1 files changed, 54 insertions, 0 deletions
diff --git a/llvm/test/Analysis/ScalarEvolution/unknown_phis.ll b/llvm/test/Analysis/ScalarEvolution/unknown_phis.ll
new file mode 100644
index 00000000000..e5335b1ae91
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/unknown_phis.ll
@@ -0,0 +1,54 @@
+; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
+
+define void @merge_values_with_ranges(i32 *%a_len_ptr, i32 *%b_len_ptr, i1 %unknown_cond) {
+
+; CHECK-LABEL: Classifying expressions for: @merge_values_with_ranges
+; CHECK:       %len = phi i32 [ %len_a, %if.true ], [ %len_b, %if.false ]
+; CHECK-NEXT:  -->  %len U: [0,2147483647) S: [0,2147483647)
+
+ entry:
+  br i1 %unknown_cond, label %if.true, label %if.false
+
+if.true:
+  %len_a = load i32, i32* %a_len_ptr, !range !0
+  br label %merge
+
+if.false:
+  %len_b = load i32, i32* %b_len_ptr, !range !0
+  br label %merge
+
+merge:
+  %len = phi i32 [ %len_a, %if.true ], [ %len_b, %if.false ]
+  ret void
+}
+
+define void @merge_values_with_ranges_looped(i32 *%a_len_ptr, i32 *%b_len_ptr) {
+
+; TODO: We could be much smarter here. So far we just make sure that we do not
+;       go into infinite loop analyzing these Phis.
+
+; CHECK-LABEL: Classifying expressions for: @merge_values_with_ranges_looped
+; CHECK:       %p1 = phi i32 [ %len_a, %entry ], [ %p2, %loop ]
+; CHECK-NEXT:  -->  %p1 U: full-set S: full-set
+; CHECK:         %p2 = phi i32 [ %len_b, %entry ], [ %p1, %loop ]
+; CHECK-NEXT:  -->  %p2 U: full-set S: full-set
+
+ entry:
+  %len_a = load i32, i32* %a_len_ptr, !range !0
+  %len_b = load i32, i32* %b_len_ptr, !range !0
+  br label %loop
+
+loop:
+  %p1 = phi i32 [ %len_a, %entry ], [ %p2, %loop ]
+  %p2 = phi i32 [ %len_b, %entry ], [ %p1, %loop ]
+  %iv = phi i32 [ 0, %entry ], [ %iv.next, %loop ]
+  %iv.next = add i32 %iv, 1
+  %loop.cond = icmp slt i32 %iv.next, 100
+  br i1 %loop.cond, label %loop, label %exit
+
+exit:
+  ret void
+}
+
+
+!0 = !{i32 0, i32 2147483647}