--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/llvm/test/Transforms/LoopDistribute/basic.ll	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,159 @@
+; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -verify-loop-info -verify-dom-info -S \
+; RUN:   < %s | FileCheck %s
+
+; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -verify-loop-info -verify-dom-info \
+; RUN:   -loop-accesses -analyze < %s | FileCheck %s --check-prefix=ANALYSIS
+
+; RUN: opt -basicaa -loop-distribute -enable-loop-distribute -loop-vectorize -force-vector-width=4 -S \
+; RUN:   < %s | FileCheck %s --check-prefix=VECTORIZE
+
+; We should distribute this loop into a safe (2nd statement) and unsafe loop
+; (1st statement):
+;   for (i = 0; i < n; i++) {
+;     A[i + 1] = A[i] * B[i];
+;     =======================
+;     C[i] = D[i] * E[i];
+;   }
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.10.0"
+
+; CHECK-LABEL: @f(
+define void @f(i32* noalias %a,
+               i32* noalias %b,
+               i32* noalias %c,
+               i32* noalias %d,
+               i32* noalias %e) {
+entry:
+  br label %for.body
+
+; Verify the two distributed loops.
+
+; CHECK: entry.split.ldist1:
+; CHECK:    br label %for.body.ldist1
+; CHECK: for.body.ldist1:
+; CHECK:    %mulA.ldist1 = mul i32 %loadB.ldist1, %loadA.ldist1
+; CHECK:    br i1 %exitcond.ldist1, label %entry.split, label %for.body.ldist1
+
+; CHECK: entry.split:
+; CHECK:    br label %for.body
+; CHECK: for.body:
+; CHECK:    %mulC = mul i32 %loadD, %loadE
+; CHECK: for.end:
+
+
+; ANALYSIS: for.body:
+; ANALYSIS-NEXT: Memory dependences are safe{{$}}
+; ANALYSIS: for.body.ldist1:
+; ANALYSIS-NEXT: Report: unsafe dependent memory operations in loop
+
+
+; VECTORIZE: mul <4 x i32>
+
+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
+
+  %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
+
+  %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
+  %loadD = load i32, i32* %arrayidxD, align 4
+
+  %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
+  %loadE = load i32, i32* %arrayidxE, align 4
+
+  %mulC = mul i32 %loadD, %loadE
+
+  %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
+  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
+}
+
+declare i32 @llvm.convergent(i32) #0
+
+; It is OK to distribute with a convergent operation, since in each
+; new loop the convergent operation has the ssame control dependency.
+; CHECK-LABEL: @f_with_convergent(
+define void @f_with_convergent(i32* noalias %a,
+                               i32* noalias %b,
+                               i32* noalias %c,
+                               i32* noalias %d,
+                               i32* noalias %e) {
+entry:
+  br label %for.body
+
+; Verify the two distributed loops.
+
+; CHECK: entry.split.ldist1:
+; CHECK:    br label %for.body.ldist1
+; CHECK: for.body.ldist1:
+; CHECK:    %mulA.ldist1 = mul i32 %loadB.ldist1, %loadA.ldist1
+; CHECK:    br i1 %exitcond.ldist1, label %entry.split, label %for.body.ldist1
+
+; CHECK: entry.split:
+; CHECK:    br label %for.body
+; CHECK: for.body:
+; CHECK:    %convergentD = call i32 @llvm.convergent(i32 %loadD)
+; CHECK:    %mulC = mul i32 %convergentD, %loadE
+; CHECK: for.end:
+
+
+; ANALYSIS: for.body:
+; ANALYSIS-NEXT: Has convergent operation in loop
+; ANALYSIS-NEXT: Report: cannot add control dependency to convergent operation
+; ANALYSIS: for.body.ldist1:
+; ANALYSIS-NEXT: Report: unsafe dependent memory operations in loop
+
+; convergent instruction happens to block vectorization
+; VECTORIZE: call i32 @llvm.convergent
+; VECTORIZE: mul i32
+
+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
+
+  %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
+
+  %arrayidxD = getelementptr inbounds i32, i32* %d, i64 %ind
+  %loadD = load i32, i32* %arrayidxD, align 4
+
+  %arrayidxE = getelementptr inbounds i32, i32* %e, i64 %ind
+  %loadE = load i32, i32* %arrayidxE, align 4
+
+  %convergentD = call i32 @llvm.convergent(i32 %loadD)
+  %mulC = mul i32 %convergentD, %loadE
+
+  %arrayidxC = getelementptr inbounds i32, i32* %c, i64 %ind
+  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
+}
+
+attributes #0 = { nounwind readnone convergent }