//
//===----------------------------------------------------------------------===//
-#include "InstCombine.h"
-#include "llvm/IntrinsicInst.h"
+#include "InstCombineInternal.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/Support/PatternMatch.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/PatternMatch.h"
using namespace llvm;
using namespace PatternMatch;
+#define DEBUG_TYPE "instcombine"
+
Instruction *InstCombiner::commonShiftTransforms(BinaryOperator &I) {
assert(I.getOperand(1)->getType() == I.getOperand(0)->getType());
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (Instruction *R = FoldOpIntoSelect(I, SI))
return R;
- if (ConstantInt *CUI = dyn_cast<ConstantInt>(Op1))
+ if (Constant *CUI = dyn_cast<Constant>(Op1))
if (Instruction *Res = FoldShiftByConstant(Op0, CUI, I))
return Res;
I.setOperand(1, Rem);
return &I;
}
-
- return 0;
+
+ return nullptr;
}
-/// CanEvaluateShifted - See if we can compute the specified value, but shifted
+/// See if we can compute the specified value, but shifted
/// logically to the left or right by some number of bits. This should return
/// true if the expression can be computed for the same cost as the current
/// expression tree. This is used to eliminate extraneous shifting from things
/// this succeeds, the GetShiftedValue function will be called to produce the
/// value.
static bool CanEvaluateShifted(Value *V, unsigned NumBits, bool isLeftShift,
- InstCombiner &IC) {
+ InstCombiner &IC, Instruction *CxtI) {
// We can always evaluate constants shifted.
if (isa<Constant>(V))
return true;
-
+
Instruction *I = dyn_cast<Instruction>(V);
if (!I) return false;
-
+
// If this is the opposite shift, we can directly reuse the input of the shift
// if the needed bits are already zero in the input. This allows us to reuse
// the value which means that we don't care if the shift has multiple uses.
// TODO: Handle opposite shift by exact value.
- ConstantInt *CI = 0;
+ ConstantInt *CI = nullptr;
if ((isLeftShift && match(I, m_LShr(m_Value(), m_ConstantInt(CI)))) ||
(!isLeftShift && match(I, m_Shl(m_Value(), m_ConstantInt(CI))))) {
if (CI->getZExtValue() == NumBits) {
return CanEvaluateTruncated(I->getOperand(0), Ty);
}
#endif
-
+
}
}
-
+
// We can't mutate something that has multiple uses: doing so would
// require duplicating the instruction in general, which isn't profitable.
if (!I->hasOneUse()) return false;
-
+
switch (I->getOpcode()) {
default: return false;
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
// Bitwise operators can all arbitrarily be arbitrarily evaluated shifted.
- return CanEvaluateShifted(I->getOperand(0), NumBits, isLeftShift, IC) &&
- CanEvaluateShifted(I->getOperand(1), NumBits, isLeftShift, IC);
-
+ return CanEvaluateShifted(I->getOperand(0), NumBits, isLeftShift, IC, I) &&
+ CanEvaluateShifted(I->getOperand(1), NumBits, isLeftShift, IC, I);
+
case Instruction::Shl: {
// We can often fold the shift into shifts-by-a-constant.
CI = dyn_cast<ConstantInt>(I->getOperand(1));
- if (CI == 0) return false;
+ if (!CI) return false;
// We can always fold shl(c1)+shl(c2) -> shl(c1+c2).
if (isLeftShift) return true;
-
+
// We can always turn shl(c)+shr(c) -> and(c2).
if (CI->getValue() == NumBits) return true;
-
+
unsigned TypeWidth = I->getType()->getScalarSizeInBits();
// We can turn shl(c1)+shr(c2) -> shl(c3)+and(c4), but it isn't
// profitable unless we know the and'd out bits are already zero.
if (CI->getZExtValue() > NumBits) {
unsigned LowBits = TypeWidth - CI->getZExtValue();
- if (MaskedValueIsZero(I->getOperand(0),
- APInt::getLowBitsSet(TypeWidth, NumBits) << LowBits))
+ if (IC.MaskedValueIsZero(I->getOperand(0),
+ APInt::getLowBitsSet(TypeWidth, NumBits) << LowBits,
+ 0, CxtI))
return true;
}
-
+
return false;
}
case Instruction::LShr: {
// We can often fold the shift into shifts-by-a-constant.
