[llvm-commits] [llvm] r173654 - Refactored out pass ObjCARCAPElim from ObjCARCOpts.cpp => ObjCARCAPElim.cpp.
Michael Gottesman
mgottesman at apple.com
Sun Jan 27 20:12:07 PST 2013
Author: mgottesman
Date: Sun Jan 27 22:12:07 2013
New Revision: 173654
URL: http://llvm.org/viewvc/llvm-project?rev=173654&view=rev
Log:
Refactored out pass ObjCARCAPElim from ObjCARCOpts.cpp => ObjCARCAPElim.cpp.
Added:
llvm/trunk/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp
Modified:
llvm/trunk/lib/Transforms/ObjCARC/CMakeLists.txt
llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
Modified: llvm/trunk/lib/Transforms/ObjCARC/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/ObjCARC/CMakeLists.txt?rev=173654&r1=173653&r2=173654&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/CMakeLists.txt (original)
+++ llvm/trunk/lib/Transforms/ObjCARC/CMakeLists.txt Sun Jan 27 22:12:07 2013
@@ -2,6 +2,7 @@ add_llvm_library(LLVMObjCARCOpts
ObjCARC.cpp
ObjCARCOpts.cpp
ObjCARCExpand.cpp
+ ObjCARCAPElim.cpp
)
add_dependencies(LLVMObjCARCOpts intrinsics_gen)
Added: llvm/trunk/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp?rev=173654&view=auto
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp (added)
+++ llvm/trunk/lib/Transforms/ObjCARC/ObjCARCAPElim.cpp Sun Jan 27 22:12:07 2013
@@ -0,0 +1,179 @@
+//===- ObjCARCOpts.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 ObjC ARC optimizations. ARC stands for Automatic
+/// Reference Counting and is a system for managing reference counts for objects
+/// in Objective C.
+///
+/// The optimizations performed include elimination of redundant, partially
+/// redundant, and inconsequential reference count operations, elimination of
+/// redundant weak pointer operations, pattern-matching and replacement of
+/// low-level operations into higher-level operations, and numerous minor
+/// simplifications.
+///
+/// This file also defines a simple ARC-aware AliasAnalysis.
+///
+/// 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.
+///
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "objc-arc-ap-elim"
+#include "ObjCARC.h"
+
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/IR/Constants.h"
+
+using namespace llvm;
+using namespace llvm::objcarc;
+
+namespace {
+ /// \brief Autorelease pool elimination.
+ class ObjCARCAPElim : public ModulePass {
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+ virtual bool runOnModule(Module &M);
+
+ static bool MayAutorelease(ImmutableCallSite CS, unsigned Depth = 0);
+ static bool OptimizeBB(BasicBlock *BB);
+
+ public:
+ static char ID;
+ ObjCARCAPElim() : ModulePass(ID) {
+ initializeObjCARCAPElimPass(*PassRegistry::getPassRegistry());
+ }
+ };
+}
+
+char ObjCARCAPElim::ID = 0;
+INITIALIZE_PASS(ObjCARCAPElim,
+ "objc-arc-apelim",
+ "ObjC ARC autorelease pool elimination",
+ false, false)
+
+Pass *llvm::createObjCARCAPElimPass() {
+ return new ObjCARCAPElim();
+}
+
+void ObjCARCAPElim::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
+}
+
+/// Interprocedurally determine if calls made by the given call site can
+/// possibly produce autoreleases.
+bool ObjCARCAPElim::MayAutorelease(ImmutableCallSite CS, unsigned Depth) {
+ if (const Function *Callee = CS.getCalledFunction()) {
+ if (Callee->isDeclaration() || Callee->mayBeOverridden())
+ return true;
+ for (Function::const_iterator I = Callee->begin(), E = Callee->end();
+ I != E; ++I) {
+ const BasicBlock *BB = I;
+ for (BasicBlock::const_iterator J = BB->begin(), F = BB->end();
+ J != F; ++J)
+ if (ImmutableCallSite JCS = ImmutableCallSite(J))
+ // This recursion depth limit is arbitrary. It's just great
+ // enough to cover known interesting testcases.
