[llvm-commits] [llvm] r148330 - in /llvm/trunk: include/llvm/InitializePasses.h include/llvm/LinkAllPasses.h include/llvm/Transforms/Scalar.h lib/Transforms/Scalar/ObjCARC.cpp lib/Transforms/Scalar/Scalar.cpp test/Transforms/ObjCARC/apelim.ll
Dan Gohman
gohman at apple.com
Tue Jan 17 12:52:24 PST 2012
Author: djg
Date: Tue Jan 17 14:52:24 2012
New Revision: 148330
URL: http://llvm.org/viewvc/llvm-project?rev=148330&view=rev
Log:
Add a new ObjC ARC optimization pass to eliminate unneeded
autorelease push+pop pairs.
Added:
llvm/trunk/test/Transforms/ObjCARC/apelim.ll
Modified:
llvm/trunk/include/llvm/InitializePasses.h
llvm/trunk/include/llvm/LinkAllPasses.h
llvm/trunk/include/llvm/Transforms/Scalar.h
llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
llvm/trunk/lib/Transforms/Scalar/Scalar.cpp
Modified: llvm/trunk/include/llvm/InitializePasses.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/InitializePasses.h?rev=148330&r1=148329&r2=148330&view=diff
==============================================================================
--- llvm/trunk/include/llvm/InitializePasses.h (original)
+++ llvm/trunk/include/llvm/InitializePasses.h Tue Jan 17 14:52:24 2012
@@ -168,6 +168,7 @@
void initializeNoProfileInfoPass(PassRegistry&);
void initializeNoPathProfileInfoPass(PassRegistry&);
void initializeObjCARCAliasAnalysisPass(PassRegistry&);
+void initializeObjCARCAPElimPass(PassRegistry&);
void initializeObjCARCExpandPass(PassRegistry&);
void initializeObjCARCContractPass(PassRegistry&);
void initializeObjCARCOptPass(PassRegistry&);
Modified: llvm/trunk/include/llvm/LinkAllPasses.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/LinkAllPasses.h?rev=148330&r1=148329&r2=148330&view=diff
==============================================================================
--- llvm/trunk/include/llvm/LinkAllPasses.h (original)
+++ llvm/trunk/include/llvm/LinkAllPasses.h Tue Jan 17 14:52:24 2012
@@ -97,6 +97,7 @@
(void) llvm::createNoAAPass();
(void) llvm::createNoProfileInfoPass();
(void) llvm::createObjCARCAliasAnalysisPass();
+ (void) llvm::createObjCARCAPElimPass();
(void) llvm::createObjCARCExpandPass();
(void) llvm::createObjCARCContractPass();
(void) llvm::createObjCARCOptPass();
Modified: llvm/trunk/include/llvm/Transforms/Scalar.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Scalar.h?rev=148330&r1=148329&r2=148330&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Scalar.h (original)
+++ llvm/trunk/include/llvm/Transforms/Scalar.h Tue Jan 17 14:52:24 2012
@@ -327,6 +327,12 @@
//===----------------------------------------------------------------------===//
//
+// ObjCARCAPElim - ObjC ARC autorelease pool elimination.
+//
+Pass *createObjCARCAPElimPass();
+
+//===----------------------------------------------------------------------===//
+//
// ObjCARCExpand - ObjC ARC preliminary simplifications.
//
Pass *createObjCARCExpandPass();
Modified: llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp?rev=148330&r1=148329&r2=148330&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/ObjCARC.cpp Tue Jan 17 14:52:24 2012
@@ -375,7 +375,7 @@
}
// Otherwise, be conservative.
- return IC_User;
+ return isa<InvokeInst>(V) ? IC_CallOrUser : IC_User;
}
/// IsRetain - Test if the the given class is objc_retain or
@@ -884,6 +884,122 @@
}
//===----------------------------------------------------------------------===//
+// ARC autorelease pool elimination.
+//===----------------------------------------------------------------------===//
+
+namespace {
+ /// ObjCARCAPElim - Autorelease pool elimination.
