Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.652 -> 1.653
---
Log message:
In function ComputeMaskedBits():
1. Replace getSignedMinValue() with getSignBit() for better code readability.
2. Replace APIntOps::shl() with operator<<= for convenience.
3. Make APInt construction more effective.
---
Diffs of the changes: (+6 -6)
InstructionCombining.cpp | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.652
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.653
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.652 Thu Mar 8
09:15:18 2007
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Mon Mar 12 00:44:52 2007
@@ -695,7 +695,7 @@
// If the sign bit of the input is known set or clear, then we know the
// top bits of the result.
- APInt InSignBit(APInt::getSignedMinValue(SrcTy->getBitWidth()));
+ APInt InSignBit(APInt::getSignBit(SrcTy->getBitWidth()));
InSignBit.zextOrTrunc(BitWidth);
if ((KnownZero & InSignBit) != 0) { // Input sign bit known zero
KnownZero |= NewBits;
@@ -716,8 +716,8 @@
Mask = APIntOps::lshr(Mask, ShiftAmt);
ComputeMaskedBits(I->getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
- KnownZero = APIntOps::shl(KnownZero, ShiftAmt);
- KnownOne = APIntOps::shl(KnownOne, ShiftAmt);
+ KnownZero <<= ShiftAmt;
+ KnownOne <<= ShiftAmt;
KnownZero |= APInt(BitWidth, 1ULL).shl(ShiftAmt)-1; // low bits known
zero.
return;
}
@@ -730,7 +730,7 @@
APInt HighBits(APInt::getAllOnesValue(BitWidth).shl(BitWidth-ShiftAmt));
// Unsigned shift right.
- Mask = APIntOps::shl(Mask, ShiftAmt);
+ Mask <<= ShiftAmt;
ComputeMaskedBits(I->getOperand(0), Mask, KnownZero,KnownOne,Depth+1);
assert((KnownZero & KnownOne) == 0&&"Bits known to be one AND zero?");
KnownZero = APIntOps::lshr(KnownZero, ShiftAmt);
@@ -747,14 +747,14 @@
APInt HighBits(APInt::getAllOnesValue(BitWidth).shl(BitWidth-ShiftAmt));
// Signed shift right.
- Mask = APIntOps::shl(Mask, ShiftAmt);
+ Mask <<= ShiftAmt;
ComputeMaskedBits(I->getOperand(0), Mask, KnownZero,KnownOne,Depth+1);
assert((KnownZero & KnownOne) == 0&&"Bits known to be one AND zero?");
KnownZero = APIntOps::lshr(KnownZero, ShiftAmt);
KnownOne = APIntOps::lshr(KnownOne, ShiftAmt);
// Handle the sign bits and adjust to where it is now in the mask.
- APInt SignBit = APInt::getSignedMinValue(BitWidth).lshr(ShiftAmt);
+ APInt SignBit(APInt::getSignBit(BitWidth).lshr(ShiftAmt));
if ((KnownZero & SignBit) != 0) { // New bits are known zero.
KnownZero |= HighBits;
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