1; RUN: opt < %s -basicaa -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.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
5declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
6declare void @llvm.init.trampoline(i8*, i8*, i8*)
7
8define void @test1(i32* %Q, i32* %P) {
9        %DEAD = load i32, i32* %Q
10        store i32 %DEAD, i32* %P
11        store i32 0, i32* %P
12        ret void
13; CHECK-LABEL: @test1(
14; CHECK-NEXT: store i32 0, i32* %P
15; CHECK-NEXT: ret void
16}
17
18; PR8576 - Should delete store of 10 even though p/q are may aliases.
19define void @test2(i32 *%p, i32 *%q) {
20  store i32 10, i32* %p, align 4
21  store i32 20, i32* %q, align 4
22  store i32 30, i32* %p, align 4
23  ret void
24; CHECK-LABEL: @test2(
25; CHECK-NEXT: store i32 20
26}
27
28
29; PR8677
30@g = global i32 1
31
32define i32 @test3(i32* %g_addr) nounwind {
33; CHECK-LABEL: @test3(
34; CHECK: load i32, i32* %g_addr
35  %g_value = load i32, i32* %g_addr, align 4
36  store i32 -1, i32* @g, align 4
37  store i32 %g_value, i32* %g_addr, align 4
38  %tmp3 = load i32, i32* @g, align 4
39  ret i32 %tmp3
40}
41
42
43define void @test4(i32* %Q) {
44        %a = load i32, i32* %Q
45        store volatile i32 %a, i32* %Q
46        ret void
47; CHECK-LABEL: @test4(
48; CHECK-NEXT: load i32
49; CHECK-NEXT: store volatile
50; CHECK-NEXT: ret void
51}
52
53define void @test5(i32* %Q) {
54        %a = load volatile i32, i32* %Q
55        store i32 %a, i32* %Q
56        ret void
57; CHECK-LABEL: @test5(
58; CHECK-NEXT: load volatile
59; CHECK-NEXT: ret void
60}
61
62; Should delete store of 10 even though memset is a may-store to P (P and Q may
63; alias).
64define void @test6(i32 *%p, i8 *%q) {
65  store i32 10, i32* %p, align 4       ;; dead.
66  call void @llvm.memset.p0i8.i64(i8* %q, i8 42, i64 900, i32 1, i1 false)
67  store i32 30, i32* %p, align 4
68  ret void
69; CHECK-LABEL: @test6(
70; CHECK-NEXT: call void @llvm.memset
71}
72
73; Should delete store of 10 even though memcpy is a may-store to P (P and Q may
74; alias).
75define void @test7(i32 *%p, i8 *%q, i8* noalias %r) {
76  store i32 10, i32* %p, align 4       ;; dead.
77  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %q, i8* %r, i64 900, i32 1, i1 false)
78  store i32 30, i32* %p, align 4
79  ret void
80; CHECK-LABEL: @test7(
81; CHECK-NEXT: call void @llvm.memcpy
82}
83
84; Do not delete stores that are only partially killed.
85define i32 @test8() {
86        %V = alloca i32
87        store i32 1234567, i32* %V
88        %V2 = bitcast i32* %V to i8*
89        store i8 0, i8* %V2
90        %X = load i32, i32* %V
91        ret i32 %X
92
93; CHECK-LABEL: @test8(
94; CHECK: store i32 1234567
95}
96
97
98; Test for byval handling.
99%struct.x = type { i32, i32, i32, i32 }
100define void @test9(%struct.x* byval  %a) nounwind  {
101	%tmp2 = getelementptr %struct.x, %struct.x* %a, i32 0, i32 0
102	store i32 1, i32* %tmp2, align 4
103	ret void
104; CHECK-LABEL: @test9(
105; CHECK-NEXT: ret void
106}
107
108; Test for inalloca handling.
109define void @test9_2(%struct.x* inalloca  %a) nounwind  {
110	%tmp2 = getelementptr %struct.x, %struct.x* %a, i32 0, i32 0
111	store i32 1, i32* %tmp2, align 4
112	ret void
113; CHECK-LABEL: @test9_2(
114; CHECK-NEXT: ret void
115}
116
117; va_arg has fuzzy dependence, the store shouldn't be zapped.
118define double @test10(i8* %X) {
119        %X_addr = alloca i8*
120        store i8* %X, i8** %X_addr
121        %tmp.0 = va_arg i8** %X_addr, double
122        ret double %tmp.0
123; CHECK-LABEL: @test10(
124; CHECK: store
125}
126
127
128; DSE should delete the dead trampoline.
