1 ; RUN: opt < %s -basicaa -dse -S | FileCheck %s 2 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" 3 4 declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind 5 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind 6 declare i8* @llvm.init.trampoline(i8*, i8*, i8*) 7 8 define void @test1(i32* %Q, i32* %P) { 9 %DEAD = load 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. 19 define 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 32 define i32 @test3(i32* %g_addr) nounwind { 33 ; CHECK-LABEL: @test3( 34 ; CHECK: load i32* %g_addr 35 %g_value = load 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* @g, align 4 39 ret i32 %tmp3 40 } 41 42 43 define void @test4(i32* %Q) { 44 %a = load 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 53 define void @test5(i32* %Q) { 54 %a = load volatile 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). 64 define 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). 75 define 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. 85 define 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* %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 } 100 define void @test9(%struct.x* byval %a) nounwind { 101 %tmp2 = getelementptr %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. 109 define void @test9_2(%struct.x* inalloca %a) nounwind { 110 %tmp2 = getelementptr %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. 118 define 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. 129 declare void @test11f() 130 define 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]* %storage, i32 0, i32 0 ; <i8*> [#uses=1] 135 %tramp = call i8* @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. 143 define void @test12({ i32, i32 }* %x) nounwind { 144 %tmp4 = getelementptr { i32, i32 }* %x, i32 0, i32 0 145 %tmp5 = load i32* %tmp4, align 4 146 %tmp7 = getelementptr { i32, i32 }* %x, i32 0, i32 1 147 %tmp8 = load 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. 159 declare void @test13f() 160 define i32* @test13() { 161 %p = tail call i8* @malloc(i32 4) 162 %P = bitcast i8* %p to i32* 163 %DEAD = load 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 } 174 175 declare noalias i8* @malloc(i32) 176 declare noalias i8* @calloc(i32, i32) 177 178 179 define void @test14(i32* %Q) { 180 %P = alloca i32 181 %DEAD = load i32* %Q 182 store i32 %DEAD, i32* %P 183 ret void 184 185 ; CHECK-LABEL: @test14( 186 ; CHECK-NEXT: ret void 187 } 188 189 190 ; PR8701 191 192 ;; Fully dead overwrite of memcpy. 193 define void @test15(i8* %P, i8* %Q) nounwind ssp { 194 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 195 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 196 ret void 197 ; CHECK-LABEL: @test15( 198 ; CHECK-NEXT: call void @llvm.memcpy 199 ; CHECK-NEXT: ret 200 } 201 202 ;; Full overwrite of smaller memcpy. 203 define void @test16(i8* %P, i8* %Q) nounwind ssp { 204 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 8, i32 1, i1 false) 205 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 206 ret void 207 ; CHECK-LABEL: @test16( 208 ; CHECK-NEXT: call void @llvm.memcpy 209 ; CHECK-NEXT: ret 210 } 211 212 ;; Overwrite of memset by memcpy. 213 define void @test17(i8* %P, i8* noalias %Q) nounwind ssp { 214 tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 false) 215 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 216 ret void 217 ; CHECK-LABEL: @test17( 218 ; CHECK-NEXT: call void @llvm.memcpy 219 ; CHECK-NEXT: ret 220 } 221 222 ; Should not delete the volatile memset. 223 define void @test17v(i8* %P, i8* %Q) nounwind ssp { 224 tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 true) 225 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 226 ret void 227 ; CHECK-LABEL: @test17v( 228 ; CHECK-NEXT: call void @llvm.memset 229 ; CHECK-NEXT: call void @llvm.memcpy 230 ; CHECK-NEXT: ret 231 } 232 233 ; PR8728 234 ; Do not delete instruction where possible situation is: 235 ; A = B 236 ; A = A 237 define void @test18(i8* %P, i8* %Q, i8* %R) nounwind ssp { 238 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) 239 tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %R, i64 12, i32 1, i1 false) 240 ret void 241 ; CHECK-LABEL: @test18( 242 ; CHECK-NEXT: call void @llvm.memcpy 243 ; CHECK-NEXT: call void @llvm.memcpy 244 ; CHECK-NEXT: ret 245 } 246 247 248 ; The store here is not dead because the byval call reads it. 249 declare void @test19f({i32}* byval align 4 %P) 250 251 define void @test19({i32} * nocapture byval align 4 %arg5) nounwind ssp { 252 bb: 253 %tmp7 = getelementptr inbounds {i32}* %arg5, i32 0, i32 0 254 store i32 912, i32* %tmp7 255 call void @test19f({i32}* byval align 4 %arg5) 256 ret void 257 258 ; CHECK-LABEL: @test19( 259 ; CHECK: store i32 912 260 ; CHECK: call void @test19f 261 } 262 263 define void @test20() { 264 %m = call i8* @malloc(i32 24) 265 store i8 0, i8* %m 266 ret void 267 } 268 ; CHECK-LABEL: @test20( 269 ; CHECK-NEXT: ret void 270 271 ; CHECK-LABEL: @test21( 272 define void @test21() { 273 %m = call i8* @calloc(i32 9, i32 7) 274 store i8 0, i8* %m 275 ; CHECK-NEXT: ret void 276 ret void 277 } 278 279 ; CHECK-LABEL: @test22( 280 define void @test22(i1 %i, i32 %k, i32 %m) nounwind { 281 %k.addr = alloca i32 282 %m.addr = alloca i32 283 %k.addr.m.addr = select i1 %i, i32* %k.addr, i32* %m.addr 284 store i32 0, i32* %k.addr.m.addr, align 4 285 ; CHECK-NEXT: ret void 286 ret void 287 } 288 289 ; PR13547 290 ; CHECK-LABEL: @test23( 291 ; CHECK: store i8 97 292 ; CHECK: store i8 0 293 declare noalias i8* @strdup(i8* nocapture) nounwind 294 define noalias i8* @test23() nounwind uwtable ssp { 295 %x = alloca [2 x i8], align 1 296 %arrayidx = getelementptr inbounds [2 x i8]* %x, i64 0, i64 0 297 store i8 97, i8* %arrayidx, align 1 298 %arrayidx1 = getelementptr inbounds [2 x i8]* %x, i64 0, i64 1 299 store i8 0, i8* %arrayidx1, align 1 300 %call = call i8* @strdup(i8* %arrayidx) nounwind 301 ret i8* %call 302 } 303 304 ; Make sure same sized store to later element is deleted 305 ; CHECK-LABEL: @test24( 306 ; CHECK-NOT: store i32 0 307 ; CHECK-NOT: store i32 0 308 ; CHECK: store i32 %b 309 ; CHECK: store i32 %c 310 ; CHECK: ret void 311 define void @test24([2 x i32]* %a, i32 %b, i32 %c) nounwind { 312 %1 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 0 313 store i32 0, i32* %1, align 4 314 %2 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 1 315 store i32 0, i32* %2, align 4 316 %3 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 0 317 store i32 %b, i32* %3, align 4 318 %4 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 1 319 store i32 %c, i32* %4, align 4 320 ret void 321 } 322 323 ; Check another case like PR13547 where strdup is not like malloc. 324 ; CHECK-LABEL: @test25( 325 ; CHECK: load i8 326 ; CHECK: store i8 0 327 ; CHECK: store i8 %tmp 328 define i8* @test25(i8* %p) nounwind { 329 %p.4 = getelementptr i8* %p, i64 4 330 %tmp = load i8* %p.4, align 1 331 store i8 0, i8* %p.4, align 1 332 %q = call i8* @strdup(i8* %p) nounwind optsize 333 store i8 %tmp, i8* %p.4, align 1 334 ret i8* %q 335 } 336