1 ; RUN: opt < %s -basicaa -dse -S | FileCheck %s 2 ; RUN: opt < %s -aa-pipeline=basic-aa -passes=dse -S | FileCheck %s 3 target 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" 4 5 declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind 6 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind 7 declare void @llvm.init.trampoline(i8*, i8*, i8*) 8 9 define void @test1(i32* %Q, i32* %P) { 10 %DEAD = load i32, i32* %Q 11 store i32 %DEAD, i32* %P 12 store i32 0, i32* %P 13 ret void 14 ; CHECK-LABEL: @test1( 15 ; CHECK-NEXT: store i32 0, i32* %P 16 ; CHECK-NEXT: ret void 17 } 18 19 ; PR8576 - Should delete store of 10 even though p/q are may aliases. 20 define void @test2(i32 *%p, i32 *%q) { 21 store i32 10, i32* %p, align 4 22 store i32 20, i32* %q, align 4 23 store i32 30, i32* %p, align 4 24 ret void 25 ; CHECK-LABEL: @test2( 26 ; CHECK-NEXT: store i32 20 27 } 28 29 30 ; PR8677 31 @g = global i32 1 32 33 define i32 @test3(i32* %g_addr) nounwind { 34 ; CHECK-LABEL: @test3( 35 ; CHECK: load i32, i32* %g_addr 36 %g_value = load i32, i32* %g_addr, align 4 37 store i32 -1, i32* @g, align 4 38 store i32 %g_value, i32* %g_addr, align 4 39 %tmp3 = load i32, i32* @g, align 4 40 ret i32 %tmp3 41 } 42 43 44 define void @test4(i32* %Q) { 45 %a = load i32, i32* %Q 46 store volatile i32 %a, i32* %Q 47 ret void 48 ; CHECK-LABEL: @test4( 49 ; CHECK-NEXT: load i32 50 ; CHECK-NEXT: store volatile 51 ; CHECK-NEXT: ret void 52 } 53 54 define void @test5(i32* %Q) { 55 %a = load volatile i32, i32* %Q 56 store i32 %a, i32* %Q 57 ret void 58 ; CHECK-LABEL: @test5( 59 ; CHECK-NEXT: load volatile 60 ; CHECK-NEXT: ret void 61 } 62 63 ; Should delete store of 10 even though memset is a may-store to P (P and Q may 64 ; alias). 65 define void @test6(i32 *%p, i8 *%q) { 66 store i32 10, i32* %p, align 4 ;; dead. 67 call void @llvm.memset.p0i8.i64(i8* %q, i8 42, i64 900, i32 1, i1 false) 68 store i32 30, i32* %p, align 4 69 ret void 70 ; CHECK-LABEL: @test6( 71 ; CHECK-NEXT: call void @llvm.memset 72 } 73 74 ; Should delete store of 10 even though memcpy is a may-store to P (P and Q may 75 ; alias). 76 define void @test7(i32 *%p, i8 *%q, i8* noalias %r) { 77 store i32 10, i32* %p, align 4 ;; dead. 78 call void @llvm.memcpy.p0i8.p0i8.i64(i8* %q, i8* %r, i64 900, i32 1, i1 false) 79 store i32 30, i32* %p, align 4 80 ret void 81 ; CHECK-LABEL: @test7( 82 ; CHECK-NEXT: call void @llvm.memcpy 83 } 84 85 ; Do not delete stores that are only partially killed. 86 define i32 @test8() { 87 %V = alloca i32 88 store i32 1234567, i32* %V 89 %V2 = bitcast i32* %V to i8* 90 store i8 0, i8* %V2 91 %X = load i32, i32* %V 92 ret i32 %X 93 94 ; CHECK-LABEL: @test8( 95 ; CHECK: store i32 1234567 96 } 97 98 99 ; Test for byval handling. 100 %struct.x = type { i32, i32, i32, i32 } 101 define void @test9(%struct.x* byval %a) nounwind { 102 %tmp2 = getelementptr %struct.x, %struct.x* %a, i32 0, i32 0 103 store i32 1, i32* %tmp2, align 4 104 ret void 105 ; CHECK-LABEL: @test9( 106 ; CHECK-NEXT: ret void 107 } 108 109 ; Test for inalloca handling. 110 define void @test9_2(%struct.x* inalloca %a) nounwind { 111 %tmp2 = getelementptr %struct.x, %struct.x* %a, i32 0, i32 0 112 store i32 1, i32* %tmp2, align 4 113 ret void 114 ; CHECK-LABEL: @test9_2( 115 ; CHECK-NEXT: ret void 116 } 117 118 ; va_arg has fuzzy dependence, the store shouldn't be zapped. 119 define double @test10(i8* %X) { 120 %X_addr = alloca i8* 121 store i8* %X, i8** %X_addr 122 %tmp.0 = va_arg i8** %X_addr, double 123 ret double %tmp.0 124 ; CHECK-LABEL: @test10( 125 ; CHECK: store 126 } 127 128 129 ; DSE should delete the dead trampoline. 