; RUN: opt -basic-aa -loop-distribute -enable-loop-distribute -loop-simplify -scoped-noalias-aa \ ; RUN: -loop-versioning -S < %s | FileCheck %s ; Test the metadata generated when versioning an already versioned loop. Here ; we invoke loop distribution to perform the first round of versioning. It ; adds memchecks for accesses that can alias across the distribution boundary. ; Then we further version the distributed loops to fully disambiguate accesses ; within each. ; ; So as an example, we add noalias between C and A during the versioning ; within loop distribution and then add noalias between C and D during the ; second explicit versioning step: ; ; for (i = 0; i < n; i++) { ; A[i + 1] = A[i] * B[i]; ; ------------------------------- ; C[i] = D[i] * E[i]; ; } ; To see it easier what's going on, I expanded every noalias/scope metadata ; reference below in a comment. For a scope I use the format scope(domain), ; e.g. scope 17 in domain 15 is written as 17(15). target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" @B = common global i32* null, align 8 @A = common global i32* null, align 8 @C = common global i32* null, align 8 @D = common global i32* null, align 8 @E = common global i32* null, align 8 define void @f() { entry: %a = load i32*, i32** @A, align 8 %b = load i32*, i32** @B, align 8 %c = load i32*, i32** @C, align 8 %d = load i32*, i32** @D, align 8 %e = load i32*, i32** @E, align 8 br label %for.body for.body: ; preds = %for.body, %entry %ind = phi i64 [ 0, %entry ], [ %add, %for.body ] %arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind ; CHECK: %loadA.ldist1 = {{.*}} !noalias !25 ; A noalias C: !25 -> { 17(15), 18(15), 19(15), 26(24) } ; ^^^^^^ %loadA = load i32, i32* %arrayidxA, align 4 %arrayidxB = getelementptr inbounds i32, i32* %b, i64 %ind %loadB = load i32, i32* %arrayidxB, align 4 %mulA = mul i32 %loadB, %loadA %add = add nuw nsw i64 %ind, 1 %arrayidxA_plus_4 = getelementptr inbounds i32, i32* %a, i64 %add store i32 %mulA, i32* %arrayidxA_plus_4, align 4 ; CHECK: for.body: %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind ; CHECK: %loadD = {{.*}} !alias.scope !31 ; D's scope: !31 -> { 18(15), 32(33) } ; ^^^^^^ %loadD = load i32, i32* %arrayidxD, align 4 %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind ; CHECK: %loadE = {{.*}} !alias.scope !34 ; E's scope: !34 -> { 19(15), 35(33) } ; ^^^^^^ %loadE = load i32, i32* %arrayidxE, align 4 %mulC = mul i32 %loadD, %loadE %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind ; CHECK: store i32 %mulC, {{.*}} !alias.scope !36, !noalias !38 ; C's scope: !36 -> { 17(15), 37(33) } ; ^^^^^^ ; C noalias D and E: !38 -> { 21(15), 32(33), 35(33) } ; ^^^^^^ ^^^^^^ store i32 %mulC, i32* %arrayidxC, align 4 %exitcond = icmp eq i64 %add, 20 br i1 %exitcond, label %for.end, label %for.body for.end: ; preds = %for.body ret void } ; Domain for the second loop versioning for the top loop after ; distribution. ; CHECK: !15 = distinct !{!15, !"LVerDomain"} ; CHECK: !17 = distinct !{!17, !15} ; CHECK: !25 = !{!17, !18, !19, !26} ; CHECK: !31 = !{!18, !32} ; CHECK: !32 = distinct !{!32, !33} ; Domain for the second loop versioning for the bottom loop after ; distribution. ; CHECK: !33 = distinct !{!33, !"LVerDomain"} ; CHECK: !34 = !{!19, !35} ; CHECK: !35 = distinct !{!35, !33} ; CHECK: !36 = !{!17, !37} ; CHECK: !38 = !{!21, !32, !35}