xref: /llvm-project/llvm/test/Transforms/InstCombine/phi-select-constant.ll (revision 3bc38fb27a12f785d8e78b8d00cbd277464ace92)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -S -passes=instcombine | FileCheck %s
3@A = extern_weak global i32, align 4
4@B = extern_weak global i32, align 4
5
6define i32 @foo(i1 %which) {
7; CHECK-LABEL: @foo(
8; CHECK-NEXT:  entry:
9; CHECK-NEXT:    br i1 [[WHICH:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
10; CHECK:       delay:
11; CHECK-NEXT:    [[CMP:%.*]] = icmp eq ptr @A, @B
12; CHECK-NEXT:    [[TMP0:%.*]] = select i1 [[CMP]], i32 2, i32 1
13; CHECK-NEXT:    br label [[FINAL]]
14; CHECK:       final:
15; CHECK-NEXT:    [[USE2:%.*]] = phi i32 [ 1, [[ENTRY:%.*]] ], [ [[TMP0]], [[DELAY]] ]
16; CHECK-NEXT:    ret i32 [[USE2]]
17;
18entry:
19  br i1 %which, label %final, label %delay
20
21delay:
22  %cmp = icmp eq ptr @A, @B
23  br label %final
24
25final:
26  %use2 = phi i1 [ false, %entry ], [ %cmp, %delay ]
27  %value = select i1 %use2, i32 2, i32 1
28  ret i32 %value
29}
30
31
32; test folding of select into phi for vectors.
33define <4 x i64> @vec1(i1 %which) {
34; CHECK-LABEL: @vec1(
35; CHECK-NEXT:  entry:
36; CHECK-NEXT:    br i1 [[WHICH:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
37; CHECK:       delay:
38; CHECK-NEXT:    br label [[FINAL]]
39; CHECK:       final:
40; CHECK-NEXT:    [[PHINODE:%.*]] = phi <4 x i64> [ zeroinitializer, [[ENTRY:%.*]] ], [ <i64 0, i64 0, i64 126, i64 127>, [[DELAY]] ]
41; CHECK-NEXT:    ret <4 x i64> [[PHINODE]]
42;
43entry:
44  br i1 %which, label %final, label %delay
45
46delay:
47  br label %final
48
49final:
50  %phinode =  phi <4 x i1> [ <i1 true, i1 true, i1 true, i1 true>, %entry ], [ <i1 true, i1 true, i1 false, i1 false>, %delay ]
51  %sel = select <4 x i1> %phinode, <4 x i64> zeroinitializer, <4 x i64> <i64 124, i64 125, i64 126, i64 127>
52  ret <4 x i64> %sel
53}
54
55define <4 x i64> @vec2(i1 %which) {
56; CHECK-LABEL: @vec2(
57; CHECK-NEXT:  entry:
58; CHECK-NEXT:    br i1 [[WHICH:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
59; CHECK:       delay:
60; CHECK-NEXT:    br label [[FINAL]]
61; CHECK:       final:
62; CHECK-NEXT:    [[PHINODE:%.*]] = phi <4 x i64> [ <i64 124, i64 125, i64 126, i64 127>, [[ENTRY:%.*]] ], [ <i64 0, i64 125, i64 0, i64 127>, [[DELAY]] ]
63; CHECK-NEXT:    ret <4 x i64> [[PHINODE]]
64;
65entry:
66  br i1 %which, label %final, label %delay
67
68delay:
69  br label %final
70
71final:
72  %phinode =  phi <4 x i1> [ <i1 false, i1 false, i1 false, i1 false>, %entry ], [ <i1 true, i1 false, i1 true, i1 false>, %delay ]
73  %sel = select <4 x i1> %phinode, <4 x i64> zeroinitializer, <4 x i64> <i64 124, i64 125, i64 126, i64 127>
74  ret <4 x i64> %sel
75}
76
77; Test PR33364
78; Insert the generated select into the same block as the incoming phi value.
79; phi has constant vectors along with a single non-constant vector as operands.