129declare void @test11f()
130define void @test11() {
131; CHECK-LABEL: @test11(
132	%storage = alloca [10 x i8], align 16		; <[10 x i8]*> [#uses=1]
133; CHECK-NOT: alloca
134	%cast = getelementptr [10 x i8], [10 x i8]* %storage, i32 0, i32 0		; <i8*> [#uses=1]
135	call void @llvm.init.trampoline( i8* %cast, i8* bitcast (void ()* @test11f to i8*), i8* null )		; <i8*> [#uses=1]
136; CHECK-NOT: trampoline
137	ret void
138; CHECK: ret void
139}
140
141
142; PR2599 - load -> store to same address.
143define void @test12({ i32, i32 }* %x) nounwind  {
144	%tmp4 = getelementptr { i32, i32 }, { i32, i32 }* %x, i32 0, i32 0
145	%tmp5 = load i32, i32* %tmp4, align 4
146	%tmp7 = getelementptr { i32, i32 }, { i32, i32 }* %x, i32 0, i32 1
147	%tmp8 = load i32, i32* %tmp7, align 4
148	%tmp17 = sub i32 0, %tmp8
149	store i32 %tmp5, i32* %tmp4, align 4
150	store i32 %tmp17, i32* %tmp7, align 4
151	ret void
152; CHECK-LABEL: @test12(
153; CHECK-NOT: tmp5
154; CHECK: ret void
155}
156
157
158; %P doesn't escape, the DEAD instructions should be removed.
159declare void @test13f()
160define i32* @test13() {
161        %p = tail call i8* @malloc(i32 4)
162        %P = bitcast i8* %p to i32*
163        %DEAD = load i32, i32* %P
164        %DEAD2 = add i32 %DEAD, 1
165        store i32 %DEAD2, i32* %P
166        call void @test13f( )
167        store i32 0, i32* %P
168        ret i32* %P
169; CHECK: @test13()
170; CHECK-NEXT: malloc
171; CHECK-NEXT: bitcast
172; CHECK-NEXT: call void
173}
174
175define i32 addrspace(1)* @test13_addrspacecast() {
176  %p = tail call i8* @malloc(i32 4)
177  %p.bc = bitcast i8* %p to i32*
178  %P = addrspacecast i32* %p.bc to i32 addrspace(1)*
179  %DEAD = load i32, i32 addrspace(1)* %P
180  %DEAD2 = add i32 %DEAD, 1
181  store i32 %DEAD2, i32 addrspace(1)* %P
182  call void @test13f( )
183  store i32 0, i32 addrspace(1)* %P
184  ret i32 addrspace(1)* %P
185; CHECK: @test13_addrspacecast()
186; CHECK-NEXT: malloc
187; CHECK-NEXT: bitcast
188; CHECK-NEXT: addrspacecast
189; CHECK-NEXT: call void
190}
191
192declare noalias i8* @malloc(i32)
193declare noalias i8* @calloc(i32, i32)
194
195
196define void @test14(i32* %Q) {
197        %P = alloca i32
198        %DEAD = load i32, i32* %Q
199        store i32 %DEAD, i32* %P
200        ret void
201
202; CHECK-LABEL: @test14(
203; CHECK-NEXT: ret void
204}
205
206
207; PR8701
208
209;; Fully dead overwrite of memcpy.
210define void @test15(i8* %P, i8* %Q) nounwind ssp {
211  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
212  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
213  ret void
214; CHECK-LABEL: @test15(
215; CHECK-NEXT: call void @llvm.memcpy
216; CHECK-NEXT: ret
217}
218
219;; Full overwrite of smaller memcpy.
220define void @test16(i8* %P, i8* %Q) nounwind ssp {
221  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 8, i32 1, i1 false)
222  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
223  ret void
224; CHECK-LABEL: @test16(
225; CHECK-NEXT: call void @llvm.memcpy
226; CHECK-NEXT: ret
227}
228
229;; Overwrite of memset by memcpy.
230define void @test17(i8* %P, i8* noalias %Q) nounwind ssp {
231  tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 false)
232  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
233  ret void
234; CHECK-LABEL: @test17(
235; CHECK-NEXT: call void @llvm.memcpy
236; CHECK-NEXT: ret
237}
238
239; Should not delete the volatile memset.
