Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.598 -> 1.599
---
Log message:
simplify some code now that types are signless
---
Diffs of the changes: (+12 -46)
InstructionCombining.cpp | 58 +++++++++--------------------------------------
1 files changed, 12 insertions(+), 46 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.598
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.599
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.598 Mon Jan 15
00:51:56 2007
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Mon Jan 15 01:02:54 2007
@@ -1927,21 +1927,6 @@
return (CI->getZExtValue() & (~0ULL >> (64-NumBits))) == (1ULL <<
(NumBits-1));
}
-/// RemoveNoopCast - Strip off nonconverting casts from the value.
-///
-static Value *RemoveNoopCast(Value *V) {
- if (CastInst *CI = dyn_cast<CastInst>(V)) {
- const Type *CTy = CI->getType();
- const Type *OpTy = CI->getOperand(0)->getType();
- if (CTy->isInteger() && OpTy->isInteger()) {
- if (CTy->getPrimitiveSizeInBits() == OpTy->getPrimitiveSizeInBits())
- return RemoveNoopCast(CI->getOperand(0));
- } else if (isa<PointerType>(CTy) && isa<PointerType>(OpTy))
- return RemoveNoopCast(CI->getOperand(0));
- }
- return V;
-}
-
Instruction *InstCombiner::visitSub(BinaryOperator &I) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
@@ -1967,21 +1952,17 @@
if (match(Op1, m_Not(m_Value(X))))
return BinaryOperator::createAdd(X,
ConstantExpr::getAdd(C, ConstantInt::get(I.getType(), 1)));
- // -((uint)X >> 31) -> ((int)X >> 31)
- // -((int)X >> 31) -> ((uint)X >> 31)
+ // -(X >>u 31) -> (X >>s 31)
+ // -(X >>s 31) -> (X >>u 31)
if (C->isNullValue()) {
- Value *NoopCastedRHS = RemoveNoopCast(Op1);
- if (ShiftInst *SI = dyn_cast<ShiftInst>(NoopCastedRHS))
+ if (ShiftInst *SI = dyn_cast<ShiftInst>(Op1))
if (SI->getOpcode() == Instruction::LShr) {
if (ConstantInt *CU = dyn_cast<ConstantInt>(SI->getOperand(1))) {
// Check to see if we are shifting out everything but the sign bit.
if (CU->getZExtValue() ==
SI->getType()->getPrimitiveSizeInBits()-1) {
// Ok, the transformation is safe. Insert AShr.
- // FIXME: Once integer types are signless, this cast should be
- // removed.
- Value *ShiftOp = SI->getOperand(0);
- return new ShiftInst(Instruction::AShr, ShiftOp, CU,
+ return new ShiftInst(Instruction::AShr, SI->getOperand(0), CU,
SI->getName());
}
}
@@ -1991,7 +1972,6 @@
// Check to see if we are shifting out everything but the sign bit.
if (CU->getZExtValue() ==
SI->getType()->getPrimitiveSizeInBits()-1) {
-
// Ok, the transformation is safe. Insert LShr.
return new ShiftInst(Instruction::LShr, SI->getOperand(0), CU,
SI->getName());
@@ -7664,28 +7644,14 @@
for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i, ++GTI)
if (isa<SequentialType>(*GTI)) {
if (CastInst *CI = dyn_cast<CastInst>(GEP.getOperand(i))) {
- Value *Src = CI->getOperand(0);
- const Type *SrcTy = Src->getType();
- const Type *DestTy = CI->getType();
- if (Src->getType()->isInteger()) {
- if (SrcTy->getPrimitiveSizeInBits() ==
- DestTy->getPrimitiveSizeInBits()) {
- // We can always eliminate a cast from ulong or long to the other.
- // We can always eliminate a cast from uint to int or the other on
- // 32-bit pointer platforms.
- if (DestTy->getPrimitiveSizeInBits() >=
TD->getPointerSizeInBits()){
- MadeChange = true;
- GEP.setOperand(i, Src);
- }
- } else if (SrcTy->getPrimitiveSizeInBits() <
- DestTy->getPrimitiveSizeInBits() &&
- SrcTy->getPrimitiveSizeInBits() == 32) {
- // We can eliminate a cast from [u]int to [u]long iff the target
- // is a 32-bit pointer target.
- if (SrcTy->getPrimitiveSizeInBits() >= TD->getPointerSizeInBits())
{
- MadeChange = true;
- GEP.setOperand(i, Src);
- }
+ if (CI->getOpcode() == Instruction::ZExt ||
+ CI->getOpcode() == Instruction::SExt) {
+ const Type *SrcTy = CI->getOperand(0)->getType();
+ // We can eliminate a cast from i32 to i64 iff the target
+ // is a 32-bit pointer target.
+ if (SrcTy->getPrimitiveSizeInBits() >= TD->getPointerSizeInBits()) {
+ MadeChange = true;
+ GEP.setOperand(i, CI->getOperand(0));
}
}
}
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