CI = dyn_cast<ConstantInt>(I->getOperand(1));
- if (CI == 0) return false;
-
+ if (!CI) return false;
+
// We can always fold lshr(c1)+lshr(c2) -> lshr(c1+c2).
if (!isLeftShift) return true;
-
+
// We can always turn lshr(c)+shl(c) -> and(c2).
if (CI->getValue() == NumBits) return true;
-
+
unsigned TypeWidth = I->getType()->getScalarSizeInBits();
// We can always turn lshr(c1)+shl(c2) -> lshr(c3)+and(c4), but it isn't
// profitable unless we know the and'd out bits are already zero.
if (CI->getValue().ult(TypeWidth) && CI->getZExtValue() > NumBits) {
unsigned LowBits = CI->getZExtValue() - NumBits;
- if (MaskedValueIsZero(I->getOperand(0),
- APInt::getLowBitsSet(TypeWidth, NumBits) << LowBits))
+ if (IC.MaskedValueIsZero(I->getOperand(0),
+ APInt::getLowBitsSet(TypeWidth, NumBits) << LowBits,
+ 0, CxtI))
return true;
}
-
+
return false;
}
case Instruction::Select: {
SelectInst *SI = cast<SelectInst>(I);
- return CanEvaluateShifted(SI->getTrueValue(), NumBits, isLeftShift, IC) &&
- CanEvaluateShifted(SI->getFalseValue(), NumBits, isLeftShift, IC);
+ return CanEvaluateShifted(SI->getTrueValue(), NumBits, isLeftShift,
+ IC, SI) &&
+ CanEvaluateShifted(SI->getFalseValue(), NumBits, isLeftShift, IC, SI);
}
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
// instructions with a single use.
PHINode *PN = cast<PHINode>(I);
- for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
- if (!CanEvaluateShifted(PN->getIncomingValue(i), NumBits, isLeftShift,IC))
+ for (Value *IncValue : PN->incoming_values())
+ if (!CanEvaluateShifted(IncValue, NumBits, isLeftShift,
+ IC, PN))
return false;
return true;
}
- }
+ }
}
-/// GetShiftedValue - When CanEvaluateShifted returned true for an expression,
+/// When CanEvaluateShifted returned true for an expression,
/// this value inserts the new computation that produces the shifted value.
static Value *GetShiftedValue(Value *V, unsigned NumBits, bool isLeftShift,
- InstCombiner &IC) {
+ InstCombiner &IC, const DataLayout &DL) {
// We can always evaluate constants shifted.
if (Constant *C = dyn_cast<Constant>(V)) {
if (isLeftShift)
V = IC.Builder->CreateLShr(C, NumBits);
// If we got a constantexpr back, try to simplify it with TD info.
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
- V = ConstantFoldConstantExpression(CE, IC.getTargetData(),
- IC.getTargetLibraryInfo());
+ V = ConstantFoldConstantExpression(CE, DL, IC.getTargetLibraryInfo());
return V;
}
-
+
Instruction *I = cast<Instruction>(V);
IC.Worklist.Add(I);
case Instruction::Or:
case Instruction::Xor:
// Bitwise operators can all arbitrarily be arbitrarily evaluated shifted.
- I->setOperand(0, GetShiftedValue(I->getOperand(0), NumBits,isLeftShift,IC));
- I->setOperand(1, GetShiftedValue(I->getOperand(1), NumBits,isLeftShift,IC));
+ I->setOperand(
+ 0, GetShiftedValue(I->getOperand(0), NumBits, isLeftShift, IC, DL));
+ I->setOperand(
+ 1, GetShiftedValue(I->getOperand(1), NumBits, isLeftShift, IC, DL));
return I;
-
+
case Instruction::Shl: {
BinaryOperator *BO = cast<BinaryOperator>(I);
unsigned TypeWidth = BO->getType()->getScalarSizeInBits();
BO->setHasNoSignedWrap(false);
return I;
}
-
+
// We turn shl(c)+lshr(c) -> and(c2) if the input doesn't already have
// zeros.
if (CI->getValue() == NumBits) {
}
return V;
}
-
+
// We turn shl(c1)+shr(c2) -> shl(c3)+and(c4), but only when we know that
// the and won't be needed.
assert(CI->getZExtValue() > NumBits);
unsigned TypeWidth = BO->getType()->getScalarSizeInBits();
// We only accept shifts-by-a-constant in CanEvaluateShifted.
