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1; RUN: opt < %s -aa-pipeline=basic-aa -passes=aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s2 3; CHECK-LABEL: test_no_lower_bound4;5; CHECK-DAG: MayAlias: i32* %a, i32* %b6define void @test_no_lower_bound(ptr %p, i64 %i) {7 %a = getelementptr i8, ptr %p, i64 48 %b = getelementptr nuw i8, ptr %p, i64 %i9 10 load i32, ptr %a11 load i32, ptr %b12 13 ret void14}15 16; CHECK-LABEL: test_lower_bound_lt_size17;18; CHECK-DAG: MayAlias: i32* %a, i32* %b19define void @test_lower_bound_lt_size(ptr %p, i64 %i) {20 %a = getelementptr i8, ptr %p21 %add = getelementptr nuw i8, ptr %p, i64 222 %b = getelementptr nuw i8, ptr %add, i64 %i23 24 load i32, ptr %a25 load i32, ptr %b26 27 ret void28}29 30; CHECK-LABEL: test_lower_bound_ge_size31;32; CHECK-DAG: NoAlias: i32* %a, i32* %b33define void @test_lower_bound_ge_size(ptr %p, i64 %i) {34 %a = getelementptr i8, ptr %p35 %add = getelementptr nuw i8, ptr %p, i64 436 %b = getelementptr nuw i8, ptr %add, i64 %i37 38 load i32, ptr %a39 load i32, ptr %b40 41 ret void42}43 44; CHECK-LABEL: test_not_all_nuw45;46; If part of the addressing is done with non-nuw GEPs, we can't use properties47; implied by the last GEP with the whole offset. In this case, the calculation48; of %add (%p + 4) could wrap the pointer index type, such that %add +<nuw> %i49; could still alias with %p.50;51; CHECK-DAG: MayAlias: i32* %a, i32* %b52define void @test_not_all_nuw(ptr %p, i64 %i) {53 %a = getelementptr i8, ptr %p54 %add = getelementptr i8, ptr %p, i64 455 %b = getelementptr nuw i8, ptr %add, i64 %i56 57 load i32, ptr %a58 load i32, ptr %b59 60 ret void61}62 63; CHECK-LABEL: test_multi_step_not_all_nuw64;65; CHECK-DAG: MayAlias: i32* %a, i32* %b66define void @test_multi_step_not_all_nuw(ptr %p, i64 %i, i64 %j, i64 %k) {67 %a = getelementptr i8, ptr %p68 %add = getelementptr i8, ptr %p, i64 469 %step1 = getelementptr i8, ptr %add, i64 %i70 %step2 = getelementptr i8, ptr %step1, i64 %j71 %b = getelementptr nuw i8, ptr %step2, i64 %k72 73 load i32, ptr %a74 load i32, ptr %b75 76 ret void77}78 79; CHECK-LABEL: test_multi_step_all_nuw80;81; CHECK-DAG: NoAlias: i32* %a, i32* %b82define void @test_multi_step_all_nuw(ptr %p, i64 %i, i64 %j, i64 %k) {83 %a = getelementptr i8, ptr %p84 %add = getelementptr nuw i8, ptr %p, i64 485 %step1 = getelementptr nuw i8, ptr %add, i64 %i86 %step2 = getelementptr nuw i8, ptr %step1, i64 %j87 %b = getelementptr nuw i8, ptr %step2, i64 %k88 89 load i32, ptr %a90 load i32, ptr %b91 92 ret void93}94 95%struct = type { i64, [2 x i32], i64 }96 97; CHECK-LABEL: test_struct_no_nuw98;99; The array access may alias with the struct elements before and after, because100; we cannot prove that (%arr + %i) does not alias with the base pointer %p.101;102; CHECK-DAG: MayAlias: i32* %arrayidx, i64* %st103; CHECK-DAG: NoAlias: i64* %after, i64* %st104; CHECK-DAG: MayAlias: i64* %after, i32* %arrayidx105 106define void @test_struct_no_nuw(ptr %st, i64 %i) {107 %arr = getelementptr i8, ptr %st, i64 8108 %arrayidx = getelementptr [2 x i32], ptr %arr, i64 0, i64 %i109 %after = getelementptr i8, ptr %st, i64 16110 111 load i64, ptr %st112 load i32, ptr %arrayidx113 load i64, ptr %after114 115 ret void116}117 118; CHECK-LABEL: test_struct_nuw119;120; We can prove that the array access does not alias with struct element before,121; because we can prove that (%arr +<nuw> %i) does not wrap the pointer index122; type (add nuw). The array access may still alias with the struct element123; after, as the add nuw property does not preclude this.124;125; CHECK-DAG: NoAlias: i32* %arrayidx, i64* %st126; CHECK-DAG: NoAlias: i64* %after, i64* %st127; CHECK-DAG: MayAlias: i64* %after, i32* %arrayidx128 129define void @test_struct_nuw(ptr %st, i64 %i) {130 %arr = getelementptr nuw i8, ptr %st, i64 8131 %arrayidx = getelementptr nuw [2 x i32], ptr %arr, i64 0, i64 %i132 %after = getelementptr nuw i8, ptr %st, i64 16133 134 load i64, ptr %st135 load i32, ptr %arrayidx136 load i64, ptr %after137 138 ret void139}140 141; CHECK-LABEL: constant_offset_overflow142;143; If subtraction of constant offsets could overflow in an unsigned sense, we144; cannot prove the lower bound between the GEPs and so