From c15637bafc57de7d1775082910bff4cc59c4f0db Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Mon, 13 Feb 2006 06:09:08 +0000 Subject: [PATCH] Be careful not to request or look at bits shifted in from outside the size of the input. This fixes the mediabench/gsm/toast failure last night. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26138 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 9b75ee13cb6..4247d8a6e29 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -939,20 +939,26 @@ bool InstCombiner::SimplifyDemandedBits(Value *V, uint64_t DemandedMask, // Compute the new bits that are at the top now. uint64_t HighBits = (1ULL << ShAmt)-1; HighBits <<= I->getType()->getPrimitiveSizeInBits() - ShAmt; - + uint64_t TypeMask = I->getType()->getIntegralTypeMask(); if (I->getType()->isUnsigned()) { // Unsigned shift right. - if (SimplifyDemandedBits(I->getOperand(0), DemandedMask << ShAmt, + if (SimplifyDemandedBits(I->getOperand(0), + (DemandedMask << ShAmt) & TypeMask, KnownZero, KnownOne, Depth+1)) return true; assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); + KnownZero &= TypeMask; + KnownOne &= TypeMask; KnownZero >>= ShAmt; KnownOne >>= ShAmt; KnownZero |= HighBits; // high bits known zero. } else { // Signed shift right. - if (SimplifyDemandedBits(I->getOperand(0), DemandedMask << ShAmt, + if (SimplifyDemandedBits(I->getOperand(0), + (DemandedMask << ShAmt) & TypeMask, KnownZero, KnownOne, Depth+1)) return true; assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); + KnownZero &= TypeMask; + KnownOne &= TypeMask; KnownZero >>= SA->getValue(); KnownOne >>= SA->getValue(); -- 2.34.1