1 files changed, 55 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopUnroll/pr31718.ll b/llvm/test/Transforms/LoopUnroll/pr31718.ll
new file mode 100644
index 00000000000..014ef7e501e
--- /dev/null
+++ b/llvm/test/Transforms/LoopUnroll/pr31718.ll
@@ -0,0 +1,55 @@
+; RUN: opt -loop-unroll -verify-loop-lcssa -S < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@b = external local_unnamed_addr global i32, align 4
+
+; CHECK-LABEL: @main
+; CHECK: exit.loopexit:
+; CHECK: {{.*}} = phi i32 [ %d.0, %h3 ]
+; CHECK: br label %exit
+; CHECK: exit.loopexit1:
+; CHECK: {{.*}} = phi i32 [ %d.0, %h3.1 ]
+; CHECK: br label %exit
+
+define void @main() local_unnamed_addr #0 {
+ph1:
+  br label %h1
+
+h1:
+  %d.0 = phi i32 [ %1, %latch1 ], [ undef, %ph1 ]
+  br label %ph2
+
+ph2:
+  br label %h2
+
+h2:
+  %0 = phi i32 [ 0, %ph2 ], [ %inc, %latch2 ]
+  br label %h3
+
+h3:
+  br i1 undef, label %latch3, label %exit
+
+latch3:
+  br i1 false, label %exit3, label %h3
+
+exit3:
+  br label %latch2
+
+latch2:
+  %inc = add nuw nsw i32 %0, 1
+  %cmp = icmp slt i32 %inc, 2
+  br i1 %cmp, label %h2, label %exit2
+
+exit2:
+  br i1 undef, label %latch1, label %ph2
+
+latch1:                 ; preds = %exit2
+  %1 = load i32, i32* @b, align 4
+  br label %h1
+
+exit:
+  %d.0.lcssa = phi i32 [ %d.0, %h3 ]
+  ret void
+}