//===----------------------------------------------------------------------===//
#include "InstCombine.h"
-#include "llvm/Target/TargetData.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/IR/DataLayout.h"
#include "llvm/Support/PatternMatch.h"
+#include "llvm/Target/TargetLibraryInfo.h"
using namespace llvm;
using namespace PatternMatch;
Scale = 0;
return ConstantInt::get(Val->getType(), 0);
}
-
+
if (BinaryOperator *I = dyn_cast<BinaryOperator>(Val)) {
+ // Cannot look past anything that might overflow.
+ OverflowingBinaryOperator *OBI = dyn_cast<OverflowingBinaryOperator>(Val);
+ if (OBI && !OBI->hasNoUnsignedWrap() && !OBI->hasNoSignedWrap()) {
+ 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'.
Offset = 0;
return I->getOperand(0);
}
-
+
if (I->getOpcode() == Instruction::Mul) {
// This value is scaled by 'RHS'.
Scale = RHS->getZExtValue();
Offset = 0;
return I->getOperand(0);
}
-
+
if (I->getOpcode() == Instruction::Add) {
- // We have X+C. Check to see if we really have (X*C2)+C1,
+ // We have X+C. Check to see if we really have (X*C2)+C1,
// where C1 is divisible by C2.
unsigned SubScale;
- Value *SubVal =
+ Value *SubVal =
DecomposeSimpleLinearExpr(I->getOperand(0), SubScale, Offset);
Offset += RHS->getZExtValue();
Scale = SubScale;
/// try to eliminate the cast by moving the type information into the alloc.
Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI,
AllocaInst &AI) {
- // This requires TargetData to get the alloca alignment and size information.
+ // This requires DataLayout 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);
// 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);
uint64_t ArrayOffset;
Value *NumElements = // See if the array size is a decomposable linear expr.
DecomposeSimpleLinearExpr(AI.getOperand(0), ArraySizeScale, ArrayOffset);
-
+
// If we can now satisfy the modulus, by using a non-1 scale, we really can
// do the xform.
if ((AllocElTySize*ArraySizeScale) % CastElTySize != 0 ||
} else {
Amt = ConstantInt::get(AI.getArraySize()->getType(), Scale);
// Insert before the alloca, not before the cast.
- Amt = AllocaBuilder.CreateMul(Amt, NumElements, "tmp");
+ Amt = AllocaBuilder.CreateMul(Amt, NumElements);
}
-
+
if (uint64_t Offset = (AllocElTySize*ArrayOffset)/CastElTySize) {
Value *Off = ConstantInt::get(AI.getArraySize()->getType(),
Offset, true);
- Amt = AllocaBuilder.CreateAdd(Amt, Off, "tmp");
+ Amt = AllocaBuilder.CreateAdd(Amt, Off);
}
-
+
AllocaInst *New = AllocaBuilder.CreateAlloca(CastElTy, Amt);
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");
- AI.replaceAllUsesWith(NewCast);
+ ReplaceInstUsesWith(AI, NewCast);
}
return ReplaceInstUsesWith(CI, New);
}
-
-
-/// EvaluateInDifferentType - Given an expression that
+/// 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*/);
// If we got a constantexpr back, try to simplify it with TD info.
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
- C = ConstantFoldConstantExpression(CE, TD);
+ C = ConstantFoldConstantExpression(CE, TD, TLI);
return C;
}
Value *RHS = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
Res = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
break;
- }
+ }
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt:
// new.
if (I->getOperand(0)->getType() == Ty)
return I->getOperand(0);
-
+
// Otherwise, must be the same type of cast, so just reinsert a new one.
// This also handles the case of zext(trunc(x)) -> zext(x).
Res = CastInst::CreateIntegerCast(I->getOperand(0), 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));
Res = NPN;
break;
}
- default:
+ default:
// TODO: Can handle more cases here.
llvm_unreachable("Unreachable!");
- break;
}
-
+
Res->takeName(I);
- return InsertNewInstBefore(Res, *I);
+ return InsertNewInstWith(Res, *I);
}
/// This function is a wrapper around CastInst::isEliminableCastPair. It
/// simply extracts arguments and returns what that function returns.
-static Instruction::CastOps
+static Instruction::CastOps
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
- TargetData *TD ///< The target data for pointer size
+ Type *DstTy, ///< The target type for the second cast instruction
+ DataLayout *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());
Instruction::CastOps secondOp = Instruction::CastOps(opcode);
-
+ Type *SrcIntPtrTy = TD && SrcTy->isPtrOrPtrVectorTy() ?
+ TD->getIntPtrType(SrcTy) : 0;
+ Type *MidIntPtrTy = TD && MidTy->isPtrOrPtrVectorTy() ?
+ TD->getIntPtrType(MidTy) : 0;
+ Type *DstIntPtrTy = TD && DstTy->isPtrOrPtrVectorTy() ?
+ TD->getIntPtrType(DstTy) : 0;
unsigned Res = CastInst::isEliminableCastPair(firstOp, secondOp, SrcTy, MidTy,
- DstTy,
- TD ? TD->getIntPtrType(CI->getContext()) : 0);
-
+ DstTy, SrcIntPtrTy, MidIntPtrTy,
+ DstIntPtrTy);
+
// We don't want to form an inttoptr or ptrtoint that converts to an integer
// type that differs from the pointer size.
- if ((Res == Instruction::IntToPtr &&
- (!TD || SrcTy != TD->getIntPtrType(CI->getContext()))) ||
- (Res == Instruction::PtrToInt &&
- (!TD || DstTy != TD->getIntPtrType(CI->getContext()))))
+ if ((Res == Instruction::IntToPtr && SrcTy != DstIntPtrTy) ||
+ (Res == Instruction::PtrToInt && DstTy != SrcIntPtrTy))
Res = 0;
-
+
return Instruction::CastOps(Res);
}
/// 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;
-
+
// If this is another cast that can be eliminated, we prefer to have it
// eliminated.
if (const CastInst *CI = dyn_cast<CastInst>(V))
if (isEliminableCastPair(CI, opc, Ty, TD))
return false;
-
+
// If this is a vector sext from a compare, then we don't want to break the
// idiom where each element of the extended vector is either zero or all ones.
if (opc == Instruction::SExt && isa<CmpInst>(V) && Ty->isVectorTy())
return false;
-
+
return true;
}
// Many cases of "cast of a cast" are eliminable. If it's eliminable we just
// eliminate it now.
if (CastInst *CSrc = dyn_cast<CastInst>(Src)) { // A->B->C cast
- if (Instruction::CastOps opc =
+ if (Instruction::CastOps opc =
isEliminableCastPair(CSrc, CI.getOpcode(), CI.getType(), TD)) {
// The first cast (CSrc) is eliminable so we need to fix up or replace
// the second cast (CI). CSrc will then have a good chance of being dead.
if (Instruction *NV = FoldOpIntoPhi(CI))
return NV;
}
-
+
return 0;
}
///
/// 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.
