diff options
Diffstat (limited to 'lib/Transforms/InstCombine')
-rw-r--r-- | lib/Transforms/InstCombine/InstCombine.h | 9 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 91 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineCalls.cpp | 47 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineCasts.cpp | 150 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineCompares.cpp | 207 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp | 33 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 100 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombinePHI.cpp | 33 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineSelect.cpp | 48 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineShifts.cpp | 9 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 16 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineVectorOps.cpp | 10 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstCombineWorklist.h | 1 | ||||
-rw-r--r-- | lib/Transforms/InstCombine/InstructionCombining.cpp | 28 |
14 files changed, 562 insertions, 220 deletions
diff --git a/lib/Transforms/InstCombine/InstCombine.h b/lib/Transforms/InstCombine/InstCombine.h index 9c2969c7ab22..9c70cf89e48c 100644 --- a/lib/Transforms/InstCombine/InstCombine.h +++ b/lib/Transforms/InstCombine/InstCombine.h @@ -11,6 +11,7 @@ #define INSTCOMBINE_INSTCOMBINE_H #include "InstCombineWorklist.h" +#include "llvm/Operator.h" #include "llvm/Pass.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/Support/IRBuilder.h" @@ -69,7 +70,6 @@ class LLVM_LIBRARY_VISIBILITY InstCombiner : public FunctionPass, public InstVisitor<InstCombiner, Instruction*> { TargetData *TD; - bool MustPreserveLCSSA; bool MadeIRChange; public: /// Worklist - All of the instructions that need to be simplified. @@ -217,8 +217,8 @@ private: Instruction *transformCallThroughTrampoline(CallSite CS); Instruction *transformZExtICmp(ICmpInst *ICI, Instruction &CI, bool DoXform = true); + Instruction *transformSExtICmp(ICmpInst *ICI, Instruction &CI); bool WillNotOverflowSignedAdd(Value *LHS, Value *RHS); - DbgDeclareInst *hasOneUsePlusDeclare(Value *V); Value *EmitGEPOffset(User *GEP); public: @@ -247,7 +247,10 @@ public: // segment of unreachable code, so just clobber the instruction. if (&I == V) V = UndefValue::get(I.getType()); - + + DEBUG(errs() << "IC: Replacing " << I << "\n" + " with " << *V << '\n'); + I.replaceAllUsesWith(V); return &I; } diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 7986d1aca762..a08446e5d519 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -14,6 +14,7 @@ #include "InstCombine.h" #include "llvm/Intrinsics.h" #include "llvm/Analysis/InstructionSimplify.h" +#include "llvm/Support/ConstantRange.h" #include "llvm/Support/PatternMatch.h" using namespace llvm; using namespace PatternMatch; @@ -330,7 +331,7 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, /// InsertRangeTest - Emit a computation of: (V >= Lo && V < Hi) if Inside is -/// true, otherwise (V < Lo || V >= Hi). In pratice, we emit the more efficient +/// true, otherwise (V < Lo || V >= Hi). In practice, we emit the more efficient /// (V-Lo) <u Hi-Lo. This method expects that Lo <= Hi. isSigned indicates /// whether to treat the V, Lo and HI as signed or not. IB is the location to /// insert new instructions. @@ -755,6 +756,54 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *NewOr = Builder->CreateOr(Val, Val2); return Builder->CreateICmp(LHSCC, NewOr, LHSCst); } + + // (icmp slt A, 0) & (icmp slt B, 0) --> (icmp slt (A&B), 0) + if (LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero()) { + Value *NewAnd = Builder->CreateAnd(Val, Val2); + return Builder->CreateICmp(LHSCC, NewAnd, LHSCst); + } + + // (icmp sgt A, -1) & (icmp sgt B, -1) --> (icmp sgt (A|B), -1) + if (LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue()) { + Value *NewOr = Builder->CreateOr(Val, Val2); + return Builder->CreateICmp(LHSCC, NewOr, LHSCst); + } + } + + // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2 + // where CMAX is the all ones value for the truncated type, + // iff the lower bits of C2 and CA are zero. + if (LHSCC == RHSCC && ICmpInst::isEquality(LHSCC) && + LHS->hasOneUse() && RHS->hasOneUse()) { + Value *V; + ConstantInt *AndCst, *SmallCst = 0, *BigCst = 0; + + // (trunc x) == C1 & (and x, CA) == C2 + if (match(Val2, m_Trunc(m_Value(V))) && + match(Val, m_And(m_Specific(V), m_ConstantInt(AndCst)))) { + SmallCst = RHSCst; + BigCst = LHSCst; + } + // (and x, CA) == C2 & (trunc x) == C1 + else if (match(Val, m_Trunc(m_Value(V))) && + match(Val2, m_And(m_Specific(V), m_ConstantInt(AndCst)))) { + SmallCst = LHSCst; + BigCst = RHSCst; + } + + if (SmallCst && BigCst) { + unsigned BigBitSize = BigCst->getType()->getBitWidth(); + unsigned SmallBitSize = SmallCst->getType()->getBitWidth(); + + // Check that the low bits are zero. + APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize); + if ((Low & AndCst->getValue()) == 0 && (Low & BigCst->getValue()) == 0) { + Value *NewAnd = Builder->CreateAnd(V, Low | AndCst->getValue()); + APInt N = SmallCst->getValue().zext(BigBitSize) | BigCst->getValue(); + Value *NewVal = ConstantInt::get(AndCst->getType()->getContext(), N); + return Builder->CreateICmp(LHSCC, NewAnd, NewVal); + } + } } // From here on, we only handle: @@ -767,7 +816,17 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE || RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE) return 0; - + + // Make a constant range that's the intersection of the two icmp ranges. + // If the intersection is empty, we know that the result is false. + ConstantRange LHSRange = + ConstantRange::makeICmpRegion(LHSCC, LHSCst->getValue()); + ConstantRange RHSRange = + ConstantRange::makeICmpRegion(RHSCC, RHSCst->getValue()); + + if (LHSRange.intersectWith(RHSRange).isEmptySet()) + return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); + // We can't fold (ugt x, C) & (sgt x, C2). if (!PredicatesFoldable(LHSCC, RHSCC)) return 0; @@ -800,10 +859,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { case ICmpInst::ICMP_EQ: switch (RHSCC) { default: llvm_unreachable("Unknown integer condition code!"); - case ICmpInst::ICMP_EQ: // (X == 13 & X == 15) -> false - case ICmpInst::ICMP_UGT: // (X == 13 & X > 15) -> false - case ICmpInst::ICMP_SGT: // (X == 13 & X > 15) -> false - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); case ICmpInst::ICMP_NE: // (X == 13 & X != 15) -> X == 13 case ICmpInst::ICMP_ULT: // (X == 13 & X < 15) -> X == 13 case ICmpInst::ICMP_SLT: // (X == 13 & X < 15) -> X == 13 @@ -851,9 +906,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) { case ICmpInst::ICMP_SLT: switch (RHSCC) { default: llvm_unreachable("Unknown integer condition code!"); - case