xref: /llvm-project/llvm/test/Transforms/JumpThreading/thread-two-bbs.ll (revision f893dccbba372792e7e7095d741f98a234654875)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S -passes=jump-threading,verify < %s | FileCheck %s
3
4target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
5target triple = "x86_64-unknown-linux-gnu"
6
7@a = global i32 0, align 4
8
9; Verify that we branch (twice) on cond2 without checking ptr.
10; Verify that we eliminate "bb.file".
11
12define void @foo(i32 %cond1, i32 %cond2) {
13; CHECK-LABEL: @foo(
14; CHECK-NEXT:  entry:
15; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq i32 [[COND1:%.*]], 0
16; CHECK-NEXT:    br i1 [[TOBOOL]], label [[BB_COND2_THREAD:%.*]], label [[BB_COND2:%.*]]
17; CHECK:       bb.cond2:
18; CHECK-NEXT:    call void @f1()
19; CHECK-NEXT:    [[TOBOOL1:%.*]] = icmp eq i32 [[COND2:%.*]], 0
20; CHECK-NEXT:    br i1 [[TOBOOL1]], label [[BB_F4:%.*]], label [[BB_F2:%.*]]
21; CHECK:       bb.cond2.thread:
22; CHECK-NEXT:    [[TOBOOL12:%.*]] = icmp eq i32 [[COND2]], 0
23; CHECK-NEXT:    br i1 [[TOBOOL12]], label [[BB_F3:%.*]], label [[BB_F2]]
24; CHECK:       bb.f2:
25; CHECK-NEXT:    call void @f2()
26; CHECK-NEXT:    br label [[EXIT:%.*]]
27; CHECK:       bb.f3:
28; CHECK-NEXT:    call void @f3()
29; CHECK-NEXT:    br label [[EXIT]]
30; CHECK:       bb.f4:
31; CHECK-NEXT:    [[PTR3:%.*]] = phi ptr [ null, [[BB_COND2]] ]
32; CHECK-NEXT:    call void @f4()
33; CHECK-NEXT:    br label [[EXIT]]
34; CHECK:       exit:
35; CHECK-NEXT:    ret void
36;
37entry:
38  %tobool = icmp eq i32 %cond1, 0
39  br i1 %tobool, label %bb.cond2, label %bb.f1
40
41bb.f1:
42  call void @f1()
43  br label %bb.cond2
44
45bb.cond2:
46  %ptr = phi ptr [ null, %bb.f1 ], [ @a, %entry ]
47  %tobool1 = icmp eq i32 %cond2, 0
48  br i1 %tobool1, label %bb.file, label %bb.f2
49
50bb.f2:
51  call void @f2()
52  br label %exit
53
54bb.file:
55  %cmp = icmp eq ptr %ptr, null
56  br i1 %cmp, label %bb.f4, label %bb.f3
57
58bb.f3:
59  call void @f3()
60  br label %exit
61
62bb.f4:
63  call void @f4()
64  br label %exit
65
66exit:
67  ret void
68}
69
70declare void @f1()
71declare void @f2()
72declare void @f3()
73declare void @f4()
74
75
76; Verify that we branch (twice) on cond2 without checking tobool again.
77; Verify that we eliminate "bb.cond1again".
78
79define void @foo2(i32 %cond1, i32 %cond2) {
80; CHECK-LABEL: @foo2(
81; CHECK-NEXT:  entry:
82; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp ne i32 [[COND1:%.*]], 0
83; CHECK-NEXT:    br i1 [[TOBOOL]], label [[BB_COND2:%.*]], label [[BB_COND2_THREAD:%.*]]
84; CHECK:       bb.cond2:
85; CHECK-NEXT:    call void @f1()
86; CHECK-NEXT:    [[TOBOOL1:%.*]] = icmp eq i32 [[COND2:%.*]], 0
87; CHECK-NEXT:    br i1 [[TOBOOL1]], label [[EXIT:%.*]], label [[BB_F3:%.*]]
88; CHECK:       bb.cond2.thread:
89; CHECK-NEXT:    call void @f2()
90; CHECK-NEXT:    [[TOBOOL11:%.*]] = icmp eq i32 [[COND2]], 0
91; CHECK-NEXT:    br i1 [[TOBOOL11]], label [[EXIT]], label [[BB_F4:%.*]]
92; CHECK:       bb.f3:
93; CHECK-NEXT:    call void @f3()
94; CHECK-NEXT:    br label [[EXIT]]
95; CHECK:       bb.f4:
96; CHECK-NEXT:    call void @f4()
97; CHECK-NEXT:    br label [[EXIT]]
98; CHECK:       exit:
99; CHECK-NEXT:    ret void
100;
101entry:
102  %tobool = icmp ne i32 %cond1, 0
103  br i1 %tobool, label %bb.f1, label %bb.f2
104
105bb.f1:
106  call void @f1()
107  br label %bb.cond2
108
109bb.f2:
110  call void @f2()
111  br label %bb.cond2
112
113bb.cond2:
114  %tobool1 = icmp eq i32 %cond2, 0
115  br i1 %tobool1, label %exit, label %bb.cond1again
116
117bb.cond1again:
118  br i1 %tobool, label %bb.f3, label %bb.f4
119
120bb.f3:
121  call void @f3()
122  br label %exit
123
124bb.f4:
125  call void @f4()
126  br label %exit
127
128exit:
129  ret void
130}
131
132
133; Verify that we thread the edge correctly.  We used to evaluate constant
134; expressions like:
135;
136;   icmp ugt ptr null, inttoptr (i64 4 to ptr)
137;
138; as "true", causing jump threading to a wrong destination.
