[llvm-commits] CVS: llvm/lib/Transforms/Scalar/InstructionCombining.cpp PredicateSimplifier.cpp Reassociate.cpp
Reid Spencer
reid at x10sys.com
Wed Nov 1 17:54:34 PST 2006
Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.533 -> 1.534
PredicateSimplifier.cpp updated: 1.30 -> 1.31
Reassociate.cpp updated: 1.64 -> 1.65
---
Log message:
For PR950: http://llvm.org/PR950 :
Replace the REM instruction with UREM, SREM and FREM.
---
Diffs of the changes: (+134 -119)
InstructionCombining.cpp | 245 ++++++++++++++++++++++++-----------------------
PredicateSimplifier.cpp | 4
Reassociate.cpp | 4
3 files changed, 134 insertions(+), 119 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.533 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.534
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.533 Wed Nov 1 01:43:41 2006
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Wed Nov 1 19:53:58 2006
@@ -131,12 +131,16 @@
Instruction *visitAdd(BinaryOperator &I);
Instruction *visitSub(BinaryOperator &I);
Instruction *visitMul(BinaryOperator &I);
+ Instruction *visitURem(BinaryOperator &I);
+ Instruction *visitSRem(BinaryOperator &I);
+ Instruction *visitFRem(BinaryOperator &I);
+ Instruction *commonRemTransforms(BinaryOperator &I);
+ Instruction *commonIRemTransforms(BinaryOperator &I);
Instruction *commonDivTransforms(BinaryOperator &I);
Instruction *commonIDivTransforms(BinaryOperator &I);
Instruction *visitUDiv(BinaryOperator &I);
Instruction *visitSDiv(BinaryOperator &I);
Instruction *visitFDiv(BinaryOperator &I);
- Instruction *visitRem(BinaryOperator &I);
Instruction *visitAnd(BinaryOperator &I);
Instruction *visitOr (BinaryOperator &I);
Instruction *visitXor(BinaryOperator &I);
@@ -2412,9 +2416,13 @@
return Result;
}
-Instruction *InstCombiner::visitRem(BinaryOperator &I) {
+/// This function implements the transforms on rem instructions that work
+/// regardless of the kind of rem instruction it is (urem, srem, or frem). It
+/// is used by the visitors to those instructions.
+/// @brief Transforms common to all three rem instructions
+Instruction *InstCombiner::commonRemTransforms(BinaryOperator &I) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
+
// 0 % X == 0, we don't need to preserve faults!
if (Constant *LHS = dyn_cast<Constant>(Op0))
if (LHS->isNullValue())
@@ -2424,34 +2432,52 @@
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
if (isa<UndefValue>(Op1))
return ReplaceInstUsesWith(I, Op1); // X % undef -> undef
-
- if (I.getType()->isSigned()) {
- if (Value *RHSNeg = dyn_castNegVal(Op1))
- if (!isa<ConstantInt>(RHSNeg) || !RHSNeg->getType()->isSigned() ||
- cast<ConstantInt>(RHSNeg)->getSExtValue() > 0) {
- // X % -Y -> X % Y
- AddUsesToWorkList(I);
- I.setOperand(1, RHSNeg);
+
+ // Handle cases involving: rem X, (select Cond, Y, Z)
+ if (SelectInst *SI = dyn_cast<SelectInst>(Op1)) {
+ // rem X, (Cond ? 0 : Y) -> rem X, Y. If the rem and the select are in
+ // the same basic block, then we replace the select with Y, and the
+ // condition of the select with false (if the cond value is in the same
+ // BB). If the select has uses other than the div, this allows them to be
+ // simplified also.
+ if (Constant *ST = dyn_cast<Constant>(SI->getOperand(1)))
+ if (ST->isNullValue()) {
+ Instruction *CondI = dyn_cast<Instruction>(SI->getOperand(0));
+ if (CondI && CondI->getParent() == I.getParent())
+ UpdateValueUsesWith(CondI, ConstantBool::getFalse());
+ else if (I.getParent() != SI->getParent() || SI->hasOneUse())
+ I.setOperand(1, SI->getOperand(2));
+ else
+ UpdateValueUsesWith(SI, SI->getOperand(2));
+ return &I;
+ }
+ // Likewise for: rem X, (Cond ? Y : 0) -> rem X, Y
+ if (Constant *ST = dyn_cast<Constant>(SI->getOperand(2)))
+ if (ST->isNullValue()) {
+ Instruction *CondI = dyn_cast<Instruction>(SI->getOperand(0));
+ if (CondI && CondI->getParent() == I.getParent())
+ UpdateValueUsesWith(CondI, ConstantBool::getTrue());
+ else if (I.getParent() != SI->getParent() || SI->hasOneUse())
+ I.setOperand(1, SI->getOperand(1));
+ else
+ UpdateValueUsesWith(SI, SI->getOperand(1));
return &I;
}
-
- // If the top bits of both operands are zero (i.e. we can prove they are
- // unsigned inputs), turn this into a urem.
