diff options
| -rw-r--r-- | lib/CodeGen/BranchFolding.cpp | 33 |
1 files changed, 0 insertions, 33 deletions
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp index 8a6b0de..d344af0 100644 --- a/lib/CodeGen/BranchFolding.cpp +++ b/lib/CodeGen/BranchFolding.cpp @@ -670,39 +670,6 @@ bool BranchFolder::TryTailMergeBlocks(MachineBasicBlock *SuccBB, // this many instructions in common. unsigned minCommonTailLength = TailMergeSize; - // If there's a successor block, there are some cases which don't require - // new branching and as such are very likely to be profitable. - if (SuccBB) { - if (SuccBB->pred_size() == MergePotentials.size() && - !MergePotentials[0].getBlock()->empty()) { - // If all the predecessors have at least one tail instruction in common, - // merging is very likely to be a win since it won't require an increase - // in static branches, and it will decrease the static instruction count. - bool AllPredsMatch = true; - MachineBasicBlock::iterator FirstNonTerm; - unsigned MinNumTerms = CountTerminators(MergePotentials[0].getBlock(), - FirstNonTerm); - if (FirstNonTerm != MergePotentials[0].getBlock()->end()) { - for (unsigned i = 1, e = MergePotentials.size(); i != e; ++i) { - MachineBasicBlock::iterator OtherFirstNonTerm; - unsigned NumTerms = CountTerminators(MergePotentials[0].getBlock(), - OtherFirstNonTerm); - if (NumTerms < MinNumTerms) - MinNumTerms = NumTerms; - if (OtherFirstNonTerm == MergePotentials[i].getBlock()->end() || - OtherFirstNonTerm->isIdenticalTo(FirstNonTerm)) { - AllPredsMatch = false; - break; - } - } - - // If they all have an instruction in common, do any amount of merging. - if (AllPredsMatch) - minCommonTailLength = MinNumTerms + 1; - } - } - } - DEBUG(errs() << "\nTryTailMergeBlocks: "; for (unsigned i = 0, e = MergePotentials.size(); i != e; ++i) errs() << "BB#" << MergePotentials[i].getBlock()->getNumber() |