1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
2; RUN: opt < %s -analyze -scalar-evolution -scalar-evolution-classify-expressions=0 | FileCheck %s
3
4; Trip counts with trivial exit conditions.
5
6define void @a(i64 %n) nounwind {
7; CHECK-LABEL: 'a'
8; CHECK-NEXT:  Determining loop execution counts for: @a
9; CHECK-NEXT:  Loop %loop: Unpredictable backedge-taken count.
10; CHECK-NEXT:  Loop %loop: Unpredictable max backedge-taken count.
11; CHECK-NEXT:  Loop %loop: Unpredictable predicated backedge-taken count.
12;
13entry:
14  %t0 = icmp sgt i64 %n, 0
15  br i1 %t0, label %loop, label %return
16
17loop:
18  %i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
19  %i.next = add nsw i64 %i, 1
20  %exitcond = icmp eq i64 %i.next, %n
21  br i1 false, label %return, label %loop
22
23return:
24  ret void
25}
26define void @b(i64 %n) nounwind {
27; CHECK-LABEL: 'b'
28; CHECK-NEXT:  Determining loop execution counts for: @b
29; CHECK-NEXT:  Loop %loop: backedge-taken count is false
30; CHECK-NEXT:  Loop %loop: max backedge-taken count is false
31; CHECK-NEXT:  Loop %loop: Predicated backedge-taken count is false
32; CHECK-NEXT:   Predicates:
33; CHECK:       Loop %loop: Trip multiple is 1
34;
35entry:
36  %t0 = icmp sgt i64 %n, 0
37  br i1 %t0, label %loop, label %return
38
39loop:
40  %i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
41  %i.next = add nsw i64 %i, 1
42  %exitcond = icmp eq i64 %i.next, %n
43  br i1 true, label %return, label %loop
44
45return:
46  ret void
47}
48define void @c(i64 %n) nounwind {
49; CHECK-LABEL: 'c'
50; CHECK-NEXT:  Determining loop execution counts for: @c
51; CHECK-NEXT:  Loop %loop: backedge-taken count is false
52; CHECK-NEXT:  Loop %loop: max backedge-taken count is false
53; CHECK-NEXT:  Loop %loop: Predicated backedge-taken count is false
54; CHECK-NEXT:   Predicates:
55; CHECK:       Loop %loop: Trip multiple is 1
56;
57entry:
58  %t0 = icmp sgt i64 %n, 0
59  br i1 %t0, label %loop, label %return
60
61loop:
62  %i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
63  %i.next = add nsw i64 %i, 1
64  %exitcond = icmp eq i64 %i.next, %n
65  br i1 false, label %loop, label %return
66
67return:
68  ret void
69}
70define void @d(i64 %n) nounwind {
71; CHECK-LABEL: 'd'
72; CHECK-NEXT:  Determining loop execution counts for: @d
73; CHECK-NEXT:  Loop %loop: Unpredictable backedge-taken count.
74; CHECK-NEXT:  Loop %loop: Unpredictable max backedge-taken count.
75; CHECK-NEXT:  Loop %loop: Unpredictable predicated backedge-taken count.
76;
77entry:
78  %t0 = icmp sgt i64 %n, 0
79  br i1 %t0, label %loop, label %return
80
81loop:
82  %i = phi i64 [ %i.next, %loop ], [ 0, %entry ]
83  %i.next = add nsw i64 %i, 1
84  %exitcond = icmp eq i64 %i.next, %n
85  br i1 true, label %loop, label %return
86
87return:
88  ret void
89}
90
91; Trip counts for non-polynomial iterations. It's theoretically possible
92; to compute a maximum count for these, but short of that, ScalarEvolution
93; should return unknown.
94
95; PR7416
96declare i1 @g() nounwind
97
98define void @nonpolynomial() {
99; CHECK-LABEL: 'nonpolynomial'
100; CHECK-NEXT:  Determining loop execution counts for: @nonpolynomial
101; CHECK-NEXT:  Loop %loophead: Unpredictable backedge-taken count.
102; CHECK-NEXT:  Loop %loophead: Unpredictable max backedge-taken count.
103; CHECK-NEXT:  Loop %loophead: Unpredictable predicated backedge-taken count.
104;
105entry:
106  br label %loophead
107loophead:
108  %x = phi i32 [0, %entry], [%x.1, %bb1], [%x.2, %bb2]
109  %y = icmp slt i32 %x, 100
110  br i1 %y, label %loopbody, label %retbb
111loopbody:
112  %z = call i1 @g()
113  br i1 %z, label %bb1, label %bb2
114bb1:
115  %x.1 = add i32 %x, 2
116  br label %loophead
117bb2:
118  %x.2 = add i32 %x, 3
119  br label %loophead
120retbb:
121  ret void
122}
123
124; PHI nodes with all constant operands.
125
126define void @constant_phi_operands() nounwind {
127; CHECK-LABEL: 'constant_phi_operands'
128; CHECK-NEXT:  Determining loop execution counts for: @constant_phi_operands
129; CHECK-NEXT:  Loop %loop: backedge-taken count is 1
130; CHECK-NEXT:  Loop %loop: max backedge-taken count is 1
131; CHECK-NEXT:  Loop %loop: Predicated backedge-taken count is 1
132; CHECK-NEXT:   Predicates:
133; CHECK:       Loop %loop: Trip multiple is 2
134;
135entry:
136  br label %loop
137
138loop:
139  %i = phi i64 [ 1, %loop ], [ 0, %entry ]
140  %exitcond = icmp eq i64 %i, 1
141  br i1 %exitcond, label %return, label %loop
142
143return:
144  ret void
145}
146
147; PR16130: Loop exit depends on an 'or' expression.
148; One side of the expression test against a value that will be skipped.
149; We can't assume undefined behavior just because we have an NSW flag.
150;
151define void @exit_orcond_nsw(i32 *%a) nounwind {
152; CHECK-LABEL: 'exit_orcond_nsw'
153; CHECK-NEXT:  Determining loop execution counts for: @exit_orcond_nsw
154; CHECK-NEXT:  Loop %for.body.i: Unpredictable backedge-taken count.
155; CHECK-NEXT:  Loop %for.body.i: max backedge-taken count is 1
156; CHECK-NEXT:  Loop %for.body.i: Unpredictable predicated backedge-taken count.
157;
158entry:
159  br label %for.body.i
160
161for.body.i:                                       ; preds = %for.body.i, %entry
162  %b.01.i = phi i32 [ 0, %entry ], [ %add.i, %for.body.i ]
163  %tobool.i = icmp ne i32 %b.01.i, 0
164  %add.i = add nsw i32 %b.01.i, 8
165  %cmp.i = icmp eq i32 %add.i, 13
166  %or.cond = or i1 %tobool.i, %cmp.i
167  br i1 %or.cond, label %exit, label %for.body.i
168
169exit:                                     ; preds = %for.body.i
170  %b.01.i.lcssa = phi i32 [ %b.01.i, %for.body.i ]
171  store i32 %b.01.i.lcssa, i32* %a, align 4
172  ret void
173}
174