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1; RUN: opt < %s -basicaa -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; CHECK-NEXT: call void @llvm.lifetime.end
84  call void @llvm.lifetime.end.p0i8(i64 10, i8* %P)
85  ret void
86; CHECK-NEXT: ret void
87}
88
89@G1 = external global i32
90@G2 = external global [4000 x i32]
91
92define i32 @test4(i8* %P) {
93  %tmp = load i32, i32* @G1
94  call void @llvm.memset.p0i8.i32(i8* bitcast ([4000 x i32]* @G2 to i8*), i8 0, i32 4000, i1 false)
95  %tmp2 = load i32, i32* @G1
96  %sub = sub i32 %tmp2, %tmp
97  ret i32 %sub
98; CHECK-LABEL: @test4
99; CHECK-NOT: load
100; CHECK: memset.p0i8.i32
101; CHECK-NOT: load
102; CHECK: ret i32 0
103}
104
105; Verify that basicaa is handling variable length memcpy, knowing it doesn't
106; write to G1.
107define i32 @test5(i8* %P, i32 %Len) {
108  %tmp = load i32, i32* @G1
109  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)
110  %tmp2 = load i32, i32* @G1
111  %sub = sub i32 %tmp2, %tmp
112  ret i32 %sub
113; CHECK: @test5
114; CHECK-NOT: load
115; CHECK: memcpy.p0i8.p0i8.i32
116; CHECK-NOT: load
117; CHECK: ret i32 0
118}
119
120define i8 @test6(i8* %p, i8* noalias %a) {
121  %x = load i8, i8* %a
122  %t = va_arg i8* %p, float
123  %y = load i8, i8* %a
124  %z = add i8 %x, %y
125  ret i8 %z
126; CHECK-LABEL: @test6
127; CHECK: load i8, i8* %a
128; CHECK-NOT: load
129; CHECK: ret
130}
131
132; PR10628
133declare void @test7decl(i32* nocapture %x)
134define i32 @test7() nounwind uwtable ssp {
135entry:
136  %x = alloca i32, align 4
137  store i32 0, i32* %x, align 4
138  %add.ptr = getelementptr inbounds i32, i32* %x, i64 1
139  call void @test7decl(i32* %add.ptr)
140  %tmp = load i32, i32* %x, align 4
141  ret i32 %tmp
142; CHECK-LABEL: @test7(
143; CHECK: store i32 0
144; CHECK: call void @test7decl
145; CHECK: load i32, i32*
146}
147
148;; Check that aa correctly handles functions marked with argmemonly
149;; attribute.
150declare i32 @func_argmemonly(i32 * %P) argmemonly
151
152;; Can not remove redundant load, function may write to it.
153; CHECK-LABEL: @test8(
154define i32 @test8(i32 *%P) {
155  %V1 = load i32, i32* %P
156  call i32 @func_argmemonly(i32* %P)
157  %V2 = load i32, i32* %P
158  %Diff = sub i32 %V1, %V2
159  ret i32 %Diff
160  ; CHECK: load
161  ; CHECK: load
162  ; CHECK: sub
163  ; CHECK: ret i32 %Diff
164}
165
166;; In this case load can be removed, function clobbers only %P2.
167; CHECK-LABEL: @test9(
168define i32 @test9(i32* %P, i32* noalias %P2) {
169  %V1 = load i32, i32* %P
170  call i32 @func_argmemonly(i32* %P2)
171  %V2 = load i32, i32* %P
172  %Diff = sub i32 %V1, %V2
173  ret i32 %Diff
174  ; CHECK-NOT: load
175  ; CHECK: ret i32 0
176}
177
178;; In this case load can *not* be removed. Function clobers only %P2 but it may
179;; alias with %P.
180; CHECK-LABEL: @test10(
181define i32 @test10(i32* %P, i32* %P2) {
182  %V1 = load i32, i32* %P
183  call i32 @func_argmemonly(i32* %P2)
184  %V2 = load i32, i32* %P
185  %Diff = sub i32 %V1, %V2
186  ret i32 %Diff
187  ; CHECK: load
188  ; CHECK: load
189  ; CHECK: sub
190  ; CHECK: ret i32 %Diff
191}
192
193; CHECK-LABEL: @test11(
194define i32 @test11(i32* %P, i32* %P2) {
195  %V1 = load i32, i32* %P
196  call i32 @func_argmemonly(i32* readonly %P2)
197  %V2 = load i32, i32* %P
198  %Diff = sub i32 %V1, %V2
199  ret i32 %Diff
200  ; CHECK-NOT: load
201  ; CHECK: ret i32 0
202}
203
204declare i32 @func_argmemonly_two_args(i32* %P, i32* %P2) argmemonly
205
206; CHECK-LABEL: @test12(
207define i32 @test12(i32* %P, i32* %P2, i32* %P3) {
208  %V1 = load i32, i32* %P
209  call i32 @func_argmemonly_two_args(i32* readonly %P2, i32* %P3)
210  %V2 = load i32, i32* %P
211  %Diff = sub i32 %V1, %V2
212  ret i32 %Diff
213  ; CHECK: load
214  ; CHECK: load
215  ; CHECK: sub
216  ; CHECK: ret i32 %Diff
217}
218
219; CHECK-LABEL: @test13(
220define i32 @test13(i32* %P, i32* %P2) {
221  %V1 = load i32, i32* %P
222  call i32 @func_argmemonly(i32* readnone %P2)
223  %V2 = load i32, i32* %P
224  %Diff = sub i32 %V1, %V2
225  ret i32 %Diff
226  ; CHECK-NOT: load
227  ; CHECK: ret i32 0
228}
229
230declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i1) nounwind
231declare void @llvm.memset.p0i8.i8(i8* nocapture, i8, i8, i1) nounwind
232declare void @llvm.memcpy.p0i8.p0i8.i8(i8* nocapture, i8* nocapture, i8, i1) nounwind
233declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i1) nounwind
234