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authorDan Gohman <gohman@apple.com>2009-02-24 02:00:40 +0000
committerDan Gohman <gohman@apple.com>2009-02-24 02:00:40 +0000
commit0001e56f15215ae4bc5fffb82eec5c4828b888f0 (patch)
treec14953e84d899048fdcd5828b6b2b4ecac2ccb2a /lib/Analysis/ValueTracking.cpp
parentc34fea3935dcc0cab13cfb5cb60471bd49089230 (diff)
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Fix a ValueTracking rule: RHS means operand 1, not 0. Add a simple
ashr instcombine to help expose this code. And apply the fix to SelectionDAG's copy of this code too. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65364 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 7ac138b90e..20fa69ea24 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -625,7 +625,7 @@ unsigned llvm::ComputeNumSignBits(Value *V, TargetData *TD, unsigned Depth) {
if (Tmp == 1) return 1; // Early out.
// Special case decrementing a value (ADD X, -1):
- if (ConstantInt *CRHS = dyn_cast<ConstantInt>(U->getOperand(0)))
+ if (ConstantInt *CRHS = dyn_cast<ConstantInt>(U->getOperand(1)))
if (CRHS->isAllOnesValue()) {
APInt KnownZero(TyBits, 0), KnownOne(TyBits, 0);
APInt Mask = APInt::getAllOnesValue(TyBits);