[UnifyFunctionExitNodes] Remove unused getters, NFC

The get{Return,Unwind,Unreachable}Block functions in
UnifyFunctionExitNodes have not been used for many years,
so just remove them.

Reviewed By: bjope

Differential Revision: https://reviews.llvm.org/D87078
This commit is contained in:
David Stenberg 2020-09-08 18:54:30 +02:00
parent c6dad5db4b
commit b3f0a94428
2 changed files with 7 additions and 33 deletions

View File

@ -7,10 +7,7 @@
//===----------------------------------------------------------------------===//
//
// This pass is used to ensure that functions have at most one return and one
// unwind instruction in them. Additionally, it keeps track of which node is
// the new exit node of the CFG. If there are no return or unwind instructions
// in the function, the getReturnBlock/getUnwindBlock methods will return a null
// pointer.
// unreachable instruction in them.
//
//===----------------------------------------------------------------------===//
@ -24,10 +21,6 @@ namespace llvm {
class BasicBlock;
struct UnifyFunctionExitNodes : public FunctionPass {
BasicBlock *ReturnBlock = nullptr;
BasicBlock *UnwindBlock = nullptr;
BasicBlock *UnreachableBlock;
public:
static char ID; // Pass identification, replacement for typeid
UnifyFunctionExitNodes();
@ -35,13 +28,6 @@ public:
// We can preserve non-critical-edgeness when we unify function exit nodes
void getAnalysisUsage(AnalysisUsage &AU) const override;
// getReturn|Unwind|UnreachableBlock - Return the new single (or nonexistent)
// return, unwind, or unreachable basic blocks in the CFG.
//
BasicBlock *getReturnBlock() const { return ReturnBlock; }
BasicBlock *getUnwindBlock() const { return UnwindBlock; }
BasicBlock *getUnreachableBlock() const { return UnreachableBlock; }
bool runOnFunction(Function &F) override;
};

View File

@ -6,10 +6,8 @@
//
//===----------------------------------------------------------------------===//
//
// This pass is used to ensure that functions have at most one return
// instruction in them. Additionally, it keeps track of which node is the new
// exit node of the CFG. If there are no exit nodes in the CFG, the getExitNode
// method will return a null pointer.
// This pass is used to ensure that functions have at most one return and one
// unreachable instruction in them.
//
//===----------------------------------------------------------------------===//
@ -61,12 +59,8 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
UnreachableBlocks.push_back(&I);
// Then unreachable blocks.
if (UnreachableBlocks.empty()) {
UnreachableBlock = nullptr;
} else if (UnreachableBlocks.size() == 1) {
UnreachableBlock = UnreachableBlocks.front();
} else {
UnreachableBlock = BasicBlock::Create(F.getContext(),
if (UnreachableBlocks.size() > 1) {
BasicBlock *UnreachableBlock = BasicBlock::Create(F.getContext(),
"UnifiedUnreachableBlock", &F);
new UnreachableInst(F.getContext(), UnreachableBlock);
@ -76,14 +70,9 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
}
}
// Now handle return blocks.
if (ReturningBlocks.empty()) {
ReturnBlock = nullptr;
return false; // No blocks return
} else if (ReturningBlocks.size() == 1) {
ReturnBlock = ReturningBlocks.front(); // Already has a single return block
// There is nothing more to do if we do not have multiple return blocks.
if (ReturningBlocks.size() <= 1)
return false;
}
// Otherwise, we need to insert a new basic block into the function, add a PHI
// nodes (if the function returns values), and convert all of the return
@ -115,6 +104,5 @@ bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
BB->getInstList().pop_back(); // Remove the return insn
BranchInst::Create(NewRetBlock, BB);
}
ReturnBlock = NewRetBlock;
return true;
}