- if ((isa<ZExtInst>(I) || isa<SExtInst>(I)) &&
+ if ((isa<ZExtInst>(I) || isa<SExtInst>(I)) &&
I->getOperand(0)->getType() == Ty)
return true;
case Instruction::Trunc:
// trunc(trunc(x)) -> trunc(x)
return true;
+ case Instruction::ZExt:
+ case Instruction::SExt:
+ // trunc(ext(x)) -> ext(x) if the source type is smaller than the new dest
+ // trunc(ext(x)) -> trunc(x) if the source type is larger than the new dest
+ return true;
case Instruction::Select: {
SelectInst *SI = cast<SelectInst>(I);
return CanEvaluateTruncated(SI->getTrueValue(), Ty) &&
// TODO: Can handle more cases here.
break;
}
-
+
return false;
}
Instruction *InstCombiner::visitTrunc(TruncInst &CI) {
if (Instruction *Result = commonCastTransforms(CI))
return Result;
-
- // See if we can simplify any instructions used by the input whose sole
+
+ // See if we can simplify any instructions used by the input whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(CI))
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
// expression tree to something weird like i93 unless the source is also
// strange.
if ((DestTy->isVectorTy() || ShouldChangeType(SrcTy, DestTy)) &&
CanEvaluateTruncated(Src, DestTy)) {
-
+
// If this cast is a truncate, evaluting in a different type always
// eliminates the cast, so it is always a win.
DEBUG(dbgs() << "ICE: EvaluateInDifferentType converting expression type"
// Canonicalize trunc x to i1 -> (icmp ne (and x, 1), 0), likewise for vector.
if (DestTy->getScalarSizeInBits() == 1) {
Constant *One = ConstantInt::get(Src->getType(), 1);
- Src = Builder->CreateAnd(Src, One, "tmp");
+ Src = Builder->CreateAnd(Src, One);
Value *Zero = Constant::getNullValue(Src->getType());
return new ICmpInst(ICmpInst::ICMP_NE, Src, Zero);
}
+ // Transform trunc(lshr (zext A), Cst) to eliminate one type conversion.
+ Value *A = 0; ConstantInt *Cst = 0;
+ if (Src->hasOneUse() &&
+ match(Src, m_LShr(m_ZExt(m_Value(A)), m_ConstantInt(Cst)))) {
+ // We have three types to worry about here, the type of A, the source of
+ // the truncate (MidSize), and the destination of the truncate. We know that
+ // ASize < MidSize and MidSize > ResultSize, but don't know the relation
+ // between ASize and ResultSize.
+ unsigned ASize = A->getType()->getPrimitiveSizeInBits();
+
+ // If the shift amount is larger than the size of A, then the result is
+ // known to be zero because all the input bits got shifted out.
+ if (Cst->getZExtValue() >= ASize)
+ return ReplaceInstUsesWith(CI, Constant::getNullValue(CI.getType()));
+
+ // Since we're doing an lshr and a zero extend, and know that the shift
+ // amount is smaller than ASize, it is always safe to do the shift in A's
+ // type, then zero extend or truncate to the result.
+ Value *Shift = Builder->CreateLShr(A, Cst->getZExtValue());
+ Shift->takeName(Src);
+ return CastInst::CreateIntegerCast(Shift, CI.getType(), false);
+ }
+
+ // Transform "trunc (and X, cst)" -> "and (trunc X), cst" so long as the dest
+ // type isn't non-native.
+ if (Src->hasOneUse() && isa<IntegerType>(Src->getType()) &&
+ ShouldChangeType(Src->getType(), CI.getType()) &&
+ match(Src, m_And(m_Value(A), m_ConstantInt(Cst)))) {
+ Value *NewTrunc = Builder->CreateTrunc(A, CI.getType(), A->getName()+".tr");
+ return BinaryOperator::CreateAnd(NewTrunc,
+ ConstantExpr::getTrunc(Cst, CI.getType()));
+ }
+
return 0;
}
// cast to integer to avoid the comparison.
if (ConstantInt *Op1C = dyn_cast<ConstantInt>(ICI->getOperand(1))) {
const APInt &Op1CV = Op1C->getValue();
-
+
// zext (x <s 0) to i32 --> x>>u31 true if signbit set.
// zext (x >s -1) to i32 --> (x>>u31)^1 true if signbit clear.
if ((ICI->getPredicate() == ICmpInst::ICMP_SLT && Op1CV == 0) ||
In->getType()->getScalarSizeInBits()-1);
In = Builder->CreateLShr(In, Sh, In->getName()+".lobit");
if (In->getType() != CI.getType())
- In = Builder->CreateIntCast(In, CI.getType(), false/*ZExt*/, "tmp");
+ In = Builder->CreateIntCast(In, CI.getType(), false/*ZExt*/);
if (ICI->getPredicate() == ICmpInst::ICMP_SGT) {
Constant *One = ConstantInt::get(In->getType(), 1);
return ReplaceInstUsesWith(CI, In);
}
-
-
-
+
// zext (X == 0) to i32 --> X^1 iff X has only the low bit set.
// zext (X == 0) to i32 --> (X>>1)^1 iff X has only the 2nd bit set.
// zext (X == 1) to i32 --> X iff X has only the low bit set.
// zext (X != 0) to i32 --> X>>1 iff X has only the 2nd bit set.
// zext (X != 1) to i32 --> X^1 iff X has only the low bit set.
// zext (X != 2) to i32 --> (X>>1)^1 iff X has only the 2nd bit set.
