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[CGObjC] Allow clang.arc.attachedcall on -O0 #164875

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208a1a0
[CGObjC] Allow clang.arc.attachedcall on -O0 on AArch64
AZero13 Oct 23, 2025
6ec8fa1
d
AZero13 Nov 2, 2025
73f1150
Update arc-unsafeclaim.m
AZero13 Nov 2, 2025
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12 changes: 4 additions & 8 deletions clang/lib/CodeGen/CGObjC.cpp
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Expand Up @@ -2415,9 +2415,7 @@ static llvm::Value *emitOptimizedARCReturnCall(llvm::Value *value,
emitAutoreleasedReturnValueMarker(CGF);

// Add operand bundle "clang.arc.attachedcall" to the call instead of emitting
// retainRV or claimRV calls in the IR. We currently do this only when the
// optimization level isn't -O0 since global-isel, which is currently run at
// -O0, doesn't know about the operand bundle.
// retainRV or claimRV calls in the IR.
ObjCEntrypoints &EPs = CGF.CGM.getObjCEntrypoints();
llvm::Function *&EP = IsRetainRV
? EPs.objc_retainAutoreleasedReturnValue
Expand All @@ -2429,11 +2427,9 @@ static llvm::Value *emitOptimizedARCReturnCall(llvm::Value *value,

llvm::Triple::ArchType Arch = CGF.CGM.getTriple().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.
if (CGF.CGM.getCodeGenOpts().OptimizationLevel > 0 &&
(Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_32 ||
Arch == llvm::Triple::x86_64)) {
if ((CGF.CGM.getCodeGenOpts().OptimizationLevel > 0 &&
Arch == llvm::Triple::x86_64) ||
Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_32) {
llvm::Value *bundleArgs[] = {EP};
llvm::OperandBundleDef OB("clang.arc.attachedcall", bundleArgs);
auto *oldCall = cast<llvm::CallBase>(value);
Expand Down
23 changes: 22 additions & 1 deletion clang/test/CodeGenObjC/arc-arm.m
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Original file line number Diff line number Diff line change
@@ -1,12 +1,17 @@
// RUN: %clang_cc1 -triple armv7-apple-darwin10 -emit-llvm -fblocks -fobjc-arc -o - %s | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -emit-llvm -fblocks -fobjc-arc -o - %s | FileCheck %s
// RUN: %clang_cc1 -triple arm64-apple-ios -emit-llvm -fblocks -fobjc-arc -o - %s | FileCheck %s -check-prefix=ARM64-ATTACHED

// use an autorelease marker on ARM64.

id test0(void) {
extern id test0_helper(void);
// CHECK: [[T0:%.*]] = call [[CC:(arm_aapcscc )?]]ptr @test0_helper()
// CHECK-NEXT: ret ptr [[T0]]
// ARM64-ATTACHED: %call1 = call ptr @test0_helper() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ARM64-ATTACHED: call void asm sideeffect "mov\09fp, fp\09\09// marker for objc_retainAutoreleaseReturnValue", ""()
// ARM64-ATTACHED: call void (...) @llvm.objc.clang.arc.noop.use(ptr %call1) #2
// ARM64-ATTACHED: %0 = tail call ptr @llvm.objc.autoreleaseReturnValue(ptr %call1) #2
// ARM64-ATTACHED: ret ptr %0
return test0_helper();
}

Expand All @@ -18,6 +23,12 @@ void test1(void) {
// CHECK-NEXT: store ptr [[T1]],
// CHECK-NEXT: call [[CC]]void @llvm.objc.storeStrong(
// CHECK-NEXT: ret void
// ARM64-ATTACHED: %call1 = call ptr @test1_helper() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ARM64-ATTACHED: call void asm sideeffect "mov\09fp, fp\09\09// marker for objc_retainAutoreleaseReturnValue", ""()
// ARM64-ATTACHED: call void (...) @llvm.objc.clang.arc.noop.use(ptr %call1) #2
// ARM64-ATTACHED: store ptr %call1,
// ARM64-ATTACHED: call void @llvm.objc.storeStrong(
// ARM64-ATTACHED: ret void
id x = test1_helper();
}

Expand All @@ -26,12 +37,22 @@ void test1(void) {
extern A *test2_helper(void);
// CHECK: [[T0:%.*]] = call [[CC]]ptr @test2_helper()
// CHECK-NEXT: ret ptr [[T0]]
// ARM64-ATTACHED: %call1 = call ptr @test2_helper() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ARM64-ATTACHED: call void asm sideeffect "mov\09fp, fp\09\09// marker for objc_retainAutoreleaseReturnValue", ""()
// ARM64-ATTACHED: call void (...) @llvm.objc.clang.arc.noop.use(ptr %call1) #2
// ARM64-ATTACHED: %0 = tail call ptr @llvm.objc.autoreleaseReturnValue(ptr %call1) #2
// ARM64-ATTACHED: ret ptr %0
return test2_helper();
}

