diff options
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 12 | ||||
| -rw-r--r-- | test/Transforms/SimplifyCFG/two-entry-phi-return.ll | 15 |
2 files changed, 21 insertions, 6 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index ac5c2ec770..b9a20c113f 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1224,6 +1224,12 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { // away... Changed |= ConstantFoldTerminator(BB); + // If there is a trivial two-entry PHI node in this basic block, and we can + // eliminate it, do so now. + if (PHINode *PN = dyn_cast<PHINode>(BB->begin())) + if (PN->getNumIncomingValues() == 2) + Changed |= FoldTwoEntryPHINode(PN); + // If this is a returning block with only PHI nodes in it, fold the return // instruction into any unconditional branch predecessors. // @@ -1915,11 +1921,5 @@ bool llvm::SimplifyCFG(BasicBlock *BB) { } } - // If there is a trivial two-entry PHI node in this basic block, and we can - // eliminate it, do so now. - if (PHINode *PN = dyn_cast<PHINode>(BB->begin())) - if (PN->getNumIncomingValues() == 2) - Changed |= FoldTwoEntryPHINode(PN); - return Changed; } diff --git a/test/Transforms/SimplifyCFG/two-entry-phi-return.ll b/test/Transforms/SimplifyCFG/two-entry-phi-return.ll new file mode 100644 index 0000000000..19814ade4d --- /dev/null +++ b/test/Transforms/SimplifyCFG/two-entry-phi-return.ll @@ -0,0 +1,15 @@ +; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis | not grep br + +define i1 @qux(i8* %m, i8* %n, i8* %o, i8* %p) nounwind { +entry: + %tmp7 = icmp eq i8* %m, %n + br i1 %tmp7, label %bb, label %UnifiedReturnBlock + +bb: + %tmp15 = icmp eq i8* %o, %p + br label %UnifiedReturnBlock + +UnifiedReturnBlock: + %result = phi i1 [ 0, %entry ], [ %tmp15, %bb ] + ret i1 %result +} |