- if ((Op1CV == 0 || Op1CV.isPowerOf2()) &&
+ if ((Op1CV == 0 || Op1CV.isPowerOf2()) &&
// This only works for EQ and NE
ICI->isEquality()) {
// If Op1C some other power of two, convert:
uint32_t BitWidth = Op1C->getType()->getBitWidth();
APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- APInt TypeMask(APInt::getAllOnesValue(BitWidth));
- ComputeMaskedBits(ICI->getOperand(0), TypeMask, KnownZero, KnownOne);
-
+ ComputeMaskedBits(ICI->getOperand(0), KnownZero, KnownOne);
+
APInt KnownZeroMask(~KnownZero);
if (KnownZeroMask.isPowerOf2()) { // Exactly 1 possible 1?
if (!DoXform) return ICI;
Res = ConstantExpr::getZExt(Res, CI.getType());
return ReplaceInstUsesWith(CI, Res);
}
-
+
uint32_t ShiftAmt = KnownZeroMask.logBase2();
Value *In = ICI->getOperand(0);
if (ShiftAmt) {
In = Builder->CreateLShr(In, ConstantInt::get(In->getType(),ShiftAmt),
In->getName()+".lobit");
}
-
+
if ((Op1CV != 0) == isNE) { // Toggle the low bit.
Constant *One = ConstantInt::get(In->getType(), 1);
- In = Builder->CreateXor(In, One, "tmp");
+ In = Builder->CreateXor(In, One);
}
-
+
if (CI.getType() == In->getType())
return ReplaceInstUsesWith(CI, In);
- else
- return CastInst::CreateIntegerCast(In, CI.getType(), false/*ZExt*/);
+ return CastInst::CreateIntegerCast(In, CI.getType(), false/*ZExt*/);
}
}
}
// 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);
APInt KnownZeroLHS(BitWidth, 0), KnownOneLHS(BitWidth, 0);
APInt KnownZeroRHS(BitWidth, 0), KnownOneRHS(BitWidth, 0);
- APInt TypeMask(APInt::getAllOnesValue(BitWidth));
- ComputeMaskedBits(LHS, TypeMask, KnownZeroLHS, KnownOneLHS);
- ComputeMaskedBits(RHS, TypeMask, KnownZeroRHS, KnownOneRHS);
+ ComputeMaskedBits(LHS, KnownZeroLHS, KnownOneLHS);
+ ComputeMaskedBits(RHS, KnownZeroRHS, KnownOneRHS);
if (KnownZeroLHS == KnownZeroRHS && KnownOneLHS == KnownOneRHS) {
APInt KnownBits = KnownZeroLHS | KnownOneLHS;
/// 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;
-
+
Instruction *I = dyn_cast<Instruction>(V);
if (!I) return false;
-
+
// If the input is a truncate from the destination type, we can trivially
- // eliminate it, even if it has multiple uses.
- // FIXME: This is currently disabled until codegen can handle this without
- // pessimizing code, PR5997.
- if (0 && isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty)
+ // eliminate it.
+ if (isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty)
return true;
-
+
// We can't extend or shrink something that has multiple uses: doing so would
// require duplicating the instruction in general, which isn't profitable.
if (!I->hasOneUse()) return false;
-
+
unsigned Opc = I->getOpcode(), Tmp;
switch (Opc) {
case Instruction::ZExt: // zext(zext(x)) -> zext(x).
// These can all be promoted if neither operand has 'bits to clear'.
if (BitsToClear == 0 && Tmp == 0)
return true;
-
+
// If the operation is an AND/OR/XOR and the bits to clear are zero in the
// other side, BitsToClear is ok.
if (Tmp == 0 &&
APInt::getHighBitsSet(VSize, BitsToClear)))
return true;
}
-
+
// Otherwise, we don't know how to analyze this BitsToClear case yet.
return false;
-
+
case Instruction::LShr:
// We can promote lshr(x, cst) if we can promote x. This requires the
// ultimate 'and' to clear out the high zero bits we're clearing out though.
Tmp != BitsToClear)
return false;
return true;
-
+
case Instruction::PHI: {
// We can change a phi if we can change all operands. Note that we never
// get into trouble with cyclic PHIs here because we only consider
}
Instruction *InstCombiner::visitZExt(ZExtInst &CI) {
- // If this zero extend is only used by a truncate, let the truncate by
+ // If this zero extend is only used by a truncate, let the truncate be
// eliminated before we try to optimize this zext.
if (CI.hasOneUse() && isa<TruncInst>(CI.use_back()))
return 0;
-
+
// If one of the common conversion will work, do it.
if (Instruction *Result = commonCastTransforms(CI))
return Result;
- // See if we can simplify any instructions used by the input whose sole
+ // See if we can simplify any instructions used by the input whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(CI))
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
// expression tree to something weird like i93 unless the source is also
// strange.
unsigned BitsToClear;
if ((DestTy->isVectorTy() || ShouldChangeType(SrcTy, DestTy)) &&
- CanEvaluateZExtd(Src, DestTy, BitsToClear)) {
+ CanEvaluateZExtd(Src, DestTy, BitsToClear)) {
assert(BitsToClear < SrcTy->getScalarSizeInBits() &&
"Unreasonable BitsToClear");
-
+
// Okay, we can transform this! Insert the new expression now.
DEBUG(dbgs() << "ICE: EvaluateInDifferentType converting expression type"
" to avoid zero extend: " << CI);
Value *Res = EvaluateInDifferentType(Src, DestTy, false);
assert(Res->getType() == DestTy);
-
+
uint32_t SrcBitsKept = SrcTy->getScalarSizeInBits()-BitsToClear;
uint32_t DestBitSize = DestTy->getScalarSizeInBits();
-
+
// If the high bits are already filled with zeros, just replace this
// cast with the result.
if (MaskedValueIsZero(Res, APInt::getHighBitsSet(DestBitSize,
DestBitSize-SrcBitsKept)))
return ReplaceInstUsesWith(CI, Res);
-
+
// We need to emit an AND to clear the high bits.
Constant *C = ConstantInt::get(Res->getType(),
APInt::getLowBitsSet(DestBitSize, SrcBitsKept));
// 'and' which will be much cheaper than the pair of casts.
if (TruncInst *CSrc = dyn_cast<TruncInst>(Src)) { // A->B->C cast
// TODO: Subsume this into EvaluateInDifferentType.
-
+
// Get the sizes of the types involved. We know that the intermediate type
// will be smaller than A or C, but don't know the relation between A and C.
