xref: /llvm-project/llvm/test/Transforms/CorrelatedValuePropagation/ashr.ll (revision b7db403e701029c801fd990dceeb219de9fb800c)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
2; RUN: opt < %s -passes=correlated-propagation -S | FileCheck %s
3
4define void @test1(i32 %n) {
5; CHECK-LABEL: define void @test1(
6; CHECK-SAME: i32 [[N:%.*]]) {
7; CHECK-NEXT:  [[ENTRY:.*]]:
8; CHECK-NEXT:    br label %[[FOR_COND:.*]]
9; CHECK:       [[FOR_COND]]:
10; CHECK-NEXT:    [[A:%.*]] = phi i32 [ [[N]], %[[ENTRY]] ], [ [[SHR:%.*]], %[[FOR_BODY:.*]] ]
11; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[A]], 1
12; CHECK-NEXT:    br i1 [[CMP]], label %[[FOR_BODY]], label %[[FOR_END:.*]]
13; CHECK:       [[FOR_BODY]]:
14; CHECK-NEXT:    [[SHR]] = lshr i32 [[A]], 5
15; CHECK-NEXT:    br label %[[FOR_COND]]
16; CHECK:       [[FOR_END]]:
17; CHECK-NEXT:    ret void
18;
19entry:
20  br label %for.cond
21
22for.cond:                                         ; preds = %for.body, %entry
23  %a = phi i32 [ %n, %entry ], [ %shr, %for.body ]
24  %cmp = icmp sgt i32 %a, 1
25  br i1 %cmp, label %for.body, label %for.end
26
27for.body:                                         ; preds = %for.cond
28  %shr = ashr i32 %a, 5
29  br label %for.cond
30
31for.end:                                          ; preds = %for.cond
32  ret void
33}
34
35;; Negative test to show transform doesn't happen unless n > 0.
36define void @test2(i32 %n) {
37; CHECK-LABEL: define void @test2(
38; CHECK-SAME: i32 [[N:%.*]]) {
39; CHECK-NEXT:  [[ENTRY:.*]]:
40; CHECK-NEXT:    br label %[[FOR_COND:.*]]
41; CHECK:       [[FOR_COND]]:
42; CHECK-NEXT:    [[A:%.*]] = phi i32 [ [[N]], %[[ENTRY]] ], [ [[SHR:%.*]], %[[FOR_BODY:.*]] ]
43; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[A]], -2
44; CHECK-NEXT:    br i1 [[CMP]], label %[[FOR_BODY]], label %[[FOR_END:.*]]
45; CHECK:       [[FOR_BODY]]:
46; CHECK-NEXT:    [[SHR]] = ashr i32 [[A]], 2
47; CHECK-NEXT:    br label %[[FOR_COND]]
48; CHECK:       [[FOR_END]]:
49; CHECK-NEXT:    ret void
50;
51entry:
52  br label %for.cond
53
54for.cond:                                         ; preds = %for.body, %entry
55  %a = phi i32 [ %n, %entry ], [ %shr, %for.body ]
56  %cmp = icmp sgt i32 %a, -2
57  br i1 %cmp, label %for.body, label %for.end
58
59for.body:                                         ; preds = %for.cond
60  %shr = ashr i32 %a, 2
61  br label %for.cond
62
63for.end:                                          ; preds = %for.cond
64  ret void
65}
66
67;; Non looping test case.
68define void @test3(i32 %n) {
69; CHECK-LABEL: define void @test3(
70; CHECK-SAME: i32 [[N:%.*]]) {
71; CHECK-NEXT:  [[ENTRY:.*:]]
72; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[N]], 0
73; CHECK-NEXT:    br i1 [[CMP]], label %[[BB:.*]], label %[[EXIT:.*]]
74; CHECK:       [[BB]]:
75; CHECK-NEXT:    [[SHR:%.*]] = lshr exact i32 [[N]], 4
76; CHECK-NEXT:    br label %[[EXIT]]
77; CHECK:       [[EXIT]]:
78; CHECK-NEXT:    ret void
79;
80entry:
81  %cmp = icmp sgt i32 %n, 0
82  br i1 %cmp, label %bb, label %exit
83
84bb:
85  %shr = ashr exact i32 %n, 4
86  br label %exit
87
88exit:
89  ret void
90}
91
92; looping case where loop has exactly one block
93; at the point of ashr, we know that the operand is always greater than 0,
94; because of the guard before it, so we can transform it to lshr.