- uint64_t Mask = 1ULL << (I.getType()->getPrimitiveSizeInBits()-1);
- if (MaskedValueIsZero(Op1, Mask) && MaskedValueIsZero(Op0, Mask)) {
- const Type *NTy = Op0->getType()->getUnsignedVersion();
- Value *LHS = InsertCastBefore(Op0, NTy, I);
- Value *RHS;
- if (Constant *R = dyn_cast<Constant>(Op1))
- RHS = ConstantExpr::getCast(R, NTy);
- else
- RHS = InsertCastBefore(Op1, NTy, I);
- Instruction *Rem = BinaryOperator::createRem(LHS, RHS, I.getName());
- InsertNewInstBefore(Rem, I);
- return new CastInst(Rem, I.getType());
- }
}
+ return 0;
+}
+
+/// This function implements the transforms common to both integer remainder
+/// instructions (urem and srem). It is called by the visitors to those integer
+/// remainder instructions.
+/// @brief Common integer remainder transforms
+Instruction *InstCombiner::commonIRemTransforms(BinaryOperator &I) {
+ Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+
+ if (Instruction *common = commonRemTransforms(I))
+ return common;
+
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
// X % 0 == undef, we don't need to preserve faults!
if (RHS->equalsInt(0))
@@ -2460,13 +2486,6 @@
if (RHS->equalsInt(1)) // X % 1 == 0
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
- // Check to see if this is an unsigned remainder with an exact power of 2,
- // if so, convert to a bitwise and.
- if (ConstantInt *C = dyn_cast<ConstantInt>(RHS))
- if (RHS->getType()->isUnsigned())
- if (isPowerOf2_64(C->getZExtValue()))
- return BinaryOperator::createAnd(Op0, SubOne(C));
-
if (Instruction *Op0I = dyn_cast<Instruction>(Op0)) {
if (SelectInst *SI = dyn_cast<SelectInst>(Op0I)) {
if (Instruction *R = FoldOpIntoSelect(I, SI, this))
@@ -2475,19 +2494,34 @@
if (Instruction *NV = FoldOpIntoPhi(I))
return NV;
}
-
- // X*C1%C2 --> 0 iff C1%C2 == 0
- if (ConstantExpr::getRem(GetFactor(Op0I), RHS)->isNullValue())
+ // (X * C1) % C2 --> 0 iff C1 % C2 == 0
+ if (ConstantExpr::getSRem(GetFactor(Op0I), RHS)->isNullValue())
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
}
}
+ return 0;
+}
+
+Instruction *InstCombiner::visitURem(BinaryOperator &I) {
+ Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+
+ if (Instruction *common = commonIRemTransforms(I))
+ return common;
+
+ if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
+ // X urem C^2 -> X and C
+ // Check to see if this is an unsigned remainder with an exact power of 2,
+ // if so, convert to a bitwise and.
+ if (ConstantInt *C = dyn_cast<ConstantInt>(RHS))
+ if (isPowerOf2_64(C->getZExtValue()))
+ return BinaryOperator::createAnd(Op0, SubOne(C));
+ }
+
if (Instruction *RHSI = dyn_cast<Instruction>(I.getOperand(1))) {
- // Turn A % (C << N), where C is 2^k, into A & ((C << N)-1) [urem only].
- if (I.getType()->isUnsigned() &&
- RHSI->getOpcode() == Instruction::Shl &&
- isa<ConstantInt>(RHSI->getOperand(0)) &&
- RHSI->getOperand(0)->getType()->isUnsigned()) {
+ // Turn A % (C << N), where C is 2^k, into A & ((C << N)-1)
+ if (RHSI->getOpcode() == Instruction::Shl &&
+ isa<ConstantInt>(RHSI->getOperand(0))) {
unsigned C1 = cast<ConstantInt>(RHSI->getOperand(0))->getZExtValue();
if (isPowerOf2_64(C1)) {
Constant *N1 = ConstantInt::getAllOnesValue(I.getType());
@@ -2496,61 +2530,60 @@
return BinaryOperator::createAnd(Op0, Add);
}
}
-
- // If this is 'urem X, (Cond ? C1, C2)' where C1&C2 are powers of two,
- // transform this into: '(Cond ? (urem X, C1) : (urem X, C2))'.
