1 files changed, 65 insertions, 0 deletions
diff --git a/test/Transforms/LoopDistribute/program-order.ll b/test/Transforms/LoopDistribute/program-order.ll
new file mode 100644
index 0000000000000..b534b79af71a4
--- /dev/null
+++ b/test/Transforms/LoopDistribute/program-order.ll
@@ -0,0 +1,65 @@
+; RUN: opt -loop-distribute -S -verify-loop-info -verify-dom-info < %s \
+; RUN:   | FileCheck %s
+
+; Distributing this loop to avoid the dependence cycle would require to
+; reorder S1 and S2 to form the two partitions: {S2} | {S1, S3}.  The analysis
+; provided by LoopAccessAnalysis does not allow us to reorder memory
+; operations so make sure we bail on this loop.
+;
+;   for (i = 0; i < n; i++) {
+;     S1: d = D[i];
+;     S2: A[i + 1] = A[i] * B[i];
+;     S3: C[i] = d * E[i];
+;   }
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.10.0"
+
+define void @f(i32* noalias %a,
+               i32* noalias %b,
+               i32* noalias %c,
+               i32* noalias %d,
+               i32* noalias %e) {
+entry:
+  br label %for.body
+
+; CHECK: entry:
+; CHECK:    br label %for.body
+; CHECK: for.body:
+; CHECK:    br i1 %exitcond, label %for.end, label %for.body
+; CHECK: for.end:
+; CHECK:    ret void
+
+for.body:                                         ; preds = %for.body, %entry
+  %ind = phi i64 [ 0, %entry ], [ %add, %for.body ]
+
+  %arrayidxA = getelementptr inbounds i32, i32* %a, i64 %ind
+  %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
+
+  %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
+  %loadD = load i32, i32* %arrayidxD, align 4
+
+  %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
+
+  %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
+
+  %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
+  %loadE = load i32, i32* %arrayidxE, align 4
+
+  %mulC = mul i32 %loadD, %loadE
+
+  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
+}