[clang] [llvm] [SimplifyCFG] Hoist common code for switch multi-case destinations (PR #165700)

[Nikita Popov via llvm-commits]

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@@ -602,3 +602,33 @@ bar:
   call void @bar()
   ret void
 }
+
+define void @test_switch_with_multicases_dest(i64 %i, ptr %Q) {
+; CHECK-LABEL: @test_switch_with_multicases_dest(
+; CHECK-NEXT:  common.ret:
+; CHECK-NEXT:    store i32 1, ptr [[Q:%.*]], align 4
+; CHECK-NEXT:    [[C:%.*]] = load i32, ptr [[Q]], align 4
+; CHECK-NEXT:    call void @bar(i32 [[C]])
+; CHECK-NEXT:    ret void
+;
+  switch i64 %i, label %bb0 [
+  i64 1, label %bb1
+  i64 2, label %bb2
+  i64 3, label %bb2
+  ]
+bb0:              ; preds = %0
+  store i32 1, ptr %Q
+  %A = load i32, ptr %Q               ; <i32> [#uses=1]
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nikic wrote:

Drop these uses comments (which haven't been emitted for a long time already).

https://github.com/llvm/llvm-project/pull/165700