ArgumentPromotion.cpp revision debcb01b0f0a15f568ca69e8f288fade4bfc7297
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 20477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman// by default it refuses to scalarize aggregates which would require passing in 21477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman// more than three operands to the function, because passing thousands of 224cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands// operands for a large array or structure is unprofitable! This limit can be 23477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman// configured or disabled, however. 249440db886627161a8413e823797569fc7b10beafChris Lattner// 25ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// Note that this transformation could also be done for arguments that are only 2655cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// stored to (returning the value instead), but does not currently. This case 2755cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// would be best handled when and if LLVM begins supporting multiple return 2855cbec317d9c30c8ae1d35eaa008ca63d1f2fce9Gordon Henriksen// values from functions. 29ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner// 30ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner//===----------------------------------------------------------------------===// 31ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 329e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner#define DEBUG_TYPE "argpromotion" 33ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Transforms/IPO.h" 34ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Constants.h" 35ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/DerivedTypes.h" 36ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Module.h" 375eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner#include "llvm/CallGraphSCCPass.h" 38ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Instructions.h" 3914ce9ef2e9013ba56e1daafebd91fe3ee1e8647eOwen Anderson#include "llvm/LLVMContext.h" 40ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Analysis/AliasAnalysis.h" 415eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner#include "llvm/Analysis/CallGraph.h" 42ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Target/TargetData.h" 43ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Support/CallSite.h" 44ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar#include "llvm/Support/Compiler.h" 45ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Support/CFG.h" 46551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 47ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar#include "llvm/Support/raw_ostream.h" 48551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/DepthFirstIterator.h" 49551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 50551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/StringExtras.h" 51ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include <set> 52ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattnerusing namespace llvm; 53ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5486453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumArgumentsPromoted , "Number of pointer arguments promoted"); 5586453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumAggregatesPromoted, "Number of aggregate arguments promoted"); 5610603e0c84d15f61443e8b17bc35f98cc46606d9Chris LattnerSTATISTIC(NumByValArgsPromoted , "Number of byval arguments promoted"); 5786453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumArgumentsDead , "Number of dead pointer args eliminated"); 58ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5986453c52ba02e743d29c08456e51006500041456Chris Lattnernamespace { 60ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner /// ArgPromotion - The 'by reference' to 'by value' argument promotion pass. 61ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner /// 629133fe28954d498fc4de13064c7d65bd811de02cReid Spencer struct VISIBILITY_HIDDEN ArgPromotion : public CallGraphSCCPass { 63ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 64ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner AU.addRequired<AliasAnalysis>(); 65ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner AU.addRequired<TargetData>(); 665eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner CallGraphSCCPass::getAnalysisUsage(AU); 67ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 68ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 695eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner virtual bool runOnSCC(const std::vector<CallGraphNode *> &SCC); 70ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 7138deef9ce58b33dba34515f23fb7dbde02164c77Dan Gohman explicit ArgPromotion(unsigned maxElements = 3) 7238deef9ce58b33dba34515f23fb7dbde02164c77Dan Gohman : CallGraphSCCPass(&ID), maxElements(maxElements) {} 734cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 74477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman /// A vector used to hold the indices of a single GEP instruction 75477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman typedef std::vector<uint64_t> IndicesVector; 76794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 77ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner private: 785eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner bool PromoteArguments(CallGraphNode *CGN); 7940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner bool isSafeToPromoteArgument(Argument *Arg, bool isByVal) const; 804cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands Function *DoPromotion(Function *F, 8110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 8210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform); 83992e97eed344a141ff581838cfdacb76a1e9559aMatthijs Kooijman /// The maximum number of elements to expand, or 0 for unlimited. 84992e97eed344a141ff581838cfdacb76a1e9559aMatthijs Kooijman unsigned maxElements; 85ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner }; 86ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 87ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 88844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanchar ArgPromotion::ID = 0; 89844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic RegisterPass<ArgPromotion> 90844731a7f1909f55935e3514c9e713a62d67662eDan GohmanX("argpromotion", "Promote 'by reference' arguments to scalars"); 91844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 92bcd203cf860269987f32b14737b200b84fc2b63eChris LattnerPass *llvm::createArgumentPromotionPass(unsigned maxElements) { 93bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner return new ArgPromotion(maxElements); 94ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 95ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 965eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattnerbool ArgPromotion::runOnSCC(const std::vector<CallGraphNode *> &SCC) { 975eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner bool Changed = false, LocalChange; 98ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 99f5afcabff887c2e9023f0c69c44f1de15b5c4347Chris Lattner do { // Iterate until we stop promoting from this SCC. 1005eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner LocalChange = false; 1015eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Attempt to promote arguments from all functions in this SCC. 1025eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner for (unsigned i = 0, e = SCC.size(); i != e; ++i) 1035eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner LocalChange |= PromoteArguments(SCC[i]); 1045eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Changed |= LocalChange; // Remember that we changed something. 