Value *A = CSrc->getOperand(0);
Value *And = Builder->CreateAnd(A, AndConst, CSrc->getName()+".mask");
return new ZExtInst(And, CI.getType());
}
-
+
if (SrcSize == DstSize) {
APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
return BinaryOperator::CreateAnd(A, ConstantInt::get(A->getType(),
AndValue));
}
if (SrcSize > DstSize) {
- Value *Trunc = Builder->CreateTrunc(A, CI.getType(), "tmp");
+ Value *Trunc = Builder->CreateTrunc(A, CI.getType());
APInt AndValue(APInt::getLowBitsSet(DstSize, MidSize));
- return BinaryOperator::CreateAnd(Trunc,
+ return BinaryOperator::CreateAnd(Trunc,
ConstantInt::get(Trunc->getType(),
AndValue));
}
Value *TI0 = TI->getOperand(0);
if (TI0->getType() == CI.getType()) {
Constant *ZC = ConstantExpr::getZExt(C, CI.getType());
- Value *NewAnd = Builder->CreateAnd(TI0, ZC, "tmp");
+ Value *NewAnd = Builder->CreateAnd(TI0, ZC);
return BinaryOperator::CreateXor(NewAnd, ZC);
}
}
Value *New = Builder->CreateZExt(X, CI.getType());
return BinaryOperator::CreateXor(New, ConstantInt::get(CI.getType(), 1));
}
-
+
+ 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*/);
+
+ 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);
+ ComputeMaskedBits(Op0, 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;
}
///
/// 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.
if (isa<Constant>(V))
return true;
-
+
Instruction *I = dyn_cast<Instruction>(V);
if (!I) return false;
-
- // If this is a truncate from the dest type, we can trivially eliminate it,
- // even if it has multiple uses.
- // FIXME: This is currently disabled until codegen can handle this without
- // pessimizing code, PR5997.
- if (0 && isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty)
+
+ // If this is a truncate from the dest type, we can trivially eliminate it.
+ if (isa<TruncInst>(I) && I->getOperand(0)->getType() == Ty)
return true;
-
+
// We can't extend or shrink something that has multiple uses: doing so would
// require duplicating the instruction in general, which isn't profitable.
if (!I->hasOneUse()) return false;
// These operators can all arbitrarily be extended if their inputs can.
return CanEvaluateSExtd(I->getOperand(0), Ty) &&
CanEvaluateSExtd(I->getOperand(1), Ty);
-
+
//case Instruction::Shl: TODO
//case Instruction::LShr: TODO
-
+
case Instruction::Select:
return CanEvaluateSExtd(I->getOperand(1), Ty) &&
CanEvaluateSExtd(I->getOperand(2), Ty);
-
+
case Instruction::PHI: {
// We can change a phi if we can change all operands. Note that we never
// get into trouble with cyclic PHIs here because we only consider
// TODO: Can handle more cases here.
break;
}
-
+
return false;
}
Instruction *InstCombiner::visitSExt(SExtInst &CI) {
- // If this sign extend is only used by a truncate, let the truncate by
- // eliminated before we try to optimize this zext.
+ // If this sign extend is only used by a truncate, let the truncate be
+ // eliminated before we try to optimize this sext.
if (CI.hasOneUse() && isa<TruncInst>(CI.use_back()))
return 0;
-
+
if (Instruction *I = commonCastTransforms(CI))
return I;
-
- // See if we can simplify any instructions used by the input whose sole
+
+ // See if we can simplify any instructions used by the input whose sole
// purpose is to compute bits we don't care about.
if (SimplifyDemandedInstructionBits(CI))
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
// cast with the result.
if (ComputeNumSignBits(Res) > DestBitSize - SrcBitSize)
return ReplaceInstUsesWith(CI, Res);
-
+
// We need to emit a shl + ashr to do the sign extend.
Value *ShAmt = ConstantInt::get(DestTy, DestBitSize-SrcBitSize);
return BinaryOperator::CreateAShr(Builder->CreateShl(Res, ShAmt, "sext"),
if (TI->hasOneUse() && TI->getOperand(0)->getType() == DestTy) {
uint32_t SrcBitSize = SrcTy->getScalarSizeInBits();
uint32_t DestBitSize = DestTy->getScalarSizeInBits();
-
+
// We need to emit a shl + ashr to do the sign extend.
Value *ShAmt = ConstantInt::get(DestTy, DestBitSize-SrcBitSize);
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);
- }
- }
- }
-
-
+
+ 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
// integers, we could turn this into a truncate to the smaller bit and then
A = Builder->CreateShl(A, ShAmtV, CI.getName());
return BinaryOperator::CreateAShr(A, ShAmtV);
}
-
+
return 0;
}
if (Instruction *I = dyn_cast<Instruction>(V))
if (I->getOpcode() == Instruction::FPExt)
return LookThroughFPExtensions(I->getOperand(0));
-
+
// If this value is a constant, return the constant in the smallest FP type
// that can accurately represent it. This allows us to turn
// (float)((double)X+2.0) into x+2.0f.
if (ConstantFP *CFP = dyn_cast<ConstantFP>(V)) {
if (CFP->getType() == Type::getPPC_FP128Ty(V->getContext()))
return V; // No constant folding of this.
+ // See if the value can be truncated to half and then reextended.
+ if (Value *V = FitsInFPType(CFP, APFloat::IEEEhalf))
+ return V;
// See if the value can be truncated to float and then reextended.
if (Value *V = FitsInFPType(CFP, APFloat::IEEEsingle))
return V;
return V;
// Don't try to shrink to various long double types.
