1 files changed, 41 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopVectorize/multi-use-reduction-bug.ll b/llvm/test/Transforms/LoopVectorize/multi-use-reduction-bug.ll
new file mode 100644
index 00000000000..4fdb0178410
--- /dev/null
+++ b/llvm/test/Transforms/LoopVectorize/multi-use-reduction-bug.ll
@@ -0,0 +1,41 @@
+; RUN: opt -indvars -loop-vectorize -force-vector-width=2 -force-vector-interleave=1 -S < %s | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+; We must not vectorize this loop. %add55 is not reduction. Its value is used
+; multiple times.
+
+; PR18526
+
+; CHECK: multiple_use_of_value
+; CHECK-NOT: <2 x i32>
+
+define void @multiple_use_of_value() {
+entry:
+  %n = alloca i32, align 4
+  %k7 = alloca i32, align 4
+  %nf = alloca i32, align 4
+  %0 = load i32, i32* %k7, align 4
+  %.neg1 = sub i32 0, %0
+  %n.promoted = load i32, i32* %n, align 4
+  %nf.promoted = load i32, i32* %nf, align 4
+  br label %for.body
+
+for.body:
+  %inc107 = phi i32 [ undef, %entry ], [ %inc10, %for.body ]
+  %inc6 = phi i32 [ %nf.promoted, %entry ], [ undef, %for.body ]
+  %add55 = phi i32 [ %n.promoted, %entry ], [ %add5, %for.body ]
+  %.neg2 = sub i32 0, %inc6
+  %add.neg = add i32 0, %add55
+  %add4.neg = add i32 %add.neg, %.neg1
+  %sub = add i32 %add4.neg, %.neg2
+  %add5 = add i32 %sub, %add55
+  %inc10 = add i32 %inc107, 1
+  %cmp = icmp ult i32 %inc10, 61
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:
+  %add5.lcssa = phi i32 [ %add5, %for.body ]
+  store i32 %add5.lcssa, i32* %n, align 4
+  ret void
+}