1055eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner } while (LocalChange); 106fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 107ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return Changed; 108ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 109ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 1109e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// PromoteArguments - This method checks the specified function to see if there 1119e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// are any promotable arguments and if it is safe to promote the function (for 1129e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// example, all callers are direct). If safe to promote some arguments, it 1139e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// calls the DoPromotion method. 1149e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// 1155eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattnerbool ArgPromotion::PromoteArguments(CallGraphNode *CGN) { 1165eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Function *F = CGN->getFunction(); 1175eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner 1185eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Make sure that it is local to this module. 119bb46f52027416598a662dc1c58f48d9d56b1a65bRafael Espindola if (!F || !F->hasLocalLinkage()) return false; 120ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 121ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // First check: see if there are any pointer arguments! If not, quick exit. 12240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner SmallVector<std::pair<Argument*, unsigned>, 16> PointerArgs; 12340c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner unsigned ArgNo = 0; 12440c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 12540c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner I != E; ++I, ++ArgNo) 126ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (isa<PointerType>(I->getType())) 12740c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner PointerArgs.push_back(std::pair<Argument*, unsigned>(I, ArgNo)); 128ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (PointerArgs.empty()) return false; 129ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 130ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Second check: make sure that all callers are direct callers. We can't 131ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // transform functions that have indirect callers. 132757068f3bad425fb126fe16ab7b8a82a636e6bbdJay Foad if (F->hasAddressTaken()) 133757068f3bad425fb126fe16ab7b8a82a636e6bbdJay Foad return false; 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) { 1400598866c052147c31b808391f58434ce3dbfb838Devang Patel bool isByVal = F->paramHasAttr(PointerArgs[i].second+1, Attribute::ByVal); 1414cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 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(); 14743e2a035309f4e353a8bd5547d10125414597e74Duncan Sands if (const StructType *STy = dyn_cast<StructType>(AgTy)) { 148bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner if (maxElements > 0 && STy->getNumElements() > maxElements) { 149ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar DEBUG(errs() << "argpromotion disable promoting argument '" 150ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << PtrArg->getName() << "' because it would require adding more" 151ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << " than " << maxElements << " arguments to the function.\n"); 152bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner } else { 153399101a5990621b0357009ab1852cc00f410a6c6Dan Gohman // If all the elements are single-value types, we can promote it. 15410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner bool AllSimple = true; 15510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) 156399101a5990621b0357009ab1852cc00f410a6c6Dan Gohman if (!STy->getElementType(i)->isSingleValueType()) { 15710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AllSimple = false; 15810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner break; 15910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 1604cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 16110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Safe to transform, don't even bother trying to "promote" it. 16210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Passing the elements as a scalar will allow scalarrepl to hack on 16310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // the new alloca we introduce. 16410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (AllSimple) { 16510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ByValArgsToTransform.insert(PtrArg); 16610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 16710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 16810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 16943e2a035309f4e353a8bd5547d10125414597e74Duncan Sands } 17010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 1714cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 17210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, see if we can promote the pointer to its value. 17310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (isSafeToPromoteArgument(PtrArg, isByVal)) 17410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ArgsToPromote.insert(PtrArg); 17540c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner } 1764cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 177ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // No promotable pointer arguments. 17810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) return false; 179ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 18010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Function *NewF = DoPromotion(F, ArgsToPromote, ByValArgsToTransform); 1815eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner 182dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Update the call graph to know that the function has been transformed. 1835eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner getAnalysis<CallGraph>().changeFunction(F, NewF); 184ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return true; 185ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 186ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 18711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// IsAlwaysValidPointer - Return true if the specified pointer is always legal 18811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// to load. 18911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattnerstatic bool IsAlwaysValidPointer(Value *V) { 19011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (isa<AllocaInst>(V) || isa<GlobalVariable>(V)) return true; 19111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) 19211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return IsAlwaysValidPointer(GEP->getOperand(0)); 19311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 19411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) 19511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return IsAlwaysValidPointer(CE->getOperand(0)); 19611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 19711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; 19811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner} 19911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// AllCalleesPassInValidPointerForArgument - Return true if we can prove that 20111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// all callees pass in a valid pointer for the specified function argument. 