Fix for PR1444: do not create two successors to the same block.
Temporarily, this breaks CodeGen/Generic/2006-02-12-InsertLibraryCall.ll
by exposing an unrelated latent problem; working on that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37323 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index afaaf51..6c632c2 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -717,12 +717,20 @@
I->getOperand(i).setMachineBasicBlock(New);
}
- // Update the successor information.
+ // Update the successor information. If New was already a successor, just
+ // remove the link to Old instead of creating another one. PR 1444.
+ bool HadSuccessorNew = false;
std::vector<MachineBasicBlock*> Succs(BB->succ_begin(), BB->succ_end());
for (int i = Succs.size()-1; i >= 0; --i)
+ if (Succs[i] == New) {
+ HadSuccessorNew = true;
+ break;
+ }
+ for (int i = Succs.size()-1; i >= 0; --i)
if (Succs[i] == Old) {
BB->removeSuccessor(Old);
- BB->addSuccessor(New);
+ if (!HadSuccessorNew)
+ BB->addSuccessor(New);
}
}