Imported Upstream version 5.18.0.179

Former-commit-id: 67aa10e65b237e1c4537630979ee99ebe1374215

external/llvm/test/Transforms/ObjCARC/empty-block.ll

@@ -0,0 +1,59 @@
+; RUN: opt -S -objc-arc < %s | FileCheck %s
+; rdar://10210274
+
+%0 = type opaque
+
+declare i8* @objc_retain(i8*)
+
+declare void @objc_release(i8*)
+
+declare i8* @objc_autoreleaseReturnValue(i8*)
+
+; Don't delete the autorelease.
+
+; CHECK-LABEL: define %0* @test0(
+; CHECK:   @objc_retain
+; CHECK: .lr.ph:
+; CHECK-NOT: @objc_r
+; CHECK: @objc_autoreleaseReturnValue
+; CHECK-NOT: @objc_
+; CHECK: }
+define %0* @test0(%0* %buffer) nounwind {
+  %1 = bitcast %0* %buffer to i8*
+  %2 = tail call i8* @objc_retain(i8* %1) nounwind
+  br i1 undef, label %.lr.ph, label %._crit_edge
+
+.lr.ph:                                           ; preds = %.lr.ph, %0
+  br i1 false, label %.lr.ph, label %._crit_edge
+
+._crit_edge:                                      ; preds = %.lr.ph, %0
+  %3 = tail call i8* @objc_retain(i8* %1) nounwind
+  tail call void @objc_release(i8* %1) nounwind, !clang.imprecise_release !0
+  %4 = tail call i8* @objc_autoreleaseReturnValue(i8* %1) nounwind
+  ret %0* %buffer
+}
+
+; Do delete the autorelease, even with the retain in a different block.
+
+; CHECK-LABEL: define %0* @test1(
+; CHECK-NOT: @objc
+; CHECK: }
+define %0* @test1() nounwind {
+  %buffer = call %0* @foo()
+  %1 = bitcast %0* %buffer to i8*
+  %2 = tail call i8* @objc_retain(i8* %1) nounwind
+  br i1 undef, label %.lr.ph, label %._crit_edge
+
+.lr.ph:                                           ; preds = %.lr.ph, %0
+  br i1 false, label %.lr.ph, label %._crit_edge
+
+._crit_edge:                                      ; preds = %.lr.ph, %0
+  %3 = tail call i8* @objc_retain(i8* %1) nounwind
+  tail call void @objc_release(i8* %1) nounwind, !clang.imprecise_release !0
+  %4 = tail call i8* @objc_autoreleaseReturnValue(i8* %1) nounwind
+  ret %0* %buffer
+}
+
+declare %0* @foo()
+
+!0 = !{}