1 files changed, 58 insertions, 0 deletions
diff --git a/test/Transforms/LoopUnroll/full-unroll-bad-cost.ll b/test/Transforms/LoopUnroll/full-unroll-bad-cost.ll
new file mode 100644
index 000000000000..e5694fbeb0ce
--- /dev/null
+++ b/test/Transforms/LoopUnroll/full-unroll-bad-cost.ll
@@ -0,0 +1,58 @@
+; RUN: opt -S -loop-unroll < %s | FileCheck %s
+
+; LLVM should not try to fully unroll this loop.
+
+declare void @f()
+declare void @g()
+declare void @h()
+
+define void @trivial_loop() {
+; CHECK-LABEL: @trivial_loop(
+ entry:
+  br label %loop
+
+ loop:
+  %idx = phi i32 [ 0, %entry ], [ %idx.inc, %loop ]
+  %idx.inc = add i32 %idx, 1
+  call void @f()
+  call void @g()
+  call void @h()
+  call void @f()
+  call void @g()
+  call void @h()
+  call void @f()
+  call void @g()
+  call void @h()
+  call void @f()
+  call void @g()
+  call void @h()
+  call void @f()
+  call void @g()
+  call void @h()
+  %be = icmp slt i32 %idx, 268435456
+  br i1 %be, label %loop, label %exit
+
+; CHECK: loop:
+; CHECK-NEXT:  %idx = phi i32 [ 0, %entry ], [ %idx.inc, %loop ]
+; CHECK-NEXT:  %idx.inc = add i32 %idx, 1
+; CHECK-NEXT:  call void @f()
+; CHECK-NEXT:  call void @g()
+; CHECK-NEXT:  call void @h()
+; CHECK-NEXT:  call void @f()
+; CHECK-NEXT:  call void @g()
+; CHECK-NEXT:  call void @h()
+; CHECK-NEXT:  call void @f()
+; CHECK-NEXT:  call void @g()
+; CHECK-NEXT:  call void @h()
+; CHECK-NEXT:  call void @f()
+; CHECK-NEXT:  call void @g()
+; CHECK-NEXT:  call void @h()
+; CHECK-NEXT:  call void @f()
+; CHECK-NEXT:  call void @g()
+; CHECK-NEXT:  call void @h()
+; CHECK-NEXT:  %be = icmp slt i32 %idx, 268435456
+; CHECK-NEXT:  br i1 %be, label %loop, label %exit
+
+ exit:
+  ret void
+}