From 265b083e84f09473de0693221b1b1777813d6e33 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Wed, 10 Apr 2002 20:33:11 +0000 Subject: [PATCH] * Add documentation * Split the CleanGCC pass into two passes, a global pass and an IP pass. Before it was just a global pass, but it did illegal things to the module, which broke other passes that were being scheduled with it by gccld. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2224 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/IPO/DeadTypeElimination.cpp | 418 ++++++++++----------- 1 file changed, 208 insertions(+), 210 deletions(-) diff --git a/lib/Transforms/IPO/DeadTypeElimination.cpp b/lib/Transforms/IPO/DeadTypeElimination.cpp index 955e9e672a7..4f2e24d462e 100644 --- a/lib/Transforms/IPO/DeadTypeElimination.cpp +++ b/lib/Transforms/IPO/DeadTypeElimination.cpp @@ -1,4 +1,4 @@ -//===- CleanupGCCOutput.cpp - Cleanup GCC Output ----------------------------=// +//===- CleanupGCCOutput.cpp - Cleanup GCC Output --------------------------===// // // This pass is used to cleanup the output of GCC. GCC's output is // unneccessarily gross for a couple of reasons. This pass does the following @@ -6,6 +6,8 @@ // // * Eliminate names for GCC types that we know can't be needed by the user. // * Eliminate names for types that are unused in the entire translation unit +// * Fix various problems that we might have in PHI nodes and casts +// * Link uses of 'void %foo(...)' to 'void %foo(sometypes)' // // Note: This code produces dead declarations, it is a good idea to run DCE // after this pass. @@ -60,194 +62,11 @@ namespace { }; } - - -// ConvertCallTo - Convert a call to a varargs function with no arg types -// specified to a concrete nonvarargs function. -// -static void ConvertCallTo(CallInst *CI, Function *Dest) { - const FunctionType::ParamTypes &ParamTys = - Dest->getFunctionType()->getParamTypes(); - BasicBlock *BB = CI->getParent(); - - // Get an iterator to where we want to insert cast instructions if the - // argument types don't agree. - // - BasicBlock::iterator BBI = find(BB->begin(), BB->end(), CI); - assert(BBI != BB->end() && "CallInst not in parent block?"); - - assert(CI->getNumOperands()-1 == ParamTys.size()&& - "Function calls resolved funny somehow, incompatible number of args"); - - vector Params; - - // Convert all of the call arguments over... inserting cast instructions if - // the types are not compatible. - for (unsigned i = 1; i < CI->getNumOperands(); ++i) { - Value *V = CI->getOperand(i); - - if (V->getType() != ParamTys[i-1]) { // Must insert a cast... - Instruction *Cast = new CastInst(V, ParamTys[i-1]); - BBI = BB->getInstList().insert(BBI, Cast)+1; - V = Cast; - } - - Params.push_back(V); - } - - // Replace the old call instruction with a new call instruction that calls - // the real function. - // - ReplaceInstWithInst(BB->getInstList(), BBI, new CallInst(Dest, Params)); +Pass *createCleanupGCCOutputPass() { + return new CleanupGCCOutput(); } -// PatchUpFunctionReferences - Go over the functions that are in the module and -// look for functions that have the same name. More often than not, there will -// be things like: -// void "foo"(...) -// void "foo"(int, int) -// because of the way things are declared in C. If this is the case, patch -// things up. -// -static bool PatchUpFunctionReferences(Module *M) { - SymbolTable *ST = M->getSymbolTable(); - if (!ST) return false; - - std::map > Functions; - - // Loop over the entries in the symbol table. If an entry is a func pointer, - // then add it to the Functions map. We do a two pass algorithm here to avoid - // problems with iterators getting invalidated if we did a one pass scheme. - // - for (SymbolTable::iterator I = ST->begin(), E = ST->end(); I != E; ++I) - if (const PointerType *PT = dyn_cast(I->first)) - if (isa(PT->getElementType())) { - SymbolTable::VarMap &Plane = I->second; - for (SymbolTable::type_iterator PI = Plane.begin(), PE = Plane.end(); - PI != PE; ++PI) { - const string &Name = PI->first; - Functions[Name].push_back(cast(PI->second)); - } - } - - bool Changed = false; - - // Now we have a list of all functions with a particular name. If there is - // more than one entry in a list, merge the functions together. - // - for (std::map >::iterator I = Functions.begin(), - E = Functions.end(); I != E; ++I) { - vector &Functions = I->second; - Function *Implementation = 0; // Find the implementation - Function *Concrete = 0; - for (unsigned i = 0; i < Functions.size(); ) { - if (!Functions[i]->isExternal()) { // Found an implementation - assert(Implementation == 0 && "Multiple definitions of the same" - " function. Case not handled yet!"); - Implementation = Functions[i]; - } else { - // Ignore functions that are never used so they don't cause spurious - // warnings... here we will actually DCE the function so that it isn't - // used later. - // - if (Functions[i]->use_size() == 0) { - M->getFunctionList().remove(Functions[i]); - delete Functions[i]; - Functions.erase(Functions.begin()+i); - Changed = true; - continue; - } - } - - if (Functions[i] && (!Functions[i]->getFunctionType()->isVarArg())) { - if (Concrete) { // Found two different functions types. Can't choose - Concrete = 0; - break; - } - Concrete = Functions[i]; - } - ++i; - } - - if (Functions.size() > 1) { // Found a multiply defined function... - // We should find exactly one non-vararg function definition, which is - // probably the implementation. Change all of the function definitions - // and uses to use it instead. - // - if (!Concrete) { - cerr << "Warning: Found functions types that are not compatible:\n"; - for (unsigned i = 0; i < Functions.size(); ++i) { - cerr << "\t" << Functions[i]->getType()->getDescription() << " %" - << Functions[i]->getName() << "\n"; - } - cerr << " No linkage of functions named '" << Functions[0]->getName() - << "' performed!\n"; - } else { - for (unsigned i = 0; i < Functions.size(); ++i) - if (Functions[i] != Concrete) { - Function *Old = Functions[i]; - const FunctionType *OldMT = Old->getFunctionType(); - const FunctionType *ConcreteMT = Concrete->getFunctionType(); - bool Broken = false; - - assert(Old->getReturnType() == Concrete->getReturnType() && - "Differing return types not handled yet!"); - assert(OldMT->getParamTypes().size() <= - ConcreteMT->getParamTypes().size() && - "Concrete type must have more specified parameters!"); - - // Check to make sure that if there are specified types, that they - // match... - // - for (unsigned i = 0; i < OldMT->getParamTypes().size(); ++i) - if (OldMT->getParamTypes()[i] != ConcreteMT->getParamTypes()[i]) { - cerr << "Parameter types conflict for" << OldMT - << " and " << ConcreteMT; - Broken = true; - } - if (Broken) break; // Can't process this one! - - - // Attempt to convert all of the uses of the old function to the - // concrete form of the function. If there is a use of the fn - // that we don't understand here we punt to avoid making a bad - // transformation. - // - // At this point, we know that the return values are the same for - // our two functions and that the Old function has no varargs fns - // specified. In otherwords it's just (...) - // - for (unsigned i = 0; i < Old->use_size(); ) { - User *U = *(Old->use_begin()+i); - if (CastInst *CI = dyn_cast(U)) { - // Convert casts directly - assert(CI->getOperand(0) == Old); - CI->setOperand(0, Concrete); - Changed = true; - } else if (CallInst *CI = dyn_cast(U)) { - // Can only fix up calls TO the argument, not args passed in. - if (CI->getCalledValue() == Old) { - ConvertCallTo(CI, Concrete); - Changed = true; - } else { - cerr << "Couldn't cleanup this function call, must be an" - << " argument or something!" << CI; - ++i; - } - } else { - cerr << "Cannot convert use of function: " << U << "\n"; - ++i; - } - } - } - } - } - } - - return Changed; -} - // ShouldNukSymtabEntry - Return true if this module level symbol table entry // should be eliminated. @@ -280,13 +99,6 @@ bool CleanupGCCOutput::doInitialization(Module *M) { if (M->hasSymbolTable()) { SymbolTable *ST = M->getSymbolTable(); - // Go over the functions that are in the module and look for methods that - // have the same name. More often than not, there will be things like: - // void "foo"(...) and void "foo"(int, int) because of the way things are - // declared in C. If this is the