mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-21 00:32:23 +00:00
023d2bbbbe
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186026 91177308-0d34-0410-b5e6-96231b3b80d8
255 lines
11 KiB
C++
255 lines
11 KiB
C++
//===- ObjCARCUtil.cpp - ObjC ARC Optimization ----------------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
/// \file
|
|
/// This file defines several utility functions used by various ARC
|
|
/// optimizations which are IMHO too big to be in a header file.
|
|
///
|
|
/// WARNING: This file knows about certain library functions. It recognizes them
|
|
/// by name, and hardwires knowledge of their semantics.
|
|
///
|
|
/// WARNING: This file knows about how certain Objective-C library functions are
|
|
/// used. Naive LLVM IR transformations which would otherwise be
|
|
/// behavior-preserving may break these assumptions.
|
|
///
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "ObjCARC.h"
|
|
#include "llvm/IR/Intrinsics.h"
|
|
|
|
using namespace llvm;
|
|
using namespace llvm::objcarc;
|
|
|
|
raw_ostream &llvm::objcarc::operator<<(raw_ostream &OS,
|
|
const InstructionClass Class) {
|
|
switch (Class) {
|
|
case IC_Retain:
|
|
return OS << "IC_Retain";
|
|
case IC_RetainRV:
|
|
return OS << "IC_RetainRV";
|
|
case IC_RetainBlock:
|
|
return OS << "IC_RetainBlock";
|
|
case IC_Release:
|
|
return OS << "IC_Release";
|
|
case IC_Autorelease:
|
|
return OS << "IC_Autorelease";
|
|
case IC_AutoreleaseRV:
|
|
return OS << "IC_AutoreleaseRV";
|
|
case IC_AutoreleasepoolPush:
|
|
return OS << "IC_AutoreleasepoolPush";
|
|
case IC_AutoreleasepoolPop:
|
|
return OS << "IC_AutoreleasepoolPop";
|
|
case IC_NoopCast:
|
|
return OS << "IC_NoopCast";
|
|
case IC_FusedRetainAutorelease:
|
|
return OS << "IC_FusedRetainAutorelease";
|
|
case IC_FusedRetainAutoreleaseRV:
|
|
return OS << "IC_FusedRetainAutoreleaseRV";
|
|
case IC_LoadWeakRetained:
|
|
return OS << "IC_LoadWeakRetained";
|
|
case IC_StoreWeak:
|
|
return OS << "IC_StoreWeak";
|
|
case IC_InitWeak:
|
|
return OS << "IC_InitWeak";
|
|
case IC_LoadWeak:
|
|
return OS << "IC_LoadWeak";
|
|
case IC_MoveWeak:
|
|
return OS << "IC_MoveWeak";
|
|
case IC_CopyWeak:
|
|
return OS << "IC_CopyWeak";
|
|
case IC_DestroyWeak:
|
|
return OS << "IC_DestroyWeak";
|
|
case IC_StoreStrong:
|
|
return OS << "IC_StoreStrong";
|
|
case IC_CallOrUser:
|
|
return OS << "IC_CallOrUser";
|
|
case IC_Call:
|
|
return OS << "IC_Call";
|
|
case IC_User:
|
|
return OS << "IC_User";
|
|
case IC_IntrinsicUser:
|
|
return OS << "IC_IntrinsicUser";
|
|
case IC_None:
|
|
return OS << "IC_None";
|
|
}
|
|
llvm_unreachable("Unknown instruction class!");
|
|
}
|
|
|
|
InstructionClass llvm::objcarc::GetFunctionClass(const Function *F) {
|
|
Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
|
|
|
|
// No (mandatory) arguments.
|
|
if (AI == AE)
|
|
return StringSwitch<InstructionClass>(F->getName())
|
|
.Case("objc_autoreleasePoolPush", IC_AutoreleasepoolPush)
|
|
.Case("clang.arc.use", IC_IntrinsicUser)
|
|
.Default(IC_CallOrUser);
|
|
|
|
// One argument.
|
|
const Argument *A0 = AI++;
|
|
if (AI == AE)
|
|
// Argument is a pointer.
|
|
if (PointerType *PTy = dyn_cast<PointerType>(A0->getType())) {
|
|
Type *ETy = PTy->getElementType();
|
|
// Argument is i8*.
