1; RUN: opt < %s -phi-values -basic-aa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s 2; RUN: opt < %s -aa-pipeline=basic-aa -passes='require<phi-values>,aa-eval' -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s 3target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" 4target triple = "x86_64-unknown-linux-gnu" 5 6; rdar://7282591 7 8@X = common global i32 0 9@Y = common global i32 0 10@Z = common global i32 0 11 12; CHECK-LABEL: foo 13; CHECK: NoAlias: i32* %P, i32* @Z 14 15define void @foo(i32 %cond) nounwind { 16entry: 17 %"alloca point" = bitcast i32 0 to i32 18 %tmp = icmp ne i32 %cond, 0 19 br i1 %tmp, label %bb, label %bb1 20 21bb: 22 br label %bb2 23 24bb1: 25 br label %bb2 26 27bb2: 28 %P = phi i32* [ @X, %bb ], [ @Y, %bb1 ] 29 %tmp1 = load i32, i32* @Z, align 4 30 store i32 123, i32* %P, align 4 31 %tmp2 = load i32, i32* @Z, align 4 32 br label %return 33 34return: 35 ret void 36} 37 38; Pointers can vary in between iterations of loops. 39; PR18068 40 41; CHECK-LABEL: pr18068 42; CHECK: MayAlias: i32* %0, i32* %arrayidx5 43; CHECK: NoAlias: i32* %arrayidx13, i32* %arrayidx5 44 45define i32 @pr18068(i32* %jj7, i32* %j) { 46entry: 47 %oa5 = alloca [100 x i32], align 16 48 br label %codeRepl 49 50codeRepl: 51 %0 = phi i32* [ %arrayidx13, %for.body ], [ %j, %entry ] 52 %targetBlock = call i1 @cond(i32* %jj7) 53 br i1 %targetBlock, label %for.body, label %bye 54 55for.body: 56 %1 = load i32, i32* %jj7, align 4 57 %idxprom4 = zext i32 %1 to i64 58 %arrayidx5 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i64 %idxprom4 59 %2 = load i32, i32* %arrayidx5, align 4 60 %sub6 = sub i32 %2, 6 61 store i32 %sub6, i32* %arrayidx5, align 4 62 ; %0 and %arrayidx5 can alias! It is not safe to DSE the above store. 63 %3 = load i32, i32* %0, align 4 64 store i32 %3, i32* %arrayidx5, align 4 65 %sub11 = add i32 %1, -1 66 %idxprom12 = zext i32 %sub11 to i64 67 %arrayidx13 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i64 %idxprom12 68 call void @inc(i32* %jj7) 69 br label %codeRepl 70 71bye: 72 %.reload = load i32, i32* %jj7, align 4 73 ret i32 %.reload 74} 75 76declare i1 @cond(i32*) 77 78declare void @inc(i32*) 79 80 81; When we have a chain of phis in nested loops we should recognise if there's 82; actually only one underlying value. 83; CHECK-LABEL: loop_phi_chain 84; CHECK: NoAlias: i32* %val1, i32* @Y 85; CHECK: NoAlias: i32* %val2, i32* @Y 86; CHECK: NoAlias: i32* %val3, i32* @Y 87define void @loop_phi_chain(i32 %a, i32 %b, i32 %c) { 88entry: 89 br label %loop1 90 91loop1: 92 %n1 = phi i32 [ 0, %entry ], [ %add1, %loop2 ] 93 %val1 = phi i32* [ @X, %entry ], [ %val2, %loop2 ] 94 %add1 = add i32 %n1, 1 95 %cmp1 = icmp ne i32 %n1, 32 96 br i1 %cmp1, label %loop2, label %end 97 98loop2: 99 %n2 = phi i32 [ 0, %loop1 ], [ %add2, %loop3 ] 100 %val2 = phi i32* [ %val1, %loop1 ], [ %val3, %loop3 ] 101 %add2 = add i32 %n2, 1 102 %cmp2 = icmp ne i32 %n2, 32 103 br i1 %cmp2, label %loop3, label %loop1 104 105loop3: 