31b98d2e99
Review feedback from r328165. Split out just the one function from the file that's used by Analysis. (As chandlerc pointed out, the original change only moved the header and not the implementation anyway - which was fine for the one function that was used (since it's a template/inlined in the header) but not in general) llvm-svn: 333954
109 lines
3.5 KiB
C++
109 lines
3.5 KiB
C++
//===- ObjCARC.h - ObjC ARC Optimization --------------*- C++ -*-----------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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/// \file
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/// This file defines common definitions/declarations used by the ObjC ARC
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/// Optimizer. ARC stands for Automatic Reference Counting and is a system for
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/// managing reference counts for objects in Objective C.
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///
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/// WARNING: This file knows about certain library functions. It recognizes them
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/// by name, and hardwires knowledge of their semantics.
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///
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/// WARNING: This file knows about how certain Objective-C library functions are
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/// used. Naive LLVM IR transformations which would otherwise be
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/// behavior-preserving may break these assumptions.
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///
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIB_TRANSFORMS_OBJCARC_OBJCARC_H
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#define LLVM_LIB_TRANSFORMS_OBJCARC_OBJCARC_H
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#include "llvm/ADT/StringSwitch.h"
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/Analysis/ObjCARCAnalysisUtils.h"
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#include "llvm/Analysis/ObjCARCInstKind.h"
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#include "llvm/Analysis/Passes.h"
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#include "llvm/Transforms/Utils/Local.h"
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#include "llvm/Analysis/ValueTracking.h"
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#include "llvm/IR/CallSite.h"
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#include "llvm/IR/InstIterator.h"
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#include "llvm/IR/Module.h"
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#include "llvm/Pass.h"
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#include "llvm/Transforms/ObjCARC.h"
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namespace llvm {
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class raw_ostream;
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}
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namespace llvm {
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namespace objcarc {
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/// Erase the given instruction.
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///
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/// Many ObjC calls return their argument verbatim,
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/// so if it's such a call and the return value has users, replace them with the
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/// argument value.
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///
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static inline void EraseInstruction(Instruction *CI) {
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Value *OldArg = cast<CallInst>(CI)->getArgOperand(0);
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bool Unused = CI->use_empty();
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if (!Unused) {
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// Replace the return value with the argument.
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assert((IsForwarding(GetBasicARCInstKind(CI)) ||
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(IsNoopOnNull(GetBasicARCInstKind(CI)) &&
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isa<ConstantPointerNull>(OldArg))) &&
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"Can't delete non-forwarding instruction with users!");
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CI->replaceAllUsesWith(OldArg);
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}
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CI->eraseFromParent();
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if (Unused)
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RecursivelyDeleteTriviallyDeadInstructions(OldArg);
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}
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/// If Inst is a ReturnRV and its operand is a call or invoke, return the
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/// operand. Otherwise return null.
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static inline const Instruction *getreturnRVOperand(const Instruction &Inst,
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ARCInstKind Class) {
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if (Class != ARCInstKind::RetainRV)
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return nullptr;
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const auto *Opnd = Inst.getOperand(0)->stripPointerCasts();
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if (const auto *C = dyn_cast<CallInst>(Opnd))
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return C;
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return dyn_cast<InvokeInst>(Opnd);
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}
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/// Return the list of PHI nodes that are equivalent to PN.
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template<class PHINodeTy, class VectorTy>
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void getEquivalentPHIs(PHINodeTy &PN, VectorTy &PHIList) {
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auto *BB = PN.getParent();
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for (auto &P : BB->phis()) {
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if (&P == &PN) // Do not add PN to the list.
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continue;
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unsigned I = 0, E = PN.getNumIncomingValues();
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for (; I < E; ++I) {
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auto *BB = PN.getIncomingBlock(I);
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auto *PNOpnd = PN.getIncomingValue(I)->stripPointerCasts();
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auto *POpnd = P.getIncomingValueForBlock(BB)->stripPointerCasts();
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if (PNOpnd != POpnd)
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break;
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}
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if (I == E)
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PHIList.push_back(&P);
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}
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}
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} // end namespace objcarc
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} // end namespace llvm
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#endif
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