130 declare void @test11f() 131 define void @test11() { 132 ; CHECK-LABEL: @test11( 133 %storage = alloca [10 x i8], align 16 ; <[10 x i8]*> [#uses=1] 134 ; CHECK-NOT: alloca 135 %cast = getelementptr [10 x i8], [10 x i8]* %storage, i32 0, i32 0 ; <i8*> [#uses=1] 136 call void @llvm.init.trampoline( i8* %cast, i8* bitcast (void ()* @test11f to i8*), i8* null ) ; <i8*> [#uses=1] 137 ; CHECK-NOT: trampoline 138 ret void 139 ; CHECK: ret void 140 } 141 142 143 ; PR2599 - load -> store to same address. 144 define void @test12({ i32, i32 }* %x) nounwind { 145 %tmp4 = getelementptr { i32, i32 }, { i32, i32 }* %x, i32 0, i32 0 146 %tmp5 = load i32, i32* %tmp4, align 4 147 %tmp7 = getelementptr { i32, i32 }, { i32, i32 }* %x, i32 0, i32 1 148 %tmp8 = load i32, i32* %tmp7, align 4 149 %tmp17 = sub i32 0, %tmp8 150 store i32 %tmp5, i32* %tmp4, align 4 151 store i32 %tmp17, i32* %tmp7, align 4 152 ret void 153 ; CHECK-LABEL: @test12( 154 ; CHECK-NOT: tmp5 155 ; CHECK: ret void 156 } 157 158 159 ; %P doesn't escape, the DEAD instructions should be removed. 160 declare void @test13f() 161 define i32* @test13() { 162 %p = tail call i8* @malloc(i32 4) 163 %P = bitcast i8* %p to i32* 164 %DEAD = load i32, i32* %P 165 %DEAD2 = add i32 %DEAD, 1 166 store i32 %DEAD2, i32* %P 167 call void @test13f( ) 168 store i32 0, i32* %P 169 ret i32* %P 170 ; CHECK: @test13() 171 ; CHECK-NEXT: malloc 172 ; CHECK-NEXT: bitcast 173 ; CHECK-NEXT: call void 174 } 175 176 define i32 addrspace(1)* @test13_addrspacecast() { 177 %p = tail call i8* @malloc(i32 4) 178 %p.bc = bitcast i8* %p to i32* 179 %P = addrspacecast i32* %p.bc to i32 addrspace(1)* 180 %DEAD = load i32, i32 addrspace(1)* %P 181 %DEAD2 = add i32 %DEAD, 1 182 store i32 %DEAD2, i32 addrspace(1)* %P 183 call void @test13f( ) 184 store i32 0, i32 addrspace(1)* %P 185 ret i32 addrspace(1)* %P 186 ; CHECK: @test13_addrspacecast() 187 ; CHECK-NEXT: malloc 188 ; CHECK-NEXT: bitcast 189 ; CHECK-NEXT: addrspacecast 190 ; CHECK-NEXT: call void 191 } 192 193 declare noalias i8* @malloc(i32) 194 declare noalias i8* @calloc(i32, i32) 195 196 197 define void @test14(i32* %Q) { 198 %P = alloca i32 199 %DEAD = load i32, i32* %Q 200 store i32 %DEAD, i32* %P 201 ret void 202 203 ; CHECK-LABEL: @test14( 204 ; CHECK-NEXT: ret void 205 } 206 207 208 ; PR8701 209 210 ;; Fully dead overwrite of memcpy. 211 define void @test15(i8* %P, i8* %Q) nounwind ssp { 212 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 213 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 214 ret void 215 ; CHECK-LABEL: @test15( 216 ; CHECK-NEXT: call void @llvm.memcpy 217 ; CHECK-NEXT: ret 218 } 219 220 ;; Full overwrite of smaller memcpy. 221 define void @test16(i8* %P, i8* %Q) nounwind ssp { 222 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 8, i32 1, i1 false) 223 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 224 ret void 225 ; CHECK-LABEL: @test16( 226 ; CHECK-NEXT: call void @llvm.memcpy 227 ; CHECK-NEXT: ret 228 } 229 230 ;; Overwrite of memset by memcpy. 231 define void @test17(i8* %P, i8* noalias %Q) nounwind ssp { 232 tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 false) 233 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 234 ret void 235 ; CHECK-LABEL: @test17( 236 ; CHECK-NEXT: call void @llvm.memcpy 237 ; CHECK-NEXT: ret 238 } 239 240 ; Should not delete the volatile memset. 