diff options
| -rw-r--r-- | lib/Transforms/Utils/SimplifyCFG.cpp | 1 | ||||
| -rw-r--r-- | test/Transforms/SimplifyCFG/preserve-branchweights-partial.ll | 37 |
2 files changed, 37 insertions, 1 deletions
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 3df3099..db8edea 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -929,7 +929,6 @@ bool SimplifyCFGOpt::FoldValueComparisonIntoPredecessors(TerminatorInst *TI, GetWeight(TI, i)->getValue().getZExtValue()); } else if (PredHasWeights) { // Split the old default's weight amongst the children - assert(PredDefaultWeight != 0); Weights.push_back(PredDefaultWeight / (1 + BBCases.size())); } } diff --git a/test/Transforms/SimplifyCFG/preserve-branchweights-partial.ll b/test/Transforms/SimplifyCFG/preserve-branchweights-partial.ll new file mode 100644 index 0000000..53d5448 --- /dev/null +++ b/test/Transforms/SimplifyCFG/preserve-branchweights-partial.ll @@ -0,0 +1,37 @@ +; RUN: opt -simplifycfg -S -o - < %s | FileCheck %s + +; This test case was written to trigger an incorrect assert statement in +; -simplifycfg. Thus we don't actually want to check the output, just that +; -simplifycfg ran successfully. Thus we only check that the function still +; exists, and that it still calls foo(). +; +; NOTE: There are some obviously dead blocks and missing branch weight +; metadata. Both of these features were key to triggering the assert. +; Additionally, the not-taken weight of the branch with a weight had to +; be 0 to trigger the assert. + +declare void @foo() nounwind uwtable + +define void @func(i32 %A) nounwind uwtable { +; CHECK: define void @func +entry: + %cmp11 = icmp eq i32 %A, 1 + br i1 %cmp11, label %if.then, label %if.else, !prof !0 + +if.then: + call void @foo() +; CHECK: call void @foo() + br label %if.else + +if.else: + %cmp17 = icmp eq i32 %A, 2 + br i1 %cmp17, label %if.then2, label %if.end + +if.then2: + br label %if.end + +if.end: + ret void +} + +!0 = metadata !{metadata !"branch_weights", i32 1, i32 0} |