1; RUN: opt < %s -basicaa -dse -S | FileCheck %s 2; RUN: opt < %s -aa-pipeline=basic-aa -passes=dse -S | FileCheck %s 3target 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 5declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind 6declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind 7declare void @llvm.init.trampoline(i8*, i8*, i8*) 8 9define 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. 20define 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 33define 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 44define 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 54define 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). 65define 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). 76define 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. 86define 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 } 101define 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. 110define 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. 119define 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. 130declare void @test11f() 131define 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. 144define 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. 160declare void @test13f() 161define 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 176define 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 193declare noalias i8* @malloc(i32) 194declare noalias i8* @calloc(i32, i32) 195 196 197define 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. 211define 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. 221define 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. 231define 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. 241define 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 255define 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. 267declare void @test19f({i32}* byval align 4 %P) 268 269define void @test19({i32} * nocapture byval align 4 %arg5) nounwind ssp { 270bb: 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 281define 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( 290define 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( 298define 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 311declare noalias i8* @strdup(i8* nocapture) nounwind 312define 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 329define 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 346define 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 359define i32 @test26(i1 %c, i32* %p) { 360entry: 361 %v = load i32, i32* %p, align 4 362 br i1 %c, label %bb1, label %bb2 363bb1: 364 br label %bb3 365bb2: 366 store i32 %v, i32* %p, align 4 367 br label %bb3 368bb3: 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 376define i32 @test27(i1 %c, i32* %p) { 377entry: 378 %v = load i32, i32* %p, align 4 379 br i1 %c, label %bb1, label %bb2 380bb1: 381 br label %bb3 382bb2: 383 br label %bb3 384bb3: 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 393define i32 @test28(i1 %c, i32* %p, i32* %p2, i32 %i) { 394entry: 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 400bb1: 401 br label %bb3 402bb2: 403 br label %bb3 404bb3: 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 413define i32 @test29(i1 %c, i32* %p, i32* %p2, i32 %i) { 414entry: 415 %v = load i32, i32* %p, align 4 416 br i1 %c, label %bb1, label %bb2 417bb1: 418 br label %bb3 419bb2: 420 ; Might overwrite value at %p 421 store i32 %i, i32* %p2, align 4 422 br label %bb3 423bb3: 424 store i32 %v, i32* %p, align 4 425 ret i32 0 426} 427 428declare 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 434define i32 @test30(i1 %c, i32* %p, i32 %i) { 435entry: 436 %v = load i32, i32* %p, align 4 437 br i1 %c, label %bb1, label %bb2 438bb1: 439 br label %bb3 440bb2: 441 ; Might overwrite value at %p 442 call void @unknown_func() 443 br label %bb3 444bb3: 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 453define i32 @test31(i1 %c, i32* %p, i32 %i) { 454entry: 455 %v = load i32, i32* %p, align 4 456 br label %bb1 457bb1: 458 store i32 %v, i32* %p, align 4 459 br i1 undef, label %bb1, label %bb2 460bb2: 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 469define i32 @test32(i1 %c, i32* %p, i32 %i) { 470entry: 471 %v = load i32, i32* %p, align 4 472 br label %bb1 473bb1: 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 478bb2: 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 486define i32 @test33(i1 %c, i32* %p, i32 %i) { 487entry: 488 br label %bb1 489bb1: 490 %v = load i32, i32* %p, align 4 491 br label %bb2 492bb2: 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 497bb3: 498 ret i32 0 499} 500 501