ConstantInt *CI = cast<ConstantInt>(BO->getOperand(1));
-
+
// We can always fold lshr(c1)+lshr(c2) -> lshr(c1+c2).
if (!isLeftShift) {
// If this is oversized composite shift, then unsigned shifts get 0.
unsigned NewShAmt = NumBits+CI->getZExtValue();
if (NewShAmt >= TypeWidth)
return Constant::getNullValue(BO->getType());
-
+
BO->setOperand(1, ConstantInt::get(BO->getType(), NewShAmt));
BO->setIsExact(false);
return I;
}
-
+
// We turn lshr(c)+shl(c) -> and(c2) if the input doesn't already have
// zeros.
if (CI->getValue() == NumBits) {
}
return V;
}
-
+
// We turn lshr(c1)+shl(c2) -> lshr(c3)+and(c4), but only when we know that
// the and won't be needed.
assert(CI->getZExtValue() > NumBits);
BO->setIsExact(false);
return BO;
}
-
+
case Instruction::Select:
- I->setOperand(1, GetShiftedValue(I->getOperand(1), NumBits,isLeftShift,IC));
- I->setOperand(2, GetShiftedValue(I->getOperand(2), NumBits,isLeftShift,IC));
+ I->setOperand(
+ 1, GetShiftedValue(I->getOperand(1), NumBits, isLeftShift, IC, DL));
+ I->setOperand(
+ 2, GetShiftedValue(I->getOperand(2), NumBits, isLeftShift, IC, DL));
return I;
case Instruction::PHI: {
// We can change a phi if we can change all operands. Note that we never
// instructions with a single use.
PHINode *PN = cast<PHINode>(I);
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
- PN->setIncomingValue(i, GetShiftedValue(PN->getIncomingValue(i),
- NumBits, isLeftShift, IC));
+ PN->setIncomingValue(i, GetShiftedValue(PN->getIncomingValue(i), NumBits,
+ isLeftShift, IC, DL));
return PN;
}
- }
+ }
}
-Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
+Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, Constant *Op1,
BinaryOperator &I) {
bool isLeftShift = I.getOpcode() == Instruction::Shl;
-
-
+
+ ConstantInt *COp1 = nullptr;
+ if (ConstantDataVector *CV = dyn_cast<ConstantDataVector>(Op1))
+ COp1 = dyn_cast_or_null<ConstantInt>(CV->getSplatValue());
+ else if (ConstantVector *CV = dyn_cast<ConstantVector>(Op1))
+ COp1 = dyn_cast_or_null<ConstantInt>(CV->getSplatValue());
+ else
+ COp1 = dyn_cast<ConstantInt>(Op1);
+
+ if (!COp1)
+ return nullptr;
+
// See if we can propagate this shift into the input, this covers the trivial
// cast of lshr(shl(x,c1),c2) as well as other more complex cases.
if (I.getOpcode() != Instruction::AShr &&
- CanEvaluateShifted(Op0, Op1->getZExtValue(), isLeftShift, *this)) {
+ CanEvaluateShifted(Op0, COp1->getZExtValue(), isLeftShift, *this, &I)) {
DEBUG(dbgs() << "ICE: GetShiftedValue propagating shift through expression"
" to eliminate shift:\n IN: " << *Op0 << "\n SH: " << I <<"\n");
-
- return ReplaceInstUsesWith(I,
- GetShiftedValue(Op0, Op1->getZExtValue(), isLeftShift, *this));
+
+ return ReplaceInstUsesWith(
+ I, GetShiftedValue(Op0, COp1->getZExtValue(), isLeftShift, *this, DL));
}
-
-
- // See if we can simplify any instructions used by the instruction whose sole
+
+ // See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
uint32_t TypeBits = Op0->getType()->getScalarSizeInBits();
-
- // shl i32 X, 32 = 0 and srl i8 Y, 9 = 0, ... just don't eliminate
- // a signed shift.
