//===----------------------------------------------------------------------===//
#include "InstCombine.h"
+#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/PatternMatch.h"
using namespace llvm;
}
if (BinaryOperator *I = dyn_cast<BinaryOperator>(Val)) {
+ // Cannot look past anything that might overflow.
+ OverflowingBinaryOperator *OBI = dyn_cast<OverflowingBinaryOperator>(Val);
+ if (OBI && !OBI->hasNoUnsignedWrap()) {
+ Scale = 1;
+ Offset = 0;
+ return Val;
+ }
+
if (ConstantInt *RHS = dyn_cast<ConstantInt>(I->getOperand(1))) {
if (I->getOpcode() == Instruction::Shl) {
// This is a value scaled by '1 << the shift amt'.
// This requires TargetData to get the alloca alignment and size information.
if (!TD) return 0;
-
const PointerType *PTy = cast<PointerType>(CI.getType());
+ PointerType *PTy = cast<PointerType>(CI.getType());
BuilderTy AllocaBuilder(*Builder);
AllocaBuilder.SetInsertPoint(AI.getParent(), &AI);
// Get the type really allocated and the type casted to.
- const Type *AllocElTy = AI.getAllocatedType();
- const Type *CastElTy = PTy->getElementType();
+ Type *AllocElTy = AI.getAllocatedType();
+ Type *CastElTy = PTy->getElementType();
if (!AllocElTy->isSized() || !CastElTy->isSized()) return 0;
unsigned AllocElTyAlign = TD->getABITypeAlignment(AllocElTy);
// 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");
- AI.replaceAllUsesWith(NewCast);
+ ReplaceInstUsesWith(AI, NewCast);
}
return ReplaceInstUsesWith(CI, New);
}
/// EvaluateInDifferentType - Given an expression that
/// CanEvaluateTruncated or CanEvaluateSExtd returns true for, actually
/// insert the code to evaluate the expression.
-Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty,
+Value *InstCombiner::EvaluateInDifferentType(Value *V, Type *Ty,
bool isSigned) {
if (Constant *C = dyn_cast<Constant>(V)) {
C = ConstantExpr::getIntegerCast(C, Ty, isSigned /*Sext or ZExt*/);
}
case Instruction::PHI: {
PHINode *OPN = cast<PHINode>(I);
- PHINode *NPN = PHINode::Create(Ty);
- NPN->reserveOperandSpace(OPN->getNumIncomingValues());
+ 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));
}
Res->takeName(I);
- return InsertNewInstBefore(Res, *I);
+ return InsertNewInstWith(Res, *I);
}
isEliminableCastPair(
const CastInst *CI, ///< The first cast instruction
unsigned opcode, ///< The opcode of the second cast instruction
- const Type *DstTy, ///< The target type for the second cast instruction
+ Type *DstTy, ///< The target type for the second cast instruction
TargetData *TD ///< The target data for pointer size
) {
- const Type *SrcTy = CI->getOperand(0)->getType(); // A from above
- const Type *MidTy = CI->getType(); // B from above
+ Type *SrcTy = CI->getOperand(0)->getType(); // A from above
+ Type *MidTy = CI->getType(); // B from above
// Get the opcodes of the two Cast instructions
Instruction::CastOps firstOp = Instruction::CastOps(CI->getOpcode());
/// the cast can be eliminated by some other simple transformation, we prefer
/// to do the simplification first.
bool InstCombiner::ShouldOptimizeCast(Instruction::CastOps opc, const Value *V,
- const Type *Ty) {
+ Type *Ty) {
// Noop casts and casts of constants should be eliminated trivially.
if (V->getType() == Ty || isa<Constant>(V)) return false;
///
/// This function works on both vectors and scalars.