240define void @test17v(i8* %P, i8* %Q) nounwind ssp {
241  tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 true)
242  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
243  ret void
244; CHECK-LABEL: @test17v(
245; CHECK-NEXT: call void @llvm.memset
246; CHECK-NEXT: call void @llvm.memcpy
247; CHECK-NEXT: ret
248}
249
250; PR8728
251; Do not delete instruction where possible situation is:
252; A = B
253; A = A
254define void @test18(i8* %P, i8* %Q, i8* %R) nounwind ssp {
255  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
256  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %R, i64 12, i32 1, i1 false)
257  ret void
258; CHECK-LABEL: @test18(
259; CHECK-NEXT: call void @llvm.memcpy
260; CHECK-NEXT: call void @llvm.memcpy
261; CHECK-NEXT: ret
262}
263
264
265; The store here is not dead because the byval call reads it.
266declare void @test19f({i32}* byval align 4 %P)
267
268define void @test19({i32} * nocapture byval align 4 %arg5) nounwind ssp {
269bb:
270  %tmp7 = getelementptr inbounds {i32}, {i32}* %arg5, i32 0, i32 0
271  store i32 912, i32* %tmp7
272  call void @test19f({i32}* byval align 4 %arg5)
273  ret void
274
275; CHECK-LABEL: @test19(
276; CHECK: store i32 912
277; CHECK: call void @test19f
278}
279
280define void @test20() {
281  %m = call i8* @malloc(i32 24)
282  store i8 0, i8* %m
283  ret void
284}
285; CHECK-LABEL: @test20(
286; CHECK-NEXT: ret void
287
288; CHECK-LABEL: @test21(
289define void @test21() {
290  %m = call i8* @calloc(i32 9, i32 7)
291  store i8 0, i8* %m
292; CHECK-NEXT: ret void
293  ret void
294}
295
296; CHECK-LABEL: @test22(
297define void @test22(i1 %i, i32 %k, i32 %m) nounwind {
298  %k.addr = alloca i32
299  %m.addr = alloca i32
300  %k.addr.m.addr = select i1 %i, i32* %k.addr, i32* %m.addr
301  store i32 0, i32* %k.addr.m.addr, align 4
302; CHECK-NEXT: ret void
303  ret void
304}
305
306; PR13547
307; CHECK-LABEL: @test23(
308; CHECK: store i8 97
309; CHECK: store i8 0
310declare noalias i8* @strdup(i8* nocapture) nounwind
311define noalias i8* @test23() nounwind uwtable ssp {
312  %x = alloca [2 x i8], align 1
313  %arrayidx = getelementptr inbounds [2 x i8], [2 x i8]* %x, i64 0, i64 0
314  store i8 97, i8* %arrayidx, align 1
315  %arrayidx1 = getelementptr inbounds [2 x i8], [2 x i8]* %x, i64 0, i64 1
316  store i8 0, i8* %arrayidx1, align 1
317  %call = call i8* @strdup(i8* %arrayidx) nounwind
318  ret i8* %call
319}
320
321; Make sure same sized store to later element is deleted
322; CHECK-LABEL: @test24(
323; CHECK-NOT: store i32 0
324; CHECK-NOT: store i32 0
325; CHECK: store i32 %b
326; CHECK: store i32 %c
327; CHECK: ret void
328define void @test24([2 x i32]* %a, i32 %b, i32 %c) nounwind {
329  %1 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 0
330  store i32 0, i32* %1, align 4
331  %2 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 1
332  store i32 0, i32* %2, align 4
333  %3 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 0
334  store i32 %b, i32* %3, align 4
335  %4 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 1
336  store i32 %c, i32* %4, align 4
337  ret void
338}
339
340; Check another case like PR13547 where strdup is not like malloc.
341; CHECK-LABEL: @test25(
342; CHECK: load i8
343; CHECK: store i8 0
344; CHECK: store i8 %tmp
345define i8* @test25(i8* %p) nounwind {
346  %p.4 = getelementptr i8, i8* %p, i64 4
347  %tmp = load i8, i8* %p.4, align 1
348  store i8 0, i8* %p.4, align 1
349  %q = call i8* @strdup(i8* %p) nounwind optsize
350  store i8 %tmp, i8* %p.4, align 1
351  ret i8* %q
352}
353
354; Remove redundant store if loaded value is in another block.
