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Add support for unreachable

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llvm-svn: 17056
This commit is contained in:
Chris Lattner
2004-10-16 18:21:33 +00:00
parent 61753bf847
commit 98e541457b
4 changed files with 30 additions and 5 deletions
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26
llvm/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
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@@ -46,13 +46,16 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
//
std::vector<BasicBlock*> ReturningBlocks;
std::vector<BasicBlock*> UnwindingBlocks;
std::vector<BasicBlock*> UnreachableBlocks;
for(Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
if (isa<ReturnInst>(I->getTerminator()))
ReturningBlocks.push_back(I);
else if (isa<UnwindInst>(I->getTerminator()))
UnwindingBlocks.push_back(I);
else if (isa<UnreachableInst>(I->getTerminator()))
UnreachableBlocks.push_back(I);
// Handle unwinding blocks first...
// Handle unwinding blocks first.
if (UnwindingBlocks.empty()) {
UnwindBlock = 0;
} else if (UnwindingBlocks.size() == 1) {
@@ -64,12 +67,29 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
for (std::vector<BasicBlock*>::iterator I = UnwindingBlocks.begin(),
E = UnwindingBlocks.end(); I != E; ++I) {
BasicBlock *BB = *I;
BB->getInstList().pop_back(); // Remove the return insn
BB->getInstList().pop_back(); // Remove the unwind insn
new BranchInst(UnwindBlock, BB);
}
}
// Now handle return blocks...
// Then unreachable blocks.
if (UnreachableBlocks.empty()) {
UnreachableBlock = 0;
} else if (UnreachableBlocks.size() == 1) {
UnreachableBlock = UnreachableBlocks.front();
} else {
UnreachableBlock = new BasicBlock("UnifiedUnreachableBlock", &F);
new UnreachableInst(UnreachableBlock);
for (std::vector<BasicBlock*>::iterator I = UnreachableBlocks.begin(),
E = UnreachableBlocks.end(); I != E; ++I) {
BasicBlock *BB = *I;
BB->getInstList().pop_back(); // Remove the unreachable inst.
new BranchInst(UnreachableBlock, BB);
}
}
// Now handle return blocks.
if (ReturningBlocks.empty()) {
ReturnBlock = 0;
return false; // No blocks return