}
-
+
return V;
}
Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
if (Instruction *I = commonCastTransforms(CI))
return I;
-
+
// If we have fptrunc(fadd (fpextend x), (fpextend y)), where x and y are
// smaller than the destination type, we can eliminate the truncate by doing
// the add as the smaller type. This applies to fadd/fsub/fmul/fdiv as well
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 &&
+ if (LHSTrunc->getType() != SrcTy &&
RHSTrunc->getType() != SrcTy) {
unsigned DstSize = CI.getType()->getScalarSizeInBits();
// If the source types were both smaller than the destination type of
return BinaryOperator::Create(OpI->getOpcode(), LHSTrunc, RHSTrunc);
}
}
- break;
+ break;
+ }
+
+ // (fptrunc (fneg x)) -> (fneg (fptrunc x))
+ if (BinaryOperator::isFNeg(OpI)) {
+ Value *InnerTrunc = Builder->CreateFPTrunc(OpI->getOperand(1),
+ CI.getType());
+ return BinaryOperator::CreateFNeg(InnerTrunc);
+ }
+ }
+
+ IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI.getOperand(0));
+ if (II) {
+ switch (II->getIntrinsicID()) {
+ default: break;
+ case Intrinsic::fabs: {
+ // (fptrunc (fabs x)) -> (fabs (fptrunc x))
+ Value *InnerTrunc = Builder->CreateFPTrunc(II->getArgOperand(0),
+ CI.getType());
+ Type *IntrinsicType[] = { CI.getType() };
+ Function *Overload =
+ Intrinsic::getDeclaration(CI.getParent()->getParent()->getParent(),
+ II->getIntrinsicID(), IntrinsicType);
+
+ Value *Args[] = { InnerTrunc };
+ return CallInst::Create(Overload, Args, II->getName());
+ }
}
}
-
+
// Fold (fptrunc (sqrt (fpext x))) -> (sqrtf x)
- // NOTE: This should be disabled by -fno-builtin-sqrt if we ever support it.
CallInst *Call = dyn_cast<CallInst>(CI.getOperand(0));
- if (Call && Call->getCalledFunction() &&
- Call->getCalledFunction()->getName() == "sqrt" &&
- Call->getNumArgOperands() == 1) {
+ if (Call && Call->getCalledFunction() && TLI->has(LibFunc::sqrtf) &&
+ Call->getCalledFunction()->getName() == TLI->getName(LibFunc::sqrt) &&
+ Call->getNumArgOperands() == 1 &&
+ Call->hasOneUse()) {
CastInst *Arg = dyn_cast<CastInst>(Call->getArgOperand(0));
if (Arg && Arg->getOpcode() == Instruction::FPExt &&
- CI.getType() == Builder->getFloatTy() &&
- Call->getType() == Builder->getDoubleTy() &&
- Arg->getType() == Builder->getDoubleTy() &&
- Arg->getOperand(0)->getType() == Builder->getFloatTy()) {
- Module* M = CI.getParent()->getParent()->getParent();
- Constant* SqrtfFunc = M->getOrInsertFunction("sqrtf",
- Call->getAttributes(),
+ CI.getType()->isFloatTy() &&
+ Call->getType()->isDoubleTy() &&
+ Arg->getType()->isDoubleTy() &&
+ Arg->getOperand(0)->getType()->isFloatTy()) {
+ Function *Callee = Call->getCalledFunction();
+ Module *M = CI.getParent()->getParent()->getParent();
+ Constant *SqrtfFunc = M->getOrInsertFunction("sqrtf",
+ Callee->getAttributes(),
Builder->getFloatTy(),
Builder->getFloatTy(),
NULL);
CallInst *ret = CallInst::Create(SqrtfFunc, Arg->getOperand(0),
"sqrtfcall");
- ret->setAttributes(Call->getAttributes());
+ ret->setAttributes(Callee->getAttributes());
+
+
+ // Remove the old Call. With -fmath-errno, it won't get marked readnone.
+ ReplaceInstUsesWith(*Call, UndefValue::get(Call->getType()));
+ EraseInstFromFunction(*Call);
return ret;
}
}
-
+
return 0;
}
// This is safe if the intermediate type has enough bits in its mantissa to
// accurately represent all values of X. For example, do not do this with
// i64->float->i64. This is also safe for sitofp case, because any negative
- // 'X' value would cause an undefined result for the fptoui.
+ // 'X' value would cause an undefined result for the fptoui.
if ((isa<UIToFPInst>(OpI) || isa<SIToFPInst>(OpI)) &&
OpI->getOperand(0)->getType() == FI.getType() &&
(int)FI.getType()->getScalarSizeInBits() < /*extra bit for sign */
Instruction *OpI = dyn_cast<Instruction>(FI.getOperand(0));
if (OpI == 0)
return commonCastTransforms(FI);
-
+
// fptosi(sitofp(X)) --> X
// fptosi(uitofp(X)) --> X
// This is safe if the intermediate type has enough bits in its mantissa to
// accurately represent all values of X. For example, do not do this with
// i64->float->i64. This is also safe for sitofp case, because any negative
- // 'X' value would cause an undefined result for the fptoui.
+ // 'X' value would cause an undefined result for the fptoui.
if ((isa<UIToFPInst>(OpI) || isa<SIToFPInst>(OpI)) &&
OpI->getOperand(0)->getType() == FI.getType() &&
(int)FI.getType()->getScalarSizeInBits() <=
OpI->getType()->getFPMantissaWidth())
return ReplaceInstUsesWith(FI, OpI->getOperand(0));
-
+
return commonCastTransforms(FI);
}
// If the source integer type is not the intptr_t type for this target, do a
// trunc or zext to the intptr_t type, then inttoptr of it. This allows the
// cast to be exposed to other transforms.
- if (TD) {
- if (CI.getOperand(0)->getType()->getScalarSizeInBits() >
- TD->getPointerSizeInBits()) {
- Value *P = Builder->CreateTrunc(CI.getOperand(0),
- TD->getIntPtrType(CI.getContext()), "tmp");
- return new IntToPtrInst(P, CI.getType());
- }
- if (CI.getOperand(0)->getType()->getScalarSizeInBits() <
- TD->getPointerSizeInBits()) {
- Value *P = Builder->CreateZExt(CI.getOperand(0),
- TD->getIntPtrType(CI.getContext()), "tmp");
- return new IntToPtrInst(P, CI.getType());
- }
+ if (TD && CI.getOperand(0)->getType()->getScalarSizeInBits() !=
+ TD->getPointerSizeInBits()) {
+ Type *Ty = TD->getIntPtrType(CI.getContext());
+ if (CI.getType()->isVectorTy()) // Handle vectors of pointers.
+ Ty = VectorType::get(Ty, CI.getType()->getVectorNumElements());
+
+ Value *P = Builder->CreateZExtOrTrunc(CI.getOperand(0), Ty);
+ return new IntToPtrInst(P, CI.getType());
}
-
+
if (Instruction *I = commonCastTransforms(CI))
return I;
/// @brief Implement the transforms for cast of pointer (bitcast/ptrtoint)
Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) {
Value *Src = CI.getOperand(0);
-
+
if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Src)) {
// If casting the result of a getelementptr instruction with no offset, turn
// this into a cast of the original pointer!
if (GEP->hasAllZeroIndices()) {
// Changing the cast operand is usually not a good idea but it is safe
- // here because the pointer operand is being replaced with another
+ // here because the pointer operand is being replaced with another
// pointer operand so the opcode doesn't need to change.
