1; RUN: opt < %s -basic-aa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s 2target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64" 3target triple = "thumbv7--linux-gnueabi" 4 5; CHECK-LABEL: test_zext_sext_amounts255 6; CHECK: NoAlias: i8* %a, i8* %b 7define void @test_zext_sext_amounts255(i8* %mem) { 8 %sext.1 = sext i8 255 to i16 9 %sext.zext.1 = zext i16 %sext.1 to i64 10 %sext.2 = sext i8 255 to i32 11 %sext.zext.2 = zext i32 %sext.2 to i64 12 %a = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.1 13 %b = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.2 14 ret void 15} 16 17; CHECK-LABEL: test_zext_sext_amounts 18; CHECK: MayAlias: i8* %a, i8* %b 19; %a and %b only PartialAlias as, although they're both zext(sext(%num)) they'll extend the sign by a different 20; number of bits before zext-ing the remainder. 21define void @test_zext_sext_amounts(i8* %mem, i8 %num) { 22 %sext.1 = sext i8 %num to i16 23 %sext.zext.1 = zext i16 %sext.1 to i64 24 %sext.2 = sext i8 %num to i32 25 %sext.zext.2 = zext i32 %sext.2 to i64 26 %a = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.1 27 %b = getelementptr inbounds i8, i8* %mem, i64 %sext.zext.2 28 ret void 29} 30 31; CHECK-LABEL: based_on_pr18068 32; CHECK: NoAlias: i8* %a, i8* %b 33; CHECK: NoAlias: i8* %a, i8* %c 34define void @based_on_pr18068(i32 %loaded, i8* %mem) { 35 %loaded.64 = zext i32 %loaded to i64 36 %add1 = add i32 %loaded, -1 ; unsigned wraps unless %loaded == 0 37 %add1.64 = zext i32 %add1 to i64 ; is zext(%loaded) always != zext(%loaded - 1)? Yes -> NoAlias 38 %sub1 = sub i32 %loaded, 1 ; unsigned wraps iff %loaded == 0 39 %sub1.64 = zext i32 %sub1 to i64 ; is zext(%loaded) always != zext(%loaded - 1)? Yes -> NoAlias 40 %a = getelementptr inbounds i8, i8* %mem, i64 %loaded.64 41 %b = getelementptr inbounds i8, i8* %mem, i64 %add1.64 42 %c = getelementptr inbounds i8, i8* %mem, i64 %sub1.64 43 ret void 44} 45 46; CHECK-LABEL: test_path_dependence 47; CHECK: MayAlias: i8* %a, i8* %b 48; CHECK: MustAlias: i8* %a, i8* %c 49; CHECK: MayAlias: i8* %a, i8* %d 50define void @test_path_dependence(i32 %p, i8* %mem) { 51 %p.minus1 = add i32 %p, -1 ; this will always unsigned-wrap, unless %p == 0 52 %p.minus1.64 = zext i32 %p.minus1 to i64 53 %p.64.again = add i64 %p.minus1.64, 1 ; either %p (if we wrapped) or 4294967296 (if we didn't) 54 55 %p.nsw.nuw.minus1 = sub nsw nuw i32 %p, 1 ; as nuw we know %p >= 1, and as nsw %p <= 2147483647 56 %p.nsw.nuw.minus1.64 = zext i32 %p.nsw.nuw.minus1 to i64 57 %p.nsw.nuw.64.again = add nsw nuw i64 %p.nsw.nuw.minus1.64, 1 ; ...so always exactly %p 58 59 %p.nsw.minus1 = sub nsw i32 %p, 1 ; only nsw, so can only guarantee %p != 0x10000000 60 %p.nsw.minus1.64 = zext i32 %p.nsw.minus1 to i64 ; when %p > 0x10000000 (ie <= 0 as a signed number) then the zext will make this a huge positive number 61 %p.nsw.64.again = add nsw i64 %p.nsw.minus1.64, 1 ; ...and so this is very much != %p 62 63 %p.64 = zext i32 %p to i64 64 %a = getelementptr inbounds i8, i8* %mem, i64 %p.64 65 %b = getelementptr inbounds i8, i8* %mem, i64 %p.64.again 66 %c = getelementptr inbounds i8, i8* %mem, i64 %p.nsw.nuw.64.again 67 %d = getelementptr inbounds i8, i8* %mem, i64 %p.nsw.64.again 68 ret void 69} 70 71; CHECK-LABEL: test_zext_sext_255 72; CHECK: NoAlias: i8* %a, i8* %b 73define void @test_zext_sext_255(i8* %mem) { 74 %zext.255 = zext i8 255 to i16 ; 0x00FF 75 %sext.255 = sext i8 255 to i16 ; 0xFFFF 76 %zext.sext.255 = zext i16 %sext.255 to i32 ; 0x0000FFFF 77 %sext.zext.255 = sext i16 %zext.255 to i32 ; 0x000000FF 78 %zext.zext.sext.255 = zext i32 %zext.sext.255 to i64 79 %zext.sext.zext.255 = zext i32 %sext.zext.255 to i64 80 %a = getelementptr inbounds i8, i8* %mem, i64 %zext.zext.sext.255 81 %b = getelementptr inbounds i8, i8* %mem, i64 %zext.sext.zext.255 82 ret void 83} 84 