1 files changed, 81 insertions, 0 deletions
diff --git a/llvm/test/Analysis/ScalarEvolution/trip-count13.ll b/llvm/test/Analysis/ScalarEvolution/trip-count13.ll
new file mode 100644
index 00000000000..37ef2fd500a
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/trip-count13.ll
@@ -0,0 +1,81 @@
+; RUN: opt -S -analyze -scalar-evolution < %s | FileCheck %s
+
+define void @u_0(i8 %rhs) {
+; E.g.: %rhs = 255, %start = 99, backedge taken 156 times
+entry:
+  %start = add i8 %rhs, 100
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
+  %iv.inc = add nuw i8 %iv, 1  ;; Note: this never unsigned-wraps
+  %iv.cmp = icmp ult i8 %iv, %rhs
+  br i1 %iv.cmp, label %loop, label %leave
+
+; CHECK-LABEL: Determining loop execution counts for: @u_0
+; CHECK-NEXT: Loop %loop: backedge-taken count is (-100 + (-1 * %rhs) + ((100 + %rhs) umax %rhs))
+; CHECK-NEXT: Loop %loop: max backedge-taken count is -1
+
+leave:
+  ret void
+}
+
+define void @u_1(i8 %start) {
+entry:
+; E.g.: %start = 99, %rhs = 255, backedge taken 156 times
+  %rhs = add i8 %start, -100
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
+  %iv.inc = add nuw i8 %iv, 1  ;; Note: this never unsigned-wraps
+  %iv.cmp = icmp ult i8 %iv, %rhs
+  br i1 %iv.cmp, label %loop, label %leave
+
+; CHECK-LABEL: Determining loop execution counts for: @u_1
+; CHECK-NEXT: Loop %loop: backedge-taken count is ((-1 * %start) + ((-100 + %start) umax %start))
+; CHECK-NEXT: Loop %loop: max backedge-taken count is -1
+
+leave:
+  ret void
+}
+
+define void @s_0(i8 %rhs) {
+entry:
+; E.g.: %rhs = 127, %start = -29, backedge taken 156 times
+  %start = add i8 %rhs, 100
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
+  %iv.inc = add nsw i8 %iv, 1  ;; Note: this never signed-wraps
+  %iv.cmp = icmp slt i8 %iv, %rhs
+  br i1 %iv.cmp, label %loop, label %leave
+
+; CHECK-LABEL: Determining loop execution counts for: @s_0
+; CHECK-NEXT: Loop %loop: backedge-taken count is (-100 + (-1 * %rhs) + ((100 + %rhs) smax %rhs))
+; CHECK-NEXT: Loop %loop: max backedge-taken count is -1
+
+leave:
+  ret void
+}
+
+define void @s_1(i8 %start) {
+entry:
+; E.g.: start = -29, %rhs = 127, %backedge taken 156 times
+  %rhs = add i8 %start, -100
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %start, %entry ], [ %iv.inc, %loop ]
+  %iv.inc = add nsw i8 %iv, 1
+  %iv.cmp = icmp slt i8 %iv, %rhs
+  br i1 %iv.cmp, label %loop, label %leave
+
+; CHECK-LABEL: Determining loop execution counts for: @s_1
+; CHECK-NEXT: Loop %loop: backedge-taken count is ((-1 * %start) + ((-100 + %start) smax %start))
+; CHECK-NEXT: Loop %loop: max backedge-taken count is -1
+
+leave:
+  ret void
+}