xref: /llvm-project/llvm/test/Transforms/InstSimplify/phi.ll (revision dd116369f646d023a2e7e5c145a1bed5dcf9a45c)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=instsimplify -S | FileCheck %s
3
4; PR12189
5define i1 @test1(i32 %x) {
6; CHECK-LABEL: @test1(
7; CHECK-NEXT:    br i1 true, label [[A:%.*]], label [[B:%.*]]
8; CHECK:       a:
9; CHECK-NEXT:    [[AA:%.*]] = or i32 [[X:%.*]], 10
10; CHECK-NEXT:    br label [[C:%.*]]
11; CHECK:       b:
12; CHECK-NEXT:    [[BB:%.*]] = or i32 [[X]], 10
13; CHECK-NEXT:    br label [[C]]
14; CHECK:       c:
15; CHECK-NEXT:    [[CC:%.*]] = phi i32 [ [[BB]], [[B]] ], [ [[AA]], [[A]] ]
16; CHECK-NEXT:    [[D:%.*]] = urem i32 [[CC]], 2
17; CHECK-NEXT:    [[E:%.*]] = icmp eq i32 [[D]], 0
18; CHECK-NEXT:    ret i1 [[E]]
19;
20  br i1 true, label %a, label %b
21
22a:
23  %aa = or i32 %x, 10
24  br label %c
25
26b:
27  %bb = or i32 %x, 10
28  br label %c
29
30c:
31  %cc = phi i32 [ %bb, %b ], [%aa, %a ]
32  %d = urem i32 %cc, 2
33  %e = icmp eq i32 %d, 0
34  ret i1 %e
35}
36
37; D63489 - https://reviews.llvm.org/D63489
38; If this single-value phi form needs to be preserved to enable
39; further analysis, then -passes=instsimplify should not be running?
40
41define i32 @lcssa-phi(i32 %x) {
42; CHECK-LABEL: @lcssa-phi(
43; CHECK-NEXT:  entry:
44; CHECK-NEXT:    br label [[END:%.*]]
45; CHECK:       end:
46; CHECK-NEXT:    ret i32 [[X:%.*]]
47;
48entry:
49  br label %end
50
51end:
52  %counter.lcssa = phi i32 [ %x, %entry ]
53  ret i32 %counter.lcssa
54}
55
56define i32 @poison(i1 %cond, i32 %v) {
57; CHECK-LABEL: @poison(
58; CHECK-NEXT:    br i1 [[COND:%.*]], label [[A:%.*]], label [[B:%.*]]
59; CHECK:       A:
60; CHECK-NEXT:    br label [[EXIT:%.*]]
61; CHECK:       B:
62; CHECK-NEXT:    br label [[EXIT]]
63; CHECK:       EXIT:
64; CHECK-NEXT:    ret i32 [[V:%.*]]
65;
66  br i1 %cond, label %A, label %B
67A:
68  br label %EXIT
69B:
70  br label %EXIT
71EXIT:
72  %w = phi i32 [%v, %A], [poison, %B]
73  ret i32 %w
74}
75
76define i32 @undef(i1 %cond, i32 %v) {
77; CHECK-LABEL: @undef(
78; CHECK-NEXT:    br i1 [[COND:%.*]], label [[A:%.*]], label [[B:%.*]]
79; CHECK:       A:
80; CHECK-NEXT:    br label [[EXIT:%.*]]
81; CHECK:       B:
82; CHECK-NEXT:    br label [[EXIT]]
83; CHECK:       EXIT:
84; CHECK-NEXT:    [[W:%.*]] = phi i32 [ [[V:%.*]], [[A]] ], [ undef, [[B]] ]
85; CHECK-NEXT:    ret i32 [[W]]
86;
87  br i1 %cond, label %A, label %B
88A:
89  br label %EXIT
90B:
91  br label %EXIT
92EXIT:
93  %w = phi i32 [%v, %A], [undef, %B]
94  ret i32 %w
95}
96
97define i8 @undef_poison(i1 %cond) {
98; CHECK-LABEL: @undef_poison(
99; CHECK-NEXT:    br i1 [[COND:%.*]], label [[A:%.*]], label [[B:%.*]]
100; CHECK:       A:
101; CHECK-NEXT:    br label [[EXIT:%.*]]
102; CHECK:       B:
103; CHECK-NEXT:    br label [[EXIT]]
104; CHECK:       EXIT:
105; CHECK-NEXT:    ret i8 undef
106;
107  br i1 %cond, label %A, label %B
108A:
109  br label %EXIT
110B:
111  br label %EXIT
112EXIT:
113  %r = phi i8 [undef, %A], [poison, %B]
114  ret i8 %r
115}
116
117define i8 @only_undef(i1 %cond) {
118; CHECK-LABEL: @only_undef(
119; CHECK-NEXT:    br i1 [[COND:%.*]], label [[A:%.*]], label [[B:%.*]]
120; CHECK:       A:
121; CHECK-NEXT:    br label [[EXIT:%.*]]
122; CHECK:       B:
123; CHECK-NEXT:    br label [[EXIT]]
124; CHECK:       EXIT:
125; CHECK-NEXT:    ret i8 undef
126;
127  br i1 %cond, label %A, label %B
128A:
129  br label %EXIT
130B:
131  br label %EXIT
132EXIT:
133  %r = phi i8 [undef, %A], [undef, %B]
134  ret i8 %r
135}
136
137define i8 @only_poison(i1 %cond) {
138; CHECK-LABEL: @only_poison(
139; CHECK-NEXT:    br i1 [[COND:%.*]], label [[A:%.*]], label [[B:%.*]]
140; CHECK:       A:
141; CHECK-NEXT:    br label [[EXIT:%.*]]
142; CHECK:       B:
143; CHECK-NEXT:    br label [[EXIT]]
144; CHECK:       EXIT:
145; CHECK-NEXT:    ret i8 poison
146;
147  br i1 %cond, label %A, label %B
148A:
149  br label %EXIT
150B:
151  br label %EXIT
152EXIT:
153  %r = phi i8 [poison, %A], [poison, %B]
154  ret i8 %r
155}
156
157; Should not fold srem to -1 due to incorrect context instruction when
158; threading over phi.
159define i32 @pr61312() {
160; CHECK-LABEL: @pr61312(
161; CHECK-NEXT:  entry:
162; CHECK-NEXT:    br label [[FOR_COND:%.*]]
163; CHECK:       for.cond:
164; CHECK-NEXT:    [[A_0:%.*]] = phi i32 [ 2, [[ENTRY:%.*]] ], [ [[DEC:%.*]], [[FOR_INC:%.*]] ]
165; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[A_0]], 0
166; CHECK-NEXT:    br i1 [[CMP]], label [[FOR_INC]], label [[FOR_END:%.*]]
167; CHECK:       for.inc:
168; CHECK-NEXT:    [[DEC]] = add nsw i32 [[A_0]], -1
169; CHECK-NEXT:    br label [[FOR_COND]]
170; CHECK:       for.end:
171; CHECK-NEXT:    [[REM:%.*]] = srem i32 -1, [[A_0]]
172; CHECK-NEXT:    ret i32 [[REM]]
173;
174entry:
175  br label %for.cond
176
177for.cond:
178  %a.0 = phi i32 [ 2, %entry ], [ %dec, %for.inc ]
179  %cmp = icmp sge i32 %a.0, 0
180  br i1 %cmp, label %for.inc, label %for.end
181
182for.inc:
183  %dec = add nsw i32 %a.0, -1
184  br label %for.cond
185
186for.end:
187  %rem = srem i32 -1, %a.0
188  ret i32 %rem
189}
190