139
140define void @icmp_ult_null_constexpr(ptr %arg1, ptr %arg2) {
141; CHECK-LABEL: @icmp_ult_null_constexpr(
142; CHECK-NEXT:  entry:
143; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq ptr [[ARG1:%.*]], null
144; CHECK-NEXT:    br i1 [[CMP1]], label [[BB_END_THREAD:%.*]], label [[BB_END:%.*]]
145; CHECK:       bb_end:
146; CHECK-NEXT:    [[CMP2:%.*]] = icmp ne ptr [[ARG2:%.*]], null
147; CHECK-NEXT:    br i1 [[CMP2]], label [[BB_CONT:%.*]], label [[BB_BAR2:%.*]]
148; CHECK:       bb_end.thread:
149; CHECK-NEXT:    call void @bar(i32 1)
150; CHECK-NEXT:    [[CMP21:%.*]] = icmp ne ptr [[ARG2]], null
151; CHECK-NEXT:    br i1 [[CMP21]], label [[BB_EXIT:%.*]], label [[BB_BAR2]]
152; CHECK:       bb_bar2:
153; CHECK-NEXT:    call void @bar(i32 2)
154; CHECK-NEXT:    br label [[BB_EXIT]]
155; CHECK:       bb_cont:
156; CHECK-NEXT:    [[CMP3:%.*]] = icmp ult ptr [[ARG1]], inttoptr (i64 4 to ptr)
157; CHECK-NEXT:    br i1 [[CMP3]], label [[BB_EXIT]], label [[BB_BAR3:%.*]]
158; CHECK:       bb_bar3:
159; CHECK-NEXT:    call void @bar(i32 3)
160; CHECK-NEXT:    br label [[BB_EXIT]]
161; CHECK:       bb_exit:
162; CHECK-NEXT:    ret void
163;
164entry:
165  %cmp1 = icmp eq ptr %arg1, null
166  br i1 %cmp1, label %bb_bar1, label %bb_end
167
168bb_bar1:
169  call void @bar(i32 1)
170  br label %bb_end
171
172bb_end:
173  %cmp2 = icmp ne ptr %arg2, null
174  br i1 %cmp2, label %bb_cont, label %bb_bar2
175
176bb_bar2:
177  call void @bar(i32 2)
178  br label %bb_exit
179
180bb_cont:
181  %cmp3 = icmp ult ptr %arg1, inttoptr (i64 4 to ptr)
182  br i1 %cmp3, label %bb_exit, label %bb_bar3
183
184bb_bar3:
185  call void @bar(i32 3)
186  br label %bb_exit
187
188bb_exit:
189  ret void
190}
191
192; This is a special-case of the above pattern:
193; Null is guaranteed to be unsigned <= all values.