- //
- if (Op1->uge(TypeBits)) {
- if (I.getOpcode() != Instruction::AShr)
- return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType()));
- // ashr i32 X, 32 --> ashr i32 X, 31
- I.setOperand(1, ConstantInt::get(I.getType(), TypeBits-1));
- return &I;
- }
-
+
+ assert(!COp1->uge(TypeBits) &&
+ "Shift over the type width should have been removed already");
+
// ((X*C1) << C2) == (X * (C1 << C2))
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0))
if (BO->getOpcode() == Instruction::Mul && isLeftShift)
if (Constant *BOOp = dyn_cast<Constant>(BO->getOperand(1)))
return BinaryOperator::CreateMul(BO->getOperand(0),
ConstantExpr::getShl(BOOp, Op1));
-
+
// Try to fold constant and into select arguments.
if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
if (Instruction *R = FoldOpIntoSelect(I, SI))
if (isa<PHINode>(Op0))
if (Instruction *NV = FoldOpIntoPhi(I))
return NV;
-
+
// Fold shift2(trunc(shift1(x,c1)), c2) -> trunc(shift2(shift1(x,c1),c2))
if (TruncInst *TI = dyn_cast<TruncInst>(Op0)) {
Instruction *TrOp = dyn_cast<Instruction>(TI->getOperand(0));
// require that the input operand is a shift-by-constant so that we have
// confidence that the shifts will get folded together. We could do this
// xform in more cases, but it is unlikely to be profitable.
- if (TrOp && I.isLogicalShift() && TrOp->isShift() &&
+ if (TrOp && I.isLogicalShift() && TrOp->isShift() &&
isa<ConstantInt>(TrOp->getOperand(1))) {
// Okay, we'll do this xform. Make the shift of shift.
- Constant *ShAmt = ConstantExpr::getZExt(Op1, TrOp->getType());
+ Constant *ShAmt = ConstantExpr::getZExt(COp1, TrOp->getType());
// (shift2 (shift1 & 0x00FF), c2)
Value *NSh = Builder->CreateBinOp(I.getOpcode(), TrOp, ShAmt,I.getName());
unsigned SrcSize = TrOp->getType()->getScalarSizeInBits();
unsigned DstSize = TI->getType()->getScalarSizeInBits();
APInt MaskV(APInt::getLowBitsSet(SrcSize, DstSize));
-
+
// The mask we constructed says what the trunc would do if occurring
// between the shifts. We want to know the effect *after* the second
// shift. We know that it is a logical shift by a constant, so adjust the
// mask as appropriate.
if (I.getOpcode() == Instruction::Shl)
- MaskV <<= Op1->getZExtValue();
+ MaskV <<= COp1->getZExtValue();
else {
assert(I.getOpcode() == Instruction::LShr && "Unknown logical shift");
- MaskV = MaskV.lshr(Op1->getZExtValue());
+ MaskV = MaskV.lshr(COp1->getZExtValue());
}
// shift1 & 0x00FF
return new TruncInst(And, I.getType());
}
}
-
+
if (Op0->hasOneUse()) {
if (BinaryOperator *Op0BO = dyn_cast<BinaryOperator>(Op0)) {
// Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
// (X + (Y << C))
Value *X = Builder->CreateBinOp(Op0BO->getOpcode(), YS, V1,
Op0BO->getOperand(1)->getName());
- uint32_t Op1Val = Op1->getLimitedValue(TypeBits);
- return BinaryOperator::CreateAnd(X, ConstantInt::get(I.getContext(),
- APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val)));
+ uint32_t Op1Val = COp1->getLimitedValue(TypeBits);
+
+ APInt Bits = APInt::getHighBitsSet(TypeBits, TypeBits - Op1Val);
+ Constant *Mask = ConstantInt::get(I.getContext(), Bits);
+ if (VectorType *VT = dyn_cast<VectorType>(X->getType()))
+ Mask = ConstantVector::getSplat(VT->getNumElements(), Mask);
+ return BinaryOperator::CreateAnd(X, Mask);
}
-
+
// Turn (Y + ((X >> C) & CC)) << C -> ((X & (CC << C)) + (Y << C))
Value *Op0BOOp1 = Op0BO->getOperand(1);
if (isLeftShift && Op0BOOp1->hasOneUse() &&
- match(Op0BOOp1,
- m_And(m_Shr(m_Value(V1), m_Specific(Op1)),
- m_ConstantInt(CC))) &&
- cast<BinaryOperator>(Op0BOOp1)->getOperand(0)->hasOneUse()) {
+ match(Op0BOOp1,
+ m_And(m_OneUse(m_Shr(m_Value(V1), m_Specific(Op1))),
+ m_ConstantInt(CC)))) {
Value *YS = // (Y << C)
Builder->CreateShl(Op0BO->getOperand(0), Op1,
Op0BO->getName());
return BinaryOperator::Create(Op0BO->getOpcode(), YS, XM);
}
}
-
+
// FALL THROUGH.
