ArgumentPromotion.cpp revision 58d74910c6b82e622ecbb57d6644d48fec5a5c0f
19e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner//===-- ArgumentPromotion.cpp - Promote by-reference arguments ------------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// The LLVM Compiler Infrastructure 4ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner//===----------------------------------------------------------------------===// 9ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// 10ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// This pass promotes "by reference" arguments to be "by value" arguments. In 11ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// practice, this means looking for internal functions that have pointer 1255cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// arguments. If it can prove, through the use of alias analysis, that an 1355cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// argument is *only* loaded, then it can pass the value into the function 14ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// instead of the address of the value. This can cause recursive simplification 159e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner// of code and lead to the elimination of allocas (especially in C++ template 169e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner// code like the STL). 17ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// 189440db886627161a8413e823797569fc7b10beafChris Lattner// This pass also handles aggregate arguments that are passed into a function, 199440db886627161a8413e823797569fc7b10beafChris Lattner// scalarizing them if the elements of the aggregate are only loaded. Note that 2055cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// it refuses to scalarize aggregates which would require passing in more than 2155cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// three operands to the function, because passing thousands of operands for a 2255cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// large array or structure is unprofitable! 239440db886627161a8413e823797569fc7b10beafChris Lattner// 24ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// Note that this transformation could also be done for arguments that are only 2555cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// stored to (returning the value instead), but does not currently. This case 2655cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// would be best handled when and if LLVM begins supporting multiple return 2755cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// values from functions. 28ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// 29ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner//===----------------------------------------------------------------------===// 30ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 319e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner#define DEBUG_TYPE "argpromotion" 32ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Transforms/IPO.h" 33ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Constants.h" 34ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/DerivedTypes.h" 35ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Module.h" 365eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner#include "llvm/CallGraphSCCPass.h" 37ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Instructions.h" 38ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Analysis/AliasAnalysis.h" 395eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner#include "llvm/Analysis/CallGraph.h" 40ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Target/TargetData.h" 41ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Support/CallSite.h" 42ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Support/CFG.h" 43551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 44551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/DepthFirstIterator.h" 45551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 46551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/StringExtras.h" 479133fe28954d498fc4de13064c7d65bd811de02cReid Spencer#include "llvm/Support/Compiler.h" 48ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include <set> 49ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattnerusing namespace llvm; 50ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5186453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumArgumentsPromoted , "Number of pointer arguments promoted"); 5286453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumAggregatesPromoted, "Number of aggregate arguments promoted"); 5310603e0c84d15f61443e8b17bc35f98cc46606d9Chris LattnerSTATISTIC(NumByValArgsPromoted , "Number of byval arguments promoted"); 5486453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumArgumentsDead , "Number of dead pointer args eliminated"); 55ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5686453c52ba02e743d29c08456e51006500041456Chris Lattnernamespace { 57ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner /// ArgPromotion - The 'by reference' to 'by value' argument promotion pass. 58ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner /// 599133fe28954d498fc4de13064c7d65bd811de02cReid Spencer struct VISIBILITY_HIDDEN ArgPromotion : public CallGraphSCCPass { 60ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 61ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner AU.addRequired<AliasAnalysis>(); 62ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner AU.addRequired<TargetData>(); 635eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner CallGraphSCCPass::getAnalysisUsage(AU); 64ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 65ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 665eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner virtual bool runOnSCC(const std::vector<CallGraphNode *> &SCC); 67ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 68794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel ArgPromotion() : CallGraphSCCPass((intptr_t)&ID) {} 69794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 70ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner private: 715eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner bool PromoteArguments(CallGraphNode *CGN); 7240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner bool isSafeToPromoteArgument(Argument *Arg, bool isByVal) const; 73a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner Function *DoPromotion(Function *F, 7410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 7510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform); 76ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner }; 77ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 781997473cf72957d0e70322e2fe6fe2ab141c58a6Devang Patel char ArgPromotion::ID = 0; 797f8897f22e88271cfa114998a4d6088e7c8e8e11Chris Lattner RegisterPass<ArgPromotion> X("argpromotion", 807f8897f22e88271cfa114998a4d6088e7c8e8e11Chris Lattner "Promote 'by reference' arguments to scalars"); 81ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 82ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 83c71ca3cdd2d7a08b043ebb717cad0beadaf47450Devang PatelPass *llvm::createArgumentPromotionPass() { 84ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return new ArgPromotion(); 85ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 86ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 875eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattnerbool ArgPromotion::runOnSCC(const std::vector<CallGraphNode *> &SCC) { 885eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner bool Changed = false, LocalChange; 89ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 90f5afcabff887c2e9023f0c69c44f1de15b5c4347Chris Lattner do { // Iterate until we stop promoting from this SCC. 915eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner LocalChange = false; 925eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Attempt to promote arguments from all functions in this SCC. 935eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner for (unsigned i = 0, e = SCC.size(); i != e; ++i) 945eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner LocalChange |= PromoteArguments(SCC[i]); 955eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Changed |= LocalChange; // Remember that we changed something. 965eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner } while (LocalChange); 97fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 98ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return Changed; 99ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 100ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 1019e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// PromoteArguments - This method checks the specified function to see if there 1029e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// are any promotable arguments and if it is safe to promote the function (for 1039e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// example, all callers are direct). If safe to promote some arguments, it 1049e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// calls the DoPromotion method. 1059e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// 1065eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattnerbool ArgPromotion::PromoteArguments(CallGraphNode *CGN) { 1075eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Function *F = CGN->getFunction(); 1085eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner 1095eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Make sure that it is local to this module. 1105eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner if (!F || !F->hasInternalLinkage()) return false; 111ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 112ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // First check: see if there are any pointer arguments! If not, quick exit. 11340c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner SmallVector<std::pair<Argument*, unsigned>, 16> PointerArgs; 11440c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner unsigned ArgNo = 0; 11540c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 11640c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner I != E; ++I, ++ArgNo) 117ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (isa<PointerType>(I->getType())) 11840c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner PointerArgs.push_back(std::pair<Argument*, unsigned>(I, ArgNo)); 119ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (PointerArgs.empty()) return false; 120ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 121ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Second check: make sure that all callers are direct callers. We can't 122ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // transform functions that have indirect callers. 123ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (Value::use_iterator UI = F->use_begin(), E = F->use_end(); 1247db5a6df78749bf0cd37870fcefe08b8849e38e6Chris Lattner UI != E; ++UI) { 1257db5a6df78749bf0cd37870fcefe08b8849e38e6Chris Lattner CallSite CS = CallSite::get(*UI); 1269e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (!CS.getInstruction()) // "Taking the address" of the function 1279e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner return false; 1289e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 1299e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Ensure that this call site is CALLING the function, not passing it as 1309e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // an argument. 131f1577014ddd13113c4a06d85bc75cd7b2dce71a9Chris Lattner if (UI.getOperandNo() != 0) 132f1577014ddd13113c4a06d85bc75cd7b2dce71a9Chris Lattner return false; 1337db5a6df78749bf0cd37870fcefe08b8849e38e6Chris Lattner } 134ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 13540c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner // Check to see which arguments are promotable. If an argument is promotable, 13640c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner // add it to ArgsToPromote. 13740c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner SmallPtrSet<Argument*, 8> ArgsToPromote; 13810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> ByValArgsToTransform; 13940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner for (unsigned i = 0; i != PointerArgs.size(); ++i) { 14010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner bool isByVal = F->paramHasAttr(PointerArgs[i].second+1, ParamAttr::ByVal); 14110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 14210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // If this is a byval argument, and if the aggregate type is small, just 14310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // pass the elements, which is always safe. 14410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Argument *PtrArg = PointerArgs[i].first; 14510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (isByVal) { 14610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType(); 14710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(AgTy)) 14810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (STy->getNumElements() <= 3) { 14910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // If all the elements are first class types, we can promote it. 15010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner bool AllSimple = true; 15110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) 15210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!STy->getElementType(i)->isFirstClassType()) { 15310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AllSimple = false; 15410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner break; 15510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 15610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 15710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Safe to transform, don't even bother trying to "promote" it. 15810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Passing the elements as a scalar will allow scalarrepl to hack on 15910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // the new alloca we introduce. 16010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (AllSimple) { 16110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ByValArgsToTransform.insert(PtrArg); 16210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 16310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 16410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 16510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 16610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 16710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, see if we can promote the pointer to its value. 16810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (isSafeToPromoteArgument(PtrArg, isByVal)) 16910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ArgsToPromote.insert(PtrArg); 17040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner } 17140c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner 172ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // No promotable pointer arguments. 