80define <2 x i8> @vec3(i1 %cond1, i1 %cond2, <2 x i1> %x, <2 x i8> %y, <2 x i8> %z) {
81; CHECK-LABEL: @vec3(
82; CHECK-NEXT:  entry:
83; CHECK-NEXT:    br i1 [[COND1:%.*]], label [[IF1:%.*]], label [[ELSE:%.*]]
84; CHECK:       if1:
85; CHECK-NEXT:    br i1 [[COND2:%.*]], label [[IF2:%.*]], label [[ELSE]]
86; CHECK:       if2:
87; CHECK-NEXT:    br label [[ELSE]]
88; CHECK:       else:
89; CHECK-NEXT:    [[PHI:%.*]] = phi <2 x i1> [ [[X:%.*]], [[IF2]] ], [ <i1 false, i1 true>, [[ENTRY:%.*]] ], [ <i1 true, i1 false>, [[IF1]] ]
90; CHECK-NEXT:    [[SEL:%.*]] = select <2 x i1> [[PHI]], <2 x i8> [[Y:%.*]], <2 x i8> [[Z:%.*]]
91; CHECK-NEXT:    ret <2 x i8> [[SEL]]
92;
93entry:
94  br i1 %cond1, label %if1, label %else
95
96if1:
97  br i1 %cond2, label %if2, label %else
98
99if2:
100  br label %else
101
102else:
103  %phi = phi <2 x i1> [ %x, %if2 ], [ <i1 0, i1 1>, %entry ], [ <i1 1, i1 0>, %if1 ]
104  %sel = select <2 x i1> %phi, <2 x i8> %y, <2 x i8> %z
105  ret <2 x i8> %sel
106}
107
108; Don't crash on unreachable IR.
109
110define void @PR48369(i32 %a, ptr %p) {
111; CHECK-LABEL: @PR48369(
112; CHECK-NEXT:  entry:
113; CHECK-NEXT:    [[PHI_CMP:%.*]] = icmp sgt i32 [[A:%.*]], 0
114; CHECK-NEXT:    br label [[BB1:%.*]]
115; CHECK:       bb1:
116; CHECK-NEXT:    [[CMP:%.*]] = phi i1 [ [[PHI_CMP]], [[DEADBB:%.*]] ], [ true, [[ENTRY:%.*]] ]
117; CHECK-NEXT:    [[SHL:%.*]] = select i1 [[CMP]], i32 256, i32 0
118; CHECK-NEXT:    store i32 [[SHL]], ptr [[P:%.*]], align 4
119; CHECK-NEXT:    br label [[END:%.*]]
120; CHECK:       deadbb:
121; CHECK-NEXT:    br label [[BB1]]
122; CHECK:       end:
123; CHECK-NEXT:    ret void
124;
125entry:
126  %phi.cmp = icmp sgt i32 %a, 0
127  br label %bb1
128
129bb1:
130  %cmp = phi i1 [ %phi.cmp, %deadbb ], [ true, %entry ]
131  %shl = select i1 %cmp, i32 256, i32 0
132  store i32 %shl, ptr %p
133  br label %end
134
135deadbb:
136  br label %bb1
137
138end:
139  ret void
140}
141
142define i16 @sink_to_unreachable_crash(i1 %a)  {
143; CHECK-LABEL: @sink_to_unreachable_crash(
144; CHECK-NEXT:  entry:
145; CHECK-NEXT:    br label [[INF_LOOP:%.*]]
146; CHECK:       inf_loop:
147; CHECK-NEXT:    br label [[INF_LOOP]]
148; CHECK:       unreachable:
149; CHECK-NEXT:    ret i16 poison
150;
151entry:
152  %s = select i1 %a, i16 0, i16 5
153  br label %inf_loop
154
155inf_loop:
156  br label %inf_loop
157
158unreachable:   ; No predecessors!
159  ret i16 %s
160}
161
162define i32 @phi_trans(i1 %c, i1 %c2, i32 %v) {
163; CHECK-LABEL: @phi_trans(
164; CHECK-NEXT:  entry:
165; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF:%.*]], label [[ELSE:%.*]]
166; CHECK:       if:
167; CHECK-NEXT:    [[V2:%.*]] = add i32 [[V:%.*]], 1
168; CHECK-NEXT:    br label [[JOIN:%.*]]
169; CHECK:       else:
170; CHECK-NEXT:    [[V3:%.*]] = mul i32 [[V]], 3
171; CHECK-NEXT:    [[V5:%.*]] = lshr i32 [[V]], 1
172; CHECK-NEXT:    [[TMP0:%.*]] = select i1 [[C2:%.*]], i32 [[V3]], i32 [[V5]]
173; CHECK-NEXT:    br label [[JOIN]]
174; CHECK:       join:
175; CHECK-NEXT:    [[PHI1:%.*]] = phi i32 [ [[V2]], [[IF]] ], [ [[TMP0]], [[ELSE]] ]
176; CHECK-NEXT:    ret i32 [[PHI1]]
177;
178entry:
179  br i1 %c, label %if, label %else
180
181if:
182  %v2 = add i32 %v, 1
183  %v4 = shl i32 %v, 1
184  br label %join
185
186else:
187  %v3 = mul i32 %v, 3