case Instruction::Sub: {
// Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
// (X + (Y << C))
Value *X = Builder->CreateBinOp(Op0BO->getOpcode(), V1, YS,
Op0BO->getOperand(0)->getName());
- uint32_t Op1Val = Op1->getLimitedValue(TypeBits);
- return BinaryOperator::CreateAnd(X, ConstantInt::get(I.getContext(),
- APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val)));
+ uint32_t Op1Val = COp1->getLimitedValue(TypeBits);
+
+ APInt Bits = APInt::getHighBitsSet(TypeBits, TypeBits - Op1Val);
+ Constant *Mask = ConstantInt::get(I.getContext(), Bits);
+ if (VectorType *VT = dyn_cast<VectorType>(X->getType()))
+ Mask = ConstantVector::getSplat(VT->getNumElements(), Mask);
+ return BinaryOperator::CreateAnd(X, Mask);
}
-
+
// Turn (((X >> C)&CC) + Y) << C -> (X + (Y << C)) & (CC << C)
if (isLeftShift && Op0BO->getOperand(0)->hasOneUse() &&
match(Op0BO->getOperand(0),
- m_And(m_Shr(m_Value(V1), m_Value(V2)),
- m_ConstantInt(CC))) && V2 == Op1 &&
- cast<BinaryOperator>(Op0BO->getOperand(0))
- ->getOperand(0)->hasOneUse()) {
+ m_And(m_OneUse(m_Shr(m_Value(V1), m_Value(V2))),
+ m_ConstantInt(CC))) && V2 == Op1) {
Value *YS = // (Y << C)
Builder->CreateShl(Op0BO->getOperand(1), Op1, Op0BO->getName());
// X & (CC << C)
Value *XM = Builder->CreateAnd(V1, ConstantExpr::getShl(CC, Op1),
V1->getName()+".mask");
-
+
return BinaryOperator::Create(Op0BO->getOpcode(), XM, YS);
}
-
+
break;
}
}
-
-
- // If the operand is an bitwise operator with a constant RHS, and the
+
+
+ // If the operand is a bitwise operator with a constant RHS, and the
// shift is the only use, we can pull it out of the shift.
if (ConstantInt *Op0C = dyn_cast<ConstantInt>(Op0BO->getOperand(1))) {
bool isValid = true; // Valid only for And, Or, Xor
bool highBitSet = false; // Transform if high bit of constant set?
-
+
switch (Op0BO->getOpcode()) {
default: isValid = false; break; // Do not perform transform!
case Instruction::Add:
highBitSet = true;
break;
}
-
+
// If this is a signed shift right, and the high bit is modified
// by the logical operation, do not perform the transformation.
// The highBitSet boolean indicates the value of the high bit of
//
if (isValid && I.getOpcode() == Instruction::AShr)
isValid = Op0C->getValue()[TypeBits-1] == highBitSet;
-
+
if (isValid) {
Constant *NewRHS = ConstantExpr::get(I.getOpcode(), Op0C, Op1);
-
+
Value *NewShift =
Builder->CreateBinOp(I.getOpcode(), Op0BO->getOperand(0), Op1);
NewShift->takeName(Op0BO);
-
+
return BinaryOperator::Create(Op0BO->getOpcode(), NewShift,
NewRHS);
}
}
}
}
-
+
// Find out if this is a shift of a shift by a constant.
