1; RUN: opt < %s -indvars -S | FileCheck %s
2
3; These tests ensure that we can compute the trip count of various forms of
4; loops.  If the trip count of the loop is computable, then we will know what
5; the exit value of the loop will be for some value, allowing us to substitute
6; it directly into users outside of the loop, making the loop dead.
7
8; CHECK-LABEL: @linear_setne(
9; CHECK: ret i32 100
10
11define i32 @linear_setne() {
12entry:
13	br label %loop
14
15loop:		; preds = %loop, %entry
16	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
17	%i.next = add i32 %i, 1		; <i32> [#uses=1]
18	%c = icmp ne i32 %i, 100		; <i1> [#uses=1]
19	br i1 %c, label %loop, label %loopexit
20
21loopexit:		; preds = %loop
22	ret i32 %i
23}
24
25; CHECK-LABEL: @linear_setne_2(
26; CHECK: ret i32 100
27
28define i32 @linear_setne_2() {
29entry:
30	br label %loop
31
32loop:		; preds = %loop, %entry
33	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
34	%i.next = add i32 %i, 2		; <i32> [#uses=1]
35	%c = icmp ne i32 %i, 100		; <i1> [#uses=1]
36	br i1 %c, label %loop, label %loopexit
37
38loopexit:		; preds = %loop
39	ret i32 %i
40}
41
42; CHECK-LABEL: @linear_setne_overflow(
43; CHECK: ret i32 0
44
45define i32 @linear_setne_overflow() {
46entry:
47	br label %loop
48
49loop:		; preds = %loop, %entry
50	%i = phi i32 [ 1024, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
51	%i.next = add i32 %i, 1024		; <i32> [#uses=1]
52	%c = icmp ne i32 %i, 0		; <i1> [#uses=1]
53	br i1 %c, label %loop, label %loopexit
54
55loopexit:		; preds = %loop
56	ret i32 %i
57}
58
59; CHECK-LABEL: @linear_setlt(
60; CHECK: ret i32 100
61
62define i32 @linear_setlt() {
63entry:
64	br label %loop
65
66loop:		; preds = %loop, %entry
67	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
68	%i.next = add i32 %i, 1		; <i32> [#uses=1]
69	%c = icmp slt i32 %i, 100		; <i1> [#uses=1]
70	br i1 %c, label %loop, label %loopexit
71
72loopexit:		; preds = %loop
73	ret i32 %i
74}
75
76; CHECK-LABEL: @quadratic_setlt(
77; CHECK: ret i32 34
78
79define i32 @quadratic_setlt() {
80entry:
81	br label %loop
82
83loop:		; preds = %loop, %entry
84	%i = phi i32 [ 7, %entry ], [ %i.next, %loop ]		; <i32> [#uses=4]
85	%i.next = add i32 %i, 3		; <i32> [#uses=1]
86	%i2 = mul i32 %i, %i		; <i32> [#uses=1]
87	%c = icmp slt i32 %i2, 1000		; <i1> [#uses=1]
88	br i1 %c, label %loop, label %loopexit
89
90loopexit:		; preds = %loop
91	ret i32 %i
92}
93
94; CHECK-LABEL: @chained(
95; CHECK: ret i32 200
96
97define i32 @chained() {
98entry:
99	br label %loop
100
101loop:		; preds = %loop, %entry
102	%i = phi i32 [ 0, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
103	%i.next = add i32 %i, 1		; <i32> [#uses=1]
104	%c = icmp ne i32 %i, 100		; <i1> [#uses=1]
105	br i1 %c, label %loop, label %loopexit
106
107loopexit:		; preds = %loop
108	br label %loop2
109
110loop2:		; preds = %loop2, %loopexit
111	%j = phi i32 [ %i, %loopexit ], [ %j.next, %loop2 ]		; <i32> [#uses=3]
112	%j.next = add i32 %j, 1		; <i32> [#uses=1]
113	%c2 = icmp ne i32 %j, 200		; <i1> [#uses=1]
114	br i1 %c2, label %loop2, label %loopexit2
115
116loopexit2:		; preds = %loop2
117	ret i32 %j
118}
119
120; CHECK-LABEL: @chained4(
121; CHECK: ret i32 400
122
123define i32 @chained4() {
124entry:
125  br label %loop
126
127loop:                                             ; preds = %loop, %entry
128  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]  ; <i32> [#uses=3]
129  %i.next = add i32 %i, 1                         ; <i32> [#uses=1]
130  %c = icmp ne i32 %i.next, 100                   ; <i1> [#uses=1]
131  br i1 %c, label %loop, label %loopexit
132
133loopexit:                                         ; preds = %loop
134  br label %loop2
135
136loop2:                                            ; preds = %loop2, %loopexit
137  %j = phi i32 [ %i.next, %loopexit ], [ %j.next, %loop2 ] ; <i32> [#uses=3]
138  %j.next = add i32 %j, 1                         ; <i32> [#uses=1]
139  %c2 = icmp ne i32 %j.next, 200                  ; <i1> [#uses=1]
140  br i1 %c2, label %loop2, label %loopexit2
141
142loopexit2:                                        ; preds = %loop
143  br label %loop8
144
145loop8:                                            ; preds = %loop2, %loopexit
146  %k = phi i32 [ %j.next, %loopexit2 ], [ %k.next, %loop8 ] ; <i32> [#uses=3]
147  %k.next = add i32 %k, 1                         ; <i32> [#uses=1]
148  %c8 = icmp ne i32 %k.next, 300                  ; <i1> [#uses=1]
149  br i1 %c8, label %loop8, label %loopexit8
150
151loopexit8:                                        ; preds = %loop2
152  br label %loop9
153
154loop9:                                            ; preds = %loop2, %loopexit
155  %l = phi i32 [ %k.next, %loopexit8 ], [ %l.next, %loop9 ] ; <i32> [#uses=3]
156  %l.next = add i32 %l, 1                         ; <i32> [#uses=1]
157  %c9 = icmp ne i32 %l.next, 400                  ; <i1> [#uses=1]
158  br i1 %c9, label %loop9, label %loopexit9
159
160loopexit9:                                        ; preds = %loop2
161  ret i32 %l.next
162}
163