///
-static bool CanEvaluateTruncated(Value *V, const Type *Ty) {
+static bool CanEvaluateTruncated(Value *V, Type *Ty) {
// We can always evaluate constants in another type.
if (isa<Constant>(V))
return true;
Instruction *I = dyn_cast<Instruction>(V);
if (!I) return false;
- const Type *OrigTy = V->getType();
+ Type *OrigTy = V->getType();
// If this is an extension from the dest type, we can eliminate it, even if it
// has multiple uses.
return &CI;
Value *Src = CI.getOperand(0);
- const Type *DestTy = CI.getType(), *SrcTy = Src->getType();
+ Type *DestTy = CI.getType(), *SrcTy = Src->getType();
// Attempt to truncate the entire input expression tree to the destination
// type. Only do this if the dest type is a simple type, don't convert the
// It is also profitable to transform icmp eq into not(xor(A, B)) because that
// may lead to additional simplifications.
if (ICI->isEquality() && CI.getType() == ICI->getOperand(0)->getType()) {
- if (const IntegerType *ITy = dyn_cast<IntegerType>(CI.getType())) {
+ if (IntegerType *ITy = dyn_cast<IntegerType>(CI.getType())) {
uint32_t BitWidth = ITy->getBitWidth();
Value *LHS = ICI->getOperand(0);
Value *RHS = ICI->getOperand(1);
/// clear the top bits anyway, doing this has no extra cost.
///
/// This function works on both vectors and scalars.
-static bool CanEvaluateZExtd(Value *V, const Type *Ty, unsigned &BitsToClear) {
+static bool CanEvaluateZExtd(Value *V, Type *Ty, unsigned &BitsToClear) {
BitsToClear = 0;
if (isa<Constant>(V))
return true;
return &CI;
Value *Src = CI.getOperand(0);
- const Type *SrcTy = Src->getType(), *DestTy = CI.getType();
+ Type *SrcTy = Src->getType(), *DestTy = CI.getType();
// Attempt to extend the entire input expression tree to the destination
// type. Only do this if the dest type is a simple type, don't convert the
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 (VectorType *VTy = dyn_cast<VectorType>(CI.getType())) {
+ if (Pred == ICmpInst::ICMP_SLT && match(Op1, m_Zero()) &&
+ Op0->getType() == CI.getType()) {
+ 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
///
/// This function works on both vectors and scalars.
///
-static bool CanEvaluateSExtd(Value *V, const Type *Ty) {
+static bool CanEvaluateSExtd(Value *V, Type *Ty) {
assert(V->getType()->getScalarSizeInBits() < Ty->getScalarSizeInBits() &&
"Can't sign extend type to a smaller type");
// If this is a constant, it can be trivially promoted.
return &CI;
Value *Src = CI.getOperand(0);
- const Type *SrcTy = Src->getType(), *DestTy = CI.getType();
+ Type *SrcTy = Src->getType(), *DestTy = CI.getType();
// Attempt to extend the entire input expression tree to the destination
// type. Only do this if the dest type is a simple type, don't convert the
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
case Instruction::FMul:
case Instruction::FDiv:
case Instruction::FRem:
- const Type *SrcTy = OpI->getType();
+ Type *SrcTy = OpI->getType();
Value *LHSTrunc = LookThroughFPExtensions(OpI->getOperand(0));
Value *RHSTrunc = LookThroughFPExtensions(OpI->getOperand(1));
if (LHSTrunc->getType() != SrcTy &&
CallInst *Call = dyn_cast<CallInst>(CI.getOperand(0));
if (Call && Call->getCalledFunction() &&
Call->getCalledFunction()->getName() == "sqrt" &&
- Call->getNumArgOperands() == 1) {
+ Call->getNumArgOperands() == 1 &&
+ Call->hasOneUse()) {
CastInst *Arg = dyn_cast<CastInst>(Call->getArgOperand(0));
if (Arg && Arg->getOpcode() == Instruction::FPExt &&
CI.getType()->isFloatTy() &&
// Remove the old Call. With -fmath-errno, it won't get marked readnone.
