[Loopinfo] Remove one latch-case in getLoopID. NFC.
getLoopID has different control flow for two cases: If there is a
single loop latch and for any other number of loop latches (0 and more
than one). The latter case should return the same result if there is
only a single latch. We can save the preceding redundant search for a
latch by handling both cases with the same code.
Differential Revision: https://reviews.llvm.org/D52118
llvm-svn: 342406
diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp
index 4664c78..07f72ad 100644
--- a/llvm/lib/Analysis/LoopInfo.cpp
+++ b/llvm/lib/Analysis/LoopInfo.cpp
@@ -213,26 +213,21 @@
MDNode *Loop::getLoopID() const {
MDNode *LoopID = nullptr;
- if (BasicBlock *Latch = getLoopLatch()) {
- LoopID = Latch->getTerminator()->getMetadata(LLVMContext::MD_loop);
- } else {
- assert(!getLoopLatch() &&
- "The loop should have no single latch at this point");
- // Go through the latch blocks and check the terminator for the metadata.
- SmallVector<BasicBlock *, 4> LatchesBlocks;
- getLoopLatches(LatchesBlocks);
- for (BasicBlock *BB : LatchesBlocks) {
- TerminatorInst *TI = BB->getTerminator();
- MDNode *MD = TI->getMetadata(LLVMContext::MD_loop);
- if (!MD)
- return nullptr;
+ // Go through the latch blocks and check the terminator for the metadata.
+ SmallVector<BasicBlock *, 4> LatchesBlocks;
+ getLoopLatches(LatchesBlocks);
+ for (BasicBlock *BB : LatchesBlocks) {
+ TerminatorInst *TI = BB->getTerminator();
+ MDNode *MD = TI->getMetadata(LLVMContext::MD_loop);
- if (!LoopID)
- LoopID = MD;
- else if (MD != LoopID)
- return nullptr;
- }
+ if (!MD)
+ return nullptr;
+
+ if (!LoopID)
+ LoopID = MD;
+ else if (MD != LoopID)
+ return nullptr;
}
if (!LoopID || LoopID->getNumOperands() == 0 ||
LoopID->getOperand(0) != LoopID)