- if (SelectInst *SI = dyn_cast<SelectInst>(Op1)) {
- // rem X, (Cond ? 0 : Y) -> rem X, Y. If the rem and the select are in
- // the same basic block, then we replace the select with Y, and the
- // condition of the select with false (if the cond value is in the same
- // BB). If the select has uses other than the div, this allows them to be
- // simplified also.
- if (Constant *ST = dyn_cast<Constant>(SI->getOperand(1)))
- if (ST->isNullValue()) {
- Instruction *CondI = dyn_cast<Instruction>(SI->getOperand(0));
- if (CondI && CondI->getParent() == I.getParent())
- UpdateValueUsesWith(CondI, ConstantBool::getFalse());
- else if (I.getParent() != SI->getParent() || SI->hasOneUse())
- I.setOperand(1, SI->getOperand(2));
- else
- UpdateValueUsesWith(SI, SI->getOperand(2));
- return &I;
- }
- // Likewise for: rem X, (Cond ? Y : 0) -> rem X, Y
- if (Constant *ST = dyn_cast<Constant>(SI->getOperand(2)))
- if (ST->isNullValue()) {
- Instruction *CondI = dyn_cast<Instruction>(SI->getOperand(0));
- if (CondI && CondI->getParent() == I.getParent())
- UpdateValueUsesWith(CondI, ConstantBool::getTrue());
- else if (I.getParent() != SI->getParent() || SI->hasOneUse())
- I.setOperand(1, SI->getOperand(1));
- else
- UpdateValueUsesWith(SI, SI->getOperand(1));
- return &I;
+ }
+
+ // urem X, (select Cond, 2^C1, 2^C2) --> select Cond, (and X, C1), (and X, C2)
+ // where C1&C2 are powers of two.
+ if (SelectInst *SI = dyn_cast<SelectInst>(Op1)) {
+ if (ConstantInt *STO = dyn_cast<ConstantInt>(SI->getOperand(1)))
+ if (ConstantInt *SFO = dyn_cast<ConstantInt>(SI->getOperand(2))) {
+ // STO == 0 and SFO == 0 handled above.
+ if (isPowerOf2_64(STO->getZExtValue()) &&
+ isPowerOf2_64(SFO->getZExtValue())) {
+ Value *TrueAnd = InsertNewInstBefore(
+ BinaryOperator::createAnd(Op0, SubOne(STO), SI->getName()+".t"), I);
+ Value *FalseAnd = InsertNewInstBefore(
+ BinaryOperator::createAnd(Op0, SubOne(SFO), SI->getName()+".f"), I);
+ return new SelectInst(SI->getOperand(0), TrueAnd, FalseAnd);
}
+ }
+ }
+
+ return 0;
+}
-
- if (ConstantInt *STO = dyn_cast<ConstantInt>(SI->getOperand(1)))
- if (ConstantInt *SFO = dyn_cast<ConstantInt>(SI->getOperand(2)))
- if (STO->getType()->isUnsigned() && SFO->getType()->isUnsigned()) {
- // STO == 0 and SFO == 0 handled above.
- if (isPowerOf2_64(STO->getZExtValue()) &&
- isPowerOf2_64(SFO->getZExtValue())) {
- Value *TrueAnd = InsertNewInstBefore(
- BinaryOperator::createAnd(Op0, SubOne(STO), SI->getName()+".t"),
- I);
- Value *FalseAnd = InsertNewInstBefore(
- BinaryOperator::createAnd(Op0, SubOne(SFO), SI->getName()+".f"),
- I);
- return new SelectInst(SI->getOperand(0), TrueAnd, FalseAnd);
- }
- }
+Instruction *InstCombiner::visitSRem(BinaryOperator &I) {
+ Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+
+ if (Instruction *common = commonIRemTransforms(I))
+ return common;
+
+ if (Value *RHSNeg = dyn_castNegVal(Op1))
+ if (!isa<ConstantInt>(RHSNeg) ||
+ cast<ConstantInt>(RHSNeg)->getSExtValue() > 0) {
+ // X % -Y -> X % Y
+ AddUsesToWorkList(I);
+ I.setOperand(1, RHSNeg);
+ return &I;
}
+
+ // If the top bits of both operands are zero (i.e. we can prove they are
+ // unsigned inputs), turn this into a urem.