case, patch things up. - // - Changed |= PatchUpFunctionReferences(M); - // Check the symbol table for superfluous type entries... // // Grab the 'type' plane of the module symbol... @@ -434,10 +246,10 @@ static inline void RefactorPredecessor(BasicBlock *BB, BasicBlock *Pred) { } -// fixLocalProblems - Loop through the function and fix problems with the PHI -// nodes in the current function. The problem is that PHI nodes might exist -// with multiple entries for the same predecessor. GCC sometimes generates code -// that looks like this: +// runOnMethod - Loop through the function and fix problems with the PHI nodes +// in the current function. The problem is that PHI nodes might exist with +// multiple entries for the same predecessor. GCC sometimes generates code that +// looks like this: // // bb7: br bool %cond1004, label %bb8, label %bb8 // bb8: %reg119 = phi uint [ 0, %bb7 ], [ 1, %bb7 ] @@ -450,7 +262,7 @@ static inline void RefactorPredecessor(BasicBlock *BB, BasicBlock *Pred) { // bb8: %reg119 = phi uint [ 0, %bbX ], [ 1, %bb7 ] // // -static bool fixLocalProblems(Function *M) { +bool CleanupGCCOutput::runOnMethod(Function *M) { bool Changed = false; // Don't use iterators because invalidation gets messy... for (unsigned MI = 0; MI < M->size(); ++MI) { @@ -480,18 +292,8 @@ static bool fixLocalProblems(Function *M) { return Changed; } - - - -// runOnFunction - This method simplifies the specified function hopefully. -// -bool CleanupGCCOutput::runOnMethod(Function *F) { - return fixLocalProblems(F); -} - bool CleanupGCCOutput::doFinalization(Module *M) { bool Changed = false; - if (M->hasSymbolTable()) { SymbolTable *ST = M->getSymbolTable(); @@ -523,7 +325,203 @@ bool CleanupGCCOutput::doFinalization(Module *M) { return Changed; } -Pass *createCleanupGCCOutputPass() { - return new CleanupGCCOutput(); + +//===----------------------------------------------------------------------===// +// +// FunctionResolvingPass - Go over the functions that are in the module and +// look for functions that have the same name. More often than not, there will +// be things like: +// void "foo"(...) +// void "foo"(int, int) +// because of the way things are declared in C. If this is the case, patch +// things up. +// +//===----------------------------------------------------------------------===// + +namespace { + struct FunctionResolvingPass : public Pass { + bool run(Module *M); + }; } +// ConvertCallTo - Convert a call to a varargs function with no arg types +// specified to a concrete nonvarargs function. +// +static void ConvertCallTo(CallInst *CI, Function *Dest) { + const FunctionType::ParamTypes &ParamTys = + Dest->getFunctionType()->getParamTypes(); + BasicBlock *BB = CI->getParent(); + + // Get an iterator to where we want to insert cast instructions if the + // argument types don't agree. + // + BasicBlock::iterator BBI = find(BB->begin(), BB->end(), CI); + assert(BBI != BB->end() && "CallInst not in parent block?"); + + assert(CI->getNumOperands()-1 == ParamTys.size()&& + "Function calls resolved funny somehow, incompatible number of args"); + + vector Params; + + // Convert all of the call arguments over... inserting cast instructions if + // the types are not compatible. + for (unsigned i = 1; i < CI->getNumOperands(); ++i) { + Value *V = CI->getOperand(i); + + if (V->getType() != ParamTys[i-1]) { // Must insert a cast... + Instruction *Cast = new CastInst(V, ParamTys[i-1]); + BBI = BB->getInstList().insert(BBI, Cast)+1; + V = Cast; + } + + Params.push_back(V); + } + + // Replace the old call instruction with a new call instruction that calls + // the real function. + // + ReplaceInstWithInst(BB->getInstList(), BBI, new CallInst(Dest, Params)); +} + + +bool FunctionResolvingPass::run(Module *M) { + SymbolTable *ST = M->getSymbolTable(); + if (!ST) return false; + + std::map > Functions; + + // Loop over the entries in the symbol table. If an entry is a func pointer, + // then add it to the Functions map. We do a two pass algorithm here to avoid + // problems with iterators getting invalidated if we did a one pass scheme. + // + for (SymbolTable::iterator I = ST->begin(), E = ST->end(); I != E; ++I) + if (const PointerType *PT = dyn_cast(I->first)) + if (isa(PT->getElementType())) { + SymbolTable::VarMap &Plane = I->second; + for (SymbolTable::type_iterator PI = Plane.begin(), PE = Plane.end(); + PI != PE; ++PI) { + const string &Name = PI->first; + Functions[Name].push_back(cast(PI->second)); + } + } + + bool Changed = false; + + // Now we have a list of all functions with a particular name. If there is + // more than one entry in a list, merge the functions together. + // + for (std::map >::iterator I = Functions.begin(), + E = Functions.end(); I != E; ++I) { + vector &Functions = I->second; + Function *Implementation = 0; // Find the implementation + Function *Concrete = 0; + for (unsigned i = 0; i < Functions.size(); ) { + if (!Functions[i]->isExternal()) { // Found an implementation + assert(Implementation == 0 && "Multiple definitions of the same" + " function. Case not handled yet!"); + Implementation = Functions[i]; + } else { + // Ignore functions that are never used so they don't cause spurious + // warnings... here we will actually DCE the function so that it isn't + // used later. + // + if (Functions[i]->use_size() == 0) { + M->getFunctionList().remove(Functions[i]); + delete Functions[i]; + Functions.erase(Functions.begin()+i); + Changed = true; + continue; + } + } + + if (Functions[i] && (!Functions[i]->getFunctionType()->isVarArg())) { + if (Concrete) { // Found two different functions types. Can't choose + Concrete = 0; + break; + } + Concrete = Functions[i]; + } + ++i; + } + + if (Functions.size() > 1) { // Found a multiply defined function... + // We should find exactly one non-vararg function definition, which is + // probably the implementation. Change all of the function definitions + // and uses to use it instead. + // + if (!Concrete) { + cerr << "Warning: Found functions types that are not compatible:\n"; + for (unsigned i = 0; i < Functions.size(); ++i) { + cerr << "\t" << Functions[i]->getType()->getDescription() << " %" + << Functions[i]->getName() << "\n"; + } + cerr << " No linkage of functions named '" << Functions[0]->getName() + << "' performed!\n"; + } else { + for (unsigned i = 0; i < Functions.size(); ++i) + if (Functions[i] != Concrete) { + Function *Old = Functions[i]; + const FunctionType *OldMT = Old->getFunctionType(); + const FunctionType *ConcreteMT = Concrete->getFunctionType(); + bool Broken = false; + + assert(Old->getReturnType() == Concrete->getReturnType() && + "Differing return types not handled yet!"); + assert(OldMT->getParamTypes().size() <= + ConcreteMT->getParamTypes().size() && + "Concrete type must have more specified parameters!"); + + // Check to make sure that if there are specified types, that they + // match... + // + for (unsigned i = 0; i < OldMT->getParamTypes().size(); ++i) + if (OldMT->getParamTypes()[i] != ConcreteMT->getParamTypes()[i]) { + cerr << "Parameter types conflict for" << OldMT + << " and " << ConcreteMT; + Broken = true; + } + if (Broken) break; // Can't process this one! + + + // Attempt to convert all of the uses of the old function to the + // concrete form of the function. If there is a use of the fn + // that we don't understand here we punt to avoid making a bad + // transformation. + // + // At this point, we know that the return values are the same for + // our two functions and that the Old function has no varargs fns + // specified. In otherwords it's just (...) + // + for (unsigned i = 0; i < Old->use_size(); ) { + User *U = *(Old->use_begin()+i); + if (CastInst *CI = dyn_cast(U)) { + // Convert casts directly + assert(CI->getOperand(0) == Old); + CI->setOperand(0, Concrete); + Changed = true; + } else if (CallInst *CI = dyn_cast(U)) { + // Can only fix up calls TO the argument, not args passed in. + if (CI->getCalledValue() == Old) { + ConvertCallTo(CI, Concrete); + Changed = true; + } else { + cerr << "Couldn't cleanup this function call, must be an" + << " argument or something!" << CI; + ++i; + } + } else { + cerr << "Cannot convert use of function: " << U << "\n"; + ++i; + } + } + } + } + } + } + + return Changed; +} + +Pass *createFunctionResolvingPass() { + return new FunctionResolvingPass(); +} -- 2.34.1