+ class ObjCARCAPElim : public ModulePass {
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+ virtual bool runOnModule(Module &M);
+
+ bool MayAutorelease(CallSite CS);
+ 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();
+}
+
+/// MayAutorelease - Interprocedurally determine if calls made by the
+/// given call site can possibly produce autoreleases.
+bool ObjCARCAPElim::MayAutorelease(CallSite CS) {
+ if (Function *Callee = CS.getCalledFunction()) {
+ if (Callee->isDeclaration() || Callee->mayBeOverridden())
+ return true;
+ for (Function::iterator I = Callee->begin(), E = Callee->end();
+ I != E; ++I) {
+ BasicBlock *BB = I;
+ for (BasicBlock::iterator J = BB->begin(), F = BB->end(); J != F; ++J)
+ if (CallSite JCS = CallSite(J))
+ if (!JCS.onlyReadsMemory() && MayAutorelease(JCS))
+ 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;
+ Inst->eraseFromParent();
+ Push->eraseFromParent();
+ }
+ Push = 0;
+ break;
+ case IC_CallOrUser:
+ if (MayAutorelease(CallSite(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;
+
+ bool Changed = false;
+
+ for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
+ Function *F = I;
+ // Only look at function definitions.
+ if (F->isDeclaration())
+ continue;
+ // Only look at global constructor functions. Unfortunately,
+ // the name is the most convenient way to recognize them.
+ if (!F->getName().startswith("_GLOBAL__I_"))
+ 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;
+}
+
+//===----------------------------------------------------------------------===//
// ARC optimization.
//===----------------------------------------------------------------------===//
Modified: llvm/trunk/lib/Transforms/Scalar/Scalar.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/Scalar.cpp?rev=148330&r1=148329&r2=148330&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/Scalar.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/Scalar.cpp Tue Jan 17 14:52:24 2012
@@ -51,6 +51,7 @@
initializeLowerExpectIntrinsicPass(Registry);
initializeMemCpyOptPass(Registry);
initializeObjCARCAliasAnalysisPass(Registry);
+ initializeObjCARCAPElimPass(Registry);
initializeObjCARCExpandPass(Registry);
initializeObjCARCContractPass(Registry);
initializeObjCARCOptPass(Registry);
Added: llvm/trunk/test/Transforms/ObjCARC/apelim.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/apelim.ll?rev=148330&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/apelim.ll (added)
+++ llvm/trunk/test/Transforms/ObjCARC/apelim.ll Tue Jan 17 14:52:24 2012
@@ -0,0 +1,51 @@
+; RUN: opt -S -objc-arc-apelim < %s | FileCheck %s
+; rdar://10227311
+
+ at x = global i32 0
+
+declare i32 @bar() nounwind
+
+define i32 @foo() nounwind {
+entry:
+ ret i32 5
+}
+
+define internal void @__cxx_global_var_init() {
+entry:
+ %call = call i32 @foo()
+ store i32 %call, i32* @x, align 4
+ ret void
+}
+
+define internal void @__dxx_global_var_init() {
+entry:
+ %call = call i32 @bar()
+ store i32 %call, i32* @x, align 4
+ ret void
+}
+
+; CHECK: define internal void @_GLOBAL__I_x()
+; CHECK-NOT: @objc
+; CHECK: }
+define internal void @_GLOBAL__I_x() {
+entry:
+ %0 = call i8* @objc_autoreleasePoolPush() nounwind
+ call void @__cxx_global_var_init()
+ call void @objc_autoreleasePoolPop(i8* %0) nounwind
+ ret void
+}
+
+; CHECK: define internal void @_GLOBAL__I_y()
+; CHECK: %0 = call i8* @objc_autoreleasePoolPush() nounwind
+; CHECK: call void @objc_autoreleasePoolPop(i8* %0) nounwind
+; CHECK: }
+define internal void @_GLOBAL__I_y() {
+entry:
+ %0 = call i8* @objc_autoreleasePoolPush() nounwind
+ call void @__dxx_global_var_init()
+ call void @objc_autoreleasePoolPop(i8* %0) nounwind
+ ret void
+}
+
+declare i8* @objc_autoreleasePoolPush()
+declare void @objc_autoreleasePoolPop(i8*)
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