355; CHECK-LABEL: @test26(
356; CHECK-NOT: store
357; CHECK: ret
358define i32 @test26(i1 %c, i32* %p) {
359entry:
360  %v = load i32, i32* %p, align 4
361  br i1 %c, label %bb1, label %bb2
362bb1:
363  br label %bb3
364bb2:
365  store i32 %v, i32* %p, align 4
366  br label %bb3
367bb3:
368  ret i32 0
369}
370
371; Remove redundant store if loaded value is in another block.
372; CHECK-LABEL: @test27(
373; CHECK-NOT: store
374; CHECK: ret
375define i32 @test27(i1 %c, i32* %p) {
376entry:
377  %v = load i32, i32* %p, align 4
378  br i1 %c, label %bb1, label %bb2
379bb1:
380  br label %bb3
381bb2:
382  br label %bb3
383bb3:
384  store i32 %v, i32* %p, align 4
385  ret i32 0
386}
387
388; Don't remove redundant store because of may-aliased store.
389; CHECK-LABEL: @test28(
390; CHECK: bb3:
391; CHECK-NEXT: store i32 %v
392define i32 @test28(i1 %c, i32* %p, i32* %p2, i32 %i) {
393entry:
394  %v = load i32, i32* %p, align 4
395
396  ; Might overwrite value at %p
397  store i32 %i, i32* %p2, align 4
398  br i1 %c, label %bb1, label %bb2
399bb1:
400  br label %bb3
401bb2:
402  br label %bb3
403bb3:
404  store i32 %v, i32* %p, align 4
405  ret i32 0
406}
407
408; Don't remove redundant store because of may-aliased store.
409; CHECK-LABEL: @test29(
410; CHECK: bb3:
411; CHECK-NEXT: store i32 %v
412define i32 @test29(i1 %c, i32* %p, i32* %p2, i32 %i) {
413entry:
414  %v = load i32, i32* %p, align 4
415  br i1 %c, label %bb1, label %bb2
416bb1:
417  br label %bb3
418bb2:
419  ; Might overwrite value at %p
420  store i32 %i, i32* %p2, align 4
421  br label %bb3
422bb3:
423  store i32 %v, i32* %p, align 4
424  ret i32 0
425}
426
427declare void @unknown_func()
428
429; Don't remove redundant store because of unknown call.
430; CHECK-LABEL: @test30(
431; CHECK: bb3:
432; CHECK-NEXT: store i32 %v
433define i32 @test30(i1 %c, i32* %p, i32 %i) {
434entry:
435  %v = load i32, i32* %p, align 4
436  br i1 %c, label %bb1, label %bb2
437bb1:
438  br label %bb3
439bb2:
440  ; Might overwrite value at %p
441  call void @unknown_func()
442  br label %bb3
443bb3:
444  store i32 %v, i32* %p, align 4
445  ret i32 0
446}
447
448; Remove redundant store if loaded value is in another block inside a loop.
449; CHECK-LABEL: @test31(
450; CHECK-NOT: store
451; CHECK: ret
452define i32 @test31(i1 %c, i32* %p, i32 %i) {
453entry:
454  %v = load i32, i32* %p, align 4
455  br label %bb1
456bb1:
457  store i32 %v, i32* %p, align 4
458  br i1 undef, label %bb1, label %bb2
459bb2:
460  ret i32 0
461}
462
463; Don't remove redundant store in a loop with a may-alias store.
464; CHECK-LABEL: @test32(
465; CHECK: bb1:
466; CHECK-NEXT: store i32 %v
467; CHECK-NEXT: call void @unknown_func
468define i32 @test32(i1 %c, i32* %p, i32 %i) {
469entry:
470  %v = load i32, i32* %p, align 4
471  br label %bb1
472bb1:
473  store i32 %v, i32* %p, align 4
474  ; Might read and overwrite value at %p
475  call void @unknown_func()
476  br i1 undef, label %bb1, label %bb2
477bb2:
478  ret i32 0
479}
480
481; Remove redundant store, which is in the lame loop as the load.
482; CHECK-LABEL: @test33(
483; CHECK-NOT: store
484; CHECK: ret
485define i32 @test33(i1 %c, i32* %p, i32 %i) {
486entry:
487  br label %bb1
488bb1:
489  %v = load i32, i32* %p, align 4
490  br label %bb2
491bb2:
492  store i32 %v, i32* %p, align 4
493  ; Might read and overwrite value at %p, but doesn't matter.
494  call void @unknown_func()
495  br i1 undef, label %bb1, label %bb3
496bb3:
497  ret i32 0
498}
499
500