+ uint64_t Mask = 1ULL << (I.getType()->getPrimitiveSizeInBits()-1);
+ if (MaskedValueIsZero(Op1, Mask) && MaskedValueIsZero(Op0, Mask)) {
+ // X srem Y -> X urem Y, iff X and Y don't have sign bit set
+ return BinaryOperator::createURem(Op0, Op1, I.getName());
}
-
+
return 0;
}
+Instruction *InstCombiner::visitFRem(BinaryOperator &I) {
+ Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+
+ return commonRemTransforms(I);
+}
+
// isMaxValueMinusOne - return true if this is Max-1
static bool isMaxValueMinusOne(const ConstantInt *C) {
if (C->getType()->isUnsigned())
@@ -4568,40 +4601,16 @@
// the second operand is a constant, simplify a bit.
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0)) {
switch (BO->getOpcode()) {
-#if 0
case Instruction::SRem:
// If we have a signed (X % (2^c)) == 0, turn it into an unsigned one.
if (CI->isNullValue() && isa<ConstantInt>(BO->getOperand(1)) &&
BO->hasOneUse()) {
int64_t V = cast<ConstantInt>(BO->getOperand(1))->getSExtValue();
if (V > 1 && isPowerOf2_64(V)) {
- Value *NewRem = InsertNewInstBefore(
- BinaryOperator::createURem(BO->getOperand(0),
- BO->getOperand(1),
- BO->getName()), I);
- return BinaryOperator::create(
- I.getOpcode(), NewRem,
- Constant::getNullValue(NewRem->getType()));
- }
- }
- break;
-#endif
-
- case Instruction::Rem:
- // If we have a signed (X % (2^c)) == 0, turn it into an unsigned one.
- if (CI->isNullValue() && isa<ConstantInt>(BO->getOperand(1)) &&
- BO->hasOneUse() && BO->getOperand(1)->getType()->isSigned()) {
- int64_t V = cast<ConstantInt>(BO->getOperand(1))->getSExtValue();
- if (V > 1 && isPowerOf2_64(V)) {
- unsigned L2 = Log2_64(V);
- const Type *UTy = BO->getType()->getUnsignedVersion();
- Value *NewX = InsertNewInstBefore(new CastInst(BO->getOperand(0),
- UTy, "tmp"), I);
- Constant *RHSCst = ConstantInt::get(UTy, 1ULL << L2);
- Value *NewRem =InsertNewInstBefore(BinaryOperator::createRem(NewX,
- RHSCst, BO->getName()), I);
+ Value *NewRem = InsertNewInstBefore(BinaryOperator::createURem(
+ BO->getOperand(0), BO->getOperand(1), BO->getName()), I);
return BinaryOperator::create(I.getOpcode(), NewRem,
- Constant::getNullValue(UTy));
+ Constant::getNullValue(BO->getType()));
}
}
break;
@@ -5766,6 +5775,8 @@
break;
case Instruction::SDiv:
case Instruction::UDiv:
+ case Instruction::SRem:
+ case Instruction::URem:
// If we are just changing the sign, rewrite.
if (DestBitSize == SrcBitSize) {
// Don't insert two casts if they cannot be eliminated. We allow two
Index: llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp
diff -u llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.30 llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.31
--- llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.30 Thu Oct 26 01:15:43 2006
+++ llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp Wed Nov 1 19:53:58 2006
@@ -788,10 +788,12 @@
Instruction::BinaryOps ops = BO.getOpcode();
switch (ops) {
+ case Instruction::URem:
+ case Instruction::SRem:
case Instruction::UDiv:
case Instruction::SDiv:
case Instruction::FDiv:
- case Instruction::Rem: {
+ case Instruction::FRem: {
Value *Divisor = BO.getOperand(1);
KP.addNotEqual(Constant::getNullValue(Divisor->getType()), Divisor);
break;
Index: llvm/lib/Transforms/Scalar/Reassociate.cpp
diff -u llvm/lib/Transforms/Scalar/Reassociate.cpp:1.64 llvm/lib/Transforms/Scalar/Reassociate.cpp:1.65
--- llvm/lib/Transforms/Scalar/Reassociate.cpp:1.64 Thu Oct 26 01:15:43 2006
+++ llvm/lib/Transforms/Scalar/Reassociate.cpp Wed Nov 1 19:53:58 2006
@@ -116,7 +116,9 @@
I->getOpcode() == Instruction::UDiv ||
I->getOpcode() == Instruction::SDiv ||
I->getOpcode() == Instruction::FDiv ||
- I->getOpcode() == Instruction::Rem)
+ I->getOpcode() == Instruction::URem ||
+ I->getOpcode() == Instruction::SRem ||
+ I->getOpcode() == Instruction::FRem)
return true;
return false;
}
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