20211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattnerstatic bool AllCalleesPassInValidPointerForArgument(Argument *Arg) { 20311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner Function *Callee = Arg->getParent(); 20411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20593e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner unsigned ArgNo = std::distance(Callee->arg_begin(), 20693e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner Function::arg_iterator(Arg)); 20711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Look at all call sites of the function. At this pointer we know we only 20911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // have direct callees. 21011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner for (Value::use_iterator UI = Callee->use_begin(), E = Callee->use_end(); 21111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner UI != E; ++UI) { 21211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner CallSite CS = CallSite::get(*UI); 21311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner assert(CS.getInstruction() && "Should only have direct calls!"); 21411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 21511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (!IsAlwaysValidPointer(CS.getArgument(ArgNo))) 21611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; 21711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner } 21811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return true; 21911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner} 22011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 221477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// Returns true if Prefix is a prefix of longer. That means, Longer has a size 222477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// that is greater than or equal to the size of prefix, and each of the 223477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// elements in Prefix is the same as the corresponding elements in Longer. 224477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// 225477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// This means it also returns true when Prefix and Longer are equal! 226477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijmanstatic bool IsPrefix(const ArgPromotion::IndicesVector &Prefix, 227477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman const ArgPromotion::IndicesVector &Longer) { 228477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Prefix.size() > Longer.size()) 229477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 230477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (unsigned i = 0, e = Prefix.size(); i != e; ++i) 231477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Prefix[i] != Longer[i]) 232477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 233477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return true; 234477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman} 235477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 236477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 237477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// Checks if Indices, or a prefix of Indices, is in Set. 238477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijmanstatic bool PrefixIn(const ArgPromotion::IndicesVector &Indices, 239477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector> &Set) { 240477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator Low; 241477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low = Set.upper_bound(Indices); 242477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Low != Set.begin()) 243477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low--; 244477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Low is now the last element smaller than or equal to Indices. This means 245477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // it points to a prefix of Indices (possibly Indices itself), if such 246477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // prefix exists. 247477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // 248477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This load is safe if any prefix of its operands is safe to load. 249477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return Low != Set.end() && IsPrefix(*Low, Indices); 250477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman} 251477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 252477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// Mark the given indices (ToMark) as safe in the the given set of indices 253477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// (Safe). Marking safe usually means adding ToMark to Safe. However, if there 254477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// is already a prefix of Indices in Safe, Indices are implicitely marked safe 255477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// already. Furthermore, any indices that Indices is itself a prefix of, are 256477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// removed from Safe (since they are implicitely safe because of Indices now). 257477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijmanstatic void MarkIndicesSafe(const ArgPromotion::IndicesVector &ToMark, 258477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector> &Safe) { 259477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator Low; 260477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low = Safe.upper_bound(ToMark); 261477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Guard against the case where Safe is empty 262477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Low != Safe.begin()) 263477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low--; 264477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Low is now the last element smaller than or equal to Indices. This 265477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // means it points to a prefix of Indices (possibly Indices itself), if 266477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // such prefix exists. 267477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Low != Safe.end()) { 268477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (IsPrefix(*Low, ToMark)) 269477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // If there is already a prefix of these indices (or exactly these 270477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // indices) marked a safe, don't bother adding these indices 271477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return; 272477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 273477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Increment Low, so we can use it as a "insert before" hint 2744cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands ++Low; 275477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 2764cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands // Insert 277477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low = Safe.insert(Low, ToMark); 278477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ++Low; 279477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // If there we're a prefix of longer index list(s), remove those 280477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator End = Safe.end(); 281477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman while (Low != End && IsPrefix(ToMark, *Low)) { 282477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator Remove = Low; 283477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ++Low; 284477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Safe.erase(Remove); 285477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 286477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman} 2879e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 2889e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// isSafeToPromoteArgument - As you might guess from the name of this method, 2899e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// it checks to see if it is both safe and useful to promote the argument. 