188  %v5 = lshr i32 %v, 1
189  br label %join
190
191join:
192  %phi1 = phi i1 [ true, %if ], [ %c2, %else ]
193  %phi2 = phi i32 [ %v2, %if ], [ %v3, %else ]
194  %phi3 = phi i32 [ %v4, %if ], [ %v5, %else ]
195  %sel = select i1 %phi1, i32 %phi2, i32 %phi3
196  ret i32 %sel
197}
198
199define i32 @dominating_values_select_same_block(i1 %c1, i1 %c2, ptr %p, ptr %p2) {
200; CHECK-LABEL: @dominating_values_select_same_block(
201; CHECK-NEXT:  entry:
202; CHECK-NEXT:    [[B:%.*]] = load i32, ptr [[P2:%.*]], align 4
203; CHECK-NEXT:    br i1 [[C1:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
204; CHECK:       delay:
205; CHECK-NEXT:    [[A:%.*]] = load i32, ptr [[P:%.*]], align 4
206; CHECK-NEXT:    [[TMP0:%.*]] = select i1 [[C2:%.*]], i32 [[A]], i32 [[B]]
207; CHECK-NEXT:    br label [[FINAL]]
208; CHECK:       final:
209; CHECK-NEXT:    [[USE2:%.*]] = phi i32 [ [[B]], [[ENTRY:%.*]] ], [ [[TMP0]], [[DELAY]] ]
210; CHECK-NEXT:    ret i32 [[USE2]]
211;
212entry:
213  %a = load i32, ptr %p
214  %b = load i32, ptr %p2
215  br i1 %c1, label %final, label %delay
216
217delay:
218  br label %final
219
220final:
221  %use2 = phi i1 [ false, %entry ], [ %c2, %delay ]
222  %value = select i1 %use2, i32 %a, i32 %b
223  ret i32 %value
224}
225
226define i32 @dominating_values_select_not_same_block(i1 %c1, i1 %c2, ptr %p, ptr %p2) {
227; CHECK-LABEL: @dominating_values_select_not_same_block(
228; CHECK-NEXT:  entry:
229; CHECK-NEXT:    [[B:%.*]] = load i32, ptr [[P2:%.*]], align 4
230; CHECK-NEXT:    br i1 [[C1:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
231; CHECK:       delay:
232; CHECK-NEXT:    [[A:%.*]] = load i32, ptr [[P:%.*]], align 4
233; CHECK-NEXT:    [[TMP0:%.*]] = select i1 [[C2:%.*]], i32 [[A]], i32 [[B]]
234; CHECK-NEXT:    br label [[FINAL]]
235; CHECK:       final:
236; CHECK-NEXT:    [[USE2:%.*]] = phi i32 [ [[B]], [[ENTRY:%.*]] ], [ [[TMP0]], [[DELAY]] ]
237; CHECK-NEXT:    br label [[SPLIT:%.*]]
238; CHECK:       split:
239; CHECK-NEXT:    ret i32 [[USE2]]
240;
241entry:
242  %a = load i32, ptr %p
243  %b = load i32, ptr %p2
244  br i1 %c1, label %final, label %delay
245
246delay:
247  br label %final
248
249final:
250  %use2 = phi i1 [ false, %entry ], [ %c2, %delay ]
251  br label %split
252
253split:
254  %value = select i1 %use2, i32 %a, i32 %b
255  ret i32 %value
256}
257
258define i32 @not_dominating_values(i1 %c1, i1 %c2, ptr %p, ptr %p2) {
259; CHECK-LABEL: @not_dominating_values(
260; CHECK-NEXT:  entry:
261; CHECK-NEXT:    [[A:%.*]] = load i32, ptr [[P:%.*]], align 4
262; CHECK-NEXT:    br i1 [[C1:%.*]], label [[FINAL:%.*]], label [[DELAY:%.*]]
263; CHECK:       delay:
264; CHECK-NEXT:    br label [[FINAL]]
265; CHECK:       final:
266; CHECK-NEXT:    [[USE2:%.*]] = phi i1 [ false, [[ENTRY:%.*]] ], [ [[C2:%.*]], [[DELAY]] ]
267; CHECK-NEXT:    [[B:%.*]] = load i32, ptr [[P2:%.*]], align 4
268; CHECK-NEXT:    [[VALUE:%.*]] = select i1 [[USE2]], i32 [[A]], i32 [[B]]
269; CHECK-NEXT:    ret i32 [[VALUE]]
270;
271entry:
272  %a = load i32, ptr %p
273  br i1 %c1, label %final, label %delay
274
275delay:
276  br label %final
277
278final:
279  %use2 = phi i1 [ false, %entry ], [ %c2, %delay ]
280  %b = load i32, ptr %p2
281  %value = select i1 %use2, i32 %a, i32 %b
282  ret i32 %value
283}
284