xref: /llvm-project/llvm/test/Transforms/DeadArgElim/fct_ptr.ll (revision 2d69827c5c754f0eca98e497ecf0e52ed54b4fd3)
1; RUN: opt -S %s -passes=deadargelim -o - | FileCheck %s
2; In that test @internal_fct is used by an instruction
3; we don't know how to rewrite (the comparison that produces
4; %cmp1).
5; Because of that use, we used to bail out on removing the
6; unused arguments for this function.
7; Yet, we should still be able to rewrite the direct calls that are
8; statically known, by replacing the related arguments with poison.
9; This is what we check on the call that produces %res2.
10
11define i32 @call_indirect(ptr readnone %fct_ptr, i32 %arg1, i32 %arg2, i32 %arg3) {
12; CHECK-LABEL: @call_indirect(
13; CHECK-NEXT:    [[CMP0:%.*]] = icmp eq ptr [[FCT_PTR:%.*]], @external_fct
14; CHECK-NEXT:    br i1 [[CMP0]], label [[CALL_EXT:%.*]], label [[CHK2:%.*]]
15; CHECK:       call_ext:
16; CHECK-NEXT:    [[RES1:%.*]] = tail call i32 @external_fct(i32 poison, i32 [[ARG2:%.*]], i32 poison)
17; CHECK-NEXT:    br label [[END:%.*]]
18; CHECK:       chk2:
19; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq ptr [[FCT_PTR]], @internal_fct
20; CHECK-NEXT:    br i1 [[CMP1]], label [[CALL_INT:%.*]], label [[CALL_OTHER:%.*]]
21; CHECK:       call_int:
22; CHECK-NEXT:    [[RES2:%.*]] = tail call i32 @internal_fct(i32 poison, i32 [[ARG2]], i32 poison)
23; CHECK-NEXT:    br label [[END]]
24; CHECK:       call_other:
25; CHECK-NEXT:    [[RES3:%.*]] = tail call i32 @other_fct(i32 [[ARG2]])
26; CHECK-NEXT:    br label [[END]]
27; CHECK:       end:
28; CHECK-NEXT:    [[FINAL_RES:%.*]] = phi i32 [ [[RES1]], [[CALL_EXT]] ], [ [[RES2]], [[CALL_INT]] ], [ [[RES3]], [[CALL_OTHER]] ]
29; CHECK-NEXT:    ret i32 [[FINAL_RES]]
30;
31  %cmp0 = icmp eq ptr %fct_ptr, @external_fct
32  br i1 %cmp0, label %call_ext, label %chk2
33
34call_ext:
35  %res1 = tail call i32 @external_fct(i32 %arg1, i32 %arg2, i32 %arg3)
36  br label %end
37
38chk2:
39  %cmp1 = icmp eq ptr %fct_ptr, @internal_fct
40  br i1 %cmp1, label %call_int, label %call_other
41
42call_int:
43  %res2 = tail call i32 @internal_fct(i32 %arg1, i32 %arg2, i32 %arg3)
44  br label %end
45
46call_other:
47  %res3 = tail call i32 @other_fct(i32 %arg1, i32 %arg2, i32 %arg3)
48  br label %end
49
50end:
51  %final_res = phi i32 [%res1, %call_ext], [%res2, %call_int], [%res3, %call_other]
52  ret i32 %final_res
53}
54
55
56define i32 @external_fct(i32 %unused_arg1, i32 %arg2, i32 %unused_arg3) {
57  ret i32 %arg2
58}
59
60define internal i32 @internal_fct(i32 %unused_arg1, i32 %arg2, i32 %unused_arg3) {
61  ret i32 %arg2
62}
63
64define internal i32 @other_fct(i32 %unused_arg1, i32 %arg2, i32 %unused_arg3) {
65  ret i32 %arg2
66}
67
68