Worklist.Add(GEP);
CI.setOperand(0, GEP->getOperand(0));
return &CI;
}
-
+
// If the GEP has a single use, and the base pointer is a bitcast, and the
// GEP computes a constant offset, see if we can convert these three
// instructions into fewer. This typically happens with unions and other
// non-type-safe code.
+ APInt Offset(TD ? TD->getPointerSizeInBits() : 1, 0);
if (TD && GEP->hasOneUse() && isa<BitCastInst>(GEP->getOperand(0)) &&
- GEP->hasAllConstantIndices()) {
- // We are guaranteed to get a constant from EmitGEPOffset.
- ConstantInt *OffsetV = cast<ConstantInt>(EmitGEPOffset(GEP));
- int64_t Offset = OffsetV->getSExtValue();
-
+ GEP->accumulateConstantOffset(*TD, Offset)) {
// 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)) {
+ if (FindElementAtOffset(GEPIdxTy, Offset.getSExtValue(), NewIndices)) {
// If we were able to index down into an element, create the GEP
// 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))
return new BitCastInst(NGEP, CI.getType());
assert(isa<PtrToIntInst>(CI));
return new PtrToIntInst(NGEP, CI.getType());
- }
+ }
}
}
-
+
return commonCastTransforms(CI);
}
// If the destination integer type is not the intptr_t type for this target,
// do a ptrtoint to intptr_t then do a trunc or zext. This allows the cast
// to be exposed to other transforms.
- if (TD) {
- if (CI.getType()->getScalarSizeInBits() < TD->getPointerSizeInBits()) {
- Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
- TD->getIntPtrType(CI.getContext()),
- "tmp");
- return new TruncInst(P, CI.getType());
- }
- if (CI.getType()->getScalarSizeInBits() > TD->getPointerSizeInBits()) {
- Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
- TD->getIntPtrType(CI.getContext()),
- "tmp");
- return new ZExtInst(P, CI.getType());
- }
+ if (TD && CI.getType()->getScalarSizeInBits() != TD->getPointerSizeInBits()) {
+ Type *Ty = TD->getIntPtrType(CI.getContext());
+ if (CI.getType()->isVectorTy()) // Handle vectors of pointers.
+ Ty = VectorType::get(Ty, CI.getType()->getVectorNumElements());
+
+ Value *P = Builder->CreatePtrToInt(CI.getOperand(0), Ty);
+ return CastInst::CreateIntegerCast(P, CI.getType(), /*isSigned=*/false);
}
-
+
return commonPointerCastTransforms(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
// same size. There is no specific reason we couldn't handle things like
// <4 x i16> -> <4 x i32> by bitcasting to <2 x i32> but haven't gotten
- // there yet.
+ // there yet.
if (SrcTy->getElementType()->getPrimitiveSizeInBits() !=
DestTy->getElementType()->getPrimitiveSizeInBits())
return 0;
-
+
SrcTy = VectorType::get(DestTy->getElementType(), SrcTy->getNumElements());
InVal = IC.Builder->CreateBitCast(InVal, SrcTy);
}
-
+
// Now that the element types match, get the shuffle mask and RHS of the
// shuffle to use, which depends on whether we're increasing or decreasing the
// size of the input.
- SmallVector<Constant*, 16> ShuffleMask;
+ SmallVector<uint32_t, 16> ShuffleMask;
Value *V2;
- const IntegerType *Int32Ty = Type::getInt32Ty(SrcTy->getContext());
-
+
if (SrcTy->getNumElements() > DestTy->getNumElements()) {
// If we're shrinking the number of elements, just shuffle in the low
// elements from the input and use undef as the second shuffle input.
V2 = UndefValue::get(SrcTy);
for (unsigned i = 0, e = DestTy->getNumElements(); i != e; ++i)
- ShuffleMask.push_back(ConstantInt::get(Int32Ty, i));
-
+ ShuffleMask.push_back(i);
+
} else {
// If we're increasing the number of elements, shuffle in all of the
// elements from InVal and fill the rest of the result elements with zeros
V2 = Constant::getNullValue(SrcTy);
unsigned SrcElts = SrcTy->getNumElements();
for (unsigned i = 0, e = SrcElts; i != e; ++i)
- ShuffleMask.push_back(ConstantInt::get(Int32Ty, i));
+ ShuffleMask.push_back(i);
// The excess elements reference the first element of the zero input.
- ShuffleMask.append(DestTy->getNumElements()-SrcElts,
- ConstantInt::get(Int32Ty, SrcElts));
+ for (unsigned i = 0, e = DestTy->getNumElements()-SrcElts; i != e; ++i)
+ ShuffleMask.push_back(SrcElts);
+ }
+
+ return new ShuffleVectorInst(InVal, V2,
+ ConstantDataVector::get(V2->getContext(),
+ ShuffleMask));
+}
+
+static bool isMultipleOfTypeSize(unsigned Value, Type *Ty) {
+ return Value % Ty->getPrimitiveSizeInBits() == 0;
+}
+
+static unsigned getTypeSizeIndex(unsigned Value, Type *Ty) {
+ return Value / Ty->getPrimitiveSizeInBits();
+}
+
+/// CollectInsertionElements - V is a value which is inserted into a vector of
+/// VecEltTy. Look through the value to see if we can decompose it into
+/// insertions into the vector. See the example in the comment for
+/// OptimizeIntegerToVectorInsertions for the pattern this handles.
+/// The type of V is always a non-zero multiple of VecEltTy's size.
+///
+/// This returns false if the pattern can't be matched or true if it can,
+/// filling in Elements with the elements found here.
+static bool CollectInsertionElements(Value *V, unsigned ElementIndex,
+ SmallVectorImpl<Value*> &Elements,
+ Type *VecEltTy) {
+ // Undef values never contribute useful bits to the result.
+ if (isa<UndefValue>(V)) return true;
+
+ // If we got down to a value of the right type, we win, try inserting into the
+ // right element.
+ if (V->getType() == VecEltTy) {
+ // Inserting null doesn't actually insert any elements.
+ if (Constant *C = dyn_cast<Constant>(V))
+ if (C->isNullValue())
+ return true;
+
+ // Fail if multiple elements are inserted into this slot.
