summaryrefslogtreecommitdiff
path: root/lib/Transforms/InstCombine
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Transforms/InstCombine')
-rw-r--r--lib/Transforms/InstCombine/InstCombineAddSub.cpp8
-rw-r--r--lib/Transforms/InstCombine/InstCombineCalls.cpp2
-rw-r--r--lib/Transforms/InstCombine/InstCombineCompares.cpp3
-rw-r--r--lib/Transforms/InstCombine/InstCombineMulDivRem.cpp11
-rw-r--r--lib/Transforms/InstCombine/InstCombineShifts.cpp109
5 files changed, 94 insertions, 39 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 18b246b5d99f..d28d615f47ea 100644
--- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -482,7 +482,7 @@ Value *FAddCombine::performFactorization(Instruction *I) {
return nullptr;
FastMathFlags Flags;
- Flags.setUnsafeAlgebra();
+ Flags.setFast();
if (I0) Flags &= I->getFastMathFlags();
if (I1) Flags &= I->getFastMathFlags();
@@ -511,7 +511,7 @@ Value *FAddCombine::performFactorization(Instruction *I) {
}
Value *FAddCombine::simplify(Instruction *I) {
- assert(I->hasUnsafeAlgebra() && "Should be in unsafe mode");
+ assert(I->isFast() && "Expected 'fast' instruction");
// Currently we are not able to handle vector type.
if (I->getType()->isVectorTy())
@@ -1386,7 +1386,7 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
if (Value *V = SimplifySelectsFeedingBinaryOp(I, LHS, RHS))
return replaceInstUsesWith(I, V);
- if (I.hasUnsafeAlgebra()) {
+ if (I.isFast()) {
if (Value *V = FAddCombine(Builder).simplify(&I))
return replaceInstUsesWith(I, V);
}
@@ -1736,7 +1736,7 @@ Instruction *InstCombiner::visitFSub(BinaryOperator &I) {
if (Value *V = SimplifySelectsFeedingBinaryOp(I, Op0, Op1))
return replaceInstUsesWith(I, V);
- if (I.hasUnsafeAlgebra()) {
+ if (I.isFast()) {
if (Value *V = FAddCombine(Builder).simplify(&I))
return replaceInstUsesWith(I, V);
}
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index 7a4abc9aca0c..a00e6f73ab8c 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -2017,7 +2017,7 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
}
case Intrinsic::fmuladd: {
// Canonicalize fast fmuladd to the separate fmul + fadd.
- if (II->hasUnsafeAlgebra()) {
+ if (II->isFast()) {
BuilderTy::FastMathFlagGuard Guard(Builder);
Builder.setFastMathFlags(II->getFastMathFlags());
Value *Mul = Builder.CreateFMul(II->getArgOperand(0),
diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp
index cb4788576c59..2974449830d9 100644
--- a/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -426,8 +426,7 @@ Instruction *InstCombiner::foldCmpLoadFromIndexedGlobal(GetElementPtrInst *GEP,
// Look for an appropriate type:
// - The type of Idx if the magic fits
- // - The smallest fitting legal type if we have a DataLayout
- // - Default to i32
+ // - The smallest fitting legal type
if (ArrayElementCount <= Idx->getType()->getIntegerBitWidth())
Ty = Idx->getType();
else
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index e6b975382671..87666360c1a0 100644
--- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -487,7 +487,7 @@ static void detectLog2OfHalf(Value *&Op, Value *&Y, IntrinsicInst *&Log2) {
IntrinsicInst *II = dyn_cast<IntrinsicInst>(Op);
if (!II)
return;
- if (II->getIntrinsicID() != Intrinsic::log2 || !II->hasUnsafeAlgebra())
+ if (II->getIntrinsicID() != Intrinsic::log2 || !II->isFast())
return;
Log2 = II;
@@ -498,7 +498,8 @@ static void detectLog2OfHalf(Value *&Op, Value *&Y, IntrinsicInst *&Log2) {
Instruction *I = dyn_cast<Instruction>(OpLog2Of);
if (!I)
return;
- if (I->getOpcode() != Instruction::FMul || !I->hasUnsafeAlgebra())
+
+ if (I->getOpcode() != Instruction::FMul || !I->isFast())
return;
if (match(I->getOperand(0), m_SpecificFP(0.5)))
@@ -601,7 +602,7 @@ Value *InstCombiner::foldFMulConst(Instruction *FMulOrDiv, Constant *C,
}
if (R) {
- R->setHasUnsafeAlgebra(true);
+ R->setFast(true);
InsertNewInstWith(R, *InsertBefore);
}
@@ -622,7 +623,7 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
SQ.getWithInstruction(&I)))
return replaceInstUsesWith(I, V);
- bool AllowReassociate = I.hasUnsafeAlgebra();
+ bool AllowReassociate = I.isFast();
// Simplify mul instructions with a constant RHS.
if (isa<Constant>(Op1)) {
@@ -1341,7 +1342,7 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) {
if (Instruction *R = FoldOpIntoSelect(I, SI))
return R;
- bool AllowReassociate = I.hasUnsafeAlgebra();
+ bool AllowReassociate = I.isFast();
bool AllowReciprocal = I.hasAllowReciprocal();
if (Constant *Op1C = dyn_cast<Constant>(Op1)) {
diff --git a/lib/Transforms/InstCombine/InstCombineShifts.cpp b/lib/Transforms/InstCombine/InstCombineShifts.cpp
index 45541c9adc0e..44bbb84686ab 100644
--- a/lib/Transforms/InstCombine/InstCombineShifts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineShifts.cpp
@@ -310,6 +310,40 @@ static Value *getShiftedValue(Value *V, unsigned NumBits, bool isLeftShift,
}
}
+// If this is a bitwise operator or add with a constant RHS we might be able
+// to pull it through a shift.
