From 430f626937c15bdad1d00f155d78a9273514c695 Mon Sep 17 00:00:00 2001 From: Zhou Sheng Date: Mon, 12 Mar 2007 05:44:52 +0000 Subject: [PATCH] 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. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35060 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 79ad33697c7..abb279f7740 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -695,7 +695,7 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero, // 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 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero, 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 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero, 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 @@ static void ComputeMaskedBits(Value *V, APInt Mask, APInt& KnownZero, 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; -- 2.34.1