241 define void @test17v(i8* %P, i8* %Q) nounwind ssp { 242 tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 true) 243 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 244 ret void 245 ; CHECK-LABEL: @test17v( 246 ; CHECK-NEXT: call void @llvm.memset 247 ; CHECK-NEXT: call void @llvm.memcpy 248 ; CHECK-NEXT: ret 249 } 250 251 ; PR8728 252 ; Do not delete instruction where possible situation is: 253 ; A = B 254 ; A = A 255 define void @test18(i8* %P, i8* %Q, i8* %R) nounwind ssp { 256 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 257 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %R, i64 12, i32 1, i1 false) 258 ret void 259 ; CHECK-LABEL: @test18( 260 ; CHECK-NEXT: call void @llvm.memcpy 261 ; CHECK-NEXT: call void @llvm.memcpy 262 ; CHECK-NEXT: ret 263 } 264 265 266 ; The store here is not dead because the byval call reads it. 267 declare void @test19f({i32}* byval align 4 %P) 268 269 define void @test19({i32} * nocapture byval align 4 %arg5) nounwind ssp { 270 bb: 271 %tmp7 = getelementptr inbounds {i32}, {i32}* %arg5, i32 0, i32 0 272 store i32 912, i32* %tmp7 273 call void @test19f({i32}* byval align 4 %arg5) 274 ret void 275 276 ; CHECK-LABEL: @test19( 277 ; CHECK: store i32 912 278 ; CHECK: call void @test19f 279 } 280 281 define void @test20() { 282 %m = call i8* @malloc(i32 24) 283 store i8 0, i8* %m 284 ret void 285 } 286 ; CHECK-LABEL: @test20( 287 ; CHECK-NEXT: ret void 288 289 ; CHECK-LABEL: @test21( 290 define void @test21() { 291 %m = call i8* @calloc(i32 9, i32 7) 292 store i8 0, i8* %m 293 ; CHECK-NEXT: ret void 294 ret void 295 } 296 297 ; CHECK-LABEL: @test22( 298 define void @test22(i1 %i, i32 %k, i32 %m) nounwind { 299 %k.addr = alloca i32 300 %m.addr = alloca i32 301 %k.addr.m.addr = select i1 %i, i32* %k.addr, i32* %m.addr 302 store i32 0, i32* %k.addr.m.addr, align 4 303 ; CHECK-NEXT: ret void 304 ret void 305 } 306 307 ; PR13547 308 ; CHECK-LABEL: @test23( 309 ; CHECK: store i8 97 310 ; CHECK: store i8 0 311 declare noalias i8* @strdup(i8* nocapture) nounwind 312 define noalias i8* @test23() nounwind uwtable ssp { 313 %x = alloca [2 x i8], align 1 314 %arrayidx = getelementptr inbounds [2 x i8], [2 x i8]* %x, i64 0, i64 0 315 store i8 97, i8* %arrayidx, align 1 316 %arrayidx1 = getelementptr inbounds [2 x i8], [2 x i8]* %x, i64 0, i64 1 317 store i8 0, i8* %arrayidx1, align 1 318 %call = call i8* @strdup(i8* %arrayidx) nounwind 319 ret i8* %call 320 } 321 322 ; Make sure same sized store to later element is deleted 323 ; CHECK-LABEL: @test24( 324 ; CHECK-NOT: store i32 0 325 ; CHECK-NOT: store i32 0 326 ; CHECK: store i32 %b 327 ; CHECK: store i32 %c 328 ; CHECK: ret void 329 define void @test24([2 x i32]* %a, i32 %b, i32 %c) nounwind { 330 %1 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 0 331 store i32 0, i32* %1, align 4 332 %2 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 1 333 store i32 0, i32* %2, align 4 334 %3 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 0 335 store i32 %b, i32* %3, align 4 336 %4 = getelementptr inbounds [2 x i32], [2 x i32]* %a, i64 0, i64 1 337 store i32 %c, i32* %4, align 4 338 ret void 339 } 340 341 ; Check another case like PR13547 where strdup is not like malloc. 342 ; CHECK-LABEL: @test25( 343 ; CHECK: load i8 344 ; CHECK: store i8 0 345 ; CHECK: store i8 %tmp 346 define i8* @test25(i8* %p) nounwind { 347 %p.4 = getelementptr i8, i8* %p, i64 4 348 %tmp = load i8, i8* %p.4, align 1 349 store i8 0, i8* %p.4, align 1 350 %q = call i8* @strdup(i8* %p) nounwind optsize 351 store i8 %tmp, i8* %p.4, align 1 352 ret i8* %q 353 } 354 355 ; Remove redundant store if loaded value is in another block. 