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authorChris Lattner <sabre@nondot.org>2011-01-04 18:19:15 +0000
committerChris Lattner <sabre@nondot.org>2011-01-04 18:19:15 +0000
commit43b40a4620c155c73ac71b48472ea2411d7c35da (patch)
tree2a91e31af838065b7c2a32dd1ad73b215b810faa /lib/Analysis/ValueTracking.cpp
parentba64b9706a1f83e8388c3c722953de16d102de27 (diff)
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fix an off-by-one bug that caused a crash analyzing
ashr's with huge shift amounts, PR8896 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122814 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/ValueTracking.cpp')
-rw-r--r--lib/Analysis/ValueTracking.cpp2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 6f58afe527..e2d7e9290a 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -337,7 +337,7 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask,
// (ashr X, C1) & C2 == 0 iff (-1 >> C1) & C2 == 0
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
// Compute the new bits that are at the top now.
- uint64_t ShiftAmt = SA->getLimitedValue(BitWidth);
+ uint64_t ShiftAmt = SA->getLimitedValue(BitWidth-1);
// Signed shift right.
APInt Mask2(Mask.shl(ShiftAmt));