id test3(void) {
extern A *test3_helper(void);
// CHECK: [[T0:%.*]] = call [[CC]]ptr @test3_helper()
// CHECK-NEXT: ret ptr [[T0]]
// ARM64-ATTACHED: %call1 = call ptr @test3_helper() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ARM64-ATTACHED: call void asm sideeffect "mov\09fp, fp\09\09// marker for objc_retainAutoreleaseReturnValue", ""()
// ARM64-ATTACHED: call void (...) @llvm.objc.clang.arc.noop.use(ptr %call1) #2
// ARM64-ATTACHED: %0 = tail call ptr @llvm.objc.autoreleaseReturnValue(ptr %call1) #2
// ARM64-ATTACHED: ret ptr %0
return test3_helper();
}
52 changes: 31 additions & 21 deletions clang/test/CodeGenObjC/arc-unsafeclaim.m
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
// RUN: %clang_cc1 -triple i386-apple-darwin11 -fobjc-runtime=macosx-fragile-10.11 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED -check-prefix=CHECK-MARKED -check-prefix=CALL

// Make sure it works on ARM64.
// RUN: %clang_cc1 -triple arm64-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED -check-prefix=CHECK-MARKED -check-prefix=CALL
// RUN: %clang_cc1 -triple arm64-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=ATTACHED-CALL

// Make sure it works on ARM.
// RUN: %clang_cc1 -triple armv7-apple-ios9 -fobjc-runtime=ios-9.0 -fobjc-arc -emit-llvm -o - %s | FileCheck %s -check-prefix=CHECK -check-prefix=CHECK-UNOPTIMIZED -check-prefix=CHECK-MARKED -check-prefix=CALL
Expand Down Expand Up @@ -41,8 +41,9 @@ void test_assign(void) {
// DISABLED-NEXT: [[T2:%.*]] = {{.*}}call ptr @llvm.objc.retainAutoreleasedReturnValue(ptr [[T0]])

// ATTACHED-CALL-LABEL: define{{.*}} void @test_assign()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_assign_assign(void) {
__unsafe_unretained id x, y;
Expand All @@ -62,8 +63,9 @@ void test_assign_assign(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_assign_assign()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_strong_assign_assign(void) {
__strong id x;
Expand All @@ -88,8 +90,9 @@ void test_strong_assign_assign(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_strong_assign_assign()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_assign_strong_assign(void) {
__unsafe_unretained id x;
Expand All @@ -114,8 +117,9 @@ void test_assign_strong_assign(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_assign_strong_assign()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_init(void) {
__unsafe_unretained id x = makeA();
Expand All @@ -131,8 +135,9 @@ void test_init(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_init()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_init_assignment(void) {
__unsafe_unretained id x;
Expand All @@ -152,8 +157,9 @@ void test_init_assignment(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_init_assignment()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_strong_init_assignment(void) {
__unsafe_unretained id x;
Expand All @@ -175,8 +181,9 @@ void test_strong_init_assignment(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_strong_init_assignment()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_init_strong_assignment(void) {
__strong id x;
Expand All @@ -200,8 +207,9 @@ void test_init_strong_assignment(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_init_strong_assignment()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.retainAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_ignored(void) {
makeA();
Expand All @@ -214,8 +222,9 @@ void test_ignored(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_ignored()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])

void test_cast_to_void(void) {
(void) makeA();
Expand All @@ -228,8 +237,9 @@ void test_cast_to_void(void) {
// CHECK-NEXT: ret void

// ATTACHED-CALL-LABEL: define{{.*}} void @test_cast_to_void()
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ],
// ATTACHED-CALL: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])
// ATTACHED-CALL: [[T0:%.*]] = call ptr @makeA() [ "clang.arc.attachedcall"(ptr @llvm.objc.unsafeClaimAutoreleasedReturnValue) ]
// ATTACHED-CALL-NEXT: call void asm sideeffect
// ATTACHED-CALL-NEXT: call void (...) @llvm.objc.clang.arc.noop.use(ptr [[T0]])


// This is always at the end of the module.
Expand Down
5 changes: 5 additions & 0 deletions llvm/lib/Target/AArch64/AArch64FastISel.cpp
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Expand Up @@ -25,6 +25,7 @@
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/ObjCARCUtil.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
Expand Down Expand Up @@ -3159,6 +3160,10 @@ bool AArch64FastISel::fastLowerCall(CallLoweringInfo &CLI) {
CLI.CB->getOperandBundle(LLVMContext::OB_kcfi))
return false;

// Allow SelectionDAG isel to handle clang.arc.attachedcall operand bundle.
if (CLI.CB && objcarc::hasAttachedCallOpBundle(CLI.CB))
return false;

// Allow SelectionDAG isel to handle tail calls.
if (IsTailCall)
return false;
Expand Down
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