17310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) return false; 174ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 17510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Function *NewF = DoPromotion(F, ArgsToPromote, ByValArgsToTransform); 1765eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner 177dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Update the call graph to know that the function has been transformed. 1785eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner getAnalysis<CallGraph>().changeFunction(F, NewF); 179ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return true; 180ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 181ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 18211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// IsAlwaysValidPointer - Return true if the specified pointer is always legal 18311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// to load. 18411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattnerstatic bool IsAlwaysValidPointer(Value *V) { 18511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (isa<AllocaInst>(V) || isa<GlobalVariable>(V)) return true; 18611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) 18711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return IsAlwaysValidPointer(GEP->getOperand(0)); 18811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 18911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) 19011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return IsAlwaysValidPointer(CE->getOperand(0)); 19111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 19211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; 19311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner} 19411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 19511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// AllCalleesPassInValidPointerForArgument - Return true if we can prove that 19611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// all callees pass in a valid pointer for the specified function argument. 19711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattnerstatic bool AllCalleesPassInValidPointerForArgument(Argument *Arg) { 19811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner Function *Callee = Arg->getParent(); 19911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20093e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner unsigned ArgNo = std::distance(Callee->arg_begin(), 20193e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner Function::arg_iterator(Arg)); 20211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Look at all call sites of the function. At this pointer we know we only 20411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // have direct callees. 20511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner for (Value::use_iterator UI = Callee->use_begin(), E = Callee->use_end(); 20611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner UI != E; ++UI) { 20711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner CallSite CS = CallSite::get(*UI); 20811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner assert(CS.getInstruction() && "Should only have direct calls!"); 20911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 21011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (!IsAlwaysValidPointer(CS.getArgument(ArgNo))) 21111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; 21211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner } 21311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return true; 21411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner} 21511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 2169e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 2179e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// isSafeToPromoteArgument - As you might guess from the name of this method, 2189e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// it checks to see if it is both safe and useful to promote the argument. 2199e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// This method limits promotion of aggregates to only promote up to three 2209e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// elements of the aggregate in order to avoid exploding the number of 2219e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// arguments passed in. 22240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattnerbool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const { 2239440db886627161a8413e823797569fc7b10beafChris Lattner // We can only promote this argument if all of the uses are loads, or are GEP 2249440db886627161a8413e823797569fc7b10beafChris Lattner // instructions (with constant indices) that are subsequently loaded. 225170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 226170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // We can also only promote the load if we can guarantee that it will happen. 227170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // Promoting a load causes the load to be unconditionally executed in the 228170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // caller, so we can't turn a conditional load into an unconditional load in 229170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // general. 230170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner bool SafeToUnconditionallyLoad = false; 231170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner if (isByVal) // ByVal arguments are always safe to load from. 232170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner SafeToUnconditionallyLoad = true; 233170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 23411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner BasicBlock *EntryBlock = Arg->getParent()->begin(); 235a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner SmallVector<LoadInst*, 16> Loads; 236a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner std::vector<SmallVector<ConstantInt*, 8> > GEPIndices; 237ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end(); 238ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner UI != E; ++UI) 239ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { 240ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (LI->isVolatile()) return false; // Don't hack volatile loads 241ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Loads.push_back(LI); 242170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 243170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // If this load occurs in the entry block, then the pointer is 244170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // unconditionally loaded. 245170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner SafeToUnconditionallyLoad |= LI->getParent() == EntryBlock; 2469440db886627161a8413e823797569fc7b10beafChris Lattner } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(*UI)) { 2479440db886627161a8413e823797569fc7b10beafChris Lattner if (GEP->use_empty()) { 2489440db886627161a8413e823797569fc7b10beafChris Lattner // Dead GEP's cause trouble later. Just remove them if we run into 2499440db886627161a8413e823797569fc7b10beafChris Lattner // them. 2509e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner getAnalysis<AliasAnalysis>().deleteValue(GEP); 25140c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner GEP->eraseFromParent(); 25240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner return isSafeToPromoteArgument(Arg, isByVal); 2539440db886627161a8413e823797569fc7b10beafChris Lattner } 2549440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that all of the indices are constants. 