Implement proper ObjC ARC objc_retainBlock "escape" analysis, so that

the optimizer doesn't eliminate objc_retainBlock calls which are needed
for their side effect of copying blocks onto the heap.
This implements rdar://10361249.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148076 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 138 insertions, 0 deletions

diff --git a/test/Transforms/ObjCARC/retain-block.ll b/test/Transforms/ObjCARC/retain-block.ll
new file mode 100644
index 0000000000..b3b62d3000
--- /dev/null
+++ b/test/Transforms/ObjCARC/retain-block.ll
@@ -0,0 +1,138 @@
+; RUN: opt -objc-arc -S < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64"
+
+!0 = metadata !{}
+
+declare i8* @objc_retain(i8*)
+declare void @callee(i8)
+declare void @use_pointer(i8*)
+declare void @objc_release(i8*)
+declare i8* @objc_retainBlock(i8*)
+declare i8* @objc_autorelease(i8*)
+
+; Basic retainBlock+release elimination.
+
+; CHECK: define void @test0(i8* %tmp) {
+; CHECK-NOT: @objc
+; CHECK: }
+define void @test0(i8* %tmp) {
+entry:
+  %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; Same as test0, but there's no copy_on_escape metadata, so there's no
+; optimization possible.
+
+; CHECK: define void @test0_no_metadata(i8* %tmp) {
+; CHECK: %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind
+; CHECK: tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+; CHECK: }
+define void @test0_no_metadata(i8* %tmp) {
+entry:
+  %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; Same as test0, but the pointer escapes, so there's no
+; optimization possible.
+
+; CHECK: define void @test0_escape(i8* %tmp, i8** %z) {
+; CHECK: %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+; CHECK: tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+; CHECK: }
+define void @test0_escape(i8* %tmp, i8** %z) {
+entry:
+  %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+  store i8* %tmp2, i8** %z
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; Same as test0_escape, but there's no intervening call.
+
+; CHECK: define void @test0_just_escape(i8* %tmp, i8** %z) {
+; CHECK: %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+; CHECK: tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+; CHECK: }
+define void @test0_just_escape(i8* %tmp, i8** %z) {
+entry:
+  %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+  store i8* %tmp2, i8** %z
+  tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; Basic nested retainBlock+release elimination.
+
+; CHECK: define void @test1(i8* %tmp) {
+; CHECK-NOT: @objc
+; CHECK: tail call i8* @objc_retain(i8* %tmp) nounwind
+; CHECK-NOT: @objc
+; CHECK: tail call void @objc_release(i8* %tmp) nounwind, !clang.imprecise_release !0
+; CHECK-NOT: @objc
+; CHECK: }
+define void @test1(i8* %tmp) {
+entry:
+  %tmp1 = tail call i8* @objc_retain(i8* %tmp) nounwind
+  %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+  tail call void @objc_release(i8* %tmp) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; Same as test1, but there's no copy_on_escape metadata, so there's no
+; retainBlock+release optimization possible. But we can still eliminate
+; the outer retain+release.
+
+; CHECK: define void @test1_no_metadata(i8* %tmp) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: tail call i8* @objc_retainBlock(i8* %tmp) nounwind
+; CHECK-NEXT: @use_pointer(i8* %tmp2)
+; CHECK-NEXT: @use_pointer(i8* %tmp2)
+; CHECK-NEXT: tail call void @objc_release(i8* %tmp) nounwind, !clang.imprecise_release !0
+; CHECK-NOT: @objc
+; CHECK: }
+define void @test1_no_metadata(i8* %tmp) {
+entry:
+  %tmp1 = tail call i8* @objc_retain(i8* %tmp) nounwind
+  %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+  tail call void @objc_release(i8* %tmp) nounwind, !clang.imprecise_release !0
+  ret void
+}
+
+; Same as test1, but the pointer escapes, so there's no
+; retainBlock+release optimization possible. But we can still eliminate
+; the outer retain+release
+
+; CHECK: define void @test1_escape(i8* %tmp, i8** %z) {
+; CHECK-NEXT: entry:
+; CHECK-NEXT: %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+; CHECK-NEXT: store i8* %tmp2, i8** %z
+; CHECK-NEXT: @use_pointer(i8* %tmp2)
+; CHECK-NEXT: @use_pointer(i8* %tmp2)
+; CHECK-NEXT: tail call void @objc_release(i8* %tmp) nounwind, !clang.imprecise_release !0
+; CHECK-NOT: @objc
+; CHECK: }
+define void @test1_escape(i8* %tmp, i8** %z) {
+entry:
+  %tmp1 = tail call i8* @objc_retain(i8* %tmp) nounwind
+  %tmp2 = tail call i8* @objc_retainBlock(i8* %tmp) nounwind, !clang.arc.copy_on_escape !0
+  store i8* %tmp2, i8** %z
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @use_pointer(i8* %tmp2)
+  tail call void @objc_release(i8* %tmp2) nounwind, !clang.imprecise_release !0
+  tail call void @objc_release(i8* %tmp) nounwind, !clang.imprecise_release !0
+  ret void
+}