+ if (Depth < 3 &&
+ !JCS.onlyReadsMemory() &&
+ MayAutorelease(JCS, Depth + 1))
+ return true;
+ }
+ return false;
+ }
+
+ return true;
+}
+
+bool ObjCARCAPElim::OptimizeBB(BasicBlock *BB) {
+ bool Changed = false;
+
+ Instruction *Push = 0;
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
+ Instruction *Inst = I++;
+ switch (GetBasicInstructionClass(Inst)) {
+ case IC_AutoreleasepoolPush:
+ Push = Inst;
+ break;
+ case IC_AutoreleasepoolPop:
+ // If this pop matches a push and nothing in between can autorelease,
+ // zap the pair.
+ if (Push && cast<CallInst>(Inst)->getArgOperand(0) == Push) {
+ Changed = true;
+ DEBUG(dbgs() << "ObjCARCAPElim::OptimizeBB: Zapping push pop "
+ "autorelease pair:\n"
+ " Pop: " << *Inst << "\n"
+ << " Push: " << *Push << "\n");
+ Inst->eraseFromParent();
+ Push->eraseFromParent();
+ }
+ Push = 0;
+ break;
+ case IC_CallOrUser:
+ if (MayAutorelease(ImmutableCallSite(Inst)))
+ Push = 0;
+ break;
+ default:
+ break;
+ }
+ }
+
+ return Changed;
+}
+
+bool ObjCARCAPElim::runOnModule(Module &M) {
+ if (!EnableARCOpts)
+ return false;
+
+ // If nothing in the Module uses ARC, don't do anything.
+ if (!ModuleHasARC(M))
+ return false;
+
+ // Find the llvm.global_ctors variable, as the first step in
+ // identifying the global constructors. In theory, unnecessary autorelease
+ // pools could occur anywhere, but in practice it's pretty rare. Global
+ // ctors are a place where autorelease pools get inserted automatically,
+ // so it's pretty common for them to be unnecessary, and it's pretty
+ // profitable to eliminate them.
+ GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
+ if (!GV)
+ return false;
+
+ assert(GV->hasDefinitiveInitializer() &&
+ "llvm.global_ctors is uncooperative!");
+
+ bool Changed = false;
+
+ // Dig the constructor functions out of GV's initializer.
+ ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
+ for (User::op_iterator OI = Init->op_begin(), OE = Init->op_end();
+ OI != OE; ++OI) {
+ Value *Op = *OI;
+ // llvm.global_ctors is an array of pairs where the second members
+ // are constructor functions.
+ Function *F = dyn_cast<Function>(cast<ConstantStruct>(Op)->getOperand(1));
+ // If the user used a constructor function with the wrong signature and
+ // it got bitcasted or whatever, look the other way.
+ if (!F)
+ continue;
+ // Only look at function definitions.
+ if (F->isDeclaration())
+ continue;
+ // Only look at functions with one basic block.
+ if (llvm::next(F->begin()) != F->end())
+ continue;
+ // Ok, a single-block constructor function definition. Try to optimize it.
+ Changed |= OptimizeBB(F->begin());
+ }
+
+ return Changed;
+}
+
Modified: llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp?rev=173654&r1=173653&r2=173654&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp (original)
+++ llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp Sun Jan 27 22:12:07 2013
@@ -30,8 +30,11 @@
#define DEBUG_TYPE "objc-arc-opts"
#include "ObjCARC.h"
+
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/STLExtras.h"
+
using namespace llvm;
using namespace llvm::objcarc;
@@ -721,154 +724,6 @@ ObjCARCAliasAnalysis::getModRefInfo(Immu
/// @}
///
-/// \defgroup ARCAPElim ARC Autorelease Pool Elimination.
-/// @{
-
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/IR/Constants.h"
-
-namespace {
- /// \brief Autorelease pool elimination.
