1 files changed, 95 insertions, 0 deletions
diff --git a/test/Transforms/LoopUnswitch/2011-11-18-SimpleSwitch.ll b/test/Transforms/LoopUnswitch/2011-11-18-SimpleSwitch.ll
new file mode 100644
index 0000000000..a8608b8772
--- /dev/null
+++ b/test/Transforms/LoopUnswitch/2011-11-18-SimpleSwitch.ll
@@ -0,0 +1,95 @@
+; REQUIRES: asserts
+; RUN: opt -loop-unswitch -disable-output -stats -info-output-file - < %s | FileCheck --check-prefix=STATS %s
+; RUN: opt -S -loop-unswitch -verify-loop-info -verify-dom-info < %s | FileCheck %s
+
+; STATS: 1 loop-simplify - Number of pre-header or exit blocks inserted
+; STATS: 2 loop-unswitch - Number of switches unswitched
+
+; CHECK:      %1 = icmp eq i32 %c, 1
+; CHECK-NEXT: br i1 %1, label %.split.us, label %..split_crit_edge
+
+; CHECK:      ..split_crit_edge:                                ; preds = %0
+; CHECK-NEXT:   br label %.split
+
+; CHECK:      .split.us:                                        ; preds = %0
+; CHECK-NEXT:   br label %loop_begin.us
+
+; CHECK:      loop_begin.us:                                    ; preds = %loop_begin.backedge.us, %.split.us
+; CHECK-NEXT:   %var_val.us = load i32* %var
+; CHECK-NEXT:   switch i32 1, label %default.us-lcssa.us [
+; CHECK-NEXT:     i32 1, label %inc.us
+
+; CHECK:      inc.us:                                           ; preds = %loop_begin.us
+; CHECK-NEXT:   call void @incf() [[NOR_NUW:#[0-9]+]]
+; CHECK-NEXT:   br label %loop_begin.backedge.us
+
+; CHECK:      .split:                                           ; preds = %..split_crit_edge
+; CHECK-NEXT:   %2 = icmp eq i32 %c, 2
+; CHECK-NEXT:   br i1 %2, label %.split.split.us, label %.split..split.split_crit_edge
+
+; CHECK:      .split..split.split_crit_edge:                    ; preds = %.split
+; CHECK-NEXT:   br label %.split.split
+
+; CHECK:      .split.split.us:                                  ; preds = %.split
+; CHECK-NEXT:   br label %loop_begin.us1
+
+; CHECK:      loop_begin.us1:                                   ; preds = %loop_begin.backedge.us5, %.split.split.us
+; CHECK-NEXT:   %var_val.us2 = load i32* %var
+; CHECK-NEXT:   switch i32 2, label %default.us-lcssa.us-lcssa.us [
+; CHECK-NEXT:     i32 1, label %inc.us4
+; CHECK-NEXT:     i32 2, label %dec.us3
+; CHECK-NEXT:   ]
+
+; CHECK:      dec.us3:                                          ; preds = %loop_begin.us1
+; CHECK-NEXT:   call void @decf() [[NOR_NUW]]
+; CHECK-NEXT:   br label %loop_begin.backedge.us5
+
+; CHECK:      .split.split:                                     ; preds = %.split..split.split_crit_edge
+; CHECK-NEXT:   br label %loop_begin
+
+; CHECK:      loop_begin:                                       ; preds = %loop_begin.backedge, %.split.split
+; CHECK-NEXT:   %var_val = load i32* %var
+; CHECK-NEXT:   switch i32 %c, label %default.us-lcssa.us-lcssa [
+; CHECK-NEXT:     i32 1, label %inc
+; CHECK-NEXT:     i32 2, label %dec
+; CHECK-NEXT:   ]
+
+; CHECK:      inc:                                              ; preds = %loop_begin
+; CHECK-NEXT:   br i1 true, label %us-unreachable.us-lcssa, label %inc.split
+
+; CHECK:      dec:                                              ; preds = %loop_begin
+; CHECK-NEXT:   br i1 true, label %us-unreachable6, label %dec.split
+
+define i32 @test(i32* %var) {
+  %mem = alloca i32
+  store i32 2, i32* %mem
+  %c = load i32* %mem
+
+  br label %loop_begin
+
+loop_begin:
+
+  %var_val = load i32* %var
+
+  switch i32 %c, label %default [
+      i32 1, label %inc
+      i32 2, label %dec
+  ]
+
+inc:
+  call void @incf() noreturn nounwind
+  br label %loop_begin
+dec:
+  call void @decf() noreturn nounwind
+  br label %loop_begin
+default:
+  br label %loop_exit
+loop_exit:
+  ret i32 0
+}
+
+declare void @incf() noreturn
+declare void @decf() noreturn
+
+; CHECK: attributes #0 = { noreturn }
+; CHECK: attributes [[NOR_NUW]] = { noreturn nounwind }