1; RUN: opt -S -jump-threading < %s | FileCheck %s
2
3declare void @foo()
4declare void @bar()
5declare void @baz()
6declare void @quux()
7
8
9; Jump threading of branch with select as condition.
10; Mostly theoretical since instruction combining simplifies all selects of
11; booleans where at least one operand is true/false/undef.
12
13; CHECK-LABEL: @test_br(
14; CHECK-NEXT: entry:
15; CHECK-NEXT: br i1 %cond, label %L1,
16define void @test_br(i1 %cond, i1 %value) nounwind {
17entry:
18  br i1 %cond, label %L0, label %L3
19L0:
20  %expr = select i1 %cond, i1 true, i1 %value
21  br i1 %expr, label %L1, label %L2
22
23L1:
24  call void @foo()
25  ret void
26L2:
27  call void @bar()
28  ret void
29L3:
30  call void @baz()
31  br label %L0
32}
33
34
35; Jump threading of switch with select as condition.
36
37; CHECK-LABEL: @test_switch(
38; CHECK-NEXT: entry:
39; CHECK-NEXT: br i1 %cond, label %L1,
40define void @test_switch(i1 %cond, i8 %value) nounwind {
41entry:
42  br i1 %cond, label %L0, label %L4
43L0:
44  %expr = select i1 %cond, i8 1, i8 %value
45  switch i8 %expr, label %L3 [i8 1, label %L1 i8 2, label %L2]
46
47L1:
48  call void @foo()
49  ret void
50L2:
51  call void @bar()
52  ret void
53L3:
54  call void @baz()
55  ret void
56L4:
57  call void @quux()
58  br label %L0
59}
60
61; Make sure the blocks in the indirectbr test aren't trivially removable as
62; successors by taking their addresses.
63@anchor = constant [3 x i8*] [
64  i8* blockaddress(@test_indirectbr, %L1),
65  i8* blockaddress(@test_indirectbr, %L2),
66  i8* blockaddress(@test_indirectbr, %L3)
67]
68
69
70; Jump threading of indirectbr with select as address.
71
72; CHECK-LABEL: @test_indirectbr(
73; CHECK-NEXT: entry:
74; CHECK-NEXT: br i1 %cond, label %L1, label %L3
75define void @test_indirectbr(i1 %cond, i8* %address) nounwind {
76entry:
77  br i1 %cond, label %L0, label %L3
78L0:
79  %indirect.goto.dest = select i1 %cond, i8* blockaddress(@test_indirectbr, %L1), i8* %address
80  indirectbr i8* %indirect.goto.dest, [label %L1, label %L2, label %L3]
81
82L1:
83  call void @foo()
84  ret void
85L2:
86  call void @bar()
87  ret void
88L3:
89  call void @baz()
90  ret void
91}
92
93
94; A more complicated case: the condition is a select based on a comparison.
95
96; CHECK-LABEL: @test_switch_cmp(
97; CHECK-NEXT: entry:
98; CHECK-NEXT: br i1 %cond, label %L0, label %[[THREADED:[A-Za-z.0-9]+]]
99; CHECK: [[THREADED]]:
100; CHECK-NEXT: call void @quux
101; CHECK-NEXT: br label %L1
102define void @test_switch_cmp(i1 %cond, i32 %val, i8 %value) nounwind {
103entry:
104  br i1 %cond, label %L0, label %L4
105L0:
106  %val.phi = phi i32 [%val, %entry], [-1, %L4]
107  %cmp = icmp slt i32 %val.phi, 0
108  %expr = select i1 %cmp, i8 1, i8 %value
109  switch i8 %expr, label %L3 [i8 1, label %L1 i8 2, label %L2]
110
111L1:
112  call void @foo()
113  ret void
114L2:
115  call void @bar()
116  ret void
117L3:
118  call void @baz()
119  ret void
120L4:
121  call void @quux()
122  br label %L0
123}
124
125; Make sure the edge value of %0 from entry to L2 includes 0 and L3 is
126; reachable.
127; CHECK: test_switch_default
128; CHECK: entry:
129; CHECK: load
130; CHECK: icmp
131; CHECK: [[THREADED:[A-Za-z.0-9]+]]:
132; CHECK: store
133; CHECK: br
134; CHECK: L2:
135; CHECK: icmp
136define void @test_switch_default(i32* nocapture %status) nounwind {
137entry:
138  %0 = load i32, i32* %status, align 4
139  switch i32 %0, label %L2 [
140    i32 5061, label %L1
141    i32 0, label %L2
142  ]
143
144L1:
145  store i32 10025, i32* %status, align 4
146  br label %L2
147
148L2:
149  %1 = load i32, i32* %status, align 4
150  %cmp57.i = icmp eq i32 %1, 0
151  br i1 %cmp57.i, label %L3, label %L4
152
153L3:
154  store i32 10000, i32* %status, align 4
155  br label %L4
156
157L4:
158  ret void
159}
160
161define void @unfold1(double %x, double %y) nounwind {
162entry:
163  %sub = fsub double %x, %y
164  %cmp = fcmp ogt double %sub, 1.000000e+01
165  br i1 %cmp, label %cond.end4, label %cond.false
166
167cond.false:                                       ; preds = %entry
168  %add = fadd double %x, %y
169  %cmp1 = fcmp ogt double %add, 1.000000e+01
170  %add. = select i1 %cmp1, double %add, double 0.000000e+00
171  br label %cond.end4
172
173cond.end4:                                        ; preds = %entry, %cond.false
174  %cond5 = phi double [ %add., %cond.false ], [ %sub, %entry ]
175  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
176  br i1 %cmp6, label %if.then, label %if.end
177
178if.then:                                          ; preds = %cond.end4
179  call void @foo()
180  br label %if.end
181
182if.end:                                           ; preds = %if.then, %cond.end4
183  ret void
184
185; CHECK-LABEL: @unfold1
186; CHECK: br i1 %cmp, label %cond.end4, label %cond.false
187; CHECK: br i1 %cmp1, label %cond.end4, label %if.then
188; CHECK: br i1 %cmp6, label %if.then, label %if.end
189; CHECK: br label %if.end
190}
191
192
193define void @unfold2(i32 %x, i32 %y) nounwind {
194entry:
195  %sub = sub nsw i32 %x, %y
196  %cmp = icmp sgt i32 %sub, 10
197  br i1 %cmp, label %cond.end4, label %cond.false
198
199cond.false:                                       ; preds = %entry
200  %add = add nsw i32 %x, %y
201  %cmp1 = icmp sgt i32 %add, 10
202  %add. = select i1 %cmp1, i32 0, i32 %add
203  br label %cond.end4
204
205cond.end4:                                        ; preds = %entry, %cond.false
206  %cond5 = phi i32 [ %add., %cond.false ], [ %sub, %entry ]
207  %cmp6 = icmp eq i32 %cond5, 0
208  br i1 %cmp6, label %if.then, label %if.end
209
210if.then:                                          ; preds = %cond.end4
211  call void @foo()
212  br label %if.end
213
214if.end:                                           ; preds = %if.then, %cond.end4
215  ret void
216
217; CHECK-LABEL: @unfold2
218; CHECK: br i1 %cmp, label %if.end, label %cond.false
219; CHECK: br i1 %cmp1, label %if.then, label %cond.end4
220; CHECK: br i1 %cmp6, label %if.then, label %if.end
221; CHECK: br label %if.end
222}
223