255a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner SmallVector<ConstantInt*, 8> Operands; 2569440db886627161a8413e823797569fc7b10beafChris Lattner for (unsigned i = 1, e = GEP->getNumOperands(); i != e; ++i) 257beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner if (ConstantInt *C = dyn_cast<ConstantInt>(GEP->getOperand(i))) 2589440db886627161a8413e823797569fc7b10beafChris Lattner Operands.push_back(C); 2599440db886627161a8413e823797569fc7b10beafChris Lattner else 2609440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a constant operand GEP! 2619440db886627161a8413e823797569fc7b10beafChris Lattner 2629440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that the only users of the GEP are load instructions. 2639440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = GEP->use_begin(), E = GEP->use_end(); 2649440db886627161a8413e823797569fc7b10beafChris Lattner UI != E; ++UI) 2659440db886627161a8413e823797569fc7b10beafChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { 2669440db886627161a8413e823797569fc7b10beafChris Lattner if (LI->isVolatile()) return false; // Don't hack volatile loads 2679440db886627161a8413e823797569fc7b10beafChris Lattner Loads.push_back(LI); 268170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 269170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // If this load occurs in the entry block, then the pointer is 270170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // unconditionally loaded. 271170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner SafeToUnconditionallyLoad |= LI->getParent() == EntryBlock; 2729440db886627161a8413e823797569fc7b10beafChris Lattner } else { 2739440db886627161a8413e823797569fc7b10beafChris Lattner return false; 2749440db886627161a8413e823797569fc7b10beafChris Lattner } 275ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 2769e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // See if there is already a GEP with these indices. If not, check to 2779e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // make sure that we aren't promoting too many elements. If so, nothing 2789e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // to do. 2799440db886627161a8413e823797569fc7b10beafChris Lattner if (std::find(GEPIndices.begin(), GEPIndices.end(), Operands) == 2809440db886627161a8413e823797569fc7b10beafChris Lattner GEPIndices.end()) { 2819440db886627161a8413e823797569fc7b10beafChris Lattner if (GEPIndices.size() == 3) { 2820a81aac4b46eed130d20714af5a1c01b05d0275eBill Wendling DOUT << "argpromotion disable promoting argument '" 2830a81aac4b46eed130d20714af5a1c01b05d0275eBill Wendling << Arg->getName() << "' because it would require adding more " 2840a81aac4b46eed130d20714af5a1c01b05d0275eBill Wendling << "than 3 arguments to the function.\n"; 2859440db886627161a8413e823797569fc7b10beafChris Lattner // We limit aggregate promotion to only promoting up to three elements 2869440db886627161a8413e823797569fc7b10beafChris Lattner // of the aggregate. 2879440db886627161a8413e823797569fc7b10beafChris Lattner return false; 2889440db886627161a8413e823797569fc7b10beafChris Lattner } 2899440db886627161a8413e823797569fc7b10beafChris Lattner GEPIndices.push_back(Operands); 2909440db886627161a8413e823797569fc7b10beafChris Lattner } 2919440db886627161a8413e823797569fc7b10beafChris Lattner } else { 2929440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a load or a GEP. 2939440db886627161a8413e823797569fc7b10beafChris Lattner } 294ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 2959e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (Loads.empty()) return true; // No users, this is a dead argument. 296ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 29711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // If we decide that we want to promote this argument, the value is going to 29811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // be unconditionally loaded in all callees. This is only safe to do if the 29911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // pointer was going to be unconditionally loaded anyway (i.e. there is a load 30011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // of the pointer in the entry block of the function) or if we can prove that 30111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // all pointers passed in are always to legal locations (for example, no null 30211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // pointers are passed in, no pointers to free'd memory, etc). 303170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner if (!SafeToUnconditionallyLoad && 304170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner !AllCalleesPassInValidPointerForArgument(Arg)) 30511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; // Cannot prove that this is safe!! 30611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 30711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Okay, now we know that the argument is only used by load instructions and 30811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // it is safe to unconditionally load the pointer. Use alias analysis to 30911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // check to see if the pointer is guaranteed to not be modified from entry of 31011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // the function to each of the load instructions. 311ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 312ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Because there could be several/many load instructions, remember which 313ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // blocks we know to be transparent to the load. 314e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner SmallPtrSet<BasicBlock*, 16> TranspBlocks; 31546f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson 31646f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 3179440db886627161a8413e823797569fc7b10beafChris Lattner TargetData &TD = getAnalysis<TargetData>(); 318ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 319ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (unsigned i = 0, e = Loads.size(); i != e; ++i) { 320ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Check to see if the load is invalidated from the start of the block to 321ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the load itself. 322ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner LoadInst *Load = Loads[i]; 323ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner BasicBlock *BB = Load->getParent(); 3249440db886627161a8413e823797569fc7b10beafChris Lattner 3259440db886627161a8413e823797569fc7b10beafChris Lattner const PointerType *LoadTy = 3269440db886627161a8413e823797569fc7b10beafChris Lattner cast<PointerType>(Load->getOperand(0)->getType()); 327514ab348fddcdffa8367685dc608b2f8d5de986dDuncan Sands unsigned LoadSize = (unsigned)TD.getTypeStoreSize(LoadTy->getElementType()); 3289440db886627161a8413e823797569fc7b10beafChris Lattner 329ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (AA.canInstructionRangeModify(BB->front(), *Load, Arg, LoadSize)) 330ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; // Pointer is invalidated! 331ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 332ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Now check every path from the entry block to the load for transparency. 333ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // To do this, we perform a depth first search on the inverse CFG from the 334ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // loading block. 335ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) 336e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner for (idf_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 16> > 337e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner I = idf_ext_begin(*PI, TranspBlocks), 338ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner E = idf_ext_end(*PI, TranspBlocks); I != E; ++I) 339ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (AA.canBasicBlockModify(**I, Arg, LoadSize)) 340ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; 341ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 342ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 343ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If the path from the entry of the function to each load is free of 344ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // instructions that potentially invalidate the load, we can make the 345ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // transformation! 346ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return true; 347ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 348ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 349beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattnernamespace { 350beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner /// GEPIdxComparator - Provide a strong ordering for GEP indices. All Value* 351beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner /// elements are instances of ConstantInt. 352beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner /// 353beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner struct GEPIdxComparator { 354beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner bool operator()(const std::vector<Value*> &LHS, 355beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner const std::vector<Value*> &RHS) const { 356beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner unsigned idx = 0; 357beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (; idx < LHS.size() && idx < RHS.size(); ++idx) { 358beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner if (LHS[idx] != RHS[idx]) { 359b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer return cast<ConstantInt>(LHS[idx])->getZExtValue() < 360b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer cast<ConstantInt>(RHS[idx])->getZExtValue(); 361beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner } 362beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner } 363beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 364beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner // Return less than if we ran out of stuff in LHS and we didn't run out of 365beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner // stuff in RHS. 366beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner return idx == LHS.size() && idx != RHS.size(); 367beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner } 368beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner }; 369beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner} 370beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 371beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 3729e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// DoPromotion - This method actually performs the promotion of the specified 3735eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// arguments, and returns the new function. At this point, we know that it's 3745eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// safe to do so. 3755eb6f6c829ddfe353f94623aa1009c72be930497Chris LattnerFunction *ArgPromotion::DoPromotion(Function *F, 37610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 37710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform) { 378fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 379ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Start by computing a new prototype for the function, which is the same as 380ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the old function, but has modified arguments. 381ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner const FunctionType *FTy = F->getFunctionType(); 382ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner std::vector<const Type*> Params; 383ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 384beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner typedef std::set<std::vector<Value*>, GEPIdxComparator> ScalarizeTable; 385beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 3869440db886627161a8413e823797569fc7b10beafChris Lattner // ScalarizedElements - If we are promoting a pointer that has elements 3879440db886627161a8413e823797569fc7b10beafChris Lattner // accessed out of it, keep track of which elements are accessed so that we 3889440db886627161a8413e823797569fc7b10beafChris Lattner // can add one argument for each. 3899440db886627161a8413e823797569fc7b10beafChris Lattner // 3909440db886627161a8413e823797569fc7b10beafChris Lattner // Arguments that are directly loaded will have a zero element value here, to 3919440db886627161a8413e823797569fc7b10beafChris Lattner // handle cases where there are both a direct load and GEP accesses. 3929440db886627161a8413e823797569fc7b10beafChris Lattner // 393beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner std::map<Argument*, ScalarizeTable> ScalarizedElements; 3949440db886627161a8413e823797569fc7b10beafChris Lattner 3959e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // OriginalLoads - Keep track of a representative load instruction from the 3969e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // original function so that we can tell the alias analysis implementation 3979e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // what the new GEP/Load instructions we are inserting look like. 3989e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner std::map<std::vector<Value*>, LoadInst*> OriginalLoads; 3999e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 400dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // ParamAttrs - Keep track of the parameter attributes for the arguments 401dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // that we are *not* promoting. For the ones that we do promote, the parameter 402dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // attributes are lost 40358d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner SmallVector<ParamAttrsWithIndex, 8> ParamAttrsVec; 40458d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner const PAListPtr &PAL = F->getParamAttrs(); 405dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 406532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 40758d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes attrs = PAL.getParamAttrs(0)) 408532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, attrs)); 409532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands 410ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner unsigned ArgIndex = 1; 411dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; 412ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ++I, ++ArgIndex) { 41310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 41410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Just add all the struct element types. 41510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 41610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 41710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) 41810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Params.push_back(STy->getElementType(i)); 41910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++NumByValArgsPromoted; 42010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!ArgsToPromote.count(I)) { 421ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Params.push_back(I->getType()); 42258d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes attrs = PAL.getParamAttrs(ArgIndex)) 42310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Params.size(), attrs)); 4249e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else if (I->use_empty()) { 4259e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner ++NumArgumentsDead; 4269e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else { 4279440db886627161a8413e823797569fc7b10beafChris Lattner // Okay, this is being promoted. Check to see if there are any GEP uses 4289440db886627161a8413e823797569fc7b10beafChris Lattner // of the argument. 429beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 4309440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; 4319440db886627161a8413e823797569fc7b10beafChris Lattner ++UI) { 4329440db886627161a8413e823797569fc7b10beafChris Lattner Instruction *User = cast<Instruction>(*UI); 43346f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson assert(isa<LoadInst>(User) || isa<GetElementPtrInst>(User)); 43446f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson std::vector<Value*> Indices(User->op_begin()+1, User->op_end()); 43546f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson ArgIndices.insert(Indices); 43646f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson LoadInst *OrigLoad; 43746f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson if (LoadInst *L = dyn_cast<LoadInst>(User)) 43846f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = L; 43946f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson else 44046f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = cast<LoadInst>(User->use_back()); 44146f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OriginalLoads[Indices] = OrigLoad; 4429440db886627161a8413e823797569fc7b10beafChris Lattner } 4439440db886627161a8413e823797569fc7b10beafChris Lattner 4449440db886627161a8413e823797569fc7b10beafChris Lattner // Add a parameter to the function for each element passed in. 445beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 4469440db886627161a8413e823797569fc7b10beafChris Lattner E = ArgIndices.end(); SI != E; ++SI) 4471ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner Params.push_back(GetElementPtrInst::getIndexedType(I->getType(), 448b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene SI->begin(), 449b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene SI->end())); 4509440db886627161a8413e823797569fc7b10beafChris Lattner 4519440db886627161a8413e823797569fc7b10beafChris Lattner if (ArgIndices.size() == 1 && ArgIndices.begin()->empty()) 4529440db886627161a8413e823797569fc7b10beafChris Lattner ++NumArgumentsPromoted; 4539440db886627161a8413e823797569fc7b10beafChris Lattner else 4549440db886627161a8413e823797569fc7b10beafChris Lattner ++NumAggregatesPromoted; 455ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 45610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 457ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 458ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner const Type *RetTy = FTy->getReturnType(); 459ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 460ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Work around LLVM bug PR56: the CWriter cannot emit varargs functions which 461ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // have zero fixed arguments. 462ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner bool ExtraArgHack = false; 463ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (Params.empty() && FTy->isVarArg()) { 464ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ExtraArgHack = true; 465c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Params.push_back(Type::Int32Ty); 466ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 467dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 468dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Construct the new function type using the new arguments. 469ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg()); 470fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 471dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Create the new function body and insert it into the module... 472ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Function *NF = new Function(NFTy, F->getLinkage(), F->getName()); 473f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner NF->setCallingConv(F->getCallingConv()); 474ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 475ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // Recompute the parameter attributes list based on the new arguments for 476ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // the function. 47758d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner NF->setParamAttrs(PAListPtr::get(ParamAttrsVec.begin(), ParamAttrsVec.end())); 47858d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner ParamAttrsVec.clear(); 479ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 480194c90ed2a8e74b5a1c5184835f84c572d524dadGordon Henriksen if (F->hasCollector()) 481194c90ed2a8e74b5a1c5184835f84c572d524dadGordon Henriksen NF->setCollector(F->getCollector()); 482ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner F->getParent()->getFunctionList().insert(F, NF); 4839e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 4849e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Get the alias analysis information that we need to update to reflect our 4859e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // changes. 4869e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 4879e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 488ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Loop over all of the callers of the function, transforming the call sites 489ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // to pass in the loaded pointers. 490ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 491ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner SmallVector<Value*, 16> Args; 492ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner while (!F->use_empty()) { 493ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner CallSite CS = CallSite::get(F->use_back()); 494ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *Call = CS.getInstruction(); 49558d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner const PAListPtr &CallPAL = CS.getParamAttrs(); 496ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 497532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 49858d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes attrs = CallPAL.getParamAttrs(0)) 499532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, attrs)); 500532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands 5019e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Loop over the operands, inserting GEP and loads in the caller as 5029e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // appropriate. 503ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner CallSite::arg_iterator AI = CS.arg_begin(); 504ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ArgIndex = 1; 505f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 506ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner I != E; ++I, ++AI, ++ArgIndex) 50710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 508ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); // Unmodified argument 509ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 51058d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes Attrs = CallPAL.getParamAttrs(ArgIndex)) 511ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs)); 512ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 51310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (ByValArgsToTransform.count(I)) { 51410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Emit a GEP and load for each element of the struct. 