+ if (ElementIndex >= Elements.size() || Elements[ElementIndex] != 0)
+ return false;
+
+ Elements[ElementIndex] = V;
+ return true;
+ }
+
+ if (Constant *C = dyn_cast<Constant>(V)) {
+ // Figure out the # elements this provides, and bitcast it or slice it up
+ // as required.
+ unsigned NumElts = getTypeSizeIndex(C->getType()->getPrimitiveSizeInBits(),
+ VecEltTy);
+ // If the constant is the size of a vector element, we just need to bitcast
+ // it to the right type so it gets properly inserted.
+ if (NumElts == 1)
+ return CollectInsertionElements(ConstantExpr::getBitCast(C, VecEltTy),
+ ElementIndex, Elements, VecEltTy);
+
+ // Okay, this is a constant that covers multiple elements. Slice it up into
+ // pieces and insert each element-sized piece into the vector.
+ if (!isa<IntegerType>(C->getType()))
+ C = ConstantExpr::getBitCast(C, IntegerType::get(V->getContext(),
+ C->getType()->getPrimitiveSizeInBits()));
+ unsigned ElementSize = VecEltTy->getPrimitiveSizeInBits();
+ Type *ElementIntTy = IntegerType::get(C->getContext(), ElementSize);
+
+ for (unsigned i = 0; i != NumElts; ++i) {
+ Constant *Piece = ConstantExpr::getLShr(C, ConstantInt::get(C->getType(),
+ i*ElementSize));
+ Piece = ConstantExpr::getTrunc(Piece, ElementIntTy);
+ if (!CollectInsertionElements(Piece, ElementIndex+i, Elements, VecEltTy))
+ return false;
+ }
+ return true;
+ }
+
+ if (!V->hasOneUse()) return false;
+
+ Instruction *I = dyn_cast<Instruction>(V);
+ if (I == 0) return false;
+ switch (I->getOpcode()) {
+ default: return false; // Unhandled case.
+ case Instruction::BitCast:
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::ZExt:
+ if (!isMultipleOfTypeSize(
+ I->getOperand(0)->getType()->getPrimitiveSizeInBits(),
+ VecEltTy))
+ return false;
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::Or:
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy) &&
+ CollectInsertionElements(I->getOperand(1), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::Shl: {
+ // Must be shifting by a constant that is a multiple of the element size.
+ ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1));
+ if (CI == 0) return false;
+ if (!isMultipleOfTypeSize(CI->getZExtValue(), VecEltTy)) return false;
+ unsigned IndexShift = getTypeSizeIndex(CI->getZExtValue(), VecEltTy);
+
+ return CollectInsertionElements(I->getOperand(0), ElementIndex+IndexShift,
+ Elements, VecEltTy);
+ }
+
+ }
+}
+
+
+/// OptimizeIntegerToVectorInsertions - If the input is an 'or' instruction, we
+/// may be doing shifts and ors to assemble the elements of the vector manually.
+/// Try to rip the code out and replace it with insertelements. This is to
+/// optimize code like this:
+///
+/// %tmp37 = bitcast float %inc to i32
+/// %tmp38 = zext i32 %tmp37 to i64
+/// %tmp31 = bitcast float %inc5 to i32
+/// %tmp32 = zext i32 %tmp31 to i64
+/// %tmp33 = shl i64 %tmp32, 32
+/// %ins35 = or i64 %tmp33, %tmp38
+/// %tmp43 = bitcast i64 %ins35 to <2 x float>
+///
+/// Into two insertelements that do "buildvector{%inc, %inc5}".
+static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI,
+ InstCombiner &IC) {
+ VectorType *DestVecTy = cast<VectorType>(CI.getType());
+ Value *IntInput = CI.getOperand(0);
+
+ SmallVector<Value*, 8> Elements(DestVecTy->getNumElements());
+ if (!CollectInsertionElements(IntInput, 0, Elements,
+ DestVecTy->getElementType()))
+ return 0;
+
+ // If we succeeded, we know that all of the element are specified by Elements
+ // or are zero if Elements has a null entry. Recast this as a set of
+ // insertions.
+ Value *Result = Constant::getNullValue(CI.getType());
+ for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
+ if (Elements[i] == 0) continue; // Unset element.
+
+ Result = IC.Builder->CreateInsertElement(Result, Elements[i],
+ IC.Builder->getInt32(i));
}
-
- Constant *Mask = ConstantVector::get(ShuffleMask.data(), ShuffleMask.size());
- return new ShuffleVectorInst(InVal, V2, Mask);
+
+ return Result;
}
+/// OptimizeIntToFloatBitCast - See if we can optimize an integer->float/double
+/// bitcast. The various long double bitcasts can't get in here.
+static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){
+ Value *Src = CI.getOperand(0);
+ 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.
+ Value *VecInput = 0;
+ // bitcast(trunc(bitcast(somevector)))
+ if (match(Src, m_Trunc(m_BitCast(m_Value(VecInput)))) &&
+ isa<VectorType>(VecInput->getType())) {
+ VectorType *VecTy = cast<VectorType>(VecInput->getType());
+ unsigned DestWidth = DestTy->getPrimitiveSizeInBits();
+
+ if (VecTy->getPrimitiveSizeInBits() % DestWidth == 0) {
+ // If the element type of the vector doesn't match the result type,
+ // bitcast it to be a vector type we can extract from.
+ if (VecTy->getElementType() != DestTy) {
+ VecTy = VectorType::get(DestTy,
+ VecTy->getPrimitiveSizeInBits() / DestWidth);
+ VecInput = IC.Builder->CreateBitCast(VecInput, VecTy);
+ }
+
+ return ExtractElementInst::Create(VecInput, IC.Builder->getInt32(0));
+ }
+ }
+
+ // bitcast(trunc(lshr(bitcast(somevector), cst))
+ ConstantInt *ShAmt = 0;
+ if (match(Src, m_Trunc(m_LShr(m_BitCast(m_Value(VecInput)),
+ m_ConstantInt(ShAmt)))) &&
+ isa<VectorType>(VecInput->getType())) {
+ VectorType *VecTy = cast<VectorType>(VecInput->getType());
+ unsigned DestWidth = DestTy->getPrimitiveSizeInBits();
+ if (VecTy->getPrimitiveSizeInBits() % DestWidth == 0 &&
+ ShAmt->getZExtValue() % DestWidth == 0) {
+ // If the element type of the vector doesn't match the result type,
+ // bitcast it to be a vector type we can extract from.
