison is against zero, then this is a check // to see if *that* bit is set. APInt Op0KnownZeroInverted = ~Op0KnownZero; - if (~Op1KnownZero == 0 && Op0KnownZeroInverted.isPowerOf2()) { + if (~Op1KnownZero == 0) { // If the LHS is an AND with the same constant, look through it. Value *LHS = nullptr; ConstantInt *LHSC = nullptr; @@ -2570,11 +2584,19 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // If the LHS is 1 << x, and we know the result is a power of 2 like 8, // then turn "((1 << x)&8) != 0" into "x == 3". + // or turn "((1 << x)&7) != 0" into "x < 3". Value *X = nullptr; if (match(LHS, m_Shl(m_One(), m_Value(X)))) { - unsigned CmpVal = Op0KnownZeroInverted.countTrailingZeros(); - return new ICmpInst(ICmpInst::ICMP_EQ, X, - ConstantInt::get(X->getType(), CmpVal)); + APInt ValToCheck = Op0KnownZeroInverted; + if (ValToCheck.isPowerOf2()) { + unsigned CmpVal = ValToCheck.countTrailingZeros(); + return new ICmpInst(ICmpInst::ICMP_EQ, X, + ConstantInt::get(X->getType(), CmpVal)); + } else if ((++ValToCheck).isPowerOf2()) { + unsigned CmpVal = ValToCheck.countTrailingZeros(); + return new ICmpInst(ICmpInst::ICMP_ULT, X, + ConstantInt::get(X->getType(), CmpVal)); + } } // If the LHS is 8 >>u x, and we know the result is a power of 2 like 1, |