BinaryOperator *ShiftOp = dyn_cast<BinaryOperator>(Op0);
if (ShiftOp && !ShiftOp->isShift())
- ShiftOp = 0;
-
+ ShiftOp = nullptr;
+
if (ShiftOp && isa<ConstantInt>(ShiftOp->getOperand(1))) {
// This is a constant shift of a constant shift. Be careful about hiding
ConstantInt *ShiftAmt1C = cast<ConstantInt>(ShiftOp->getOperand(1));
uint32_t ShiftAmt1 = ShiftAmt1C->getLimitedValue(TypeBits);
- uint32_t ShiftAmt2 = Op1->getLimitedValue(TypeBits);
+ uint32_t ShiftAmt2 = COp1->getLimitedValue(TypeBits);
assert(ShiftAmt2 != 0 && "Should have been simplified earlier");
- if (ShiftAmt1 == 0) return 0; // Will be simplified in the future.
+ if (ShiftAmt1 == 0) return nullptr; // Will be simplified in the future.
Value *X = ShiftOp->getOperand(0);
-
+
IntegerType *Ty = cast<IntegerType>(I.getType());
-
+
// Check for (X << c1) << c2 and (X >> c1) >> c2
if (I.getOpcode() == ShiftOp->getOpcode()) {
uint32_t AmtSum = ShiftAmt1+ShiftAmt2; // Fold into one big shift.
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
AmtSum = TypeBits-1; // Saturate to 31 for i32 ashr.
}
-
+
return BinaryOperator::Create(I.getOpcode(), X,
ConstantInt::get(Ty, AmtSum));
}
-
+
if (ShiftAmt1 == ShiftAmt2) {
// If we have ((X << C) >>u C), turn this into X & (-1 >>u C).
if (I.getOpcode() == Instruction::LShr &&
return NewLShr;
}
Value *Shift = Builder->CreateLShr(X, ShiftDiffCst);
-
+
APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt2));
return BinaryOperator::CreateAnd(Shift,
ConstantInt::get(I.getContext(),Mask));
return NewShl;
}
Value *Shift = Builder->CreateShl(X, ShiftDiffCst);
-
+
APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt2));
return BinaryOperator::CreateAnd(Shift,
ConstantInt::get(I.getContext(),Mask));
}
-
+
// We can't handle (X << C1) >>s C2, it shifts arbitrary bits in. However,
// we can handle (X <<nsw C1) >>s C2 since it only shifts in sign bits.
if (I.getOpcode() == Instruction::AShr &&
}
}
}
- return 0;
+ return nullptr;
}
Instruction *InstCombiner::visitShl(BinaryOperator &I) {
- if (Value *V = SimplifyShlInst(I.getOperand(0), I.getOperand(1),
- I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
- TD))
+ if (Value *V = SimplifyVectorOp(I))
return ReplaceInstUsesWith(I, V);
-
+
+ if (Value *V =
+ SimplifyShlInst(I.getOperand(0), I.getOperand(1), I.hasNoSignedWrap(),
+ I.hasNoUnsignedWrap(), DL, TLI, DT, AC))
+ return ReplaceInstUsesWith(I, V);
+
if (Instruction *V = commonShiftTransforms(I))
return V;
-
+
if (ConstantInt *Op1C = dyn_cast<ConstantInt>(I.getOperand(1))) {
unsigned ShAmt = Op1C->getZExtValue();
-
+
// If the shifted-out value is known-zero, then this is a NUW shift.