- class ObjCARCAPElim : public ModulePass {
- virtual void getAnalysisUsage(AnalysisUsage &AU) const;
- virtual bool runOnModule(Module &M);
-
- static bool MayAutorelease(ImmutableCallSite CS, unsigned Depth = 0);
- static bool OptimizeBB(BasicBlock *BB);
-
- public:
- static char ID;
- ObjCARCAPElim() : ModulePass(ID) {
- initializeObjCARCAPElimPass(*PassRegistry::getPassRegistry());
- }
- };
-}
-
-char ObjCARCAPElim::ID = 0;
-INITIALIZE_PASS(ObjCARCAPElim,
- "objc-arc-apelim",
- "ObjC ARC autorelease pool elimination",
- false, false)
-
-Pass *llvm::createObjCARCAPElimPass() {
- return new ObjCARCAPElim();
-}
-
-void ObjCARCAPElim::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesCFG();
-}
-
-/// Interprocedurally determine if calls made by the given call site can
-/// possibly produce autoreleases.
-bool ObjCARCAPElim::MayAutorelease(ImmutableCallSite CS, unsigned Depth) {
- if (const Function *Callee = CS.getCalledFunction()) {
- if (Callee->isDeclaration() || Callee->mayBeOverridden())
- return true;
- for (Function::const_iterator I = Callee->begin(), E = Callee->end();
- I != E; ++I) {
- const BasicBlock *BB = I;
- for (BasicBlock::const_iterator J = BB->begin(), F = BB->end();
- J != F; ++J)
- if (ImmutableCallSite JCS = ImmutableCallSite(J))
- // This recursion depth limit is arbitrary. It's just great
- // enough to cover known interesting testcases.
- if (Depth < 3 &&
- !JCS.onlyReadsMemory() &&
- MayAutorelease(JCS, Depth + 1))
- return true;
- }
- return false;
- }
-
- return true;
-}
-
-bool ObjCARCAPElim::OptimizeBB(BasicBlock *BB) {
- bool Changed = false;
-
- Instruction *Push = 0;
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) {
- Instruction *Inst = I++;
- switch (GetBasicInstructionClass(Inst)) {
- case IC_AutoreleasepoolPush:
- Push = Inst;
- break;
- case IC_AutoreleasepoolPop:
- // If this pop matches a push and nothing in between can autorelease,
- // zap the pair.
- if (Push && cast<CallInst>(Inst)->getArgOperand(0) == Push) {
- Changed = true;
- DEBUG(dbgs() << "ObjCARCAPElim::OptimizeBB: Zapping push pop "
- "autorelease pair:\n"
- " Pop: " << *Inst << "\n"
- << " Push: " << *Push << "\n");
- Inst->eraseFromParent();
- Push->eraseFromParent();
- }
- Push = 0;
- break;
- case IC_CallOrUser:
- if (MayAutorelease(ImmutableCallSite(Inst)))
- Push = 0;
- break;
- default:
- break;
- }
- }
-
- return Changed;
-}
-
-bool ObjCARCAPElim::runOnModule(Module &M) {
- if (!EnableARCOpts)
- return false;
-
- // If nothing in the Module uses ARC, don't do anything.
- if (!ModuleHasARC(M))
- return false;
-
- // Find the llvm.global_ctors variable, as the first step in
- // identifying the global constructors. In theory, unnecessary autorelease
- // pools could occur anywhere, but in practice it's pretty rare. Global
- // ctors are a place where autorelease pools get inserted automatically,
- // so it's pretty common for them to be unnecessary, and it's pretty
- // profitable to eliminate them.
- GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
- if (!GV)
- return false;
-
- assert(GV->hasDefinitiveInitializer() &&
- "llvm.global_ctors is uncooperative!");
-
- bool Changed = false;
-
- // Dig the constructor functions out of GV's initializer.
- ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
- for (User::op_iterator OI = Init->op_begin(), OE = Init->op_end();
- OI != OE; ++OI) {
- Value *Op = *OI;
- // llvm.global_ctors is an array of pairs where the second members
- // are constructor functions.
- Function *F = dyn_cast<Function>(cast<ConstantStruct>(Op)->getOperand(1));
- // If the user used a constructor function with the wrong signature and
- // it got bitcasted or whatever, look the other way.
- if (!F)
- continue;
- // Only look at function definitions.
- if (F->isDeclaration())
- continue;
- // Only look at functions with one basic block.
- if (llvm::next(F->begin()) != F->end())
- continue;
- // Ok, a single-block constructor function definition. Try to optimize it.
- Changed |= OptimizeBB(F->begin());
- }
-
- return Changed;
-}
-
-/// @}
-///
/// \defgroup ARCOpt ARC Optimization.
/// @{
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