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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; BasicAA should detect NoAliases in PHIs and Selects.4 5; Two PHIs in the same block.6; CHECK-LABEL: Function: foo7; CHECK: NoAlias: double* %a, double* %b8define void @foo(i1 %m, ptr noalias %x, ptr noalias %y) {9entry:10 br i1 %m, label %true, label %false11 12true:13 br label %exit14 15false:16 br label %exit17 18exit:19 %a = phi ptr [ %x, %true ], [ %y, %false ]20 %b = phi ptr [ %x, %false ], [ %y, %true ]21 store volatile double 0.0, ptr %a22 store volatile double 1.0, ptr %b23 ret void24}25 26; Two selects with the same condition.27; CHECK-LABEL: Function: bar28; CHECK: NoAlias: double* %a, double* %b29define void @bar(i1 %m, ptr noalias %x, ptr noalias %y) {30entry:31 %a = select i1 %m, ptr %x, ptr %y32 %b = select i1 %m, ptr %y, ptr %x33 store volatile double 0.000000e+00, ptr %a34 store volatile double 1.000000e+00, ptr %b35 ret void36}37 38; Two PHIs with disjoint sets of inputs.39; CHECK-LABEL: Function: qux40; CHECK: NoAlias: double* %a, double* %b41define void @qux(i1 %m, ptr noalias %x, ptr noalias %y,42 i1 %n, ptr noalias %v, ptr noalias %w) {43entry:44 br i1 %m, label %true, label %false45 46true:47 br label %exit48 49false:50 br label %exit51 52exit:53 %a = phi ptr [ %x, %true ], [ %y, %false ]54 br i1 %n, label %ntrue, label %nfalse55 56ntrue:57 br label %nexit58 59nfalse:60 br label %nexit61 62nexit:63 %b = phi ptr [ %v, %ntrue ], [ %w, %nfalse ]64 store volatile double 0.0, ptr %a65 store volatile double 1.0, ptr %b66 ret void67}68 69; Two selects with disjoint sets of arms.70; CHECK-LABEL: Function: fin71; CHECK: NoAlias: double* %a, double* %b72define void @fin(i1 %m, ptr noalias %x, ptr noalias %y,73 i1 %n, ptr noalias %v, ptr noalias %w) {74entry:75 %a = select i1 %m, ptr %x, ptr %y76 %b = select i1 %n, ptr %v, ptr %w77 store volatile double 0.000000e+00, ptr %a78 store volatile double 1.000000e+00, ptr %b79 ret void80}81 82; On the first iteration, sel1 = a1, sel2 = a2, phi = a383; On the second iteration, sel1 = a2, sel1 = a1, phi = a284; As such, sel1 and phi may alias.85; CHECK-LABEL: Function: select_backedge86; CHECK: NoAlias: i32* %sel1, i32* %sel287; CHECK: MayAlias: i32* %phi, i32* %sel188; CHECK: MayAlias: i32* %phi, i32* %sel289define void @select_backedge() {90entry:91 %a1 = alloca i3292 %a2 = alloca i3293 %a3 = alloca i3294 br label %loop95 96loop:97 %phi = phi ptr [ %a3, %entry ], [ %sel2, %loop ]98 %c = phi i1 [ true, %entry ], [ false, %loop ]99 %sel1 = select i1 %c, ptr %a1, ptr %a2100 %sel2 = select i1 %c, ptr %a2, ptr %a1101 load i32, ptr %sel1102 load i32, ptr %sel2103 load i32, ptr %phi104 br label %loop105}106