ICmpInst::ICMP_EQ: // (X s< 13 & X == 15) -> false - case ICmpInst::ICMP_SGT: // (X s< 13 & X s> 15) -> false - return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0); case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change break; case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13 @@ -1438,6 +1490,18 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *NewOr = Builder->CreateOr(Val, Val2); return Builder->CreateICmp(LHSCC, NewOr, LHSCst); } + + // (icmp slt A, 0) | (icmp slt B, 0) --> (icmp slt (A|B), 0) + if (LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero()) { + Value *NewOr = Builder->CreateOr(Val, Val2); + return Builder->CreateICmp(LHSCC, NewOr, LHSCst); + } + + // (icmp sgt A, -1) | (icmp sgt B, -1) --> (icmp sgt (A&B), -1) + if (LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue()) { + Value *NewAnd = Builder->CreateAnd(Val, Val2); + return Builder->CreateICmp(LHSCC, NewAnd, LHSCst); + } } // (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1) @@ -1975,7 +2039,14 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) { } } } - + + // or(sext(A), B) -> A ? -1 : B where A is an i1 + // or(A, sext(B)) -> B ? -1 : A where B is an i1 + if (match(Op0, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1)) + return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op1); + if (match(Op1, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1)) + return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op0); + // Note: If we've gotten to the point of visiting the outer OR, then the // inner one couldn't be simplified. If it was a constant, then it won't // be simplified by a later pass either, so we try swapping the inner/outer diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp index 0e464507a7e4..726105f75d6f 100644 --- a/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -475,7 +475,36 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { } } break; - case Intrinsic::umul_with_overflow: + case Intrinsic::umul_with_overflow: { + Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1); + unsigned BitWidth = cast<IntegerType>(LHS->getType())->getBitWidth(); + APInt Mask = APInt::getAllOnesValue(BitWidth); + + APInt LHSKnownZero(BitWidth, 0); + APInt LHSKnownOne(BitWidth, 0); + ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne); + APInt RHSKnownZero(BitWidth, 0); + APInt RHSKnownOne(BitWidth, 0); + ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne); + + // Get the largest possible values for each operand. + APInt LHSMax = ~LHSKnownZero; + APInt RHSMax = ~RHSKnownZero; + + // If multiplying the maximum values does not overflow then we can turn + // this into a plain NUW mul. + bool Overflow; + LHSMax.umul_ov(RHSMax, Overflow); + if (!Overflow) { + Value *Mul = Builder->CreateNUWMul(LHS, RHS, "umul_with_overflow"); + Constant *V[] = { + UndefValue::get(LHS->getType()), + Builder->getFalse() + }; + Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); + return InsertValueInst::Create(Struct, Mul, 0); + } + } // FALL THROUGH case Intrinsic::smul_with_overflow: // Canonicalize constants into the RHS. if (isa<Constant>(II->getArgOperand(0)) && @@ -508,11 +537,7 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { break; case Intrinsic::ppc_altivec_lvx: case Intrinsic::ppc_altivec_lvxl: - case Intrinsic::x86_sse_loadu_ps: - case Intrinsic::x86_sse2_loadu_pd: - case Intrinsic::x86_sse2_loadu_dq: - // Turn PPC lvx -> load if the pointer is known aligned. - // Turn X86 loadups -> load if the pointer is known aligned. + // Turn PPC lvx -> load if the pointer is known aligned. if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, TD) >= 16) { Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0), PointerType::getUnqual(II->getType())); @@ -731,9 +756,13 @@ protected: dyn_cast<ConstantInt>(CI->getArgOperand(SizeCIOp))) { if (SizeCI->isAllOnesValue()) return true; - if (isString) - return SizeCI->getZExtValue() >= - GetStringLength(CI->getArgOperand(SizeArgOp)); + if (isString) { + uint64_t Len = GetStringLength(CI->getArgOperand(SizeArgOp)); + // If the length is 0 we don't know how long it is and so we can't + // remove the check. + if (Len == 0) return false; + return SizeCI->getZExtValue() >= Len; + } if (ConstantInt *Arg = dyn_cast<ConstantInt>( CI->getArgOperand(SizeArgOp))) return SizeCI->getZExtValue() >= Arg->getZExtValue(); diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index b432641a1403..6f70de865764 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -87,10 +87,8 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI, // If the allocation has multiple uses, only promote it if we are strictly // increasing the alignment of the resultant allocation. If we keep it the - // same, we open the door to infinite loops of various kinds. (A reference - // from a dbg.declare doesn't count as a use for this purpose.) - if (!AI.hasOneUse() && !hasOneUsePlusDeclare(&AI) && - CastElTyAlign == AllocElTyAlign) return 0; + // same, we open the door to infinite loops of various kinds. + if (!AI.hasOneUse() && CastElTyAlign == AllocElTyAlign) return 0; uint64_t AllocElTySize = TD->getTypeAllocSize(AllocElTy); uint64_t CastElTySize = TD->getTypeAllocSize(CastElTy); @@ -128,15 +126,10 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI, New->setAlignment(AI.getAlignment()); New->takeName(&AI); - // If the allocation has one real use plus a dbg.declare, just remove the - // declare. - if (DbgDeclareInst *DI = hasOneUsePlusDeclare(&AI)) { - EraseInstFromFunction(*(Instruction*)DI); - } // If the allocation has multiple real uses, insert a cast and change all // things that used it to use the new cast. This will also hack on CI, but it // will die soon. - else if (!AI.hasOneUse()) { + if (!AI.hasOneUse()) { // New is the allocation instruction, pointer typed. AI is the original // allocation instruction, also pointer typed. Thus, cast to use is BitCast. Value *NewCast = AllocaBuilder.CreateBitCast(New, AI.getType(), "tmpcast"); @@ -203,7 +196,7 @@ Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty, } case Instruction::PHI: { PHINode *OPN = cast<PHINode>(I); - PHINode *NPN = PHINode::Create(Ty); + PHINode *NPN = PHINode::Create(Ty, OPN->getNumIncomingValues()); for (unsigned i = 0, e = OPN->getNumIncomingValues(); i != e; ++i) { Value *V =EvaluateInDifferentType(OPN->getIncomingValue(i), Ty, isSigned); NPN->addIncoming(V, OPN->getIncomingBlock(i)); @@ -883,6 +876,102 @@ Instruction *InstCombiner::visitZExt(ZExtInst &CI) { return 0; } +/// transformSExtICmp - Transform (sext icmp) to bitwise / integer operations +/// in order to eliminate the icmp. +Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) { + Value *Op0 = ICI->getOperand(0), *Op1 = ICI->getOperand(1); + ICmpInst::Predicate Pred = ICI->getPredicate(); + + if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) { + // (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if negative + // (x >s -1) ? -1 : 0 -> not (ashr x, 31) -> all ones if positive + if ((Pred == ICmpInst::ICMP_SLT && Op1C->isZero()) || + (Pred == ICmpInst::ICMP_SGT && Op1C->isAllOnesValue())) { + + Value *Sh = ConstantInt::get(Op0->getType(), + Op0->getType()->getScalarSizeInBits()-1); + Value *In = Builder->CreateAShr(Op0, Sh, Op0->getName()+".lobit"); + if (In->getType() != CI.getType()) + In = Builder->CreateIntCast(In, CI.getType(), true/*SExt*/, "tmp"); + + if (Pred == ICmpInst::ICMP_SGT) + In = Builder->CreateNot(In, In->getName()+".not"); + return ReplaceInstUsesWith(CI, In); + } + + // If we know that only one bit of the LHS of the icmp can be set and we + // have an equality comparison with zero or a power of 2, we can transform + // the icmp and sext into bitwise/integer operations. + if (ICI->hasOneUse() && + ICI->isEquality() && (Op1C->isZero() || Op1C->getValue().isPowerOf2())){ + unsigned BitWidth = Op1C->getType()->getBitWidth(); + APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0); + APInt TypeMask(APInt::getAllOnesValue(BitWidth)); + ComputeMaskedBits(Op0, TypeMask, KnownZero, KnownOne); + + APInt KnownZeroMask(~KnownZero); + if (KnownZeroMask.isPowerOf2()) { + Value *In = ICI->getOperand(0); + + // If the icmp tests for a known zero bit we can constant fold it. + if (!Op1C->isZero() && Op1C->getValue() != KnownZeroMask) { + Value *V = Pred == ICmpInst::ICMP_NE ? + ConstantInt::getAllOnesValue(CI.getType()) : + ConstantInt::getNullValue(CI.getType()); + return ReplaceInstUsesWith(CI, V); + } + + if (!Op1C->isZero() == (Pred == ICmpInst::ICMP_NE)) { + // sext ((x & 2^n) == 0) -> (x >> n) - 1 + // sext ((x & 2^n) != 2^n) -> (x >> n) - 1 + unsigned ShiftAmt = KnownZeroMask.countTrailingZeros(); + // Perform a right shift to place the desired bit in the LSB. + if (ShiftAmt) + In = Builder->CreateLShr(In, + ConstantInt::get(In->getType(), ShiftAmt)); + + // At this point "In" is either 1 or 0. Subtract 1 to turn + // {1, 0} -> {0, -1}. + In = Builder->CreateAdd(In, + ConstantInt::getAllOnesValue(In->getType()), + "sext"); + } else { + // sext ((x & 2^n) != 0) -> (x << bitwidth-n) a>> bitwidth-1 + // sext ((x & 2^n) == 2^n) -> (x << bitwidth-n) a>> bitwidth-1 + unsigned ShiftAmt = KnownZeroMask.countLeadingZeros(); + // Perform a left shift to place the desired bit in the MSB. + if (ShiftAmt) + In = Builder->CreateShl(In, + ConstantInt::get(In->getType(), ShiftAmt)); + + // Distribute the bit over the whole bit width. + In = Builder->CreateAShr(In, ConstantInt::get(In->getType(), + BitWidth - 1), "sext"); + } + + if (CI.getType() == In->getType()) + return ReplaceInstUsesWith(CI, In); + return CastInst::CreateIntegerCast(In, CI.getType(), true/*SExt*/); + } + } + } + + // vector (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if signed. + if (const VectorType *VTy = dyn_cast<VectorType>(CI.getType())) { + if (Pred == ICmpInst::ICMP_SLT && match(Op1, m_Zero()) && + Op0->getType() == CI.getType()) { + const Type *EltTy = VTy->getElementType(); + + // splat the shift constant to a constant vector. + Constant *VSh = ConstantInt::get(VTy, EltTy->getScalarSizeInBits()-1); + Value *In = Builder->CreateAShr(Op0, VSh, Op0->getName()+".lobit"); + return ReplaceInstUsesWith(CI, In); + } + } + + return 0; +} + /// CanEvaluateSExtd - Return true if we can take the specified value /// and return it as type Ty without inserting any new casts and without /// changing the value of the common low bits. This is used by code that tries @@ -1006,44 +1095,9 @@ Instruction *InstCombiner::visitSExt(SExtInst &CI) { Value *Res = Builder->CreateShl(TI->getOperand(0), ShAmt, "sext"); return BinaryOperator::CreateAShr(Res, ShAmt); } - - - // (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if signed - // (x >s -1) ? -1 : 0 -> ashr x, 31 -> all ones if not signed - { - ICmpInst::Predicate Pred; Value *CmpLHS; ConstantInt *CmpRHS; - if (match(Src, m_ICmp(Pred, m_Value(CmpLHS), m_ConstantInt(CmpRHS)))) { - // sext (x <s 0) to i32 --> x>>s31 true if signbit set. - // sext (x >s -1) to i32 --> (x>>s31)^-1 true if signbit clear. - if ((Pred == ICmpInst::ICMP_SLT && CmpRHS->isZero()) || - (Pred == ICmpInst::ICMP_SGT && CmpRHS->isAllOnesValue())) { - Value *Sh = ConstantInt::get(CmpLHS->getType(), - CmpLHS->getType()->getScalarSizeInBits()-1); - Value *In = Builder->CreateAShr(CmpLHS, Sh, CmpLHS->getName()+".lobit"); - if (In->getType() != CI.getType()) - In = Builder->CreateIntCast(In, CI.getType(), true/*SExt*/, "tmp"); - - if (Pred == ICmpInst::ICMP_SGT) - In = Builder->CreateNot(In, In->getName()+".not"); - return ReplaceInstUsesWith(CI, In); - } - } - } - // vector (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if signed. - if (const VectorType *VTy = dyn_cast<VectorType>(DestTy)) { - ICmpInst::Predicate Pred; Value *CmpLHS; - if (match(Src, m_ICmp(Pred, m_Value(CmpLHS), m_Zero()))) { - if (Pred == ICmpInst::ICMP_SLT && CmpLHS->getType() == DestTy) { - const Type *EltTy = VTy->getElementType(); - - // splat the shift constant to a constant vector. - Constant *VSh = ConstantInt::get(VTy, EltTy->getScalarSizeInBits()-1); - Value *In = Builder->CreateAShr(CmpLHS, VSh,CmpLHS->getName()+".lobit"); - return ReplaceInstUsesWith(CI, In); - } - } - } + if (ICmpInst *ICI = dyn_cast<ICmpInst>(Src)) + return transformSExtICmp(ICI, CI); // If the input is a shl/ashr pair of a same constant, then this is a sign // extension from a smaller value. If we could trust arbitrary bitwidth diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index 999de3409750..bb9b88bfe6a7 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -699,7 +699,7 @@ Instruction *InstCombiner::FoldICmpAddOpCst(ICmpInst &ICI, return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(X->getContext())); // From this point on, we know that (X+C <= X) --> (X+C < X) because C != 0, - // so the values can never be equal. Similiarly for all other "or equals" + // so the values can never be equal. Similarly for all other "or equals" // operators. // (X+1) <u X --> X >u (MAXUINT-1) --> X == 255 @@ -1289,13 +1289,21 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, } case Instruction::LShr: // (icmp pred (shr X, ShAmt), CI) - case Instruction::AShr: - // Only handle equality comparisons of shift-by-constant. - if (ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1))) - if (Instruction *Res = FoldICmpShrCst(ICI, cast<BinaryOperator>(LHSI), - ShAmt)) + case Instruction::AShr: { + // Handle equality comparisons of shift-by-constant. + BinaryOperator *BO = cast<BinaryOperator>(LHSI); + if (ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1))) { + if (Instruction *Res = FoldICmpShrCst(ICI, BO, ShAmt)) return Res; + } + + // Handle exact shr's. + if (ICI.isEquality() && BO->isExact() && BO->hasOneUse()) { + if (RHSV.isMinValue()) + return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), RHS); + } break; + } case Instruction::SDiv: case Instruction::UDiv: @@ -1376,9 +1384,9 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, if (Value *NegVal = dyn_castNegVal(BOp1)) return new ICmpInst(ICI.getPredicate(), BOp0, NegVal); - else if (Value *NegVal = dyn_castNegVal(BOp0)) + if (Value *NegVal = dyn_castNegVal(BOp0)) return new ICmpInst(ICI.getPredicate(), NegVal, BOp1); - else if (BO->hasOneUse()) { + if (BO->hasOneUse()) { Value *Neg = Builder->CreateNeg(BOp1); Neg->takeName(BO); return new ICmpInst(ICI.getPredicate(), BOp0, Neg); @@ -1855,11 +1863,11 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return new ICmpInst(ICmpInst::ICMP_SLT, Op0, ConstantInt::get(CI->getContext(), CI->getValue()+1)); case ICmpInst::ICMP_UGE: - assert(!CI->isMinValue(false)); // A >=u MIN -> TRUE + assert(!CI->isMinValue(false)); // A >=u MIN -> TRUE return new ICmpInst(ICmpInst::ICMP_UGT, Op0, ConstantInt::get(CI->getContext(), CI->getValue()-1)); case ICmpInst::ICMP_SGE: - assert(!CI->isMinValue(true)); // A >=s MIN -> TRUE + assert(!CI->isMinValue(true)); // A >=s MIN -> TRUE return new ICmpInst(ICmpInst::ICMP_SGT, Op0, ConstantInt::get(CI->getContext(), CI->getValue()-1)); } @@ -1907,18 +1915,18 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // that code below can assume that Min != Max. if (!isa<Constant>(Op0) && Op0Min == Op0Max) return new ICmpInst(I.getPredicate(), - ConstantInt::get(I.getContext(), Op0Min), Op1); + ConstantInt::get(Op0->getType(), Op0Min), Op1); if (!isa<Constant>(Op1) && Op1Min == Op1Max) return new ICmpInst(I.getPredicate(), Op0, - ConstantInt::get(I.getContext(), Op1Min)); + ConstantInt::get(Op1->getType(), Op1Min)); // Based on the range information we know about the LHS, see if we can - // simplify this comparison. For example, (x&4) < 8 is always true. + // simplify this comparison. For example, (x&4) < 8 is always true. switch (I.getPredicate()) { default: llvm_unreachable("Unknown icmp opcode!"); case ICmpInst::ICMP_EQ: { if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max)) - return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext())); + 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 @@ -1955,7 +1963,7 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } case ICmpInst::ICMP_NE: { if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max)) - return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext())); + 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 @@ -1992,9 +2000,9 @@ 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.getContext())); + 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.getContext())); + 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)) { @@ -2010,9 +2018,9 @@ 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.getContext())); + 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.getContext())); + 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); @@ -2029,9 +2037,9 @@ 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.getContext())); + 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.getContext())); + 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)) { @@ -2042,9 +2050,9 @@ 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.getContext())); + 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.getContext())); + 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); @@ -2057,30 +2065,30 @@ 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.getContext())); + 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.getContext())); + 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.getContext())); + 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.getContext())); + 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.getContext())); + 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.getContext())); + 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.getContext())); + 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.getContext())); + return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); break; } @@ -2306,6 +2314,35 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { BO0->hasOneUse() && BO1->hasOneUse()) return new ICmpInst(Pred, D, B); + BinaryOperator *SRem = NULL; + // icmp (srem X, Y), Y + if (BO0 && BO0->getOpcode() == Instruction::SRem && + Op1 == BO0->getOperand(1)) + SRem = BO0; + // icmp Y, (srem X, Y) + else if (BO1 && BO1->getOpcode() == Instruction::SRem && + Op0 == BO1->getOperand(1)) + SRem = BO1; + if (SRem) { + // We don't check hasOneUse to avoid increasing register pressure because + // the value we use is the same value this instruction was already using. + switch (SRem == BO0 ? ICmpInst::getSwappedPredicate(Pred) : Pred) { + default: break; + case ICmpInst::ICMP_EQ: + return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + case ICmpInst::ICMP_NE: + return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); + case ICmpInst::ICMP_SGT: + case ICmpInst::ICMP_SGE: + return new ICmpInst(ICmpInst::ICMP_SGT, SRem->getOperand(1), + Constant::getAllOnesValue(SRem->getType())); + case ICmpInst::ICMP_SLT: + case ICmpInst::ICMP_SLE: + return new ICmpInst(ICmpInst::ICMP_SLT, SRem->getOperand(1), + Constant::getNullValue(SRem->getType())); + } + } + if (BO0 && BO1 && BO0->getOpcode() == BO1->getOpcode() && BO0->hasOneUse() && BO1->hasOneUse() && BO0->getOperand(1) == BO1->getOperand(1)) { @@ -2356,6 +2393,27 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } } break; + case Instruction::UDiv: + case Instruction::LShr: + if (I.isSigned()) + break; + // fall-through + case Instruction::SDiv: + case Instruction::AShr: + if (!BO0->isExact() && !BO1->isExact()) + break; + return new ICmpInst(I.getPredicate(), BO0->getOperand(0), + BO1->getOperand(0)); + case Instruction::Shl: { + bool NUW = BO0->hasNoUnsignedWrap() && BO1->hasNoUnsignedWrap(); + bool NSW = BO0->hasNoSignedWrap() && BO1->hasNoSignedWrap(); + if (!NUW && !NSW) + break; + if (!NSW && I.isSigned()) + break; + return new ICmpInst(I.getPredicate(), BO0->getOperand(0), + BO1->getOperand(0)); + } } } } @@ -2425,9 +2483,8 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { } // (X&Z) == (Y&Z) -> (X^Y) & Z == 0 - if (Op0->hasOneUse() && Op1->hasOneUse() && - match(Op0, m_And(m_Value(A), m_Value(B))) && - match(Op1, m_And(m_Value(C), m_Value(D)))) { + if (match(Op0, m_OneUse(m_And(m_Value(A), m_Value(B)))) && + match(Op1, m_OneUse(m_And(m_Value(C), m_Value(D))))) { Value *X = 0, *Y = 0, *Z = 0; if (A == C) { @@ -2448,6 +2505,32 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { return &I; } } + + // Transform "icmp eq (trunc (lshr(X, cst1)), cst" to + // "icmp (and X, mask), cst" + uint64_t ShAmt = 0; + ConstantInt *Cst1; + if (Op0->hasOneUse() && + match(Op0, m_Trunc(m_OneUse(m_LShr(m_Value(A), + m_ConstantInt(ShAmt))))) && + match(Op1, m_ConstantInt(Cst1)) && + // Only do this when A has multiple uses. This is most important to do + // when it exposes other optimizations. + !A->hasOneUse()) { + unsigned ASize =cast<IntegerType>(A->getType())->getPrimitiveSizeInBits(); + + if (ShAmt < ASize) { + APInt MaskV = + APInt::getLowBitsSet(ASize, Op0->getType()->getPrimitiveSizeInBits()); + MaskV <<= ShAmt; + + APInt CmpV = Cst1->getValue().zext(ASize); + CmpV <<= ShAmt; + + Value *Mask = Builder->CreateAnd(A, Builder->getInt(MaskV)); + return new ICmpInst(I.getPredicate(), Mask, Builder->getInt(CmpV)); + } + } } { @@ -2704,6 +2787,42 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { if (Constant *RHSC = dyn_cast<Constant>(Op1)) { if (Instruction *LHSI = dyn_cast<Instruction>(Op0)) switch (LHSI->getOpcode()) { + case Instruction::FPExt: { + // fcmp (fpext x), C -> fcmp x, (fptrunc C) if fptrunc is lossless + FPExtInst *LHSExt = cast<FPExtInst>(LHSI); + ConstantFP *RHSF = dyn_cast<ConstantFP>(RHSC); + if (!RHSF) + break; + + // We can't convert a PPC double double. + if (RHSF->getType()->isPPC_FP128Ty()) + break; + + const fltSemantics *Sem; + // FIXME: This shouldn't be here. + if (LHSExt->getSrcTy()->isFloatTy()) + Sem = &APFloat::IEEEsingle; + else if (LHSExt->getSrcTy()->isDoubleTy()) + Sem = &APFloat::IEEEdouble; + else if (LHSExt->getSrcTy()->isFP128Ty()) + Sem = &APFloat::IEEEquad; + else if (LHSExt->getSrcTy()->isX86_FP80Ty()) + Sem = &APFloat::x87DoubleExtended; + else + break; + + bool Lossy; + APFloat F = RHSF->getValueAPF(); + F.convert(*Sem, APFloat::rmNearestTiesToEven, &Lossy); + + // Avoid lossy conversions and denormals. + if (!Lossy && + F.compare(APFloat::getSmallestNormalized(*Sem)) != + APFloat::cmpLessThan) + return new FCmpInst(I.getPredicate(), LHSExt->getOperand(0), + ConstantFP::get(RHSC->getContext(), F)); + break; + } case Instruction::PHI: // Only fold fcmp into the PHI if the phi and fcmp are in the same // block. If in the same block, we're encouraging jump threading. If @@ -2742,6 +2861,14 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { return SelectInst::Create(LHSI->getOperand(0), Op1, Op2); break; } + case Instruction::FSub: { + // fcmp pred (fneg x), C -> fcmp swap(pred) x, -C + Value *Op; + if (match(LHSI, m_FNeg(m_Value(Op)))) + return new FCmpInst(I.getSwappedPredicate(), Op, + ConstantExpr::getFNeg(RHSC)); + break; + } case Instruction::Load: if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(LHSI->getOperand(0))) { @@ -2755,5 +2882,17 @@ Instruction *InstCombiner::visitFCmpInst(FCmpInst &I) { } } + // fcmp pred (fneg x), (fneg y) -> fcmp swap(pred) x, y + Value *X, *Y; + if (match(Op0, m_FNeg(m_Value(X))) && match(Op1, m_FNeg(m_Value(Y)))) + return new FCmpInst(I.getSwappedPredicate(), X, Y); + + // fcmp (fpext x), (fpext y) -> fcmp x, y + if (FPExtInst *LHSExt = dyn_cast<FPExtInst>(Op0)) + if (FPExtInst *RHSExt = dyn_cast<FPExtInst>(Op1)) + if (LHSExt->getSrcTy() == RHSExt->getSrcTy()) + return new FCmpInst(I.getPredicate(), LHSExt->getOperand(0), + RHSExt->getOperand(0)); + return Changed ? &I : 0; } diff --git a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index 78ff7346abe4..432adc9d046d 100644 --- a/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -364,34 +364,12 @@ static bool equivalentAddressValues(Value *A, Value *B) { return false; } -// If this instruction has two uses, one of which is a llvm.dbg.declare, -// return the llvm.dbg.declare. -DbgDeclareInst *InstCombiner::hasOneUsePlusDeclare(Value *V) { - if (!V->hasNUses(2)) - return 0; - for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); - UI != E; ++UI) { - User *U = *UI; - if (DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(U)) - return DI; - if (isa<BitCastInst>(U) && U->hasOneUse()) { - if (DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(*U->use_begin())) - return DI; - } - } - return 0; -} - Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { Value *Val = SI.getOperand(0); Value *Ptr = SI.getOperand(1); // If the RHS is an alloca with a single use, zapify the store, making the // alloca dead. - // If the RHS is an alloca with a two uses, the other one being a - // llvm.dbg.declare, zapify the store and the declare, making the - // alloca dead. We must do this to prevent declares from affecting - // codegen. if (!SI.isVolatile()) { if (Ptr->hasOneUse()) { if (isa<AllocaInst>(Ptr)) @@ -400,17 +378,9 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) { if (isa<AllocaInst>(GEP->getOperand(0))) { if (GEP->getOperand(0)->hasOneUse()) return EraseInstFromFunction(SI); - if (DbgDeclareInst *DI = hasOneUsePlusDeclare(GEP->getOperand(0))) { - EraseInstFromFunction(*DI); - return EraseInstFromFunction(SI); - } } } } - if (DbgDeclareInst *DI = hasOneUsePlusDeclare(Ptr)) { - EraseInstFromFunction(*DI); - return EraseInstFromFunction(SI); - } } // Attempt to improve the alignment. @@ -621,8 +591,7 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) { // Insert a PHI node now if we need it. Value *MergedVal = OtherStore->getOperand(0); if (MergedVal != SI.getOperand(0)) { - PHINode *PN = PHINode::Create(MergedVal->getType(), "storemerge"); - PN->reserveOperandSpace(2); + PHINode *PN = PHINode::Create(MergedVal->getType(), 2, "storemerge"); PN->addIncoming(SI.getOperand(0), SI.getParent()); PN->addIncoming(OtherStore->getOperand(0), OtherBB); MergedVal = InsertNewInstBefore(PN, DestBB->front()); diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index d1a1fd6ddfac..57fb08aca266 100644 --- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -320,6 +320,10 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) { } } + // See if we can fold away this div instruction. + if (SimplifyDemandedInstructionBits(I)) + return &I; + // (X - (X rem Y)) / Y -> X / Y; usually originates as ((X / Y) * Y) / Y Value *X = 0, *Z = 0; if (match(Op0, m_Sub(m_Value(X), m_Value(Z)))) { // (X - Z) / Y; Y = Op1 @@ -332,6 +336,19 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) { return 0; } +/// dyn_castZExtVal - Checks if V is a zext or constant that can +/// be truncated to Ty without losing bits. +static Value *dyn_castZExtVal(Value *V, const Type *Ty) { + if (ZExtInst *Z = dyn_cast<ZExtInst>(V)) { + if (Z->getSrcTy() == Ty) + return Z->getOperand(0); + } else if (ConstantInt *C = dyn_cast<ConstantInt>(V)) { + if (C->getValue().getActiveBits() <= cast<IntegerType>(Ty)->getBitWidth()) + return ConstantExpr::getTrunc(C, Ty); + } + return 0; +} + Instruction *InstCombiner::visitUDiv(BinaryOperator &I) { Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); @@ -390,6 +407,14 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) { return SelectInst::Create(Cond, TSI, FSI); } } + + // (zext A) udiv (zext B) --> zext (A udiv B) + if (ZExtInst *ZOp0 = dyn_cast<ZExtInst>(Op0)) + if (Value *ZOp1 = dyn_castZExtVal(Op1, ZOp0->getSrcTy())) + return new ZExtInst(Builder->CreateUDiv(ZOp0->getOperand(0), ZOp1, "div", + I.isExact()), + I.getType()); + return 0; } @@ -452,27 +477,17 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) { if (Value *V = SimplifyFDivInst(Op0, Op1, TD)) return ReplaceInstUsesWith(I, V); - return 0; -} + if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) { + const APFloat &Op1F = Op1C->getValueAPF(); -/// This function implements the transforms on rem instructions that work -/// regardless of the kind of rem instruction it is (urem, srem, or frem). It -/// is used by the visitors to those instructions. -/// @brief Transforms common to all three rem instructions -Instruction *InstCombiner::commonRemTransforms(BinaryOperator &I) { - Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); - - if (isa<UndefValue>(Op0)) { // undef % X -> 0 - if (I.getType()->isFPOrFPVectorTy()) - return ReplaceInstUsesWith(I, Op0); // X % undef -> undef (could be SNaN) - return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); + // If the divisor has an exact multiplicative inverse we can turn the fdiv + // into a cheaper fmul. + APFloat Reciprocal(Op1F.getSemantics()); + if (Op1F.getExactInverse(&Reciprocal)) { + ConstantFP *RFP = ConstantFP::get(Builder->getContext(), Reciprocal); + return BinaryOperator::CreateFMul(Op0, RFP); + } } - if (isa<UndefValue>(Op1)) - return ReplaceInstUsesWith(I, Op1); // X % undef -> undef - - // Handle cases involving: rem X, (select Cond, Y, Z) - if (isa<SelectInst>(Op1) && SimplifyDivRemOfSelect(I)) - return &I; return 0; } @@ -484,26 +499,11 @@ Instruction *InstCombiner::commonRemTransforms(BinaryOperator &I) { Instruction *InstCombiner::commonIRemTransforms(BinaryOperator &I) { Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); - if (Instruction *common = commonRemTransforms(I)) - return common; - - // X % X == 0 - if (Op0 == Op1) - return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); - - // 0 % X == 0 for integer, we don't need to preserve faults! - if (Constant *LHS = dyn_cast<Constant>(Op0)) - if (LHS->isNullValue()) - return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); + // Handle cases involving: rem X, (select Cond, Y, Z) + if (isa<SelectInst>(Op1) && SimplifyDivRemOfSelect(I)) + return &I; if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) { - // X % 0 == undef, we don't need to preserve faults! - if (RHS->equalsInt(0)) - return ReplaceInstUsesWith(I, UndefValue::get(I.getType())); - - if (RHS->equalsInt(1)) // X % 1 == 0 - return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); - if (Instruction *Op0I = dyn_cast<Instruction>(Op0)) { if (SelectInst *SI = dyn_cast<SelectInst>(Op0I)) { if (Instruction *R = FoldOpIntoSelect(I, SI)) @@ -525,6 +525,9 @@ Instruction *InstCombiner::commonIRemTransforms(BinaryOperator &I) { Instruction *InstCombiner::visitURem(BinaryOperator &I) { Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); + if (Value *V = SimplifyURemInst(Op0, Op1, TD)) + return ReplaceInstUsesWith(I, V); + if (Instruction *common = commonIRemTransforms(I)) return common; @@ -552,13 +555,22 @@ Instruction *InstCombiner::visitURem(BinaryOperator &I) { return SelectInst::Create(Cond, TrueAnd, FalseAnd); } } - + + // (zext A) urem (zext B) --> zext (A urem B) + if (ZExtInst *ZOp0 = dyn_cast<ZExtInst>(Op0)) + if (Value *ZOp1 = dyn_castZExtVal(Op1, ZOp0->getSrcTy())) + return new ZExtInst(Builder->CreateURem(ZOp0->getOperand(0), ZOp1), + I.getType()); + return 0; } Instruction *InstCombiner::visitSRem(BinaryOperator &I) { Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); + if (Value *V = SimplifySRemInst(Op0, Op1, TD)) + return ReplaceInstUsesWith(I, V); + // Handle the integer rem common cases if (Instruction *Common = commonIRemTransforms(I)) return Common; @@ -617,6 +629,14 @@ Instruction *InstCombiner::visitSRem(BinaryOperator &I) { } Instruction *InstCombiner::visitFRem(BinaryOperator &I) { - return commonRemTransforms(I); -} + Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); + + if (Value *V = SimplifyFRemInst(Op0, Op1, TD)) + return ReplaceInstUsesWith(I, V); + + // Handle cases involving: rem X, (select Cond, Y, Z) + if (isa<SelectInst>(Op1) && SimplifyDivRemOfSelect(I)) + return &I; + return 0; +} diff --git a/lib/Transforms/InstCombine/InstCombinePHI.cpp b/lib/Transforms/InstCombine/InstCombinePHI.cpp index 297a18c40a97..abf61bbaf3a6 100644 --- a/lib/Transforms/InstCombine/InstCombinePHI.cpp +++ b/lib/Transforms/InstCombine/InstCombinePHI.cpp @@ -80,18 +80,16 @@ Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) { Value *InRHS = FirstInst->getOperand(1); PHINode *NewLHS = 0, *NewRHS = 0; if (LHSVal == 0) { - NewLHS = PHINode::Create(LHSType, + NewLHS = PHINode::Create(LHSType, PN.getNumIncomingValues(), FirstInst->getOperand(0)->getName() + ".pn"); - NewLHS->reserveOperandSpace(PN.getNumOperands()/2); NewLHS->addIncoming(InLHS, PN.getIncomingBlock(0)); InsertNewInstBefore(NewLHS, PN); LHSVal = NewLHS; } if (RHSVal == 0) { - NewRHS = PHINode::Create(RHSType, + NewRHS = PHINode::Create(RHSType, PN.getNumIncomingValues(), FirstInst->getOperand(1)->getName() + ".pn"); - NewRHS->reserveOperandSpace(PN.getNumOperands()/2); NewRHS->addIncoming(InRHS, PN.getIncomingBlock(0)); InsertNewInstBefore(NewRHS, PN); RHSVal = NewRHS; @@ -202,11 +200,10 @@ Instruction *InstCombiner::FoldPHIArgGEPIntoPHI(PHINode &PN) { for (unsigned i = 0, e = FixedOperands.size(); i != e; ++i) { if (FixedOperands[i]) continue; // operand doesn't need a phi. Value *FirstOp = FirstInst->getOperand(i); - PHINode *NewPN = PHINode::Create(FirstOp->getType(), + PHINode *NewPN = PHINode::Create(FirstOp->getType(), e, FirstOp->getName()+".pn"); InsertNewInstBefore(NewPN, PN); - NewPN->reserveOperandSpace(e); NewPN->addIncoming(FirstOp, PN.getIncomingBlock(0)); OperandPhis[i] = NewPN; FixedOperands[i] = NewPN; @@ -240,7 +237,7 @@ Instruction *InstCombiner::FoldPHIArgGEPIntoPHI(PHINode &PN) { /// obvious the value of the load is not changed from the point of the load to /// the end of the block it is in. /// -/// Finally, it is safe, but not profitable, to sink a load targetting a +/// Finally, it is safe, but not profitable, to sink a load