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| author | Chris Lattner <sabre@nondot.org> | 2004-10-17 21:23:26 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2004-10-17 21:23:26 +0000 |
| commit | 96db59e48a76e95d33404e84e3b6b60984a35982 (patch) | |
| tree | e05bbba42ccc6127e70468c3d7d241bbe4a3cbc7 /llvm/lib/Transforms/Utils/Local.cpp | |
| parent | e29d634a94d7e748abd7294b4024c3f6b7ee1def (diff) | |
| download | bcm5719-llvm-96db59e48a76e95d33404e84e3b6b60984a35982.tar.gz bcm5719-llvm-96db59e48a76e95d33404e84e3b6b60984a35982.zip | |
Enhance hasConstantValue to ignore undef values in phi nodes. This allows it
to think that PHI[4, undef] == 4.
llvm-svn: 17096
Diffstat (limited to 'llvm/lib/Transforms/Utils/Local.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/Local.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp index fe27f308cf0..b188884a405 100644 --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/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; |