|
|
if (ETy->isIntegerTy(8))
|
|
return StringSwitch<InstructionClass>(F->getName())
|
|
.Case("objc_retain", IC_Retain)
|
|
.Case("objc_retainAutoreleasedReturnValue", IC_RetainRV)
|
|
.Case("objc_retainBlock", IC_RetainBlock)
|
|
.Case("objc_release", IC_Release)
|
|
.Case("objc_autorelease", IC_Autorelease)
|
|
.Case("objc_autoreleaseReturnValue", IC_AutoreleaseRV)
|
|
.Case("objc_autoreleasePoolPop", IC_AutoreleasepoolPop)
|
|
.Case("objc_retainedObject", IC_NoopCast)
|
|
.Case("objc_unretainedObject", IC_NoopCast)
|
|
.Case("objc_unretainedPointer", IC_NoopCast)
|
|
.Case("objc_retain_autorelease", IC_FusedRetainAutorelease)
|
|
.Case("objc_retainAutorelease", IC_FusedRetainAutorelease)
|
|
.Case("objc_retainAutoreleaseReturnValue",IC_FusedRetainAutoreleaseRV)
|
|
.Case("objc_sync_enter", IC_User)
|
|
.Case("objc_sync_exit", IC_User)
|
|
.Default(IC_CallOrUser);
|
|
|
|
// Argument is i8**
|
|
if (PointerType *Pte = dyn_cast<PointerType>(ETy))
|
|
if (Pte->getElementType()->isIntegerTy(8))
|
|
return StringSwitch<InstructionClass>(F->getName())
|
|
.Case("objc_loadWeakRetained", IC_LoadWeakRetained)
|
|
.Case("objc_loadWeak", IC_LoadWeak)
|
|
.Case("objc_destroyWeak", IC_DestroyWeak)
|
|
.Default(IC_CallOrUser);
|
|
}
|
|
|
|
// Two arguments, first is i8**.
|
|
const Argument *A1 = AI++;
|
|
if (AI == AE)
|
|
if (PointerType *PTy = dyn_cast<PointerType>(A0->getType()))
|
|
if (PointerType *Pte = dyn_cast<PointerType>(PTy->getElementType()))
|
|
if (Pte->getElementType()->isIntegerTy(8))
|
|
if (PointerType *PTy1 = dyn_cast<PointerType>(A1->getType())) {
|
|
Type *ETy1 = PTy1->getElementType();
|
|
// Second argument is i8*
|
|
if (ETy1->isIntegerTy(8))
|
|
return StringSwitch<InstructionClass>(F->getName())
|
|
.Case("objc_storeWeak", IC_StoreWeak)
|
|
.Case("objc_initWeak", IC_InitWeak)
|
|
.Case("objc_storeStrong", IC_StoreStrong)
|
|
.Default(IC_CallOrUser);
|
|
// Second argument is i8**.
|
|
if (PointerType *Pte1 = dyn_cast<PointerType>(ETy1))
|
|
if (Pte1->getElementType()->isIntegerTy(8))
|
|
return StringSwitch<InstructionClass>(F->getName())
|
|
.Case("objc_moveWeak", IC_MoveWeak)
|
|
.Case("objc_copyWeak", IC_CopyWeak)
|
|
// Ignore annotation calls. This is important to stop the
|
|
// optimizer from treating annotations as uses which would
|
|
// make the state of the pointers they are attempting to
|
|
// elucidate to be incorrect.
|
|
.Case("llvm.arc.annotation.topdown.bbstart", IC_None)
|
|
.Case("llvm.arc.annotation.topdown.bbend", IC_None)
|
|
.Case("llvm.arc.annotation.bottomup.bbstart", IC_None)
|
|
.Case("llvm.arc.annotation.bottomup.bbend", IC_None)
|
|
.Default(IC_CallOrUser);
|
|
}
|
|
|
|
// Anything else.
|
|
return IC_CallOrUser;
|
|
}
|
|
|
|
/// \brief Determine what kind of construct V is.
|
|
InstructionClass
|
|
llvm::objcarc::GetInstructionClass(const Value *V) {
|
|
if (const Instruction *I = dyn_cast<Instruction>(V)) {
|
|
// Any instruction other than bitcast and gep with a pointer operand have a
|
|
// use of an objc pointer. Bitcasts, GEPs, Selects, PHIs transfer a pointer
|
|
// to a subsequent use, rather than using it themselves, in this sense.
|
|
// As a short cut, several other opcodes are known to have no pointer
|
|
// operands of interest. And ret is never followed by a release, so it's
|
|
// not interesting to examine.
