1; RUN: opt < %s -basic-aa -gvn -dse -S | FileCheck %s
2target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
3
4declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture)
5
6declare void @external(i32*)
7
8define i32 @test0(i8* %P) {
9  %A = alloca i32
10  call void @external(i32* %A)
11
12  store i32 0, i32* %A
13
14  call void @llvm.memset.p0i8.i32(i8* %P, i8 0, i32 42, i1 false)
15
16  %B = load i32, i32* %A
17  ret i32 %B
18
19; CHECK-LABEL: @test0
20; CHECK: ret i32 0
21}
22
23define i8 @test1() {
24; CHECK-LABEL: @test1
25  %A = alloca i8
26  %B = alloca i8
27
28  store i8 2, i8* %B  ;; Not written to by memcpy
29
30  call void @llvm.memcpy.p0i8.p0i8.i8(i8* %A, i8* %B, i8 -1, i1 false)
31
32  %C = load i8, i8* %B
33  ret i8 %C
34; CHECK: ret i8 2
35}
36
37define i8 @test2(i8* %P) {
38; CHECK-LABEL: @test2
39  %P2 = getelementptr i8, i8* %P, i32 127
40  store i8 1, i8* %P2  ;; Not dead across memset
41  call void @llvm.memset.p0i8.i8(i8* %P, i8 2, i8 127, i1 false)
42  %A = load i8, i8* %P2
43  ret i8 %A
44; CHECK: ret i8 1
45}
46
47define i8 @test2a(i8* %P) {
48; CHECK-LABEL: @test2
49  %P2 = getelementptr i8, i8* %P, i32 126
50
51  ;; FIXME: DSE isn't zapping this dead store.
52  store i8 1, i8* %P2  ;; Dead, clobbered by memset.
53
54  call void @llvm.memset.p0i8.i8(i8* %P, i8 2, i8 127, i1 false)
55  %A = load i8, i8* %P2
56  ret i8 %A
57; CHECK-NOT: load
58; CHECK: ret i8 2
59}
60
61define void @test3(i8* %P, i8 %X) {
62; CHECK-LABEL: @test3
63; CHECK-NOT: store
64; CHECK-NOT: %Y
65  %Y = add i8 %X, 1     ;; Dead, because the only use (the store) is dead.
66
67  %P2 = getelementptr i8, i8* %P, i32 2
68  store i8 %Y, i8* %P2  ;; Not read by lifetime.end, should be removed.
69; CHECK: store i8 2, i8* %P2
70  call void @llvm.lifetime.end.p0i8(i64 1, i8* %P)
71  store i8 2, i8* %P2
72; CHECK-NOT: store
73  ret void
74; CHECK: ret void
75}
76
77define void @test3a(i8* %P, i8 %X) {
78; CHECK-LABEL: @test3a
79  %Y = add i8 %X, 1     ;; Dead, because the only use (the store) is dead.
80
81  %P2 = getelementptr i8, i8* %P, i32 2
82  store i8 %Y, i8* %P2
83  call void @llvm.lifetime.end.p0i8(i64 10, i8* %P)
84  ret void
85; CHECK-NEXT: ret void
86}
87
88@G1 = external global i32
89@G2 = external global [4000 x i32]
90
91define i32 @test4(i8* %P) {
92  %tmp = load i32, i32* @G1
93  call void @llvm.memset.p0i8.i32(i8* bitcast ([4000 x i32]* @G2 to i8*), i8 0, i32 4000, i1 false)
94  %tmp2 = load i32, i32* @G1
95  %sub = sub i32 %tmp2, %tmp
96  ret i32 %sub
97; CHECK-LABEL: @test4
98; CHECK-NOT: load
99; CHECK: memset.p0i8.i32
100; CHECK-NOT: load
101; CHECK: ret i32 0
102}
103
104; Verify that basicaa is handling variable length memcpy, knowing it doesn't
105; write to G1.
