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-rw-r--r--lib/CodeGen/BranchFolding.cpp15
1 files changed, 15 insertions, 0 deletions
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 583009c74a..26353035ae 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -1092,6 +1092,21 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) {
} else {
DidChange = true;
PMBB->ReplaceUsesOfBlockWith(MBB, CurTBB);
+ // If this change resulted in PMBB ending in a conditional
+ // branch where both conditions go to the same destination,
+ // change this to an unconditional branch (and fix the CFG).
+ MachineBasicBlock *NewCurTBB = 0, *NewCurFBB = 0;
+ SmallVector<MachineOperand, 4> NewCurCond;
+ bool NewCurUnAnalyzable = TII->AnalyzeBranch(*PMBB, NewCurTBB,
+ NewCurFBB, NewCurCond, true);
+ if (!NewCurUnAnalyzable && NewCurTBB && NewCurTBB == NewCurFBB) {
+ TII->RemoveBranch(*PMBB);
+ NewCurCond.clear();
+ TII->InsertBranch(*PMBB, NewCurTBB, 0, NewCurCond);
+ MadeChange = true;
+ ++NumBranchOpts;
+ PMBB->CorrectExtraCFGEdges(NewCurTBB, NewCurFBB, false);
+ }
}
}