Avoid a bug in the path count computation, preventing an infinite

loop repeatedlt making the same change. This is for rdar://11256239.

llvm-svn: 155160

1 files changed, 48 insertions, 0 deletions

diff --git a/llvm/test/Transforms/ObjCARC/split-backedge.ll b/llvm/test/Transforms/ObjCARC/split-backedge.ll
new file mode 100644
index 00000000000..08e2dce1f55
--- /dev/null
+++ b/llvm/test/Transforms/ObjCARC/split-backedge.ll
@@ -0,0 +1,48 @@
+; RUN: opt -S -objc-arc < %s | FileCheck %s
+
+; Handle a retain+release pair entirely contained within a split loop backedge.
+; rdar://11256239
+
+; CHECK: define void @test0
+; CHECK: call i8* @objc_retain(i8* %call) nounwind
+; CHECK: call i8* @objc_retain(i8* %call) nounwind
+; CHECK: call i8* @objc_retain(i8* %cond) nounwind
+; CHECK: call void @objc_release(i8* %call) nounwind
+; CHECK: call void @objc_release(i8* %call) nounwind
+; CHECK: call void @objc_release(i8* %cond) nounwind
+define void @test0() {
+entry:
+  br label %while.body
+
+while.body:                                       ; preds = %while.cond
+  %call = invoke i8* @returner()
+          to label %invoke.cont unwind label %lpad, !clang.arc.no_objc_arc_exceptions !0
+
+invoke.cont:                                      ; preds = %while.body
+  %t0 = call i8* @objc_retain(i8* %call) nounwind
+  %t1 = call i8* @objc_retain(i8* %call) nounwind
+  %call.i1 = invoke i8* @returner()
+          to label %invoke.cont1 unwind label %lpad
+
+invoke.cont1:                                     ; preds = %invoke.cont
+  %cond = select i1 undef, i8* null, i8* %call
+  %t2 = call i8* @objc_retain(i8* %cond) nounwind
+  call void @objc_release(i8* %call) nounwind
+  call void @objc_release(i8* %call) nounwind
+  call void @use_pointer(i8* %cond)
+  call void @objc_release(i8* %cond) nounwind
+  br label %while.body
+
+lpad:                                             ; preds = %invoke.cont, %while.body
+  %t4 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__objc_personality_v0 to i8*)
+          catch i8* null
+  ret void
+}
+
+declare i8* @returner()
+declare i32 @__objc_personality_v0(...)
+declare void @objc_release(i8*)
+declare i8* @objc_retain(i8*)
+declare void @use_pointer(i8*)
+
+!0 = metadata !{}