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| author | Nate Begeman <natebegeman@mac.com> | 2005-08-04 23:24:19 +0000 |
|---|---|---|
| committer | Nate Begeman <natebegeman@mac.com> | 2005-08-04 23:24:19 +0000 |
| commit | b392321cae84aa9ac37966ce0d3f73a34bee8b11 (patch) | |
| tree | 1dd95fa0d70c36c83a8b37e5f5dc4c77d15b8c56 /llvm/lib/Transforms/Utils/Local.cpp | |
| parent | a75342d89f59426934ed634a15c6585197ff55cc (diff) | |
| download | bcm5719-llvm-b392321cae84aa9ac37966ce0d3f73a34bee8b11.tar.gz bcm5719-llvm-b392321cae84aa9ac37966ce0d3f73a34bee8b11.zip | |
Fix a fixme in CondPropagate.cpp by moving a PhiNode optimization into
BasicBlock's removePredecessor routine. This requires shuffling around
the definition and implementation of hasContantValue from Utils.h,cpp into
Instructions.h,cpp
llvm-svn: 22664
Diffstat (limited to 'llvm/lib/Transforms/Utils/Local.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/Local.cpp | 34 |
1 files changed, 0 insertions, 34 deletions
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp index 4ce9d8f11a1..9744af3c605 100644 --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/lib/Transforms/Utils/Local.cpp @@ -406,37 +406,3 @@ bool llvm::dceInstruction(BasicBlock::iterator &BBI) { } return false; } - -//===----------------------------------------------------------------------===// -// PHI Instruction Simplification -// - -/// hasConstantValue - If the specified PHI node always merges together the same -/// value, return the value, otherwise return null. -/// -Value *llvm::hasConstantValue(PHINode *PN) { - // If the PHI node only has one incoming value, eliminate the PHI node... - if (PN->getNumIncomingValues() == 1) - return PN->getIncomingValue(0); - - // Otherwise if all of the incoming values are the same for the PHI, replace - // the PHI node with the incoming value. - // - Value *InVal = 0; - for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) - 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 - InVal = PN->getIncomingValue(i); - - // The only case that could cause InVal to be null is if we have a PHI node - // that only has entries for itself. In this case, there is no entry into the - // loop, so kill the PHI. - // - if (InVal == 0) InVal = UndefValue::get(PN->getType()); - - // All of the incoming values are the same, return the value now. - return InVal; -} |