356 ; CHECK-LABEL: @test26( 357 ; CHECK-NOT: store 358 ; CHECK: ret 359 define i32 @test26(i1 %c, i32* %p) { 360 entry: 361 %v = load i32, i32* %p, align 4 362 br i1 %c, label %bb1, label %bb2 363 bb1: 364 br label %bb3 365 bb2: 366 store i32 %v, i32* %p, align 4 367 br label %bb3 368 bb3: 369 ret i32 0 370 } 371 372 ; Remove redundant store if loaded value is in another block. 373 ; CHECK-LABEL: @test27( 374 ; CHECK-NOT: store 375 ; CHECK: ret 376 define i32 @test27(i1 %c, i32* %p) { 377 entry: 378 %v = load i32, i32* %p, align 4 379 br i1 %c, label %bb1, label %bb2 380 bb1: 381 br label %bb3 382 bb2: 383 br label %bb3 384 bb3: 385 store i32 %v, i32* %p, align 4 386 ret i32 0 387 } 388 389 ; Don't remove redundant store because of may-aliased store. 390 ; CHECK-LABEL: @test28( 391 ; CHECK: bb3: 392 ; CHECK-NEXT: store i32 %v 393 define i32 @test28(i1 %c, i32* %p, i32* %p2, i32 %i) { 394 entry: 395 %v = load i32, i32* %p, align 4 396 397 ; Might overwrite value at %p 398 store i32 %i, i32* %p2, align 4 399 br i1 %c, label %bb1, label %bb2 400 bb1: 401 br label %bb3 402 bb2: 403 br label %bb3 404 bb3: 405 store i32 %v, i32* %p, align 4 406 ret i32 0 407 } 408 409 ; Don't remove redundant store because of may-aliased store. 410 ; CHECK-LABEL: @test29( 411 ; CHECK: bb3: 412 ; CHECK-NEXT: store i32 %v 413 define i32 @test29(i1 %c, i32* %p, i32* %p2, i32 %i) { 414 entry: 415 %v = load i32, i32* %p, align 4 416 br i1 %c, label %bb1, label %bb2 417 bb1: 418 br label %bb3 419 bb2: 420 ; Might overwrite value at %p 421 store i32 %i, i32* %p2, align 4 422 br label %bb3 423 bb3: 424 store i32 %v, i32* %p, align 4 425 ret i32 0 426 } 427 428 declare void @unknown_func() 429 430 ; Don't remove redundant store because of unknown call. 431 ; CHECK-LABEL: @test30( 432 ; CHECK: bb3: 433 ; CHECK-NEXT: store i32 %v 434 define i32 @test30(i1 %c, i32* %p, i32 %i) { 435 entry: 436 %v = load i32, i32* %p, align 4 437 br i1 %c, label %bb1, label %bb2 438 bb1: 439 br label %bb3 440 bb2: 441 ; Might overwrite value at %p 442 call void @unknown_func() 443 br label %bb3 444 bb3: 445 store i32 %v, i32* %p, align 4 446 ret i32 0 447 } 448 449 ; Remove redundant store if loaded value is in another block inside a loop. 450 ; CHECK-LABEL: @test31( 451 ; CHECK-NOT: store 452 ; CHECK: ret 453 define i32 @test31(i1 %c, i32* %p, i32 %i) { 454 entry: 455 %v = load i32, i32* %p, align 4 456 br label %bb1 457 bb1: 458 store i32 %v, i32* %p, align 4 459 br i1 undef, label %bb1, label %bb2 460 bb2: 461 ret i32 0 462 } 463 464 ; Don't remove redundant store in a loop with a may-alias store. 465 ; CHECK-LABEL: @test32( 466 ; CHECK: bb1: 467 ; CHECK-NEXT: store i32 %v 468 ; CHECK-NEXT: call void @unknown_func 469 define i32 @test32(i1 %c, i32* %p, i32 %i) { 470 entry: 471 %v = load i32, i32* %p, align 4 472 br label %bb1 473 bb1: 474 store i32 %v, i32* %p, align 4 475 ; Might read and overwrite value at %p 476 call void @unknown_func() 477 br i1 undef, label %bb1, label %bb2 478 bb2: 479 ret i32 0 480 } 481 482 ; Remove redundant store, which is in the lame loop as the load. 483 ; CHECK-LABEL: @test33( 484 ; CHECK-NOT: store 485 ; CHECK: ret 486 define i32 @test33(i1 %c, i32* %p, i32 %i) { 487 entry: 488 br label %bb1 489 bb1: 490 %v = load i32, i32* %p, align 4 491 br label %bb2 492 bb2: 493 store i32 %v, i32* %p, align 4 494 ; Might read and overwrite value at %p, but doesn't matter. 495 call void @unknown_func() 496 br i1 undef, label %bb1, label %bb3 497 bb3: 498 ret i32 0 499 } 500 501
