noalias-version-twice.ll
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; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -loop-simplify -scoped-noalias \
; 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}