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Revert "Use clang.arc.attachedcall for emission of objc_retainAutoreleasedReturnValue" #68095

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Merged
merged 1 commit into from
Aug 23, 2023
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Revert "Use clang.arc.attachedcall for emission of objc_retainAutoreleasedReturnValue" #68095

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34 changes: 2 additions & 32 deletions lib/IRGen/GenObjC.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -150,47 +150,17 @@ llvm::InlineAsm *IRGenModule::getObjCRetainAutoreleasedReturnValueMarker() {
/// Reclaim an autoreleased return value.
llvm::Value *irgen::emitObjCRetainAutoreleasedReturnValue(IRGenFunction &IGF,
llvm::Value *value) {
auto &IGM = IGF.IGM;
// Call the inline-assembly marker if we need one.
if (auto marker = IGM.getObjCRetainAutoreleasedReturnValueMarker()) {
if (auto marker = IGF.IGM.getObjCRetainAutoreleasedReturnValueMarker()) {
IGF.Builder.CreateAsmCall(marker, {});
}

const auto &triple = IGF.IGM.Context.LangOpts.Target;
const auto &arch = triple.getArch();

// FIXME: Do this on all targets and at -O0 too. This can be enabled only if
// the target backend knows how to handle the operand bundle.
// Don't use clang.arc.attachedcall on non-darwin platforms for now. On these
// platforms we have a workaround in-place to deal with the un-availability of
// a arc runtime -- we have implemented objc_retainAutoreleasedReturnValue in
// a library (src/swift/DispatchStubs.cc) as swift_retain.
// Using clang.arc.attachedcall enables a LLVM optimization that can transform
// objc_retainAutoreleasedReturnValue into objc_retain in some circumstances.
// There is no objc_retain stub defined and we would run into missing symbol
// errors.
if (IGM.getOptions().shouldOptimize() && triple.isOSDarwin() &&
(arch == llvm::Triple::aarch64 ||
arch == llvm::Triple::x86_64)) {
auto EP = llvm::Intrinsic::getDeclaration(&IGM.Module,
(llvm::Intrinsic::ID)llvm::Intrinsic::objc_retainAutoreleasedReturnValue);
llvm::Value *bundleArgs[] = {EP};
llvm::OperandBundleDef OB("clang.arc.attachedcall", bundleArgs);
auto *oldCall = cast<llvm::CallBase>(value);
llvm::CallBase *newCall = llvm::CallBase::addOperandBundle(
oldCall, llvm::LLVMContext::OB_clang_arc_attachedcall, OB, oldCall);
newCall->copyMetadata(*oldCall);
oldCall->replaceAllUsesWith(newCall);
oldCall->eraseFromParent();
auto noop = IGF.Builder.CreateIntrinsicCall(llvm::Intrinsic::objc_clang_arc_noop_use, newCall);
noop->addFnAttr(llvm::Attribute::NoUnwind);
return newCall;
}
CastToInt8PtrTy savedType(IGF, value);

auto call = IGF.Builder.CreateIntrinsicCall(
llvm::Intrinsic::objc_retainAutoreleasedReturnValue, value);

const llvm::Triple &triple = IGF.IGM.Context.LangOpts.Target;
if (triple.getArch() == llvm::Triple::x86_64) {
// Don't tail call objc_retainAutoreleasedReturnValue. This blocks the
// autoreleased return optimization.
Expand Down
6 changes: 3 additions & 3 deletions test/IRGen/objc_retainAutoreleasedReturnValue.swift
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@@ -1,5 +1,5 @@
// RUN: %target-swift-frontend -module-name objc_retainAutoreleasedReturnValue -import-objc-header %S/Inputs/StaticInline.h %s -emit-ir | %FileCheck %s
// RUN: %target-swift-frontend -module-name objc_retainAutoreleasedReturnValue -O -import-objc-header %S/Inputs/StaticInline.h %s -emit-ir -disable-llvm-optzns | %FileCheck %s --check-prefix=OPT
// RUN: %target-swift-frontend -module-name objc_retainAutoreleasedReturnValue -O -import-objc-header %S/Inputs/StaticInline.h %s -emit-ir | %FileCheck %s --check-prefix=OPT

// REQUIRES: objc_interop
// REQUIRES: CPU=x86_64
Expand Down Expand Up @@ -32,6 +32,6 @@ public func test(_ dict: NSDictionary) {

// OPT-LABEL: define {{.*}}swiftcc void @"$s34objc_retainAutoreleasedReturnValue10useClosureyySo12NSDictionaryC_yADXEtF09$s34objc_bcd16Value4testyySo12H10CFyADXEfU_Tf1nc_n"(ptr %0)
// OPT: entry:
// OPT: [[R:%.*]] = call ptr @objc_msgSend({{.*}}) [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue)
// OPT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[R]])
// OPT: call {{.*}}@objc_msgSend
// OPT: notail call ptr @llvm.objc.retainAutoreleasedReturnValue
// OPT: ret void