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authorChris Lattner <sabre@nondot.org>2004-10-17 21:23:26 +0000
committerChris Lattner <sabre@nondot.org>2004-10-17 21:23:26 +0000
commit8143c2bc0de4f39bef0432a25d9a111be4767fa1 (patch)
tree7d2b206a7d7fead5814639ba25c8ca63e1f23f75
parentc30bda7540de573c887e00bb76ac78d85f56acd4 (diff)
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Enhance hasConstantValue to ignore undef values in phi nodes. This allows it
to think that PHI[4, undef] == 4. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17096 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Transforms/Utils/Local.cpp5
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index fe27f30..b188884 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -353,7 +353,8 @@ Value *llvm::hasConstantValue(PHINode *PN) {
//
Value *InVal = 0;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
- if (PN->getIncomingValue(i) != PN) // Not the PHI node itself...
+ if (PN->getIncomingValue(i) != PN && // Not the PHI node itself...
+ !isa<UndefValue>(PN->getIncomingValue(i)))
if (InVal && PN->getIncomingValue(i) != InVal)
return 0; // Not the same, bail out.
else
@@ -363,7 +364,7 @@ Value *llvm::hasConstantValue(PHINode *PN) {
// that only has entries for itself. In this case, there is no entry into the
// loop, so kill the PHI.
//
- if (InVal == 0) InVal = Constant::getNullValue(PN->getType());
+ if (InVal == 0) InVal = UndefValue::get(PN->getType());
// All of the incoming values are the same, return the value now.
return InVal;