diff options
| -rw-r--r-- | lib/Transforms/Utils/Local.cpp | 6 | ||||
| -rw-r--r-- | test/Transforms/SimplifyCFG/preserve-branchweights.ll | 18 |
2 files changed, 22 insertions, 2 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 12e5b3e9d2e..7a101da18ff 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -125,8 +125,10 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions, // dest. If so, eliminate it as an explicit compare. if (i.getCaseSuccessor() == DefaultDest) { MDNode* MD = SI->getMetadata(LLVMContext::MD_prof); - // MD should have 2 + NumCases operands. - if (MD && MD->getNumOperands() == 2 + SI->getNumCases()) { + unsigned NCases = SI->getNumCases(); + // Fold the case metadata into the default if there will be any branches + // left, unless the metadata doesn't match the switch. + if (NCases > 1 && MD && MD->getNumOperands() == 2 + NCases) { // Collect branch weights into a vector. SmallVector<uint32_t, 8> Weights; for (unsigned MD_i = 1, MD_e = MD->getNumOperands(); MD_i < MD_e; diff --git a/test/Transforms/SimplifyCFG/preserve-branchweights.ll b/test/Transforms/SimplifyCFG/preserve-branchweights.ll index beef5270082..2219ac481ae 100644 --- a/test/Transforms/SimplifyCFG/preserve-branchweights.ll +++ b/test/Transforms/SimplifyCFG/preserve-branchweights.ll @@ -293,6 +293,23 @@ c: ret void } +;; test12 - Don't crash if the whole switch is removed +define void @test12(i32 %M, i32 %N) nounwind uwtable { +entry: + switch i32 %N, label %sw.bb [ + i32 1, label %sw.bb + ], !prof !9 +; CHECK: test12 +; CHECK-NOT: switch + +sw.bb: + call void @helper(i32 0) + br label %sw.epilog + +sw.epilog: + ret void +} + !0 = metadata !{metadata !"branch_weights", i32 3, i32 5} !1 = metadata !{metadata !"branch_weights", i32 1, i32 1} !2 = metadata !{metadata !"branch_weights", i32 1, i32 2} @@ -302,6 +319,7 @@ c: !6 = metadata !{metadata !"branch_weights", i32 1, i32 3} !7 = metadata !{metadata !"branch_weights", i32 33, i32 9, i32 8, i32 7} !8 = metadata !{metadata !"branch_weights", i32 33, i32 9, i32 8} +!9 = metadata !{metadata !"branch_weights", i32 7, i32 6} ; CHECK: !0 = metadata !{metadata !"branch_weights", i32 5, i32 11} ; CHECK: !1 = metadata !{metadata !"branch_weights", i32 1, i32 5} |