xref: /llvm-project/llvm/test/Transforms/DeadArgElim/keepalive.ll (revision 055fb7795aa219a3d274d280ec9129784f169f56) 
1; RUN: opt < %s -passes=deadargelim -S | FileCheck %s
2
3declare token @llvm.call.preallocated.setup(i32)
4declare ptr @llvm.call.preallocated.arg(token, i32)
5
6%Ty = type <{ i32, i32 }>
7
8; Check if the pass doesn't modify anything that doesn't need changing. We feed
9; an unused argument to each function to lure it into changing _something_ about
10; the function and then changing too much.
11
12; This checks if the return value attributes are not removed
13; CHECK: define internal zeroext i32 @test1() #1
14define internal zeroext i32 @test1(i32 %DEADARG1) nounwind {
15;
16;
17  ret i32 1
18}
19
20; This checks if the struct doesn't get non-packed
21; CHECK-LABEL: define internal <{ i32, i32 }> @test2(
22define internal <{ i32, i32 }> @test2(i32 %DEADARG1) {
23;
24;
25  ret <{ i32, i32 }> <{ i32 1, i32 2 }>
26}
27
28; We use this external function to make sure the return values don't become dead
29declare void @user(i32, <{ i32, i32 }>)
30
31define void @caller() {
32;
33;
34  %B = call i32 @test1(i32 1)
35  %C = call <{ i32, i32 }> @test2(i32 2)
36  call void @user(i32 %B, <{ i32, i32 }> %C)
37  ret void
38}
39
40; We can't remove 'this' here, as that would put argmem in ecx instead of
41; memory.
42define internal x86_thiscallcc i32 @unused_this(ptr %this, ptr inalloca(i32) %argmem) {
43;
44;
45  %v = load i32, ptr %argmem
46  ret i32 %v
47}
48; CHECK-LABEL: define internal x86_thiscallcc i32 @unused_this(ptr %this, ptr inalloca(i32) %argmem)
49
50define i32 @caller2() {
51;
52;
53  %t = alloca i32
54  %m = alloca inalloca i32
55  store i32 42, ptr %m
56  %v = call x86_thiscallcc i32 @unused_this(ptr %t, ptr inalloca(i32) %m)
57  ret i32 %v
58}
59
60; We can't remove 'this' here, as that would put argmem in ecx instead of
61; memory.
62define internal x86_thiscallcc i32 @unused_this_preallocated(ptr %this, ptr preallocated(i32) %argmem) {
63;
64;
65  %v = load i32, ptr %argmem
66  ret i32 %v
67}
68; CHECK-LABEL: define internal x86_thiscallcc i32 @unused_this_preallocated(ptr %this, ptr preallocated(i32) %argmem)
69
70define i32 @caller3() {
71;
72;
73  %t = alloca i32
74  %c = call token @llvm.call.preallocated.setup(i32 1)
75  %M = call ptr @llvm.call.preallocated.arg(token %c, i32 0) preallocated(i32)
76  store i32 42, ptr %M
77  %v = call x86_thiscallcc i32 @unused_this_preallocated(ptr %t, ptr preallocated(i32) %M) ["preallocated"(token %c)]
78  ret i32 %v
79}
80
81; CHECK: attributes #0 = { nocallback nofree nosync nounwind willreturn }
82; CHECK: attributes #1 = { nounwind }
83