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1; This test ensures that IVUsers works correctly in the legacy pass manager
2; without LCSSA and in the specific ways that some of its users (LSR) require.
3;
4; FIXME: We need some way to match the precision here in the new PM where loop
5; passes *always* work on LCSSA. This should stop using a different set of
6; checks at that point.
7
8; RUN: opt < %s -analyze -iv-users -enable-new-pm=0 | FileCheck %s --check-prefixes=CHECK,CHECK-NO-LCSSA
9; RUN: opt < %s -disable-output -passes='print<iv-users>' 2>&1 | FileCheck %s
10
11; Provide legal integer types.
12target datalayout = "n8:16:32:64"
13
14; The value of %r is dependent on a polynomial iteration expression.
15;
16; CHECK-LABEL: IV Users for loop %foo.loop
17; CHECK-NO-LCSSA: {1,+,3,+,2}<%foo.loop>
18define i64 @foo(i64 %n) {
19entry:
20  br label %foo.loop
21
22foo.loop:
23  %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %foo.loop ]
24  %indvar.next = add i64 %indvar, 1
25  %c = icmp eq i64 %indvar.next, %n
26  br i1 %c, label %exit, label %foo.loop
27
28exit:
29  %r = mul i64 %indvar.next, %indvar.next
30  ret i64 %r
31}
32
33; PR15470: LSR miscompile. The test1 function should return '1'.
34; It is valid to fold SCEVUnknown into the recurrence because it
35; was defined before the loop.
36;
37; SCEV does not know how to denormalize chained recurrences, so make
38; sure they aren't marked as post-inc users.
39;
40; CHECK-LABEL: IV Users for loop %test1.loop
41; CHECK-NO-LCSSA: %sext.us = {0,+,(16777216 + (-16777216 * %sub.us)<nuw><nsw>)<nuw><nsw>,+,33554432}<%test1.loop> (post-inc with loop %test1.loop) in    %f = ashr i32 %sext.us, 24
42define i32 @test1(i1 %cond) {
43entry:
44  %sub.us = select i1 %cond, i32 0, i32 0
45  br label %test1.loop
46
47test1.loop:
48  %inc1115.us = phi i32 [ 0, %entry ], [ %inc11.us, %test1.loop ]
49  %inc11.us = add nsw i32 %inc1115.us, 1
50  %cmp.us = icmp slt i32 %inc11.us, 2
51  br i1 %cmp.us, label %test1.loop, label %for.end
52
53for.end:
54  %tobool.us = icmp eq i32 %inc1115.us, 0
55  %mul.us = shl i32 %inc1115.us, 24
56  %sub.cond.us = sub nsw i32 %inc1115.us, %sub.us
57  %sext.us = mul i32 %mul.us, %sub.cond.us
58  %f = ashr i32 %sext.us, 24
59  br label %exit
60
61exit:
62  ret i32 %f
63}
64
65; PR15470: LSR miscompile. The test2 function should return '1'.
66; It is illegal to fold SCEVUnknown (sext.us) into the recurrence
67; because it is defined after the loop where this recurrence belongs.
68;
69; SCEV does not know how to denormalize chained recurrences, so make
70; sure they aren't marked as post-inc users.
71;
72; CHECK-LABEL: IV Users for loop %test2.loop
73; CHECK-NO-LCSSA: %sub.cond.us = ((-1 * %sub.us)<nuw><nsw> + {0,+,1}<nuw><nsw><%test2.loop>) (post-inc with loop %test2.loop) in    %sext.us = mul i32 %mul.us, %sub.cond.us
74define i32 @test2() {
75entry:
76  br label %test2.loop
77
78test2.loop:
79  %inc1115.us = phi i32 [ 0, %entry ], [ %inc11.us, %test2.loop ]
80  %inc11.us = add nsw i32 %inc1115.us, 1
81  %cmp.us = icmp slt i32 %inc11.us, 2
82  br i1 %cmp.us, label %test2.loop, label %for.end
83
84for.end:
85  %tobool.us = icmp eq i32 %inc1115.us, 0
86  %sub.us = select i1 %tobool.us, i32 0, i32 0
87  %mul.us = shl i32 %inc1115.us, 24
88  %sub.cond.us = sub nsw i32 %inc1115.us, %sub.us
89  %sext.us = mul i32 %mul.us, %sub.cond.us
90  %f = ashr i32 %sext.us, 24
91  br label %exit
92
93exit:
94  ret i32 %f
95}
96