51510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 51610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 51710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *Idxs[2] = { ConstantInt::get(Type::Int32Ty, 0), 0 }; 51810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 51910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Idxs[1] = ConstantInt::get(Type::Int32Ty, i); 52010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *Idx = new GetElementPtrInst(*AI, Idxs, Idxs+2, 52110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner (*AI)->getName()+"."+utostr(i), 52210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Call); 52310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // TODO: Tell AA about the new values? 52410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Args.push_back(new LoadInst(Idx, Idx->getName()+".val", Call)); 52510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 52610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!I->use_empty()) { 5279e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Non-dead argument: insert GEPs and loads as appropriate. 528beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 529beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 5309440db886627161a8413e823797569fc7b10beafChris Lattner E = ArgIndices.end(); SI != E; ++SI) { 5319440db886627161a8413e823797569fc7b10beafChris Lattner Value *V = *AI; 5329e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner LoadInst *OrigLoad = OriginalLoads[*SI]; 5339e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (!SI->empty()) { 534b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene V = new GetElementPtrInst(V, SI->begin(), SI->end(), 5351ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner V->getName()+".idx", Call); 5369e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad->getOperand(0), V); 5379e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } 5389440db886627161a8413e823797569fc7b10beafChris Lattner Args.push_back(new LoadInst(V, V->getName()+".val", Call)); 5399e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad, Args.back()); 5409440db886627161a8413e823797569fc7b10beafChris Lattner } 541ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 542ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 543ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (ExtraArgHack) 544c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Args.push_back(Constant::getNullValue(Type::Int32Ty)); 545ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 546ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Push any varargs arguments on the list 547ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner for (; AI != CS.arg_end(); ++AI, ++ArgIndex) { 548ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); 54958d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes Attrs = CallPAL.getParamAttrs(ArgIndex)) 550ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs)); 551ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner } 552ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 553ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *New; 554ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) { 555ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner New = new InvokeInst(NF, II->getNormalDest(), II->getUnwindDest(), 556f1355a55f8d815f5385e9a4432195f03b65f3a42David Greene Args.begin(), Args.end(), "", Call); 557f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv()); 55858d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner cast<InvokeInst>(New)->setParamAttrs(PAListPtr::get(ParamAttrsVec.begin(), 55958d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner ParamAttrsVec.end())); 560ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } else { 56152eec548206d0b135b55ba52dd0e82e978f15ae5David Greene New = new CallInst(NF, Args.begin(), Args.end(), "", Call); 562f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<CallInst>(New)->setCallingConv(CS.getCallingConv()); 56358d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner cast<CallInst>(New)->setParamAttrs(PAListPtr::get(ParamAttrsVec.begin(), 56458d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner ParamAttrsVec.end())); 5651430ef134d36888b99d2e6fedd2b025882593538Chris Lattner if (cast<CallInst>(Call)->isTailCall()) 5661430ef134d36888b99d2e6fedd2b025882593538Chris Lattner cast<CallInst>(New)->setTailCall(); 567ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 568ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.clear(); 569ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ParamAttrsVec.clear(); 570ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5719e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Update the alias analysis implementation to know that we are replacing 5729e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // the old call with a new one. 5739e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(Call, New); 5749e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 575ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (!Call->use_empty()) { 576ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Call->replaceAllUsesWith(New); 577046800a7125cd497613efc0e1ea15cb595666585Chris Lattner New->takeName(Call); 578ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 579fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 580ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Finally, remove the old call from the program, reducing the use-count of 581ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // F. 58240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner Call->eraseFromParent(); 583ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 584ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 585ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Since we have now created the new function, splice the body of the old 586ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function right into the new function, leaving the old rotting hulk of the 587ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function empty. 588ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList()); 589ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 590ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Loop over the argument list, transfering uses of the old arguments over to 591ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the new arguments, also transfering over the names as well. 592ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 59393e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(), 59410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2 = NF->arg_begin(); I != E; ++I) { 59510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 596ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If this is an unmodified argument, move the name and users over to the 597ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // new version. 598ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner I->replaceAllUsesWith(I2); 599046800a7125cd497613efc0e1ea15cb595666585Chris Lattner I2->takeName(I); 6009e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(I, I2); 601ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ++I2; 60210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 60310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 60410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 60510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 60610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // In the callee, we create an alloca, and store each of the new incoming 60710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // arguments into the alloca. 60810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Instruction *InsertPt = NF->begin()->begin(); 60910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 61010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Just add all the struct element types. 