[llvm] [llvm-reduce] Add a pass to replace unconditinal branches with returns (PR #180993)

[Juan Manuel Martinez Caamaño via llvm-commits]

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@@ -0,0 +1,40 @@
+; RUN: llvm-reduce -abort-on-invalid-reduction --delta-passes=simplify-unconditional-branch --test FileCheck --test-arg --check-prefix=CHECK-INTERESTINGNESS --test-arg %s --test-arg --input-file %s -o %t
+; RUN: FileCheck --check-prefix=RESULT %s < %t
+
+; CHECK_INTERESTINGNESS-LABEL: define void @test_void
+; CHECK-INTERESTINGNESS: %A = alloca i32
+; CHECK-INTERESTINGNESS: store i32 %V, ptr %A
+
+; RESULT-LABEL: define void @test_void
+; RESULT: entry:
+; RESULT-NEXT: %A = alloca i32
+; RESULT-NEXT: store i32 %V, ptr %A
+; RESULT-NEXT: ret void
+
+define void @test_void(i32 %V) {
+entry:
+  %A = alloca i32
+  br label %loop.body
+loop.body:
+  store i32 %V, ptr %A
+  br label %loop.body
+}
+
+; CHECK_INTERESTINGNESS-LABEL: define float @test_float
+; CHECK-INTERESTINGNESS: %A = alloca float
+; CHECK-INTERESTINGNESS: store float %V, ptr %A
+
+; RESULT-LABEL: define float @test_float
+; RESULT: entry:
+; RESULT-NEXT: %A = alloca float
+; RESULT-NEXT: store float %V, ptr %A
+; RESULT-NEXT: ret float 0
+
+define float @test_float(float %V) {
+entry:
+  %A = alloca float
+  br label %loop.body
+loop.body:
+  store float %V, ptr %A
+  br label %loop.body
+}
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jmmartinez wrote:

I've added tests with phi-nodes: from the loop, from a third block with a conditional branch, and from a third block with a switch with repeated incoming blocks.

https://github.com/llvm/llvm-project/pull/180993