1; RUN: opt < %s -tailcallelim -S | FileCheck %s
2
3declare void @noarg()
4declare void @use(i32*)
5declare void @use_nocapture(i32* nocapture)
6declare void @use2_nocapture(i32* nocapture, i32* nocapture)
7
8; Trivial case. Mark @noarg with tail call.
9define void @test0() {
10; CHECK: tail call void @noarg()
11	call void @noarg()
12	ret void
13}
14
15; PR615. Make sure that we do not move the alloca so that it interferes with the tail call.
16define i32 @test1() {
17; CHECK: i32 @test1()
18; CHECK-NEXT: alloca
19	%A = alloca i32		; <i32*> [#uses=2]
20	store i32 5, i32* %A
21	call void @use(i32* %A)
22; CHECK: tail call i32 @test1
23	%X = tail call i32 @test1()		; <i32> [#uses=1]
24	ret i32 %X
25}
26
27; This function contains intervening instructions which should be moved out of the way
28define i32 @test2(i32 %X) {
29; CHECK: i32 @test2
30; CHECK-NOT: call
31; CHECK: ret i32
32entry:
33	%tmp.1 = icmp eq i32 %X, 0		; <i1> [#uses=1]
34	br i1 %tmp.1, label %then.0, label %endif.0
35then.0:		; preds = %entry
36	%tmp.4 = add i32 %X, 1		; <i32> [#uses=1]
37	ret i32 %tmp.4
38endif.0:		; preds = %entry
39	%tmp.10 = add i32 %X, -1		; <i32> [#uses=1]
40	%tmp.8 = call i32 @test2(i32 %tmp.10)		; <i32> [#uses=1]
41	%DUMMY = add i32 %X, 1		; <i32> [#uses=0]
42	ret i32 %tmp.8
43}
44
45; Though this case seems to be fairly unlikely to occur in the wild, someone
46; plunked it into the demo script, so maybe they care about it.
47define i32 @test3(i32 %c) {
48; CHECK: i32 @test3
49; CHECK-NOT: call
50; CHECK: ret i32 0
51entry:
52	%tmp.1 = icmp eq i32 %c, 0		; <i1> [#uses=1]
53	br i1 %tmp.1, label %return, label %else
54else:		; preds = %entry
55	%tmp.5 = add i32 %c, -1		; <i32> [#uses=1]
56	%tmp.3 = call i32 @test3(i32 %tmp.5)		; <i32> [#uses=0]
57	ret i32 0
58return:		; preds = %entry
59	ret i32 0
60}
61
62; Make sure that a nocapture pointer does not stop adding a tail call marker to
63; an unrelated call and additionally that we do not mark the nocapture call with
64; a tail call.
65;
66; rdar://14324281
67define void @test4() {
68; CHECK: void @test4
69; CHECK-NOT: tail call void @use_nocapture
70; CHECK: tail call void @noarg()
71; CHECK: ret void
72  %a = alloca i32
73  call void @use_nocapture(i32* %a)
74  call void @noarg()
75  ret void
76}
77
78; Make sure that we do not perform TRE even with a nocapture use. This is due to
79; bad codegen caused by PR962.
80;
81; rdar://14324281.
82define i32* @test5(i32* nocapture %A, i1 %cond) {
83; CHECK: i32* @test5
84; CHECK-NOT: tailrecurse:
85; CHECK: ret i32* null
86  %B = alloca i32
87  br i1 %cond, label %cond_true, label %cond_false
88cond_true:
89  call i32* @test5(i32* %B, i1 false)
90  ret i32* null
91cond_false:
92  call void @use2_nocapture(i32* %A, i32* %B)
93  call void @noarg()
94  ret i32* null
95}
96
97; PR14143: Make sure that we do not mark functions with nocapture allocas with tail.
98;
99; rdar://14324281.
100define void @test6(i32* %a, i32* %b) {
101; CHECK-LABEL: @test6(
102; CHECK-NOT: tail call
103; CHECK: ret void
104  %c = alloca [100 x i8], align 16
105  %tmp = bitcast [100 x i8]* %c to i32*
106  call void @use2_nocapture(i32* %b, i32* %tmp)
107  ret void
108}
109
110; PR14143: Make sure that we do not mark functions with nocapture allocas with tail.
111;
112; rdar://14324281
113define void @test7(i32* %a, i32* %b) nounwind uwtable {
114entry:
115; CHECK-LABEL: @test7(
116; CHECK-NOT: tail call
117; CHECK: ret void
118  %c = alloca [100 x i8], align 16
119  %0 = bitcast [100 x i8]* %c to i32*
120  call void @use2_nocapture(i32* %0, i32* %a)
121  call void @use2_nocapture(i32* %b, i32* %0)
122  ret void
123}
124
125; If we have a mix of escaping captured/non-captured allocas, ensure that we do
126; not do anything including marking callsites with the tail call marker.
127;
128; rdar://14324281.
129define i32* @test8(i32* nocapture %A, i1 %cond) {
130; CHECK: i32* @test8
131; CHECK-NOT: tailrecurse:
132; CHECK-NOT: tail call
133; CHECK: ret i32* null
134  %B = alloca i32
135  %B2 = alloca i32
136  br i1 %cond, label %cond_true, label %cond_false
137cond_true:
138  call void @use(i32* %B2)
139  call i32* @test8(i32* %B, i1 false)
140  ret i32* null
141cond_false:
142  call void @use2_nocapture(i32* %A, i32* %B)
143  call void @noarg()
144  ret i32* null
145}
146