targeting a /// non-address-taken alloca. Doing so will cause us to not promote the alloca /// to a register. static bool isSafeAndProfitableToSinkLoad(LoadInst *L) { @@ -340,8 +337,8 @@ Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) { // Okay, they are all the same operation. Create a new PHI node of the // correct type, and PHI together all of the LHS's of the instructions. PHINode *NewPN = PHINode::Create(FirstLI->getOperand(0)->getType(), + PN.getNumIncomingValues(), PN.getName()+".in"); - NewPN->reserveOperandSpace(PN.getNumOperands()/2); Value *InVal = FirstLI->getOperand(0); NewPN->addIncoming(InVal, PN.getIncomingBlock(0)); @@ -446,8 +443,8 @@ Instruction *InstCombiner::FoldPHIArgOpIntoPHI(PHINode &PN) { // Okay, they are all the same operation. Create a new PHI node of the // correct type, and PHI together all of the LHS's of the instructions. PHINode *NewPN = PHINode::Create(FirstInst->getOperand(0)->getType(), + PN.getNumIncomingValues(), PN.getName()+".in"); - NewPN->reserveOperandSpace(PN.getNumOperands()/2); Value *InVal = FirstInst->getOperand(0); NewPN->addIncoming(InVal, PN.getIncomingBlock(0)); @@ -699,7 +696,8 @@ Instruction *InstCombiner::SliceUpIllegalIntegerPHI(PHINode &FirstPhi) { if ((EltPHI = ExtractedVals[LoweredPHIRecord(PN, Offset, Ty)]) == 0) { // Otherwise, Create the new PHI node for this user. - EltPHI = PHINode::Create(Ty, PN->getName()+".off"+Twine(Offset), PN); + EltPHI = PHINode::Create(Ty, PN->getNumIncomingValues(), + PN->getName()+".off"+Twine(Offset), PN); assert(EltPHI->getType() != PN->getType() && "Truncate didn't shrink phi?"); @@ -776,9 +774,6 @@ Instruction *InstCombiner::SliceUpIllegalIntegerPHI(PHINode &FirstPhi) { // PHINode simplification // Instruction *InstCombiner::visitPHINode(PHINode &PN) { - // If LCSSA is around, don't mess with Phi nodes - if (MustPreserveLCSSA) return 0; - if (Value *V = SimplifyInstruction(&PN, TD)) return ReplaceInstUsesWith(PN, V); @@ -826,18 +821,18 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) { // quick check to see if the PHI node only contains a single non-phi value, if // so, scan to see if the phi cycle is actually equal to that value. { - unsigned InValNo = 0, NumOperandVals = PN.getNumIncomingValues(); + unsigned InValNo = 0, NumIncomingVals = PN.getNumIncomingValues(); // Scan for the first non-phi operand. - while (InValNo != NumOperandVals && + while (InValNo != NumIncomingVals && isa<PHINode>(PN.getIncomingValue(InValNo))) ++InValNo; - if (InValNo != NumOperandVals) { - Value *NonPhiInVal = PN.getOperand(InValNo); + if (InValNo != NumIncomingVals) { + Value *NonPhiInVal = PN.getIncomingValue(InValNo); // Scan the rest of the operands to see if there are any conflicts, if so // there is no need to recursively scan other phis. - for (++InValNo; InValNo != NumOperandVals; ++InValNo) { + for (++InValNo; InValNo != NumIncomingVals; ++InValNo) { Value *OpVal = PN.getIncomingValue(InValNo); if (OpVal != NonPhiInVal && !isa<PHINode>(OpVal)) break; @@ -846,7 +841,7 @@ Instruction *InstCombiner::visitPHINode(PHINode &PN) { // If we scanned over all operands, then we have one unique value plus // phi values. Scan PHI nodes to see if they all merge in each other or // the value. - if (InValNo == NumOperandVals) { + if (InValNo == NumIncomingVals) { SmallPtrSet<PHINode*, 16> ValueEqualPHIs; if (PHIsEqualValue(&PN, NonPhiInVal, ValueEqualPHIs)) return ReplaceInstUsesWith(PN, NonPhiInVal); diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp index 97abc769ae5f..61a433a9c00c 100644 --- a/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -214,7 +214,7 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal, unsigned OpToFold = 0; if ((SFO & 1) && FalseVal == TVI->getOperand(0)) { OpToFold = 1; - } else if ((SFO & 2) && FalseVal == TVI->getOperand(1)) { + } else if ((SFO & 2) && FalseVal == TVI->getOperand(1)) { OpToFold = 2; } @@ -227,9 +227,16 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal, Instruction *NewSel = SelectInst::Create(SI.getCondition(), OOp, C); InsertNewInstBefore(NewSel, SI); NewSel->takeName(TVI); - if (BinaryOperator *BO = dyn_cast<BinaryOperator>(TVI)) - return BinaryOperator::Create(BO->getOpcode(), FalseVal, NewSel); - llvm_unreachable("Unknown instruction!!"); + BinaryOperator *TVI_BO = cast<BinaryOperator>(TVI); + BinaryOperator *BO = BinaryOperator::Create(TVI_BO->getOpcode(), + FalseVal, NewSel); + if (isa<PossiblyExactOperator>(BO)) + BO->setIsExact(TVI_BO->isExact()); + if (isa<OverflowingBinaryOperator>(BO)) { + BO->setHasNoUnsignedWrap(TVI_BO->hasNoUnsignedWrap()); + BO->setHasNoSignedWrap(TVI_BO->hasNoSignedWrap()); + } + return BO; } } } @@ -243,7 +250,7 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal, unsigned OpToFold = 0; if ((SFO & 1) && TrueVal == FVI->getOperand(0)) { OpToFold = 1; - } else if ((SFO & 2) && TrueVal == FVI->getOperand(1)) { + } else if ((SFO & 2) && TrueVal == FVI->getOperand(1)) { OpToFold = 2; } @@ -256,9 +263,16 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal, Instruction *NewSel = SelectInst::Create(SI.getCondition(), C, OOp); InsertNewInstBefore(NewSel, SI); NewSel->takeName(FVI); - if (BinaryOperator *BO = dyn_cast<BinaryOperator>(FVI)) - return BinaryOperator::Create(BO->getOpcode(), TrueVal, NewSel); - llvm_unreachable("Unknown instruction!!"); + BinaryOperator *FVI_BO = cast<BinaryOperator>(FVI); + BinaryOperator *BO = BinaryOperator::Create(FVI_BO->getOpcode(), + TrueVal, NewSel); + if (isa<PossiblyExactOperator>(BO)) + BO->setIsExact(FVI_BO->isExact()); + if (isa<OverflowingBinaryOperator>(BO)) { + BO->setHasNoUnsignedWrap(FVI_BO->hasNoUnsignedWrap()); + BO->setHasNoSignedWrap(FVI_BO->hasNoSignedWrap()); + } + return BO; } } } @@ -424,6 +438,19 @@ Instruction *InstCombiner::visitSelectInstWithICmp(SelectInst &SI, return ReplaceInstUsesWith(SI, TrueVal); /// NOTE: if we wanted to, this is where to detect integer MIN/MAX } + + if (isa<Constant>(CmpRHS)) { + if (CmpLHS == TrueVal && Pred == ICmpInst::ICMP_EQ) { + // Transform (X == C) ? X : Y -> (X == C) ? C : Y + SI.setOperand(1, CmpRHS); + Changed = true; + } else if (CmpLHS == FalseVal && Pred == ICmpInst::ICMP_NE) { + // Transform (X != C) ? Y : X -> (X != C) ? Y : C + SI.setOperand(2, CmpRHS); + Changed = true; + } + } + return Changed ? &SI : 0; } @@ -503,9 +530,8 @@ static Value *foldSelectICmpAnd(const SelectInst &SI, ConstantInt *TrueVal, if (!IC || !IC->isEquality()) return 0; - if (ConstantInt *C = dyn_cast<ConstantInt>(IC->getOperand(1))) - if (!C->isZero()) - return 0; + if (!match(IC->getOperand(1), m_Zero())) + return 0; ConstantInt *AndRHS; Value *LHS = IC->getOperand(0); diff --git a/lib/Transforms/InstCombine/InstCombineShifts.cpp b/lib/Transforms/InstCombine/InstCombineShifts.cpp