1; RUN: opt -S -early-cse < %s | FileCheck %s
2; RUN: opt < %s -S -basicaa -early-cse-memssa | FileCheck %s
3
4declare void @llvm.experimental.guard(i1,...)
5
6define i32 @test0(i32* %ptr, i1 %cond) {
7; We can do store to load forwarding over a guard, since it does not
8; clobber memory
9
10; CHECK-LABEL: @test0(
11; CHECK-NEXT:  store i32 40, i32* %ptr
12; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond) [ "deopt"() ]
13; CHECK-NEXT:  ret i32 40
14
15  store i32 40, i32* %ptr
16  call void(i1,...) @llvm.experimental.guard(i1 %cond) [ "deopt"() ]
17  %rval = load i32, i32* %ptr
18  ret i32 %rval
19}
20
21define i32 @test1(i32* %val, i1 %cond) {
22; We can CSE loads over a guard, since it does not clobber memory
23
24; CHECK-LABEL: @test1(
25; CHECK-NEXT:  %val0 = load i32, i32* %val
26; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond) [ "deopt"() ]
27; CHECK-NEXT:  ret i32 0
28
29  %val0 = load i32, i32* %val
30  call void(i1,...) @llvm.experimental.guard(i1 %cond) [ "deopt"() ]
31  %val1 = load i32, i32* %val
32  %rval = sub i32 %val0, %val1
33  ret i32 %rval
34}
35
36define i32 @test2() {
37; Guards on "true" get removed
38
39; CHECK-LABEL: @test2(
40; CHECK-NEXT: ret i32 0
41  call void(i1, ...) @llvm.experimental.guard(i1 true) [ "deopt"() ]
42  ret i32 0
43}
44
45define i32 @test3(i32 %val) {
46; After a guard has executed the condition it was guarding is known to
47; be true.
48
49; CHECK-LABEL: @test3(
50; CHECK-NEXT:  %cond0 = icmp slt i32 %val, 40
51; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond0) [ "deopt"() ]
52; CHECK-NEXT:  ret i32 -1
53
54  %cond0 = icmp slt i32 %val, 40
55  call void(i1,...) @llvm.experimental.guard(i1 %cond0) [ "deopt"() ]
56  %cond1 = icmp slt i32 %val, 40
57  call void(i1,...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
58
59  %cond2 = icmp slt i32 %val, 40
60  %rval = sext i1 %cond2 to i32
61  ret i32 %rval
62}
63
64define i32 @test3.unhandled(i32 %val) {
65; After a guard has executed the condition it was guarding is known to
66; be true.
67
68; CHECK-LABEL: @test3.unhandled(
69; CHECK-NEXT:  %cond0 = icmp slt i32 %val, 40
70; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond0) [ "deopt"() ]
71; CHECK-NEXT:  %cond1 = icmp sge i32 %val, 40
72; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
73; CHECK-NEXT:  ret i32 0
74
75; Demonstrates a case we do not yet handle (it is legal to fold %cond2
76; to false)
77  %cond0 = icmp slt i32 %val, 40
78  call void(i1,...) @llvm.experimental.guard(i1 %cond0) [ "deopt"() ]
79  %cond1 = icmp sge i32 %val, 40
80  call void(i1,...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
81  ret i32 0
82}
83
84define i32 @test4(i32 %val, i1 %c) {
85; Same as test3, but with some control flow involved.
86
87; CHECK-LABEL: @test4(
88; CHECK: entry:
89; CHECK-NEXT:  %cond0 = icmp slt i32 %val, 40
90; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond0
91; CHECK-NEXT:  br label %bb0
92
93; CHECK:     bb0:
94; CHECK-NEXT:  %cond2 = icmp ult i32 %val, 200
95; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond2
96; CHECK-NEXT:  br i1 %c, label %left, label %right
97
98; CHECK:     left:
99; CHECK-NEXT:  ret i32 0
100
101; CHECK:     right:
102; CHECK-NEXT:  ret i32 20
103
104entry:
105  %cond0 = icmp slt i32 %val, 40
106  call void(i1,...) @llvm.experimental.guard(i1 %cond0) [ "deopt"() ]
107  %cond1 = icmp slt i32 %val, 40
108  call void(i1,...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
109  br label %bb0
110
111bb0:
112  %cond2 = icmp ult i32 %val, 200
113  call void(i1,...) @llvm.experimental.guard(i1 %cond2) [ "deopt"() ]
114  br i1 %c, label %left, label %right
115
116left:
117  %cond3 = icmp ult i32 %val, 200
118  call void(i1,...) @llvm.experimental.guard(i1 %cond3) [ "deopt"() ]
119  ret i32 0
120
121right:
122 ret i32 20
123}
124
125define i32 @test5(i32 %val, i1 %c) {
126; Same as test4, but the %left block has mutliple predecessors.
127
128; CHECK-LABEL: @test5(
129
130; CHECK: entry:
131; CHECK-NEXT:  %cond0 = icmp slt i32 %val, 40
132; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond0
133; CHECK-NEXT:  br label %bb0
134
135; CHECK: bb0:
136; CHECK-NEXT:  %cond2 = icmp ult i32 %val, 200
137; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %cond2
138; CHECK-NEXT:  br i1 %c, label %left, label %right
139
140; CHECK: left:
141; CHECK-NEXT:  br label %right
142
143; CHECK: right:
144; CHECK-NEXT:  br label %left
145
146entry:
147  %cond0 = icmp slt i32 %val, 40
148  call void(i1,...) @llvm.experimental.guard(i1 %cond0) [ "deopt"() ]
149  %cond1 = icmp slt i32 %val, 40
150  call void(i1,...) @llvm.experimental.guard(i1 %cond1) [ "deopt"() ]
151  br label %bb0
152
153bb0:
154  %cond2 = icmp ult i32 %val, 200
155  call void(i1,...) @llvm.experimental.guard(i1 %cond2) [ "deopt"() ]
156  br i1 %c, label %left, label %right
157
158left:
159  %cond3 = icmp ult i32 %val, 200
160  call void(i1,...) @llvm.experimental.guard(i1 %cond3) [ "deopt"() ]
161  br label %right
162
163right:
164  br label %left
165}
166
167define void @test6(i1 %c, i32* %ptr) {
168; Check that we do not DSE over calls to @llvm.experimental.guard.
169; Guard intrinsics do _read_ memory, so th call to guard below needs
170; to see the store of 500 to %ptr
171
172; CHECK-LABEL: @test6(
173; CHECK-NEXT:  store i32 500, i32* %ptr
174; CHECK-NEXT:  call void (i1, ...) @llvm.experimental.guard(i1 %c) [ "deopt"() ]
175; CHECK-NEXT:  store i32 600, i32* %ptr
176
177
178  store i32 500, i32* %ptr
179  call void(i1,...) @llvm.experimental.guard(i1 %c) [ "deopt"() ]
180  store i32 600, i32* %ptr
181  ret void
182}
183