194
195define void @icmp_ule_null_constexpr(ptr %arg1, ptr %arg2) {
196; CHECK-LABEL: @icmp_ule_null_constexpr(
197; CHECK-NEXT:  entry:
198; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq ptr [[ARG1:%.*]], null
199; CHECK-NEXT:    br i1 [[CMP1]], label [[BB_END_THREAD:%.*]], label [[BB_END:%.*]]
200; CHECK:       bb_end:
201; CHECK-NEXT:    [[CMP2:%.*]] = icmp ne ptr [[ARG2:%.*]], null
202; CHECK-NEXT:    br i1 [[CMP2]], label [[BB_CONT:%.*]], label [[BB_BAR2:%.*]]
203; CHECK:       bb_end.thread:
204; CHECK-NEXT:    call void @bar(i32 1)
205; CHECK-NEXT:    [[CMP21:%.*]] = icmp ne ptr [[ARG2]], null
206; CHECK-NEXT:    br i1 [[CMP21]], label [[BB_EXIT:%.*]], label [[BB_BAR2]]
207; CHECK:       bb_bar2:
208; CHECK-NEXT:    call void @bar(i32 2)
209; CHECK-NEXT:    br label [[BB_EXIT]]
210; CHECK:       bb_cont:
211; CHECK-NEXT:    [[CMP3:%.*]] = icmp ule ptr [[ARG1]], inttoptr (i64 4 to ptr)
212; CHECK-NEXT:    br i1 [[CMP3]], label [[BB_EXIT]], label [[BB_BAR3:%.*]]
213; CHECK:       bb_bar3:
214; CHECK-NEXT:    call void @bar(i32 3)
215; CHECK-NEXT:    br label [[BB_EXIT]]
216; CHECK:       bb_exit:
217; CHECK-NEXT:    ret void
218;
219entry:
220  %cmp1 = icmp eq ptr %arg1, null
221  br i1 %cmp1, label %bb_bar1, label %bb_end
222
223bb_bar1:
224  call void @bar(i32 1)
225  br label %bb_end
226
227bb_end:
228  %cmp2 = icmp ne ptr %arg2, null
229  br i1 %cmp2, label %bb_cont, label %bb_bar2
230
231bb_bar2:
232  call void @bar(i32 2)
233  br label %bb_exit
234
235bb_cont:
236  %cmp3 = icmp ule ptr %arg1, inttoptr (i64 4 to ptr)
237  br i1 %cmp3, label %bb_exit, label %bb_bar3
238
239bb_bar3:
240  call void @bar(i32 3)
241  br label %bb_exit
242
243bb_exit:
244  ret void
245}
246
247declare void @bar(i32)
248
249
250;; Test that we skip unconditional PredBB when threading jumps through two
251;; successive basic blocks.
252
253define i32 @foo4(ptr %0) {
254; CHECK-LABEL: @foo4(
255; CHECK-NEXT:  entry:
256; CHECK-NEXT:    [[SIZE:%.*]] = call i64 @get_size(ptr [[TMP0:%.*]])
257; CHECK-NEXT:    [[GOOD:%.*]] = icmp ugt i64 [[SIZE]], 3
258; CHECK-NEXT:    br i1 [[GOOD]], label [[PRED_BB:%.*]], label [[PRED_PRED_BB:%.*]]
259; CHECK:       pred.pred.bb:
260; CHECK-NEXT:    call void @effect()
261; CHECK-NEXT:    br label [[PRED_BB]]
262; CHECK:       pred.bb:
263; CHECK-NEXT:    [[V:%.*]] = load i32, ptr [[TMP0]], align 4
264; CHECK-NEXT:    br label [[BB:%.*]]
265; CHECK:       bb:
266; CHECK-NEXT:    call void @effect1(ptr blockaddress(@foo4, [[BB]]))
267; CHECK-NEXT:    br i1 [[GOOD]], label [[EXIT:%.*]], label [[EXIT]]
268; CHECK:       exit:
269; CHECK-NEXT:    ret i32 [[V]]
270;
271entry:
272  %size = call i64 @get_size(ptr %0)
273  %good = icmp ugt i64 %size, 3
274  br i1 %good, label %pred.bb, label %pred.pred.bb
275
276pred.pred.bb:                                        ; preds = %entry
277  call void @effect()
278  br label %pred.bb
279pred.bb:                                             ; preds = %pred.pred.bb, %entry
280  %v = load i32, ptr %0
281  br label %bb
282
283bb:                                                  ; preds = %pred.bb
284  call void @effect1(ptr blockaddress(@foo4, %bb))
285  br i1 %good, label %cont2, label %cont1
286
287cont1:                                               ; preds = %bb
288  br i1 %good, label %exit, label %cont2
289cont2:                                               ; preds = %bb
290  br label %exit
291exit:                                                ; preds = %cont1, %cont2
292  ret i32 %v
293}
294
295declare i64 @get_size(ptr)
296declare void @effect()
297declare void @effect1(ptr)
298