Add support for objc_unsafeClaimAutoreleasedReturnValue to the

ObjC ARC Optimizer.

The main implication of this is:

1. Ensuring that we treat it conservatively in terms of optimization.
2. We put the ASM marker on it so that the runtime can recognize
objc_unsafeClaimAutoreleasedReturnValue from releaseRV.

<rdar://problem/21567064>

Patch by Michael Gottesman!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@258970 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 58 insertions, 3 deletions

diff --git a/test/Transforms/ObjCARC/basic.ll b/test/Transforms/ObjCARC/basic.ll
index fc1d087794d..a6fdf5efa1a 100644
--- a/test/Transforms/ObjCARC/basic.ll
+++ b/test/Transforms/ObjCARC/basic.ll
@@ -4,6 +4,7 @@ target datalayout = "e-p:64:64:64"
 
 declare i8* @objc_retain(i8*)
 declare i8* @objc_retainAutoreleasedReturnValue(i8*)
+declare i8* @objc_unsafeClaimAutoreleasedReturnValue(i8*)
 declare void @objc_release(i8*)
 declare i8* @objc_autorelease(i8*)
 declare i8* @objc_autoreleaseReturnValue(i8*)
@@ -2573,6 +2574,27 @@ return:                                           ; preds = %if.then, %entry
   ret i8* %retval
 }
 
+; CHECK-LABEL: define i8* @test65d(
+; CHECK: if.then:
+; CHECK-NOT: @objc_autorelease
+; CHECK: return:
+; CHECK:   call i8* @objc_autoreleaseReturnValue(
+; CHECK: }
+define i8* @test65d(i1 %x) {
+entry:
+  br i1 %x, label %return, label %if.then
+
+if.then:                                          ; preds = %entry
+  %c = call i8* @returner()
+  %s = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %c) nounwind
+  br label %return
+
+return:                                           ; preds = %if.then, %entry
+  %retval = phi i8* [ %s, %if.then ], [ null, %entry ]
+  %q = call i8* @objc_autoreleaseReturnValue(i8* %retval) nounwind
+  ret i8* %retval
+}
+
 ; An objc_retain can serve as a may-use for a different pointer.
 ; rdar://11931823
 
diff --git a/test/Transforms/ObjCARC/contract-marker.ll b/test/Transforms/ObjCARC/contract-marker.ll
index a8282607cb3..bf70d4e9d04 100644
--- a/test/Transforms/ObjCARC/contract-marker.ll
+++ b/test/Transforms/ObjCARC/contract-marker.ll
@@ -1,9 +1,9 @@
 ; RUN: opt -S -objc-arc-contract < %s | FileCheck %s
 
-; CHECK: define void @foo() {
+; CHECK-LABEL: define void @foo() {
 ; CHECK:      %call = tail call i32* @qux()
 ; CHECK-NEXT: %tcall = bitcast i32* %call to i8*
-; CHECK-NEXT: call void asm sideeffect "mov\09r7, r7\09\09@ marker for objc_retainAutoreleaseReturnValue", ""()
+; CHECK-NEXT: call void asm sideeffect "mov\09r7, r7\09\09@ marker for return value optimization", ""()
 ; CHECK-NEXT: %0 = tail call i8* @objc_retainAutoreleasedReturnValue(i8* %tcall) [[NUW:#[0-9]+]]
 ; CHECK: }
 
@@ -16,12 +16,30 @@ entry:
   ret void
 }
 
+; CHECK-LABEL: define void @foo2() {
+; CHECK:      %call = tail call i32* @qux()
+; CHECK-NEXT: %tcall = bitcast i32* %call to i8*
+; CHECK-NEXT: call void asm sideeffect "mov\09r7, r7\09\09@ marker for return value optimization", ""()
+; CHECK-NEXT: %0 = tail call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %tcall) [[NUW:#[0-9]+]]
+; CHECK: }
+
+define void @foo2() {
+entry:
+  %call = tail call i32* @qux()
+  %tcall = bitcast i32* %call to i8*
+  %0 = tail call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %tcall) nounwind
+  tail call void @bar(i8* %0)
+  ret void
+}
+
+
 declare i32* @qux()
 declare i8* @objc_retainAutoreleasedReturnValue(i8*)
+declare i8* @objc_unsafeClaimAutoreleasedReturnValue(i8*)
 declare void @bar(i8*)
 
 !clang.arc.retainAutoreleasedReturnValueMarker = !{!0}
 
-!0 = !{!"mov\09r7, r7\09\09@ marker for objc_retainAutoreleaseReturnValue"}
+!0 = !{!"mov\09r7, r7\09\09@ marker for return value optimization"}
 
 ; CHECK: attributes [[NUW]] = { nounwind }
diff --git a/test/Transforms/ObjCARC/tail-call-invariant-enforcement.ll b/test/Transforms/ObjCARC/tail-call-invariant-enforcement.ll
index 1ec61c84810..3073abf7bf5 100644
--- a/test/Transforms/ObjCARC/tail-call-invariant-enforcement.ll
+++ b/test/Transforms/ObjCARC/tail-call-invariant-enforcement.ll
@@ -5,6 +5,7 @@ declare i8* @objc_retain(i8* %x)
 declare i8* @objc_autorelease(i8* %x)
 declare i8* @objc_autoreleaseReturnValue(i8* %x)
 declare i8* @objc_retainAutoreleasedReturnValue(i8* %x)
+declare i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %x)
 declare i8* @tmp(i8*)
 
 ; Never tail call objc_autorelease.
@@ -85,5 +86,19 @@ entry:
   ret i8* %tmp0
 }
 
+; Always tail call objc_unsafeClaimAutoreleasedReturnValue.
+; CHECK: define i8* @test6(i8* %x) [[NUW]] {
+; CHECK: %tmp0 = tail call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %y) [[NUW]]
+; CHECK: %tmp1 = tail call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %z) [[NUW]]
+; CHECK: }
+define i8* @test6(i8* %x) nounwind {
+entry:
+  %y = call i8* @tmp(i8* %x)
+  %tmp0 = call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %y)
+  %z = call i8* @tmp(i8* %x)
+  %tmp1 = tail call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %z)
+  ret i8* %x
+}
+
 ; CHECK: attributes [[NUW]] = { nounwind }