1 files changed, 106 insertions, 0 deletions
diff --git a/test/Transforms/LoopVersioning/noalias-version-twice.ll b/test/Transforms/LoopVersioning/noalias-version-twice.ll
new file mode 100644
index 0000000000000..81ec0c0dc9f69
--- /dev/null
+++ b/test/Transforms/LoopVersioning/noalias-version-twice.ll
@@ -0,0 +1,106 @@
+; RUN: opt -basicaa -loop-distribute -scoped-noalias -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}