- Call->replaceAllUsesWith(UndefValue::get(Call->getType()));
+ ReplaceInstUsesWith(*Call, UndefValue::get(Call->getType()));
EraseInstFromFunction(*Call);
return ret;
}
// Get the base pointer input of the bitcast, and the type it points to.
Value *OrigBase = cast<BitCastInst>(GEP->getOperand(0))->getOperand(0);
- const Type *GEPIdxTy =
+ Type *GEPIdxTy =
cast<PointerType>(OrigBase->getType())->getElementType();
SmallVector<Value*, 8> NewIndices;
if (FindElementAtOffset(GEPIdxTy, Offset, NewIndices)) {
// and bitcast the result. This eliminates one bitcast, potentially
// two.
Value *NGEP = cast<GEPOperator>(GEP)->isInBounds() ?
- Builder->CreateInBoundsGEP(OrigBase,
- NewIndices.begin(), NewIndices.end()) :
- Builder->CreateGEP(OrigBase, NewIndices.begin(), NewIndices.end());
+ Builder->CreateInBoundsGEP(OrigBase, NewIndices) :
+ Builder->CreateGEP(OrigBase, NewIndices);
NGEP->takeName(GEP);
if (isa<BitCastInst>(CI))
/// replace it with a shuffle (and vector/vector bitcast) if possible.
///
/// The source and destination vector types may have different element types.
-static Instruction *OptimizeVectorResize(Value *InVal, const VectorType *DestTy,
+static Instruction *OptimizeVectorResize(Value *InVal, VectorType *DestTy,
InstCombiner &IC) {
// We can only do this optimization if the output is a multiple of the input
// element size, or the input is a multiple of the output element size.
// Convert the input type to have the same element type as the output.
- const VectorType *SrcTy = cast<VectorType>(InVal->getType());
+ VectorType *SrcTy = cast<VectorType>(InVal->getType());
if (SrcTy->getElementType() != DestTy->getElementType()) {
// The input types don't need to be identical, but for now they must be the
// size of the input.
SmallVector<Constant*, 16> ShuffleMask;
Value *V2;
- const IntegerType *Int32Ty = Type::getInt32Ty(SrcTy->getContext());
+ IntegerType *Int32Ty = Type::getInt32Ty(SrcTy->getContext());
if (SrcTy->getNumElements() > DestTy->getNumElements()) {
// If we're shrinking the number of elements, just shuffle in the low
return new ShuffleVectorInst(InVal, V2, ConstantVector::get(ShuffleMask));
}
-static bool isMultipleOfTypeSize(unsigned Value, const Type *Ty) {
+static bool isMultipleOfTypeSize(unsigned Value, Type *Ty) {
return Value % Ty->getPrimitiveSizeInBits() == 0;
}
-static unsigned getTypeSizeIndex(unsigned Value, const Type *Ty) {
+static unsigned getTypeSizeIndex(unsigned Value, Type *Ty) {
return Value / Ty->getPrimitiveSizeInBits();
}
/// filling in Elements with the elements found here.
static bool CollectInsertionElements(Value *V, unsigned ElementIndex,
SmallVectorImpl<Value*> &Elements,
- const Type *VecEltTy) {
+ Type *VecEltTy) {
// Undef values never contribute useful bits to the result.
if (isa<UndefValue>(V)) return true;
C = ConstantExpr::getBitCast(C, IntegerType::get(V->getContext(),
C->getType()->getPrimitiveSizeInBits()));
unsigned ElementSize = VecEltTy->getPrimitiveSizeInBits();
- const Type *ElementIntTy = IntegerType::get(C->getContext(), ElementSize);
+ Type *ElementIntTy = IntegerType::get(C->getContext(), ElementSize);
for (unsigned i = 0; i != NumElts; ++i) {
Constant *Piece = ConstantExpr::getLShr(C, ConstantInt::get(C->getType(),
/// Into two insertelements that do "buildvector{%inc, %inc5}".