95declare void @llvm.experimental.guard(i1,...)
96define void @test4(i32 %n) {
97; CHECK-LABEL: define void @test4(
98; CHECK-SAME: i32 [[N:%.*]]) {
99; CHECK-NEXT:  [[ENTRY:.*]]:
100; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[N]], 0
101; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP:.*]], label %[[EXIT:.*]]
102; CHECK:       [[LOOP]]:
103; CHECK-NEXT:    [[A:%.*]] = phi i32 [ [[N]], %[[ENTRY]] ], [ [[SHR:%.*]], %[[LOOP]] ]
104; CHECK-NEXT:    [[COND:%.*]] = icmp sgt i32 [[A]], 2
105; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 [[COND]]) [ "deopt"() ]
106; CHECK-NEXT:    [[SHR]] = lshr i32 [[A]], 1
107; CHECK-NEXT:    br i1 [[COND]], label %[[LOOP]], label %[[EXIT]]
108; CHECK:       [[EXIT]]:
109; CHECK-NEXT:    ret void
110;
111entry:
112  %cmp = icmp sgt i32 %n, 0
113  br i1 %cmp, label %loop, label %exit
114
115loop:
116  %a = phi i32 [ %n, %entry ], [ %shr, %loop ]
117  %cond = icmp sgt i32 %a, 2
118  call void(i1,...) @llvm.experimental.guard(i1 %cond) [ "deopt"() ]
119  %shr = ashr i32 %a, 1
120  br i1 %cond, label %loop, label %exit
121
122exit:
123  ret void
124}
125
126; same test as above with assume instead of guard.
127declare void @llvm.assume(i1)
128define void @test5(i32 %n) {
129; CHECK-LABEL: define void @test5(
130; CHECK-SAME: i32 [[N:%.*]]) {
131; CHECK-NEXT:  [[ENTRY:.*]]:
132; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[N]], 0
133; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP:.*]], label %[[EXIT:.*]]
134; CHECK:       [[LOOP]]:
135; CHECK-NEXT:    [[A:%.*]] = phi i32 [ [[N]], %[[ENTRY]] ], [ [[SHR:%.*]], %[[LOOP]] ]
136; CHECK-NEXT:    [[COND:%.*]] = icmp samesign ugt i32 [[A]], 4
137; CHECK-NEXT:    call void @llvm.assume(i1 [[COND]])
138; CHECK-NEXT:    [[SHR]] = lshr i32 [[A]], 1
139; CHECK-NEXT:    [[LOOPCOND:%.*]] = icmp samesign ugt i32 [[SHR]], 8
140; CHECK-NEXT:    br i1 [[LOOPCOND]], label %[[LOOP]], label %[[EXIT]]
141; CHECK:       [[EXIT]]:
142; CHECK-NEXT:    ret void
143;
144entry:
145  %cmp = icmp sgt i32 %n, 0
146  br i1 %cmp, label %loop, label %exit
147
148loop:
149  %a = phi i32 [ %n, %entry ], [ %shr, %loop ]
150  %cond = icmp sgt i32 %a, 4
151  call void @llvm.assume(i1 %cond)
152  %shr = ashr i32 %a, 1
153  %loopcond = icmp sgt i32 %shr, 8
154  br i1 %loopcond, label %loop, label %exit
155
156exit:
157  ret void
158}
159
160; check that ashr of -1 or 0 is optimized away
161define i32 @test6(i32 %f, i32 %g) {
162; CHECK-LABEL: define range(i32 -1, 1) i32 @test6(
163; CHECK-SAME: i32 [[F:%.*]], i32 [[G:%.*]]) {
164; CHECK-NEXT:  [[ENTRY:.*:]]
165; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[F]], 1
166; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i32 [[TMP0]], 2
167; CHECK-NEXT:    tail call void @llvm.assume(i1 [[TMP1]])
168; CHECK-NEXT:    ret i32 [[F]]
169;
170entry:
171  %0 = add i32 %f, 1
172  %1 = icmp ult i32 %0, 2
173  tail call void @llvm.assume(i1 %1)
174  %shr = ashr i32 %f, %g
175  ret i32 %shr
176}
177
178; same test as above with different numbers
179define i32 @test7(i32 %f, i32 %g) {
180; CHECK-LABEL: define range(i32 -1, 1) i32 @test7(
181; CHECK-SAME: i32 [[F:%.*]], i32 [[G:%.*]]) {
182; CHECK-NEXT:  [[ENTRY:.*:]]
183; CHECK-NEXT:    [[TMP0:%.*]] = and i32 [[F]], -2
184; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 [[TMP0]], 6
185; CHECK-NEXT:    tail call void @llvm.assume(i1 [[TMP1]])
186; CHECK-NEXT:    [[SUB:%.*]] = add nsw i32 [[F]], -7
187; CHECK-NEXT:    ret i32 [[SUB]]
188;
189entry:
190  %0 = and i32 %f, -2
191  %1 = icmp eq i32 %0, 6
192  tail call void @llvm.assume(i1 %1)
193  %sub = add nsw i32 %f, -7
194  %shr = ashr i32 %sub, %g
195  ret i32 %shr
196}
197
198; check that ashr of -2 or 1 is not optimized away
199define i32 @test8(i32 %f, i32 %g, i1 %s) {
200; CHECK-LABEL: define range(i32 -2, 2) i32 @test8(
201; CHECK-SAME: i32 [[F:%.*]], i32 [[G:%.*]], i1 [[S:%.*]]) {
202; CHECK-NEXT:  [[ENTRY:.*:]]
203; CHECK-NEXT:    [[TMP0:%.*]] = ashr i32 -2, [[F]]
204; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 1, [[G]]
205; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[S]], i32 [[TMP0]], i32 [[TMP1]]
206; CHECK-NEXT:    ret i32 [[TMP2]]
207;
208entry:
209  %0 = ashr i32 -2, %f
210  %1 = ashr i32 1, %g
211  %2 = select i1 %s, i32 %0, i32 %1
212  ret i32 %2
213}
214
215define i32 @may_including_undef(i1 %c.1, i1 %c.2) {
216; CHECK-LABEL: define range(i32 -1073741824, 1073741824) i32 @may_including_undef(
217; CHECK-SAME: i1 [[C_1:%.*]], i1 [[C_2:%.*]]) {
218; CHECK-NEXT:    br i1 [[C_1]], label %[[TRUE_1:.*]], label %[[FALSE:.*]]
219; CHECK:       [[TRUE_1]]:
220; CHECK-NEXT:    br i1 [[C_2]], label %[[TRUE_2:.*]], label %[[EXIT:.*]]
221; CHECK:       [[TRUE_2]]:
222; CHECK-NEXT:    br label %[[EXIT]]
223; CHECK:       [[FALSE]]:
224; CHECK-NEXT:    br label %[[EXIT]]
225; CHECK:       [[EXIT]]:
226; CHECK-NEXT:    [[P:%.*]] = phi i32 [ 2, %[[TRUE_1]] ], [ 4, %[[TRUE_2]] ], [ undef, %[[FALSE]] ]
227; CHECK-NEXT:    [[R:%.*]] = ashr i32 [[P]], 1
228; CHECK-NEXT:    ret i32 [[R]]
229;
230  br i1 %c.1, label %true.1, label %false
231
232true.1:
233  br i1 %c.2, label %true.2, label %exit
234
235true.2:
236  br label %exit
237
238false:
239  br label %exit
240
241exit:
242  %p = phi i32 [ 2, %true.1 ], [ 4, %true.2], [ undef, %false ]
243  %r = ashr i32 %p, 1
244  ret i32 %r
245}
246