2909e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// This method limits promotion of aggregates to only promote up to three 2919e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// elements of the aggregate in order to avoid exploding the number of 2929e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// arguments passed in. 29340c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattnerbool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const { 294477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman typedef std::set<IndicesVector> GEPIndicesSet; 295477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 296477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Quick exit for unused arguments 297477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Arg->use_empty()) 298477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return true; 299477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 3009440db886627161a8413e823797569fc7b10beafChris Lattner // We can only promote this argument if all of the uses are loads, or are GEP 3019440db886627161a8413e823797569fc7b10beafChris Lattner // instructions (with constant indices) that are subsequently loaded. 302477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // 303477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Promoting the argument causes it to be loaded in the caller 304477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // unconditionally. This is only safe if we can prove that either the load 305477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // would have happened in the callee anyway (ie, there is a load in the entry 306477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // block) or the pointer passed in at every call site is guaranteed to be 307477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // valid. 308477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // In the former case, invalid loads can happen, but would have happened 309477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // anyway, in the latter case, invalid loads won't happen. This prevents us 310477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // from introducing an invalid load that wouldn't have happened in the 311477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // original code. 312477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // 313477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This set will contain all sets of indices that are loaded in the entry 314477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // block, and thus are safe to unconditionally load in the caller. 315477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman GEPIndicesSet SafeToUnconditionallyLoad; 316170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 317477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This set contains all the sets of indices that we are planning to promote. 318477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This makes it possible to limit the number of arguments added. 319477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman GEPIndicesSet ToPromote; 3204cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 321477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // If the pointer is always valid, any load with first index 0 is valid. 322477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if(isByVal || AllCalleesPassInValidPointerForArgument(Arg)) 323477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman SafeToUnconditionallyLoad.insert(IndicesVector(1, 0)); 324477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 325477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // First, iterate the entry block and mark loads of (geps of) arguments as 326477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // safe. 32711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner BasicBlock *EntryBlock = Arg->getParent()->begin(); 328477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Declare this here so we can reuse it 329477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Indices; 330477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (BasicBlock::iterator I = EntryBlock->begin(), E = EntryBlock->end(); 331477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman I != E; ++I) 332477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (LoadInst *LI = dyn_cast<LoadInst>(I)) { 333477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Value *V = LI->getPointerOperand(); 334477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) { 335477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman V = GEP->getPointerOperand(); 336477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (V == Arg) { 337477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This load actually loads (part of) Arg? Check the indices then. 338477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.reserve(GEP->getNumIndices()); 339477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end(); 340477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman II != IE; ++II) 341477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (ConstantInt *CI = dyn_cast<ConstantInt>(*II)) 342477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.push_back(CI->getSExtValue()); 343477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman else 344477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // We found a non-constant GEP index for this argument? Bail out 345477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // right away, can't promote this argument at all. 346477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 347477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 348477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Indices checked out, mark them as safe 349477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman MarkIndicesSafe(Indices, SafeToUnconditionallyLoad); 350477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.clear(); 351477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 352477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } else if (V == Arg) { 353477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Direct loads are equivalent to a GEP with a single 0 index. 354477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman MarkIndicesSafe(IndicesVector(1, 0), SafeToUnconditionallyLoad); 355477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 356477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 357477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 358477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Now, iterate all uses of the argument to see if there are any uses that are 359477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // not (GEP+)loads, or any (GEP+)loads that are not safe to promote. 