106 %n3 = phi i32 [ 0, %loop2 ], [ %add3, %loop3 ] 107 %val3 = phi i32* [ %val2, %loop2 ], [ %val3, %loop3 ] 108 store i32 0, i32* %val3, align 4 109 store i32 0, i32* @Y, align 4 110 %add3 = add i32 %n3, 1 111 %cmp3 = icmp ne i32 %n3, 32 112 br i1 %cmp3, label %loop3, label %loop2 113 114end: 115 ret void 116} 117 118; CHECK-LABEL: phi_and_select 119; CHECK: MustAlias: i32* %p, i32* %s 120define void @phi_and_select(i1 %c, i1 %c2, i32* %x, i32* %y) { 121entry: 122 br i1 %c, label %true, label %false 123 124true: 125 br label %exit 126 127false: 128 br label %exit 129 130exit: 131 %p = phi i32* [ %x, %true ], [ %y, %false ] 132 %s = select i1 %c2, i32* %p, i32* %p 133 store i32 0, i32* %p 134 store i32 0, i32* %s 135 ret void 136} 137 138; CHECK-LABEL: phi_and_phi_cycle 139; CHECK: NoAlias: i32* %p1, i32* %p2 140define void @phi_and_phi_cycle(i32* noalias %x, i32* noalias %y) { 141entry: 142 br label %loop 143 144loop: 145 %p1 = phi i32* [ %x, %entry ], [ %p1.next, %loop ] 146 %p2 = phi i32* [ %y, %entry ], [ %p2.next, %loop ] 147 %p1.next = getelementptr i32, i32* %p1, i64 1 148 %p2.next = getelementptr i32, i32* %p1, i64 2 149 store i32 0, i32* %p1 150 store i32 0, i32* %p2 151 br label %loop 152} 153 154; CHECK-LABEL: phi_and_gep_unknown_size 155; CHECK: Just Mod: call void @llvm.memset.p0i8.i32(i8* %g, i8 0, i32 %size, i1 false) <-> call void @llvm.memset.p0i8.i32(i8* %z, i8 0, i32 %size, i1 false) 156; TODO: This should be NoModRef. 157define void @phi_and_gep_unknown_size(i1 %c, i8* %x, i8* %y, i8* noalias %z, i32 %size) { 158entry: 159 br i1 %c, label %true, label %false 160 161true: 162 br label %exit 163 164false: 165 br label %exit 166 167exit: 168 %p = phi i8* [ %x, %true ], [ %y, %false ] 169 %g = getelementptr inbounds i8, i8* %p, i64 1 170 call void @llvm.memset.p0i8.i32(i8* %g, i8 0, i32 %size, i1 false) 171 call void @llvm.memset.p0i8.i32(i8* %z, i8 0, i32 %size, i1 false) 172 ret void 173} 174 175declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1) 176 177; CHECK-LABEL: unsound_inequality 178; CHECK: MayAlias: i32* %arrayidx13, i32* %phi 179; CHECK: MayAlias: i32* %arrayidx5, i32* %phi 180; CHECK: NoAlias: i32* %arrayidx13, i32* %arrayidx5 181 182; When recursively reasoning about phis, we can't use predicates between 183; two values as we might be comparing the two from different iterations. 184define i32 @unsound_inequality(i32* %jj7, i32* %j) { 185entry: 186 %oa5 = alloca [100 x i32], align 16 187 br label %for.body 188 189for.body: ; preds = %for.body, %entry 190 %phi = phi i32* [ %arrayidx13, %for.body ], [ %j, %entry ] 191 %idx = load i32, i32* %jj7, align 4 192 %arrayidx5 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i32 %idx 193 store i32 0, i32* %arrayidx5, align 4 194 store i32 0, i32* %phi, align 4 195 %notequal = add i32 %idx, 1 196 %arrayidx13 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i32 %notequal 197 store i32 0, i32* %arrayidx13, align 4 198 br label %for.body 199} 200