106define i32 @test5(i8* %P, i32 %Len) {
107  %tmp = load i32, i32* @G1
108  call void @llvm.memcpy.p0i8.p0i8.i32(i8* bitcast ([4000 x i32]* @G2 to i8*), i8* bitcast (i32* @G1 to i8*), i32 %Len, i1 false)
109  %tmp2 = load i32, i32* @G1
110  %sub = sub i32 %tmp2, %tmp
111  ret i32 %sub
112; CHECK: @test5
113; CHECK-NOT: load
114; CHECK: memcpy.p0i8.p0i8.i32
115; CHECK-NOT: load
116; CHECK: ret i32 0
117}
118
119define i8 @test6(i8* %p, i8* noalias %a) {
120  %x = load i8, i8* %a
121  %t = va_arg i8* %p, float
122  %y = load i8, i8* %a
123  %z = add i8 %x, %y
124  ret i8 %z
125; CHECK-LABEL: @test6
126; CHECK: load i8, i8* %a
127; CHECK-NOT: load
128; CHECK: ret
129}
130
131; PR10628
132declare void @test7decl(i32* nocapture %x)
133define i32 @test7() nounwind uwtable ssp {
134entry:
135  %x = alloca i32, align 4
136  store i32 0, i32* %x, align 4
137  %add.ptr = getelementptr inbounds i32, i32* %x, i64 1
138  call void @test7decl(i32* %add.ptr)
139  %tmp = load i32, i32* %x, align 4
140  ret i32 %tmp
141; CHECK-LABEL: @test7(
142; CHECK: store i32 0
143; CHECK: call void @test7decl
144; CHECK: load i32, i32*
145}
146
147;; Check that aa correctly handles functions marked with argmemonly
148;; attribute.
149declare i32 @func_argmemonly(i32 * %P) argmemonly
150
151;; Can not remove redundant load, function may write to it.
152; CHECK-LABEL: @test8(
153define i32 @test8(i32 *%P) {
154  %V1 = load i32, i32* %P
155  call i32 @func_argmemonly(i32* %P)
156  %V2 = load i32, i32* %P
157  %Diff = sub i32 %V1, %V2
158  ret i32 %Diff
159  ; CHECK: load
160  ; CHECK: load
161  ; CHECK: sub
162  ; CHECK: ret i32 %Diff
163}
164
165;; In this case load can be removed, function clobbers only %P2.
166; CHECK-LABEL: @test9(
167define i32 @test9(i32* %P, i32* noalias %P2) {
168  %V1 = load i32, i32* %P
169  call i32 @func_argmemonly(i32* %P2)
170  %V2 = load i32, i32* %P
171  %Diff = sub i32 %V1, %V2
172  ret i32 %Diff
173  ; CHECK-NOT: load
174  ; CHECK: ret i32 0
175}
176
177;; In this case load can *not* be removed. Function clobers only %P2 but it may
178;; alias with %P.
179; CHECK-LABEL: @test10(
180define i32 @test10(i32* %P, i32* %P2) {
181  %V1 = load i32, i32* %P
182  call i32 @func_argmemonly(i32* %P2)
183  %V2 = load i32, i32* %P
184  %Diff = sub i32 %V1, %V2
185  ret i32 %Diff
186  ; CHECK: load
187  ; CHECK: load
188  ; CHECK: sub
189  ; CHECK: ret i32 %Diff
190}
191
192; CHECK-LABEL: @test11(
193define i32 @test11(i32* %P, i32* %P2) {
194  %V1 = load i32, i32* %P
195  call i32 @func_argmemonly(i32* readonly %P2)
196  %V2 = load i32, i32* %P
197  %Diff = sub i32 %V1, %V2
198  ret i32 %Diff
199  ; CHECK-NOT: load
200  ; CHECK: ret i32 0
201}
202
203declare i32 @func_argmemonly_two_args(i32* %P, i32* %P2) argmemonly
204
205; CHECK-LABEL: @test12(
206define i32 @test12(i32* %P, i32* %P2, i32* %P3) {
207  %V1 = load i32, i32* %P
208  call i32 @func_argmemonly_two_args(i32* readonly %P2, i32* %P3)
209  %V2 = load i32, i32* %P
210  %Diff = sub i32 %V1, %V2
211  ret i32 %Diff
212  ; CHECK: load
213  ; CHECK: load
214  ; CHECK: sub
215  ; CHECK: ret i32 %Diff
216}
217
218; CHECK-LABEL: @test13(
219define i32 @test13(i32* %P, i32* %P2) {
220  %V1 = load i32, i32* %P
221  call i32 @func_argmemonly(i32* readnone %P2)
222  %V2 = load i32, i32* %P
223  %Diff = sub i32 %V1, %V2
224  ret i32 %Diff
225  ; CHECK-NOT: load
226  ; CHECK: ret i32 0
227}
228
229declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i1) nounwind
230declare void @llvm.memset.p0i8.i8(i8* nocapture, i8, i8, i1) nounwind
231declare void @llvm.memcpy.p0i8.p0i8.i8(i8* nocapture, i8* nocapture, i8, i1) nounwind
232declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i1) nounwind
233