diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 26 |
1 files changed, 10 insertions, 16 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index 61a8e5b..125c74a 100644 --- a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -142,7 +142,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, Instruction *I = dyn_cast<Instruction>(V); if (!I) { - ComputeMaskedBits(V, DemandedMask, KnownZero, KnownOne, Depth); + ComputeMaskedBits(V, KnownZero, KnownOne, Depth); return 0; // Only analyze instructions. } @@ -156,10 +156,8 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, // this instruction has a simpler value in that context. if (I->getOpcode() == Instruction::And) { // If either the LHS or the RHS are Zero, the result is zero. - ComputeMaskedBits(I->getOperand(1), DemandedMask, - RHSKnownZero, RHSKnownOne, Depth+1); - ComputeMaskedBits(I->getOperand(0), DemandedMask & ~RHSKnownZero, - LHSKnownZero, LHSKnownOne, Depth+1); + ComputeMaskedBits(I->getOperand(1), RHSKnownZero, RHSKnownOne, Depth+1); + ComputeMaskedBits(I->getOperand(0), LHSKnownZero, LHSKnownOne, Depth+1); // If all of the demanded bits are known 1 on one side, return the other. // These bits cannot contribute to the result of the 'and' in this @@ -180,10 +178,8 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, // only bits from X or Y are demanded. // If either the LHS or the RHS are One, the result is One. - ComputeMaskedBits(I->getOperand(1), DemandedMask, - RHSKnownZero, RHSKnownOne, Depth+1); - ComputeMaskedBits(I->getOperand(0), DemandedMask & ~RHSKnownOne, - LHSKnownZero, LHSKnownOne, Depth+1); + ComputeMaskedBits(I->getOperand(1), RHSKnownZero, RHSKnownOne, Depth+1); + ComputeMaskedBits(I->getOperand(0), LHSKnownZero, LHSKnownOne, Depth+1); // If all of the demanded bits are known zero on one side, return the // other. These bits cannot contribute to the result of the 'or' in this @@ -206,7 +202,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, } // Compute the KnownZero/KnownOne bits to simplify things downstream. - ComputeMaskedBits(I, DemandedMask, KnownZero, KnownOne, Depth); + ComputeMaskedBits(I, KnownZero, KnownOne, Depth); return 0; } @@ -219,7 +215,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, switch (I->getOpcode()) { default: - ComputeMaskedBits(I, DemandedMask, KnownZero, KnownOne, Depth); + ComputeMaskedBits(I, KnownZero, KnownOne, Depth); break; case Instruction::And: // If either the LHS or the RHS are Zero, the result is zero. @@ -570,7 +566,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, // Otherwise just hand the sub off to ComputeMaskedBits to fill in // the known zeros and ones. - ComputeMaskedBits(V, DemandedMask, KnownZero, KnownOne, Depth); + ComputeMaskedBits(V, KnownZero, KnownOne, Depth); // Turn this into a xor if LHS is 2^n-1 and the remaining bits are known // zero. @@ -729,10 +725,8 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, // The sign bit is the LHS's sign bit, except when the result of the // remainder is zero. if (DemandedMask.isNegative() && KnownZero.isNonNegative()) { - APInt Mask2 = APInt::getSignBit(BitWidth); APInt LHSKnownZero(BitWidth, 0), LHSKnownOne(BitWidth, 0); - ComputeMaskedBits(I->getOperand(0), Mask2, LHSKnownZero, LHSKnownOne, - Depth+1); + ComputeMaskedBits(I->getOperand(0), LHSKnownZero, LHSKnownOne, Depth+1); // If it's known zero, our sign bit is also zero. if (LHSKnownZero.isNegative()) KnownZero |= LHSKnownZero; @@ -795,7 +789,7 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask, return 0; } } - ComputeMaskedBits(V, DemandedMask, KnownZero, KnownOne, Depth); + ComputeMaskedBits(V, KnownZero, KnownOne, Depth); break; } |