+static bool canShiftBinOpWithConstantRHS(BinaryOperator &Shift,
+ BinaryOperator *BO,
+ const APInt &C) {
+ bool IsValid = true; // Valid only for And, Or Xor,
+ bool HighBitSet = false; // Transform ifhigh bit of constant set?
+
+ switch (BO->getOpcode()) {
+ default: IsValid = false; break; // Do not perform transform!
+ case Instruction::Add:
+ IsValid = Shift.getOpcode() == Instruction::Shl;
+ break;
+ case Instruction::Or:
+ case Instruction::Xor:
+ HighBitSet = false;
+ break;
+ case Instruction::And:
+ 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
+ // the constant which would cause it to be modified for this
+ // operation.
+ //
+ if (IsValid && Shift.getOpcode() == Instruction::AShr)
+ IsValid = C.isNegative() == HighBitSet;
+
+ return IsValid;
+}
+
Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, Constant *Op1,
BinaryOperator &I) {
bool isLeftShift = I.getOpcode() == Instruction::Shl;
@@ -472,33 +506,7 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, Constant *Op1,
// shift is the only use, we can pull it out of the shift.
const APInt *Op0C;
if (match(Op0BO->getOperand(1), m_APInt(Op0C))) {
- 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:
- isValid = isLeftShift;
- break;
- case Instruction::Or:
- case Instruction::Xor:
- highBitSet = false;
- break;
- case Instruction::And:
- 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
- // the constant which would cause it to be modified for this
- // operation.
- //
- if (isValid && I.getOpcode() == Instruction::AShr)
- isValid = Op0C->isNegative() == highBitSet;
-
- if (isValid) {
+ if (canShiftBinOpWithConstantRHS(I, Op0BO, *Op0C)) {
Constant *NewRHS = ConstantExpr::get(I.getOpcode(),
cast<Constant>(Op0BO->getOperand(1)), Op1);
@@ -525,6 +533,53 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, Constant *Op1,
return BinaryOperator::CreateSub(NewRHS, NewShift);
}
}
+
+ // If we have a select that conditionally executes some binary operator,
+ // see if we can pull it the select and operator through the shift.
+ //
+ // For example, turning:
+ // shl (select C, (add X, C1), X), C2
+ // Into:
+ // Y = shl X, C2
+ // select C, (add Y, C1 << C2), Y
+ Value *Cond;
+ BinaryOperator *TBO;
+ Value *FalseVal;
+ if (match(Op0, m_Select(m_Value(Cond), m_OneUse(m_BinOp(TBO)),
+ m_Value(FalseVal)))) {
+ const APInt *C;
+ if (!isa<Constant>(FalseVal) && TBO->getOperand(0) == FalseVal &&
+ match(TBO->getOperand(1), m_APInt(C)) &&
+ canShiftBinOpWithConstantRHS(I, TBO, *C)) {
+ Constant *NewRHS = ConstantExpr::get(I.getOpcode(),
+ cast<Constant>(TBO->getOperand(1)), Op1);
+
+ Value *NewShift =
+ Builder.CreateBinOp(I.getOpcode(), FalseVal, Op1);
+ Value *NewOp = Builder.CreateBinOp(TBO->getOpcode(), NewShift,
+ NewRHS);
+ return SelectInst::Create(Cond, NewOp, NewShift);
+ }
+ }
+
+ BinaryOperator *FBO;
+ Value *TrueVal;
+ if (match(Op0, m_Select(m_Value(Cond), m_Value(TrueVal),
+ m_OneUse(m_BinOp(FBO))))) {
+ const APInt *C;
+ if (!isa<Constant>(TrueVal) && FBO->getOperand(0) == TrueVal &&
+ match(FBO->getOperand(1), m_APInt(C)) &&
+ canShiftBinOpWithConstantRHS(I, FBO, *C)) {
+ Constant *NewRHS = ConstantExpr::get(I.getOpcode(),
+ cast<Constant>(FBO->getOperand(1)), Op1);
+
+ Value *NewShift =
+ Builder.CreateBinOp(I.getOpcode(), TrueVal, Op1);
+ Value *NewOp = Builder.CreateBinOp(FBO->getOpcode(), NewShift,
+ NewRHS);
+ return SelectInst::Create(Cond, NewShift, NewOp);
+ }
+ }
}
return nullptr;
View Lorry Controller Status