diff options
| -rw-r--r-- | lib/Transforms/Scalar/LoopDeletion.cpp | 2 | ||||
| -rw-r--r-- | test/Transforms/LoopDeletion/multiple-exit-conditions.ll | 27 |
2 files changed, 28 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/LoopDeletion.cpp b/lib/Transforms/Scalar/LoopDeletion.cpp index 5f93756a05..8133a06f3f 100644 --- a/lib/Transforms/Scalar/LoopDeletion.cpp +++ b/lib/Transforms/Scalar/LoopDeletion.cpp @@ -167,7 +167,7 @@ bool LoopDeletion::runOnLoop(Loop* L, LPPassManager& LPM) { // Don't remove loops for which we can't solve the trip count. // They could be infinite, in which case we'd be changing program behavior. ScalarEvolution& SE = getAnalysis<ScalarEvolution>(); - const SCEV *S = SE.getBackedgeTakenCount(L); + const SCEV *S = SE.getMaxBackedgeTakenCount(L); if (isa<SCEVCouldNotCompute>(S)) return Changed; diff --git a/test/Transforms/LoopDeletion/multiple-exit-conditions.ll b/test/Transforms/LoopDeletion/multiple-exit-conditions.ll new file mode 100644 index 0000000000..87f8f46105 --- /dev/null +++ b/test/Transforms/LoopDeletion/multiple-exit-conditions.ll @@ -0,0 +1,27 @@ +; RUN: opt < %s -loop-deletion -S | FileCheck %s + +; ScalarEvolution can prove the loop iteration is finite, even though +; it can't represent the exact trip count as an expression. That's +; good enough to let the loop be deleted. + +; CHECK: entry: +; CHECK-NEXT: br label %return + +; CHECK: return: +; CHECK-NEXT: ret void + +define void @foo(i64 %n, i64 %m) nounwind { +entry: + br label %bb + +bb: + %x.0 = phi i64 [ 0, %entry ], [ %t0, %bb ] + %t0 = add i64 %x.0, 1 + %t1 = icmp slt i64 %x.0, %n + %t3 = icmp sgt i64 %x.0, %m + %t4 = and i1 %t1, %t3 + br i1 %t4, label %bb, label %return + +return: + ret void +} |