they may still alias.145;146; CHECK-DAG: MayAlias: i32* %a, i32* %b147 148define void @constant_offset_overflow(ptr %p, i64 %i) {149 %a = getelementptr i8, ptr %p, i64 -8150 %add = getelementptr nuw i8, ptr %p, i64 4151 %b = getelementptr nuw i8, ptr %add, i64 %i152 153 load i32, ptr %a154 load i32, ptr %b155 156 ret void157}158 159; CHECK-LABEL: equal_var_idx_noalias160;161; If GEPs have equal variable indices, we can prove NoAlias when the Scale of162; the RHS GEP is greater, as in this scenario the constant lower bound holds.163;164; CHECK-DAG: NoAlias: i32* %a, i32* %b165 166define void @equal_var_idx_noalias(ptr %p, i64 %i) {167 %a = getelementptr i8, ptr %p, i64 %i168 169 %add = getelementptr nuw i8, ptr %p, i64 4170 %b = getelementptr nuw i16, ptr %add, i64 %i171 172 load i32, ptr %a173 load i32, ptr %b174 175 ret void176}177 178; CHECK-LABEL: equal_var_idx_alias179;180; If GEPs have equal variable indices, we cannot prove NoAlias when the Scale of181; the RHS GEP is ult Scale of the LHS GEP.182;183; CHECK-DAG: MayAlias: i32* %a, i32* %b184 185define void @equal_var_idx_alias(ptr %p, i64 %i) {186 %a = getelementptr i32, ptr %p, i64 %i187 188 %add = getelementptr nuw i8, ptr %p, i64 4189 %b = getelementptr nuw i16, ptr %add, i64 %i190 191 load i32, ptr %b192 load i32, ptr %a193 194 ret void195}196 197; CHECK-LABEL: both_var_idx198;199; If the RHS GEP has unmatched variable indices, we cannot prove a constant200; lower bound between GEPs.201;202; CHECK-DAG: MayAlias: i32* %a, i32* %b203 204define void @both_var_idx(ptr %p, i64 %i, i64 %j) {205 %a = getelementptr i8, ptr %p, i64 %i206 207 %add = getelementptr nuw i8, ptr %p, i64 4208 %b = getelementptr nuw i8, ptr %add, i64 %j209 210 load i32, ptr %a211 load i32, ptr %b212 213 ret void214}215 216; CHECK-LABEL: add_no_nuw217; CHECK: MayAlias: i8* %gep, i8* %p218define i8 @add_no_nuw(ptr %p, i64 %n) {219 store i8 3, ptr %p220 221 %add = add i64 %n, 1222 %gep = getelementptr nuw i8, ptr %p, i64 %add223 %val = load i8, ptr %gep224 ret i8 %val225}226 227; CHECK-LABEL: add_nuw228; CHECK: NoAlias: i8* %gep, i8* %p229define i8 @add_nuw(ptr %p, i64 %n) {230 store i8 3, ptr %p231 232 %add = add nuw i64 %n, 1233 %gep = getelementptr nuw i8, ptr %p, i64 %add234 %val = load i8, ptr %gep235 ret i8 %val236}237 238; CHECK-LABEL: add_no_nuw239; CHECK: MayAlias: i8* %gep, i16* %p240define i8 @add_no_nuw_scale(ptr %p, i64 %n) {241 store i16 3, ptr %p242 243 %add = add i64 %n, 1244 %gep = getelementptr nuw i16, ptr %p, i64 %add245 %val = load i8, ptr %gep246 ret i8 %val247}248 249; CHECK-LABEL: add_nuw250; CHECK: NoAlias: i8* %gep, i16* %p251define i8 @add_nuw_scale(ptr %p, i64 %n) {252 store i16 3, ptr %p253 254 %add = add nuw i64 %n, 1255 %gep = getelementptr nuw i16, ptr %p, i64 %add256 %val = load i8, ptr %gep257 ret i8 %val258}259 260; CHECK-LABEL: sub_nuw261; CHECK: MayAlias: i8* %gep, i8* %p262define i8 @sub_nuw(ptr %p, i64 %n) {263 store i8 3, ptr %p264 265 %add = sub nuw i64 %n, 1266 %gep = getelementptr nuw i8, ptr %p, i64 %add267 %val = load i8, ptr %gep268 ret i8 %val269}270 271; CHECK-LABEL: mul_no_nuw272; CHECK: MayAlias: i8* %gep, i16* %p273define i8 @mul_no_nuw(ptr %p, i64 %n) {274 store i16 3, ptr %p275 276 %add = add nuw i64 %n, 1277 %mul = mul i64 %add, 2278 %gep = getelementptr nuw i8, ptr %p, i64 %mul279 %val = load i8, ptr %gep280 ret i8 %val281}282 283; CHECK-LABEL: mul_nuw284; CHECK: NoAlias: i8* %gep, i16* %p285define i8 @mul_nuw(ptr %p, i64 %n) {286 store i16 3, ptr %p287 288 %add = add nuw i64 %n, 1289 %mul = mul nuw i64 %add, 2290 %gep = getelementptr nuw i8, ptr %p, i64 %mul291 %val = load i8, ptr %gep292 ret i8 %val293}294 295; CHECK-LABEL: shl_no_nuw296; CHECK: MayAlias: i8* %gep, i16* %p297define i8 @shl_no_nuw(ptr %p, i64 %n) {298 store i16 3, ptr %p299 300 %add = add nuw i64 %n, 1301 %shl = shl i64 %add, 1302 %gep = getelementptr nuw i8, ptr %p, i64 %shl303 %val = load i8, ptr %gep304 ret i8 %val305}306 307; CHECK-LABEL: shl_nuw308; CHECK: NoAlias: i8* %gep, i16* %p309define i8 @shl_nuw(ptr %p, i64 %n) {310 store i16 3, ptr %p311 312 %add = add nuw i64 %n, 1313 %shl = shl nuw i64 %add, 1314 %gep = getelementptr nuw i8, ptr %p, i64 %shl315 %val = load i8, ptr %gep316 ret i8 %val317}318