Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.685 -> 1.686
---
Log message:
Make more uses of getHighBitsSet and get rid of some pointless & of an
APInt with its type mask.
---
Diffs of the changes: (+12 -12)
InstructionCombining.cpp | 24 ++++++++++++------------
1 files changed, 12 insertions(+), 12 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.685
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.686
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.685 Sat Mar 24
21:03:12 2007
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Sat Mar 24 23:26:16 2007
@@ -685,9 +685,9 @@
case Instruction::ZExt: {
// Compute the bits in the result that are not present in the input.
const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
- APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
-
uint32_t SrcBitWidth = SrcTy->getBitWidth();
+ APInt NewBits(APInt::getHighBitsSet(BitWidth, BitWidth - SrcBitWidth));
+
ComputeMaskedBits(I->getOperand(0), APInt(Mask).trunc(SrcBitWidth),
KnownZero.trunc(SrcBitWidth), KnownOne.trunc(SrcBitWidth), Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
@@ -700,9 +700,9 @@
case Instruction::SExt: {
// Compute the bits in the result that are not present in the input.
const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
- APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
-
uint32_t SrcBitWidth = SrcTy->getBitWidth();
+ APInt NewBits(APInt::getHighBitsSet(BitWidth, BitWidth - SrcBitWidth));
+
ComputeMaskedBits(I->getOperand(0), APInt(Mask).trunc(SrcBitWidth),
KnownZero.trunc(SrcBitWidth), KnownOne.trunc(SrcBitWidth), Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
@@ -743,7 +743,7 @@
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
// Compute the new bits that are at the top now.
uint64_t ShiftAmt = SA->getZExtValue();
- APInt HighBits(APInt::getAllOnesValue(BitWidth).shl(BitWidth-ShiftAmt));
+ APInt HighBits(APInt::getHighBitsSet(BitWidth, ShiftAmt));
// Unsigned shift right.
APInt Mask2(Mask.shl(ShiftAmt));
@@ -760,7 +760,7 @@
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
// Compute the new bits that are at the top now.
uint64_t ShiftAmt = SA->getZExtValue();
- APInt HighBits(APInt::getAllOnesValue(BitWidth).shl(BitWidth-ShiftAmt));
+ APInt HighBits(APInt::getHighBitsSet(BitWidth, ShiftAmt));
// Signed shift right.
APInt Mask2(Mask.shl(ShiftAmt));
@@ -830,8 +830,7 @@
KnownOne.getBitWidth() == BitWidth &&
Min.getBitWidth() == BitWidth && Max.getBitWidth() == BitWidth &&
"Ty, KnownZero, KnownOne and Min, Max must have equal bitwidth.");
- APInt TypeBits(APInt::getAllOnesValue(BitWidth));
- APInt UnknownBits = ~(KnownZero|KnownOne) & TypeBits;
+ APInt UnknownBits = ~(KnownZero|KnownOne);
APInt SignBit(APInt::getSignBit(BitWidth));
@@ -860,8 +859,7 @@
KnownOne.getBitWidth() == BitWidth &&
Min.getBitWidth() == BitWidth && Max.getBitWidth() &&
"Ty, KnownZero, KnownOne and Min, Max must have equal bitwidth.");
- APInt TypeBits(APInt::getAllOnesValue(BitWidth));
- APInt UnknownBits = ~(KnownZero|KnownOne) & TypeBits;
+ APInt UnknownBits = ~(KnownZero|KnownOne);
// The minimum value is when the unknown bits are all zeros.
Min = KnownOne;
@@ -1118,7 +1116,8 @@
case Instruction::ZExt: {
// Compute the bits in the result that are not present in the input.
const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
- APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
+ uint32_t SrcBitWidth = SrcTy->getBitWidth();
+ APInt NewBits(APInt::getHighBitsSet(BitWidth, BitWidth - SrcBitWidth));
DemandedMask &= SrcTy->getMask().zext(BitWidth);
uint32_t zextBf = SrcTy->getBitWidth();
@@ -1137,7 +1136,8 @@
case Instruction::SExt: {
// Compute the bits in the result that are not present in the input.
const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
- APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
+ uint32_t SrcBitWidth = SrcTy->getBitWidth();
+ APInt NewBits(APInt::getHighBitsSet(BitWidth, BitWidth - SrcBitWidth));
// Get the sign bit for the source type
APInt InSignBit(APInt::getSignBit(SrcTy->getPrimitiveSizeInBits()));
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