Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.407 -> 1.408
---
Log message:
Simplify the code a bit more
---
Diffs of the changes: (+5 -3)
InstructionCombining.cpp | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.407
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.408
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.407 Fri Jan 6
01:12:35 2006
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Fri Jan 6 01:22:22 2006
@@ -3449,13 +3449,15 @@
Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantUInt *Op1,
ShiftInst &I) {
bool isLeftShift = I.getOpcode() == Instruction::Shl;
+ bool isSignedShift = Op0->getType()->isSigned();
+ bool isUnsignedShift = !isSignedShift;
// shl uint X, 32 = 0 and shr ubyte Y, 9 = 0, ... just don't eliminate shr
// of a signed value.
//
unsigned TypeBits = Op0->getType()->getPrimitiveSizeInBits();
if (Op1->getValue() >= TypeBits) {
- if (!Op0->getType()->isSigned() || isLeftShift)
+ if (isUnsignedShift || isLeftShift)
return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType()));
else {
I.setOperand(1, ConstantUInt::get(Type::UByteTy, TypeBits-1));
@@ -3625,7 +3627,7 @@
// the constant which would cause it to be modified for this
// operation.
//
- if (isValid && !isLeftShift && !I.getType()->isUnsigned()) {
+ if (isValid && !isLeftShift && isSignedShift) {
uint64_t Val = Op0C->getRawValue();
isValid = ((Val & (1 << (TypeBits-1))) != 0) == highBitSet;
}
@@ -3665,7 +3667,7 @@
// Check for (A << c1) >> c2 or visaversa. If we are dealing with
// signed types, we can only support the (A >> c1) << c2 configuration,
// because it can not turn an arbitrary bit of A into a sign bit.
- if (I.getType()->isUnsigned() || isLeftShift) {
+ if (isUnsignedShift || isLeftShift) {
// Calculate bitmask for what gets shifted off the edge...
Constant *C = ConstantIntegral::getAllOnesValue(I.getType());
if (isLeftShift)
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