- if (!I.hasNoUnsignedWrap() &&
+ if (!I.hasNoUnsignedWrap() &&
MaskedValueIsZero(I.getOperand(0),
- APInt::getHighBitsSet(Op1C->getBitWidth(), ShAmt))) {
+ APInt::getHighBitsSet(Op1C->getBitWidth(), ShAmt),
+ 0, &I)) {
I.setHasNoUnsignedWrap();
return &I;
}
-
+
// If the shifted out value is all signbits, this is a NSW shift.
if (!I.hasNoSignedWrap() &&
- ComputeNumSignBits(I.getOperand(0)) > ShAmt) {
+ ComputeNumSignBits(I.getOperand(0), 0, &I) > ShAmt) {
I.setHasNoSignedWrap();
return &I;
}
match(I.getOperand(1), m_Constant(C2)))
return BinaryOperator::CreateShl(ConstantExpr::getShl(C1, C2), A);
- return 0;
+ return nullptr;
}
Instruction *InstCombiner::visitLShr(BinaryOperator &I) {
- if (Value *V = SimplifyLShrInst(I.getOperand(0), I.getOperand(1),
- I.isExact(), TD))
+ if (Value *V = SimplifyVectorOp(I))
+ return ReplaceInstUsesWith(I, V);
+
+ if (Value *V = SimplifyLShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
+ DL, TLI, DT, AC))
return ReplaceInstUsesWith(I, V);
if (Instruction *R = commonShiftTransforms(I))
return R;
-
+
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
+
if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
unsigned ShAmt = Op1C->getZExtValue();
return new ZExtInst(Cmp, II->getType());
}
}
-
+
// If the shifted-out value is known-zero, then this is an exact shift.
- if (!I.isExact() &&
- MaskedValueIsZero(Op0,APInt::getLowBitsSet(Op1C->getBitWidth(),ShAmt))){
+ if (!I.isExact() &&
+ MaskedValueIsZero(Op0, APInt::getLowBitsSet(Op1C->getBitWidth(), ShAmt),
+ 0, &I)){
I.setIsExact();
return &I;
- }
+ }
}
-
- return 0;
+
+ return nullptr;
}
Instruction *InstCombiner::visitAShr(BinaryOperator &I) {
- if (Value *V = SimplifyAShrInst(I.getOperand(0), I.getOperand(1),
- I.isExact(), TD))
+ if (Value *V = SimplifyVectorOp(I))
+ return ReplaceInstUsesWith(I, V);
+
+ if (Value *V = SimplifyAShrInst(I.getOperand(0), I.getOperand(1), I.isExact(),
+ DL, TLI, DT, AC))
return ReplaceInstUsesWith(I, V);
if (Instruction *R = commonShiftTransforms(I))
return R;
-
+
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
unsigned ShAmt = Op1C->getZExtValue();
-
+
// If the input is a SHL by the same constant (ashr (shl X, C), C), then we
// have a sign-extend idiom.
Value *X;
if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1)))) {
- // If the left shift is just shifting out partial signbits, delete the
- // extension.
- if (cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap())
- return ReplaceInstUsesWith(I, X);
-
// If the input is an extension from the shifted amount value, e.g.
// %x = zext i8 %A to i32
// %y = shl i32 %x, 24
}
// If the shifted-out value is known-zero, then this is an exact shift.
- if (!I.isExact() &&
- MaskedValueIsZero(Op0,APInt::getLowBitsSet(Op1C->getBitWidth(),ShAmt))){
+ if (!I.isExact() &&
+ MaskedValueIsZero(Op0,APInt::getLowBitsSet(Op1C->getBitWidth(),ShAmt),
+ 0, &I)){
I.setIsExact();
return &I;
}
- }
-
+ }
+
// See if we can turn a signed shr into an unsigned shr.
if (MaskedValueIsZero(Op0,
- APInt::getSignBit(I.getType()->getScalarSizeInBits())))
+ APInt::getSignBit(I.getType()->getScalarSizeInBits()),
+ 0, &I))
return BinaryOperator::CreateLShr(Op0, Op1);
-
- // Arithmetic shifting an all-sign-bit value is a no-op.
- unsigned NumSignBits = ComputeNumSignBits(Op0);
- if (NumSignBits == Op0->getType()->getScalarSizeInBits())
- return ReplaceInstUsesWith(I, Op0);
-
- return 0;
-}
+ return nullptr;
+}
projects / oota-llvm.git / blobdiff