diff options
| -rw-r--r-- | lib/CodeGen/UnreachableBlockElim.cpp | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp index 7b338126d4..c0d4494d5b 100644 --- a/lib/CodeGen/UnreachableBlockElim.cpp +++ b/lib/CodeGen/UnreachableBlockElim.cpp @@ -58,13 +58,25 @@ FunctionPass *llvm::createUnreachableBlockEliminationPass() { return new UnreachableBlockElim(); } +static void MarkReachableFrom(BasicBlock *BB, + SmallPtrSet<BasicBlock*, 8> &Reachable) { + for (df_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 8> > I = + df_ext_begin(BB, Reachable), E = df_ext_end(BB, Reachable); I != E; ++I) + ; // Mark all reachable blocks. +} + bool UnreachableBlockElim::runOnFunction(Function &F) { SmallPtrSet<BasicBlock*, 8> Reachable; // Mark all reachable blocks. - for (df_ext_iterator<Function*, SmallPtrSet<BasicBlock*, 8> > I = - df_ext_begin(&F, Reachable), E = df_ext_end(&F, Reachable); I != E; ++I) - /* Mark all reachable blocks */; + MarkReachableFrom(&F.getEntryBlock(), Reachable); + + // Mark any address-taken blocks. We don't want codegen to delete these + // because the address may already be referenced by another function and the + // label may be referenced. + for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) + if (I->hasAddressTaken() && !Reachable.count(I)) + MarkReachableFrom(I, Reachable); // Loop over all dead blocks, remembering them and deleting all instructions // in them. |