85; CHECK-LABEL: test_zext_sext_num 86; CHECK: MayAlias: i8* %a, i8* %b 87; %a and %b NoAlias if %num == 255 (see @test_zext_sext_255), but %a and %b NoAlias for other values of %num (e.g. 0) 88define void @test_zext_sext_num(i8* %mem, i8 %num) { 89 %zext.num = zext i8 %num to i16 90 %sext.num = sext i8 %num to i16 91 %zext.sext.num = zext i16 %sext.num to i32 92 %sext.zext.num = sext i16 %zext.num to i32 93 %zext.zext.sext.num = zext i32 %zext.sext.num to i64 94 %zext.sext.zext.num = zext i32 %sext.zext.num to i64 95 %a = getelementptr inbounds i8, i8* %mem, i64 %zext.zext.sext.num 96 %b = getelementptr inbounds i8, i8* %mem, i64 %zext.sext.zext.num 97 ret void 98} 99 100; CHECK-LABEL: uncompressStream 101; CHECK: MustAlias: i8* %a, i8* %b 102; CHECK: NoAlias: i8* %a, i8* %c 103define void @uncompressStream(i8* %mem) { 104 %zext.255 = zext i8 255 to i32 105 %sext.255 = sext i8 255 to i32 106 %a = getelementptr inbounds i8, i8* %mem, i32 255 107 %b = getelementptr inbounds i8, i8* %mem, i32 %zext.255 108 %c = getelementptr inbounds i8, i8* %mem, i32 %sext.255 109 ret void 110} 111 112; CHECK-LABEL: constantOffsetHeuristic_i3_i32 113; CHECK: NoAlias: i32* %a, i32* %b 114; CHECK: NoAlias: i32* %a, i32* %c 115; CHECK: NoAlias: i32* %b, i32* %c 116define void @constantOffsetHeuristic_i3_i32(i32* %mem, i3 %val) { 117 %zext.plus.7 = add nsw i3 %val, 7 118 %zext.plus.4 = add nsw i3 %val, 4 119 %zext.val = zext i3 %val to i32 120 %zext.4 = zext i3 %zext.plus.4 to i32 121 %zext.7 = zext i3 %zext.plus.7 to i32 122 %a = getelementptr inbounds i32, i32* %mem, i32 %zext.4 123 %b = getelementptr inbounds i32, i32* %mem, i32 %zext.7 124 %c = getelementptr inbounds i32, i32* %mem, i32 %zext.val 125 ret void 126} 127 128; CHECK-LABEL: constantOffsetHeuristic_i8_i32 129; CHECK: NoAlias: i32* %a, i32* %b 130; CHECK: NoAlias: i32* %a, i32* %c 131; CHECK: NoAlias: i32* %b, i32* %c 132define void @constantOffsetHeuristic_i8_i32(i32* %mem, i8 %val) { 133 %zext.plus.7 = add nsw i8 %val, 7 134 %zext.plus.4 = add nsw i8 %val, 4 135 %zext.val = zext i8 %val to i32 136 %zext.4 = zext i8 %zext.plus.4 to i32 137 %zext.7 = zext i8 %zext.plus.7 to i32 138 %a = getelementptr inbounds i32, i32* %mem, i32 %zext.4 139 %b = getelementptr inbounds i32, i32* %mem, i32 %zext.7 140 %c = getelementptr inbounds i32, i32* %mem, i32 %zext.val 141 ret void 142} 143 144; CHECK-LABEL: constantOffsetHeuristic_i3_i8 145; CHECK: MayAlias: i32* %a, i32* %b 146; CHECK: NoAlias: i32* %a, i32* %c 147; CHECK: MayAlias: i32* %b, i32* %c 148define void @constantOffsetHeuristic_i3_i8(i8* %mem, i3 %val) { 149 %zext.plus.7 = add nsw i3 %val, 7 150 %zext.plus.4 = add nsw i3 %val, 4 151 %zext.val = zext i3 %val to i32 152 %zext.4 = zext i3 %zext.plus.4 to i32 153 %zext.7 = zext i3 %zext.plus.7 to i32 154 %a.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.4 155 %b.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.7 156 %c.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.val 157 %a = bitcast i8* %a.8 to i32* 158 %b = bitcast i8* %b.8 to i32* 159 %c = bitcast i8* %c.8 to i32* 160 ret void 161} 162 163; CHECK-LABEL: constantOffsetHeuristic_i8_i8 164; CHECK: MayAlias: i32* %a, i32* %b 165; CHECK: NoAlias: i32* %a, i32* %c 166; CHECK: NoAlias: i32* %b, i32* %c 167define void @constantOffsetHeuristic_i8_i8(i8* %mem, i8 %val) { 168 %zext.plus.7 = add nsw i8 %val, 7 169 %zext.plus.4 = add nsw i8 %val, 4 170 %zext.val = zext i8 %val to i32 171 %zext.4 = zext i8 %zext.plus.4 to i32 172 %zext.7 = zext i8 %zext.plus.7 to i32 173 %a.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.4 174 %b.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.7 175 %c.8 = getelementptr inbounds i8, i8* %mem, i32 %zext.val 176 %a = bitcast i8* %a.8 to i32* 177 %b = bitcast i8* %b.8 to i32* 178 %c = bitcast i8* %c.8 to i32* 179 ret void 180} 181