diff options
| author | Dan Gohman <gohman@apple.com> | 2009-10-30 23:15:43 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2009-10-30 23:15:43 +0000 |
| commit | 0e747beb3cfc48ebcb0a2f8b962f0d0de525d979 (patch) | |
| tree | e8b9bca499f75373d7e7249bdd2b015f6d23a86b | |
| parent | 1107c63efe3bc39965bf85f823b0aed65d4bb166 (diff) | |
| download | external_llvm-0e747beb3cfc48ebcb0a2f8b962f0d0de525d979.zip external_llvm-0e747beb3cfc48ebcb0a2f8b962f0d0de525d979.tar.gz external_llvm-0e747beb3cfc48ebcb0a2f8b962f0d0de525d979.tar.bz2 | |
Add a comment about a missed opportunity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85635 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 859b875..8e1fb98 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1753,8 +1753,13 @@ static bool SimplifyCondBranchToCondBranch(BranchInst *PBI, BranchInst *BI) { /// nodes in this block. This doesn't try to be clever about PHI nodes /// which differ only in the order of the incoming values, but instcombine /// orders them so it usually won't matter. +/// static bool EliminateDuplicatePHINodes(BasicBlock *BB) { bool Changed = false; + + // This implementation doesn't currently consider undef operands + // specially. Theroetically, two phis which are identical except for + // one having an undef where the other doesn't could be collapsed. // Map from PHI hash values to PHI nodes. If multiple PHIs have // the same hash value, the element is the first PHI in the |