+ if (VecTy->getElementType() != DestTy) {
+ VecTy = VectorType::get(DestTy,
+ VecTy->getPrimitiveSizeInBits() / DestWidth);
+ VecInput = IC.Builder->CreateBitCast(VecInput, VecTy);
+ }
+
+ unsigned Elt = ShAmt->getZExtValue() / DestWidth;
+ return ExtractElementInst::Create(VecInput, IC.Builder->getInt32(Elt));
+ }
+ }
+ return 0;
+}
+
Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
// 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 (SrcPTy->getAddressSpace() != DstPTy->getAddressSpace())
return 0;
-
+
// If we are casting a alloca to a pointer to a type of the same
// size, rewrite the allocation instruction to allocate the "right" type.
// There is no need to modify malloc calls because it is their bitcast that
if (AllocaInst *AI = dyn_cast<AllocaInst>(Src))
if (Instruction *V = PromoteCastOfAllocation(CI, *AI))
return V;
-
+
// If the source and destination are pointers, and this cast is equivalent
// to a getelementptr X, 0, 0, 0... turn it into the appropriate gep.
// This can enhance SROA and other transforms that want type-safe pointers.
Constant *ZeroUInt =
Constant::getNullValue(Type::getInt32Ty(CI.getContext()));
unsigned NumZeros = 0;
- while (SrcElTy != DstElTy &&
+ while (SrcElTy != DstElTy &&
isa<CompositeType>(SrcElTy) && !SrcElTy->isPointerTy() &&
SrcElTy->getNumContainedTypes() /* not "{}" */) {
SrcElTy = cast<CompositeType>(SrcElTy)->getTypeAtIndex(ZeroUInt);
// 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 (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
+ // Try to optimize int -> float bitcasts.
+ if ((DestTy->isFloatTy() || DestTy->isDoubleTy()) && isa<IntegerType>(SrcTy))
+ if (Instruction *I = OptimizeIntToFloatBitCast(CI, *this))
+ return I;
+
+ 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,
Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
// FIXME: Canonicalize bitcast(insertelement) -> insertelement(bitcast)
}
-
- // If this is a cast from an integer to vector, check to see if the input
- // is a trunc or zext of a bitcast from vector. If so, we can replace all
- // the casts with a shuffle and (potentially) a bitcast.
- if (isa<IntegerType>(SrcTy) && (isa<TruncInst>(Src) || isa<ZExtInst>(Src))){
- CastInst *SrcCast = cast<CastInst>(Src);
- if (BitCastInst *BCIn = dyn_cast<BitCastInst>(SrcCast->getOperand(0)))
- if (isa<VectorType>(BCIn->getOperand(0)->getType()))
- if (Instruction *I = OptimizeVectorResize(BCIn->getOperand(0),
+
+ if (isa<IntegerType>(SrcTy)) {
+ // If this is a cast from an integer to vector, check to see if the input
+ // is a trunc or zext of a bitcast from vector. If so, we can replace all
+ // the casts with a shuffle and (potentially) a bitcast.
+ if (isa<TruncInst>(Src) || isa<ZExtInst>(Src)) {
+ CastInst *SrcCast = cast<CastInst>(Src);
+ if (BitCastInst *BCIn = dyn_cast<BitCastInst>(SrcCast->getOperand(0)))
+ if (isa<VectorType>(BCIn->getOperand(0)->getType()))
+ if (Instruction *I = OptimizeVectorResize(BCIn->getOperand(0),
cast<VectorType>(DestTy), *this))
- return I;
+ return I;
+ }
+
+ // If the input is an 'or' instruction, we may be doing shifts and ors to
+ // assemble the elements of the vector manually. Try to rip the code out
+ // and replace it with insertelements.
+ if (Value *V = OptimizeIntegerToVectorInsertions(CI, *this))
+ return ReplaceInstUsesWith(CI, V);
}
}
- if (const VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
- if (SrcVTy->getNumElements() == 1 && !DestTy->isVectorTy()) {
- Value *Elem =
- Builder->CreateExtractElement(Src,
- Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
- return CastInst::Create(Instruction::BitCast, Elem, DestTy);
+ if (VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
+ if (SrcVTy->getNumElements() == 1) {
+ // If our destination is not a vector, then make this a straight
+ // scalar-scalar cast.
+ if (!DestTy->isVectorTy()) {
+ Value *Elem =
+ Builder->CreateExtractElement(Src,
+ Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
+ return CastInst::Create(Instruction::BitCast, Elem, DestTy);
+ }
+
+ // Otherwise, see if our source is an insert. If so, then use the scalar
+ // component directly.
+ if (InsertElementInst *IEI =
+ dyn_cast<InsertElementInst>(CI.getOperand(0)))
+ return CastInst::Create(Instruction::BitCast, IEI->getOperand(1),
+ DestTy);
}
}
if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(Src)) {
// Okay, we have (bitcast (shuffle ..)). Check to see if this is
// a bitcast to a vector with the same # elts.
- if (SVI->hasOneUse() && DestTy->isVectorTy() &&
+ if (SVI->hasOneUse() && DestTy->isVectorTy() &&
cast<VectorType>(DestTy)->getNumElements() ==
SVI->getType()->getNumElements() &&
SVI->getType()->getNumElements() ==
// If either of the operands is a cast from CI.getType(), then
// evaluating the shuffle in the casted destination's type will allow
// us to eliminate at least one cast.
- if (((Tmp = dyn_cast<BitCastInst>(SVI->getOperand(0))) &&
+ if (((Tmp = dyn_cast<BitCastInst>(SVI->getOperand(0))) &&
Tmp->getOperand(0)->getType() == DestTy) ||
- ((Tmp = dyn_cast<BitCastInst>(SVI->getOperand(1))) &&
+ ((Tmp = dyn_cast<BitCastInst>(SVI->getOperand(1))) &&
Tmp->getOperand(0)->getType() == DestTy)) {
Value *LHS = Builder->CreateBitCast(SVI->getOperand(0), DestTy);
Value *RHS = Builder->CreateBitCast(SVI->getOperand(1), DestTy);
}
}
}
-
+
if (SrcTy->isPointerTy())
return commonPointerCastTransforms(CI);
return commonCastTransforms(CI);
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