xref: /llvm-project/llvm/test/Transforms/DeadArgElim/deadretval.ll (revision 055fb7795aa219a3d274d280ec9129784f169f56) 
1; RUN: opt < %s -passes=deadargelim -S | FileCheck %s
2
3@g0 = global i8 0, align 8
4
5; CHECK-NOT: DEAD
6
7; Dead arg only used by dead retval
8define internal i32 @test(i32 %DEADARG) {
9        ret i32 %DEADARG
10}
11
12define i32 @test2(i32 %A) {
13        %DEAD = call i32 @test( i32 %A )                ; <i32> [#uses=0]
14        ret i32 123
15}
16
17define i32 @test3() {
18        %X = call i32 @test2( i32 3232 )                ; <i32> [#uses=1]
19        %Y = add i32 %X, -123           ; <i32> [#uses=1]
20        ret i32 %Y
21}
22
23; The callee function's return type shouldn't be changed if the call result is
24; used.
25
26; CHECK-LABEL: define internal ptr @callee4()
27
28define internal ptr @callee4(ptr %a0) {
29  ret ptr @g0;
30}
31
32declare void @llvm.objc.clang.arc.noop.use(...)
33
34; CHECK-LABEL: define ptr @test4(
35; CHECK: tail call ptr @callee4() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
36
37define ptr @test4() {
38  %call = tail call ptr @callee4(ptr @g0) [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
39  call void (...) @llvm.objc.clang.arc.noop.use(ptr %call)
40  ret ptr @g0
41}
42
43declare ptr @llvm.objc.retainAutoreleasedReturnValue(ptr)
44