|
|
switch (I->getOpcode()) {
|
|
case Instruction::Call: {
|
|
const CallInst *CI = cast<CallInst>(I);
|
|
// Check for calls to special functions.
|
|
if (const Function *F = CI->getCalledFunction()) {
|
|
InstructionClass Class = GetFunctionClass(F);
|
|
if (Class != IC_CallOrUser)
|
|
return Class;
|
|
|
|
// None of the intrinsic functions do objc_release. For intrinsics, the
|
|
// only question is whether or not they may be users.
|
|
switch (F->getIntrinsicID()) {
|
|
case Intrinsic::returnaddress: case Intrinsic::frameaddress:
|
|
case Intrinsic::stacksave: case Intrinsic::stackrestore:
|
|
case Intrinsic::vastart: case Intrinsic::vacopy: case Intrinsic::vaend:
|
|
case Intrinsic::objectsize: case Intrinsic::prefetch:
|
|
case Intrinsic::stackprotector:
|
|
case Intrinsic::eh_return_i32: case Intrinsic::eh_return_i64:
|
|
case Intrinsic::eh_typeid_for: case Intrinsic::eh_dwarf_cfa:
|
|
case Intrinsic::eh_sjlj_lsda: case Intrinsic::eh_sjlj_functioncontext:
|
|
case Intrinsic::init_trampoline: case Intrinsic::adjust_trampoline:
|
|
case Intrinsic::lifetime_start: case Intrinsic::lifetime_end:
|
|
case Intrinsic::invariant_start: case Intrinsic::invariant_end:
|
|
// Don't let dbg info affect our results.
|
|
case Intrinsic::dbg_declare: case Intrinsic::dbg_value:
|
|
// Short cut: Some intrinsics obviously don't use ObjC pointers.
|
|
return IC_None;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
return GetCallSiteClass(CI);
|
|
}
|
|
case Instruction::Invoke:
|
|
return GetCallSiteClass(cast<InvokeInst>(I));
|
|
case Instruction::BitCast:
|
|
case Instruction::GetElementPtr:
|
|
case Instruction::Select: case Instruction::PHI:
|
|
case Instruction::Ret: case Instruction::Br:
|
|
case Instruction::Switch: case Instruction::IndirectBr:
|
|
case Instruction::Alloca: case Instruction::VAArg:
|
|
case Instruction::Add: case Instruction::FAdd:
|
|
case Instruction::Sub: case Instruction::FSub:
|
|
case Instruction::Mul: case Instruction::FMul:
|
|
case Instruction::SDiv: case Instruction::UDiv: case Instruction::FDiv:
|
|
case Instruction::SRem: case Instruction::URem: case Instruction::FRem:
|
|
case Instruction::Shl: case Instruction::LShr: case Instruction::AShr:
|
|
case Instruction::And: case Instruction::Or: case Instruction::Xor:
|
|
case Instruction::SExt: case Instruction::ZExt: case Instruction::Trunc:
|
|
case Instruction::IntToPtr: case Instruction::FCmp:
|
|
case Instruction::FPTrunc: case Instruction::FPExt:
|
|
case Instruction::FPToUI: case Instruction::FPToSI:
|
|
case Instruction::UIToFP: case Instruction::SIToFP:
|
|
case Instruction::InsertElement: case Instruction::ExtractElement:
|
|
case Instruction::ShuffleVector:
|
|
case Instruction::ExtractValue:
|
|
break;
|
|
case Instruction::ICmp:
|
|
// Comparing a pointer with null, or any other constant, isn't an
|
|
// interesting use, because we don't care what the pointer points to, or
|
|
// about the values of any other dynamic reference-counted pointers.
|
|
if (IsPotentialRetainableObjPtr(I->getOperand(1)))
|
|
return IC_User;
|
|
break;
|
|
default:
|
|
// For anything else, check all the operands.
|
|
// Note that this includes both operands of a Store: while the first
|
|
// operand isn't actually being dereferenced, it is being stored to
|
|
// memory where we can no longer track who might read it and dereference
|
|
// it, so we have to consider it potentially used.
|
|
for (User::const_op_iterator OI = I->op_begin(), OE = I->op_end();
|
|
OI != OE; ++OI)
|
|
if (IsPotentialRetainableObjPtr(*OI))
|
|
return IC_User;
|
|
}
|
|
}
|
|
|
|
// Otherwise, it's totally inert for ARC purposes.
|
|
return IC_None;
|
|
}
|