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authorNuno Lopes <nunoplopes@sapo.pt>2012-07-03 21:15:40 +0000
committerNuno Lopes <nunoplopes@sapo.pt>2012-07-03 21:15:40 +0000
commit0fd518beb38568e58eeec86876bb597bab06b722 (patch)
treea0b18ec4e81ab9be8669c3442f61e28c3bda1845 /lib/Analysis/ValueTracking.cpp
parent86b032b2abcf8a66282241937861156fc432fa33 (diff)
PHINode::hasConstantValue(): return undef if the PHI is fully recursive.
Thanks Duncan for the idea git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159687 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 d245783ec6..cea34e16e7 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -694,7 +694,7 @@ void llvm::ComputeMaskedBits(Value *V, APInt &KnownZero, APInt &KnownOne,
// taking conservative care to avoid excessive recursion.
if (Depth < MaxDepth - 1 && !KnownZero && !KnownOne) {
// Skip if every incoming value references to ourself.
- if (P->hasConstantValue() == P)
+ if (dyn_cast_or_null<UndefValue>(P->hasConstantValue()))
break;
KnownZero = APInt::getAllOnesValue(BitWidth);