61110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 61210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *TheAlloca = new AllocaInst(AgTy, 0, "", InsertPt); 61310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 61410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *Idxs[2] = { ConstantInt::get(Type::Int32Ty, 0), 0 }; 61510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 61610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 61710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Idxs[1] = ConstantInt::get(Type::Int32Ty, i); 61810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *Idx = new GetElementPtrInst(TheAlloca, Idxs, Idxs+2, 61910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner TheAlloca->getName()+"."+utostr(i), 62010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner InsertPt); 62110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2->setName(I->getName()+"."+utostr(i)); 62210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner new StoreInst(I2++, Idx, InsertPt); 62310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 62410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 62510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Anything that used the arg should now use the alloca. 62610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I->replaceAllUsesWith(TheAlloca); 62710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner TheAlloca->takeName(I); 62810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(I, TheAlloca); 62910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 63010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 63110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 63210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (I->use_empty()) { 6339e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.deleteValue(I); 63410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 63510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 63610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 63710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, if we promoted this argument, then all users are load 63810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // instructions, and all loads should be using the new argument that we 63910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // added. 64010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 64110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 64210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!I->use_empty()) { 64310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(I->use_back())) { 64410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(ArgIndices.begin()->empty() && 64510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner "Load element should sort to front!"); 64610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2->setName(I->getName()+".val"); 64710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->replaceAllUsesWith(I2); 64810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(LI, I2); 64910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->eraseFromParent(); 65010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner DOUT << "*** Promoted load of argument '" << I->getName() 65110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner << "' in function '" << F->getName() << "'\n"; 65210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else { 65310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->use_back()); 65410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner std::vector<Value*> Operands(GEP->op_begin()+1, GEP->op_end()); 65510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 65610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Function::arg_iterator TheArg = I2; 65710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (ScalarizeTable::iterator It = ArgIndices.begin(); 65810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner *It != Operands; ++It, ++TheArg) { 65910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(It != ArgIndices.end() && "GEP not handled??"); 66010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 6619440db886627161a8413e823797569fc7b10beafChris Lattner 66210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner std::string NewName = I->getName(); 66310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = Operands.size(); i != e; ++i) 66410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(Operands[i])) 66510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner NewName += "." + CI->getValue().toStringUnsigned(10); 66610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner else 66710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner NewName += ".x"; 66810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner TheArg->setName(NewName+".val"); 66910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 67010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner DOUT << "*** Promoted agg argument '" << TheArg->getName() 67110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner << "' of function '" << F->getName() << "'\n"; 67210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 67310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // All of the uses must be load instructions. Replace them all with 67410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // the argument specified by ArgNo. 67510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!GEP->use_empty()) { 67610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LoadInst *L = cast<LoadInst>(GEP->use_back()); 67710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->replaceAllUsesWith(TheArg); 67810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(L, TheArg); 67910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->eraseFromParent(); 6809440db886627161a8413e823797569fc7b10beafChris Lattner } 68110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.deleteValue(GEP); 68210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GEP->eraseFromParent(); 683ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 684ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 685ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 68610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Increment I2 past all of the arguments added for this promoted pointer. 68710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = ArgIndices.size(); i != e; ++i) 68810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++I2; 68910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 69010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 6919e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Notify the alias analysis implementation that we inserted a new argument. 6929e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (ExtraArgHack) 693c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer AA.copyValue(Constant::getNullValue(Type::Int32Ty), NF->arg_begin()); 6949e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 6959e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 6969e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Tell the alias analysis that the old function is about to disappear. 6979e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(F, NF); 6989e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 699ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Now that the old function is dead, delete it. 70040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner F->eraseFromParent(); 7015eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner return NF; 702ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 703