[PATCH] D128224: [DSE] Don't remove nounwind invokes

[Heejin Ahn via Phabricator via llvm-commits]

aheejin updated this revision to Diff 438786.
aheejin marked 2 inline comments as done.
aheejin added a comment.

Address comments


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D128224/new/

https://reviews.llvm.org/D128224

Files:
  llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
  llvm/test/Transforms/DeadStoreElimination/nounwind-invoke.ll


Index: llvm/test/Transforms/DeadStoreElimination/nounwind-invoke.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/DeadStoreElimination/nounwind-invoke.ll
@@ -0,0 +1,45 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --prefix-filecheck-ir-name abc
+; RUN: opt -dse -S < %s | FileCheck %s
+
+; Make sure invokes are not removed as dead stores.
+define void @test_nounwind_invoke() personality i8* bitcast (i32 (...)*  @__gxx_personality_v0 to i8*) {
+; CHECK-LABEL: @test_nounwind_invoke(
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[TMP:%.*]] = alloca i32, align 4
+; CHECK-NEXT:    invoke void @foo(i32* [[TMP]])
+; CHECK-NEXT:    to label [[BB1:%.*]] unwind label [[BB2:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    call void @llvm.lifetime.end.p0i32(i64 4, i32* [[TMP]])
+; CHECK-NEXT:    ret void
+; CHECK:       bb2:
+; CHECK-NEXT:    [[ABCTMP1:%.*]] = landingpad { i8*, i32 }
+; CHECK-NEXT:    cleanup
+; CHECK-NEXT:    resume { i8*, i32 } [[ABCTMP1]]
+;
+bb:
+  %tmp = alloca i32, align 4
+  ; 'foo' is 'argmemonly', meaning it can only write to memory pointed by %tmp.
+  ; And this def is killed by 'call @llvm.lifetime.end.p0i32' in bb1 without
+  ; being used elsewhere, becoming a dead store. But we shouldn't remove this
+  ; because invokes are terminators and thus cannot be removed.
+  invoke void @foo(i32* %tmp)
+  to label %bb1 unwind label %bb2
+
+bb1:                                              ; preds = %bb
+  call void @llvm.lifetime.end.p0i32(i64 4, i32* %tmp)
+  ret void
+
+bb2:                                              ; preds = %bb
+  %tmp1 = landingpad { i8*, i32 }
+  cleanup
+  resume { i8*, i32 } %tmp1
+}
+
+; Function Attrs: argmemonly nocallback nofree nosync nounwind willreturn
+declare void @llvm.lifetime.end.p0i32(i64 immarg, i32* nocapture) #0
+; Function Attrs: argmemonly nounwind willreturn
+declare void @foo(i32*) #1
+declare i32 @__gxx_personality_v0(...)
+
+attributes #0 = { argmemonly nocallback nofree nosync nounwind willreturn }
+attributes #1 = { argmemonly nounwind willreturn }
Index: llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
+++ llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp
@@ -1014,7 +1014,7 @@
       if (CB->isLifetimeStartOrEnd())
         return false;
 
-      return CB->use_empty() && CB->willReturn() && CB->doesNotThrow();
+      return CB->use_empty() && CB->willReturn() && CB->doesNotThrow() && !CB->isTerminator();
     }
 
     return false;


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