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author | Bill Wendling <isanbard@gmail.com> | 2013-10-19 11:27:12 +0000 |
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committer | Bill Wendling <isanbard@gmail.com> | 2013-10-19 11:27:12 +0000 |
commit | d5b7f2b62cdb3a14162c57e27c06a27dda9a78c4 (patch) | |
tree | 0bd1a02066e426eebb49c415b1d758b3a4f1d832 /lib/Transforms | |
parent | 4805bf59b9e41a95336c066ec58194ff6801694a (diff) | |
download | external_llvm-d5b7f2b62cdb3a14162c57e27c06a27dda9a78c4.zip external_llvm-d5b7f2b62cdb3a14162c57e27c06a27dda9a78c4.tar.gz external_llvm-d5b7f2b62cdb3a14162c57e27c06a27dda9a78c4.tar.bz2 |
Perform an intelligent splice of the predecessor with the single successor.
If the predecessor's being spliced into a landing pad, then we need the PHIs to
come first and the rest of the predecessor's code to come *after* the landing
pad instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193035 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
-rw-r--r-- | lib/Transforms/Utils/Local.cpp | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 82b8da3..78217c8 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -503,7 +503,19 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) { // Splice all the instructions from PredBB to DestBB. PredBB->getTerminator()->eraseFromParent(); - DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList()); + + // First splice over the PHI nodes. + BasicBlock::iterator PI = PredBB->begin(); + while (isa<PHINode>(PI)) + ++PI; + + if (PI != PredBB->begin()) + DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList(), + PredBB->begin(), PI); + + // Now splice over the rest of the instructions. + DestBB->getInstList().splice(DestBB->getFirstInsertionPt(), + PredBB->getInstList(), PI, PredBB->end()); if (P) { DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>(); @@ -513,6 +525,7 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) { DT->eraseNode(PredBB); } } + // Nuke BB. PredBB->eraseFromParent(); } |