static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI,
InstCombiner &IC) {
- const VectorType *DestVecTy = cast<VectorType>(CI.getType());
+ VectorType *DestVecTy = cast<VectorType>(CI.getType());
Value *IntInput = CI.getOperand(0);
SmallVector<Value*, 8> Elements(DestVecTy->getNumElements());
/// bitcast. The various long double bitcasts can't get in here.
static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){
Value *Src = CI.getOperand(0);
- const Type *DestTy = CI.getType();
+ Type *DestTy = CI.getType();
// If this is a bitcast from int to float, check to see if the int is an
// extraction from a vector.
// bitcast(trunc(bitcast(somevector)))
if (match(Src, m_Trunc(m_BitCast(m_Value(VecInput)))) &&
isa<VectorType>(VecInput->getType())) {
- const VectorType *VecTy = cast<VectorType>(VecInput->getType());
+ VectorType *VecTy = cast<VectorType>(VecInput->getType());
unsigned DestWidth = DestTy->getPrimitiveSizeInBits();
if (VecTy->getPrimitiveSizeInBits() % DestWidth == 0) {
if (match(Src, m_Trunc(m_LShr(m_BitCast(m_Value(VecInput)),
m_ConstantInt(ShAmt)))) &&
isa<VectorType>(VecInput->getType())) {
- const VectorType *VecTy = cast<VectorType>(VecInput->getType());
+ VectorType *VecTy = cast<VectorType>(VecInput->getType());
unsigned DestWidth = DestTy->getPrimitiveSizeInBits();
if (VecTy->getPrimitiveSizeInBits() % DestWidth == 0 &&
ShAmt->getZExtValue() % DestWidth == 0) {
// If the operands are integer typed then apply the integer transforms,
// otherwise just apply the common ones.
Value *Src = CI.getOperand(0);
- const Type *SrcTy = Src->getType();
- const Type *DestTy = CI.getType();
+ Type *SrcTy = Src->getType();
+ Type *DestTy = CI.getType();
// Get rid of casts from one type to the same type. These are useless and can
// be replaced by the operand.
if (DestTy == Src->getType())
return ReplaceInstUsesWith(CI, Src);
- if (
const PointerType *DstPTy = dyn_cast<PointerType>(DestTy)) {
-
const PointerType *SrcPTy = cast<PointerType>(SrcTy);
- const Type *DstElTy = DstPTy->getElementType();
- const Type *SrcElTy = SrcPTy->getElementType();
+ if (PointerType *DstPTy = dyn_cast<PointerType>(DestTy)) {
+ PointerType *SrcPTy = cast<PointerType>(SrcTy);
+ Type *DstElTy = DstPTy->getElementType();
+ Type *SrcElTy = SrcPTy->getElementType();
// If the address spaces don't match, don't eliminate the bitcast, which is
// required for changing types.
// If we found a path from the src to dest, create the getelementptr now.
if (SrcElTy == DstElTy) {
SmallVector<Value*, 8> Idxs(NumZeros+1, ZeroUInt);
- return GetElementPtrInst::CreateInBounds(Src, Idxs.begin(), Idxs.end(),"",
- ((Instruction*)NULL));
+ return GetElementPtrInst::CreateInBounds(Src, Idxs);
}
}
if (Instruction *I = OptimizeIntToFloatBitCast(CI, *this))
return I;
- if (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
+ if (VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
if (DestVTy->getNumElements() == 1 && !SrcTy->isVectorTy()) {
Value *Elem = Builder->CreateBitCast(Src, DestVTy->getElementType());
return InsertElementInst::Create(UndefValue::get(DestTy), Elem,
}
}
- if (const VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
+ if (VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
if (SrcVTy->getNumElements() == 1 && !DestTy->isVectorTy()) {
Value *Elem =
Builder->CreateExtractElement(Src,
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