index a7f800587bb6..811f94976f68 100644 --- a/lib/Transforms/InstCombine/InstCombineShifts.cpp +++ b/lib/Transforms/InstCombine/InstCombineShifts.cpp @@ -644,7 +644,14 @@ Instruction *InstCombiner::visitShl(BinaryOperator &I) { return &I; } } - + + // (C1 << A) << C2 -> (C1 << C2) << A + Constant *C1, *C2; + Value *A; + if (match(I.getOperand(0), m_OneUse(m_Shl(m_Constant(C1), m_Value(A)))) && + match(I.getOperand(1), m_Constant(C2))) + return BinaryOperator::CreateShl(ConstantExpr::getShl(C1, C2), A); + return 0; } diff --git a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index bda8cea4e41f..6e727ce6e35c 100644 --- a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -684,6 +684,10 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, break; case Instruction::SRem: if (ConstantInt *Rem = dyn_cast<ConstantInt>(I->getOperand(1))) { + // X % -1 demands all the bits because we don't want to introduce + // INT_MIN % -1 (== undef) by accident. + if (Rem->isAllOnesValue()) + break; APInt RA = Rem->getValue().abs(); if (RA.isPowerOf2()) { if (DemandedMask.ult(RA)) // srem won't affect demanded bits @@ -712,6 +716,18 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, assert(!(KnownZero & KnownOne) && "Bits known to be one AND zero?"); } } + + // The sign bit is the LHS's sign bit, except when the result of the + // remainder is zero. + if (DemandedMask.isNegative() && KnownZero.isNonNegative()) { + APInt Mask2 = APInt::getSignBit(BitWidth); + APInt LHSKnownZero(BitWidth, 0), LHSKnownOne(BitWidth, 0); + ComputeMaskedBits(I->getOperand(0), Mask2, LHSKnownZero, LHSKnownOne, + Depth+1); + // If it's known zero, our sign bit is also zero. + if (LHSKnownZero.isNegative()) + KnownZero |= LHSKnownZero; + } break; case Instruction::URem: { APInt KnownZero2(BitWidth, 0), KnownOne2(BitWidth, 0); diff --git a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp index 5caa12dfdfa5..ad6a8d054ee7 100644 --- a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp +++ b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp @@ -230,8 +230,16 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) { ConstantInt::get(Int32Ty, SrcIdx, false)); } + } else if (CastInst *CI = dyn_cast<CastInst>(I)) { + // Canonicalize extractelement(cast) -> cast(extractelement) + // bitcasts can change the number of vector elements and they cost nothing + if (CI->hasOneUse() && EI.hasOneUse() && + (CI->getOpcode() != Instruction::BitCast)) { + Value *EE = Builder->CreateExtractElement(CI->getOperand(0), + EI.getIndexOperand()); + return CastInst::Create(CI->getOpcode(), EE, EI.getType()); + } } - // FIXME: Canonicalize extractelement(bitcast) -> bitcast(extractelement) } return 0; } diff --git a/lib/Transforms/InstCombine/InstCombineWorklist.h b/lib/Transforms/InstCombine/InstCombineWorklist.h index 9100a851f16e..32009c39ec25 100644 --- a/lib/Transforms/InstCombine/InstCombineWorklist.h +++ b/lib/Transforms/InstCombine/InstCombineWorklist.h @@ -53,6 +53,7 @@ public: void AddInitialGroup(Instruction *const *List, unsigned NumEntries) { assert(Worklist.empty() && "Worklist must be empty to add initial group"); Worklist.reserve(NumEntries+16); + WorklistMap.resize(NumEntries); DEBUG(errs() << "IC: ADDING: " << NumEntries << " instrs to worklist\n"); for (; NumEntries; --NumEntries) { Instruction *I = List[NumEntries-1]; diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp index 37123d0621eb..7a84598c3a0d 100644 --- a/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -76,7 +76,6 @@ INITIALIZE_PASS(InstCombiner, "instcombine", "Combine redundant instructions", false, false) void InstCombiner::getAnalysisUsage(AnalysisUsage &AU) const { - AU.addPreservedID(LCSSAID); AU.setPreservesCFG(); } @@ -600,8 +599,7 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { } // Okay, we can do the transformation: create the new PHI node. - PHINode *NewPN = PHINode::Create(I.getType(), ""); - NewPN->reserveOperandSpace(PN->getNumOperands()/2); + PHINode *NewPN = PHINode::Create(I.getType(), PN->getNumIncomingValues(), ""); InsertNewInstBefore(NewPN, *PN); NewPN->takeName(PN); @@ -850,22 +848,23 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { GetElementPtrInst::Create(Src->getOperand(0), Indices.begin(), Indices.end(), GEP.getName()); } - + // Handle gep(bitcast x) and gep(gep x, 0, 0, 0). Value *StrippedPtr = PtrOp->stripPointerCasts(); - if (StrippedPtr != PtrOp) { - const PointerType *StrippedPtrTy =cast<PointerType>(StrippedPtr->getType()); + const PointerType *StrippedPtrTy =cast<PointerType>(StrippedPtr->getType()); + if (StrippedPtr != PtrOp && + StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace()) { bool HasZeroPointerIndex = false; if (ConstantInt *C = dyn_cast<ConstantInt>(GEP.getOperand(1))) HasZeroPointerIndex = C->isZero(); - + // Transform: GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ... // into : GEP [10 x i8]* X, i32 0, ... // // Likewise, transform: GEP (bitcast i8* X to [0 x i8]*), i32 0, ... // into : GEP i8* X, ... - // + // // This occurs when the program declares an array extern like "int X[];" if (HasZeroPointerIndex) { const PointerType *CPTy = cast<PointerType>(PtrOp->getType()); @@ -976,7 +975,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { } } } - + /// See if we can simplify: /// X = bitcast A* to B* /// Y = gep X, <...constant indices...> @@ -984,12 +983,14 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) { /// analysis of unions. If "A" is also a bitcast, wait for A/X to be merged. if (BitCastInst *BCI = dyn_cast<BitCastInst>(PtrOp)) { if (TD && - !isa<BitCastInst>(BCI->getOperand(0)) && GEP.hasAllConstantIndices()) { + !isa<BitCastInst>(BCI->getOperand(0)) && GEP.hasAllConstantIndices() && + StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace()) { + // Determine how much the GEP moves the pointer. We are guaranteed to get // a constant back from EmitGEPOffset. ConstantInt *OffsetV = cast<ConstantInt>(EmitGEPOffset(&GEP)); int64_t Offset = OffsetV->getSExtValue(); - + // If this GEP instruction doesn't move the pointer, just replace the GEP // with a bitcast of the real input to the dest type. if (Offset == 0) { @@ -1635,7 +1636,6 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { bool InstCombiner::runOnFunction(Function &F) { - MustPreserveLCSSA = mustPreserveAnalysisID(LCSSAID); TD = getAnalysisIfAvailable<TargetData>(); @@ -1648,6 +1648,10 @@ bool InstCombiner::runOnFunction(Function &F) { bool EverMadeChange = false; + // Lower dbg.declare intrinsics otherwise their value may be clobbered + // by instcombiner. + EverMadeChange = LowerDbgDeclare(F); + // Iterate while there is work to do. unsigned Iteration = 0; while (DoOneIteration(F, Iteration++)) |