360a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner SmallVector<LoadInst*, 16> Loads; 361477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Operands; 362ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end(); 363477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman UI != E; ++UI) { 364477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.clear(); 365ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { 366ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (LI->isVolatile()) return false; // Don't hack volatile loads 367ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Loads.push_back(LI); 368477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Direct loads are equivalent to a GEP with a zero index and then a load. 369477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.push_back(0); 3709440db886627161a8413e823797569fc7b10beafChris Lattner } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(*UI)) { 3719440db886627161a8413e823797569fc7b10beafChris Lattner if (GEP->use_empty()) { 3729440db886627161a8413e823797569fc7b10beafChris Lattner // Dead GEP's cause trouble later. Just remove them if we run into 3739440db886627161a8413e823797569fc7b10beafChris Lattner // them. 3749e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner getAnalysis<AliasAnalysis>().deleteValue(GEP); 37540c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner GEP->eraseFromParent(); 376477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // TODO: This runs the above loop over and over again for dead GEPS 377477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Couldn't we just do increment the UI iterator earlier and erase the 378477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // use? 37940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner return isSafeToPromoteArgument(Arg, isByVal); 3809440db886627161a8413e823797569fc7b10beafChris Lattner } 381477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 3829440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that all of the indices are constants. 383477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator i = GEP->idx_begin(), e = GEP->idx_end(); 384477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman i != e; ++i) 3855e46321d665d6b1f445aff70d8eabb4870a6cf0eGabor Greif if (ConstantInt *C = dyn_cast<ConstantInt>(*i)) 386477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.push_back(C->getSExtValue()); 3879440db886627161a8413e823797569fc7b10beafChris Lattner else 3889440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a constant operand GEP! 3899440db886627161a8413e823797569fc7b10beafChris Lattner 3909440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that the only users of the GEP are load instructions. 3919440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = GEP->use_begin(), E = GEP->use_end(); 3929440db886627161a8413e823797569fc7b10beafChris Lattner UI != E; ++UI) 3939440db886627161a8413e823797569fc7b10beafChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { 3949440db886627161a8413e823797569fc7b10beafChris Lattner if (LI->isVolatile()) return false; // Don't hack volatile loads 3959440db886627161a8413e823797569fc7b10beafChris Lattner Loads.push_back(LI); 3969440db886627161a8413e823797569fc7b10beafChris Lattner } else { 397477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Other uses than load? 3989440db886627161a8413e823797569fc7b10beafChris Lattner return false; 3999440db886627161a8413e823797569fc7b10beafChris Lattner } 4009440db886627161a8413e823797569fc7b10beafChris Lattner } else { 4019440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a load or a GEP. 4029440db886627161a8413e823797569fc7b10beafChris Lattner } 4034cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 404477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Now, see if it is safe to promote this load / loads of this GEP. Loading 405477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // is safe if Operands, or a prefix of Operands, is marked as safe. 406477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (!PrefixIn(Operands, SafeToUnconditionallyLoad)) 407477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 408ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 409477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // See if we are already promoting a load with these indices. If not, check 410477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // to make sure that we aren't promoting too many elements. If so, nothing 411477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // to do. 412477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (ToPromote.find(Operands) == ToPromote.end()) { 413477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (maxElements > 0 && ToPromote.size() == maxElements) { 414ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar DEBUG(errs() << "argpromotion not promoting argument '" 415ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << Arg->getName() << "' because it would require adding more " 416ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << "than " << maxElements << " arguments to the function.\n"); 417477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // We limit aggregate promotion to only promoting up to a fixed number 418477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // of elements of the aggregate. 419477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 420477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 421477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ToPromote.insert(Operands); 422477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 423477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 424ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 425477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Loads.empty()) return true; // No users, this is a dead argument. 42611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 42711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Okay, now we know that the argument is only used by load instructions and 428477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // it is safe to unconditionally perform all of them. Use alias analysis to 42911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // check to see if the pointer is guaranteed to not be modified from entry of 43011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // the function to each of the load instructions. 431ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 432ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Because there could be several/many load instructions, remember which 433ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // blocks we know to be transparent to the load. 434e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner SmallPtrSet<BasicBlock*, 16> TranspBlocks; 43546f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson 43646f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 4379440db886627161a8413e823797569fc7b10beafChris Lattner TargetData &TD = getAnalysis<TargetData>(); 438ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 439ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (unsigned i = 0, e = Loads.size(); i != e; ++i) { 440ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Check to see if the load is invalidated from the start of the block to 441ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the load itself. 442ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner LoadInst *Load = Loads[i]; 443ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner BasicBlock *BB = Load->getParent(); 4449440db886627161a8413e823797569fc7b10beafChris Lattner 4459440db886627161a8413e823797569fc7b10beafChris Lattner const PointerType *LoadTy = 446477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman cast<PointerType>(Load->getPointerOperand()->getType()); 447514ab348fddcdffa8367685dc608b2f8d5de986dDuncan Sands unsigned LoadSize = (unsigned)TD.getTypeStoreSize(LoadTy->getElementType()); 4489440db886627161a8413e823797569fc7b10beafChris Lattner 449ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (AA.canInstructionRangeModify(BB->front(), *Load, Arg, LoadSize)) 450ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; // Pointer is invalidated! 451ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 452ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Now check every path from the entry block to the load for transparency. 453ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // To do this, we perform a depth first search on the inverse CFG from the 454ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // loading block. 455ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) 456e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner for (idf_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 16> > 457e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner I = idf_ext_begin(*PI, TranspBlocks), 458ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner E = idf_ext_end(*PI, TranspBlocks); I != E; ++I) 459ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (AA.canBasicBlockModify(**I, Arg, LoadSize)) 460ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; 461ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 462ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 463ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If the path from the entry of the function to each load is free of 464ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // instructions that potentially invalidate the load, we can make the 465ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // transformation! 466ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return true; 467ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 468ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 4699e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// DoPromotion - This method actually performs the promotion of the specified 4705eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// arguments, and returns the new function. At this point, we know that it's 4715eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// safe to do so. 4725eb6f6c829ddfe353f94623aa1009c72be930497Chris LattnerFunction *ArgPromotion::DoPromotion(Function *F, 47310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 47410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform) { 475fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 476ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Start by computing a new prototype for the function, which is the same as 477ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the old function, but has modified arguments. 478ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner const FunctionType *FTy = F->getFunctionType(); 479ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner std::vector<const Type*> Params; 480ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 481477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman typedef std::set<IndicesVector> ScalarizeTable; 482beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 4839440db886627161a8413e823797569fc7b10beafChris Lattner // ScalarizedElements - If we are promoting a pointer that has elements 4849440db886627161a8413e823797569fc7b10beafChris Lattner // accessed out of it, keep track of which elements are accessed so that we 4859440db886627161a8413e823797569fc7b10beafChris Lattner // can add one argument for each. 4869440db886627161a8413e823797569fc7b10beafChris Lattner // 4879440db886627161a8413e823797569fc7b10beafChris Lattner // Arguments that are directly loaded will have a zero element value here, to 4889440db886627161a8413e823797569fc7b10beafChris Lattner // handle cases where there are both a direct load and GEP accesses. 4899440db886627161a8413e823797569fc7b10beafChris Lattner // 490beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner std::map<Argument*, ScalarizeTable> ScalarizedElements; 4919440db886627161a8413e823797569fc7b10beafChris Lattner 4929e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // OriginalLoads - Keep track of a representative load instruction from the 4939e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // original function so that we can tell the alias analysis implementation 4949e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // what the new GEP/Load instructions we are inserting look like. 495477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::map<IndicesVector, LoadInst*> OriginalLoads; 4969e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 4970598866c052147c31b808391f58434ce3dbfb838Devang Patel // Attributes - Keep track of the parameter attributes for the arguments 498dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // that we are *not* promoting. For the ones that we do promote, the parameter 499dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // attributes are lost 5000598866c052147c31b808391f58434ce3dbfb838Devang Patel SmallVector<AttributeWithIndex, 8> AttributesVec; 5010598866c052147c31b808391f58434ce3dbfb838Devang Patel const AttrListPtr &PAL = F->getAttributes(); 502dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 503532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 50419c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = PAL.getRetAttributes()) 5050598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(0, attrs)); 5064cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 507477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // First, determine the new argument list 508ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner unsigned ArgIndex = 1; 509dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; 510ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ++I, ++ArgIndex) { 51110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 512477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Simple byval argument? Just add all the struct element types. 51310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 51410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 51510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) 51610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Params.push_back(STy->getElementType(i)); 51710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++NumByValArgsPromoted; 51810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!ArgsToPromote.count(I)) { 519477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Unchanged argument 520ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Params.push_back(I->getType()); 52119c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = PAL.getParamAttributes(ArgIndex)) 5220598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(Params.size(), attrs)); 5239e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else if (I->use_empty()) { 524477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Dead argument (which are always marked as promotable) 5259e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner ++NumArgumentsDead; 5269e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else { 527477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Okay, this is being promoted. This means that the only uses are loads 528477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // or GEPs which are only used by loads 529477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 530477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // In this table, we will track which indices are loaded from the argument 531477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // (where direct loads are tracked as no indices). 532beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 5339440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; 5349440db886627161a8413e823797569fc7b10beafChris Lattner ++UI) { 5359440db886627161a8413e823797569fc7b10beafChris Lattner Instruction *User = cast<Instruction>(*UI); 53646f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson assert(isa<LoadInst>(User) || isa<GetElementPtrInst>(User)); 537477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Indices; 538477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.reserve(User->getNumOperands() - 1); 539477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Since loads will only have a single operand, and GEPs only a single 540477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // non-index operand, this will record direct loads without any indices, 541477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // and gep+loads with the GEP indices. 542477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator II = User->op_begin() + 1, IE = User->op_end(); 543477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman II != IE; ++II) 544477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.push_back(cast<ConstantInt>(*II)->getSExtValue()); 545477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // GEPs with a single 0 index can be merged with direct loads 546477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Indices.size() == 1 && Indices.front() == 0) 547477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.clear(); 54846f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson ArgIndices.insert(Indices); 54946f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson LoadInst *OrigLoad; 55046f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson if (LoadInst *L = dyn_cast<LoadInst>(User)) 55146f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = L; 55246f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson else 553477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Take any load, we will use it only to update Alias Analysis 55446f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = cast<LoadInst>(User->use_back()); 55546f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OriginalLoads[Indices] = OrigLoad; 5569440db886627161a8413e823797569fc7b10beafChris Lattner } 5579440db886627161a8413e823797569fc7b10beafChris Lattner 5589440db886627161a8413e823797569fc7b10beafChris Lattner // Add a parameter to the function for each element passed in. 559beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 560477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman E = ArgIndices.end(); SI != E; ++SI) { 561b079a391c8b85d088dabce715d99be5917af88faTorok Edwin // not allowed to dereference ->begin() if size() is 0 5621ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner Params.push_back(GetElementPtrInst::getIndexedType(I->getType(), 5635b7dfbd89a0a0b7b59603bf9eb0f3f58534b4dd5David Greene SI->begin(), 5645b7dfbd89a0a0b7b59603bf9eb0f3f58534b4dd5David Greene SI->end())); 565477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman assert(Params.back()); 566477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 5679440db886627161a8413e823797569fc7b10beafChris Lattner 5689440db886627161a8413e823797569fc7b10beafChris Lattner if (ArgIndices.size() == 1 && ArgIndices.begin()->empty()) 5699440db886627161a8413e823797569fc7b10beafChris Lattner ++NumArgumentsPromoted; 5709440db886627161a8413e823797569fc7b10beafChris Lattner else 5719440db886627161a8413e823797569fc7b10beafChris Lattner ++NumAggregatesPromoted; 572ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 57310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 574ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 57519c874638d9478a5d5028854817a5ee72293bb2bDevang Patel // Add any function attributes. 57619c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = PAL.getFnAttributes()) 57719c874638d9478a5d5028854817a5ee72293bb2bDevang Patel AttributesVec.push_back(AttributeWithIndex::get(~0, attrs)); 57819c874638d9478a5d5028854817a5ee72293bb2bDevang Patel 579ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner const Type *RetTy = FTy->getReturnType(); 580e922c0201916e0b980ab3cfe91e1413e68d55647Owen Anderson LLVMContext &Context = RetTy->getContext(); 581ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 582ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Work around LLVM bug PR56: the CWriter cannot emit varargs functions which 583ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // have zero fixed arguments. 584ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner bool ExtraArgHack = false; 585ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (Params.empty() && FTy->isVarArg()) { 586ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ExtraArgHack = true; 587c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Params.push_back(Type::Int32Ty); 588ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 589dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 590dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Construct the new function type using the new arguments. 591debcb01b0f0a15f568ca69e8f288fade4bfc7297Owen Anderson FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg()); 592fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 593dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Create the new function body and insert it into the module... 594051a950000e21935165db56695e35bade668193bGabor Greif Function *NF = Function::Create(NFTy, F->getLinkage(), F->getName()); 59528c3cff8250b3fe2adc6479306fe7dbdb48a1bdbDuncan Sands NF->copyAttributesFrom(F); 596ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 597ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // Recompute the parameter attributes list based on the new arguments for 598ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // the function. 5990598866c052147c31b808391f58434ce3dbfb838Devang Patel NF->setAttributes(AttrListPtr::get(AttributesVec.begin(), AttributesVec.end())); 6000598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.clear(); 60128c3cff8250b3fe2adc6479306fe7dbdb48a1bdbDuncan Sands 602ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner F->getParent()->getFunctionList().insert(F, NF); 6032b3407f5b3d8626b924c532bcfea15daaf1bd3c0Zhou Sheng NF->takeName(F); 6049e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 6059e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Get the alias analysis information that we need to update to reflect our 6069e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // changes. 6079e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 6089e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 60934c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands // Get the callgraph information that we need to update to reflect our 61034c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands // changes. 61134c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands CallGraph &CG = getAnalysis<CallGraph>(); 61234c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands 613ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Loop over all of the callers of the function, transforming the call sites 614ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // to pass in the loaded pointers. 615ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 616ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner SmallVector<Value*, 16> Args; 617ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner while (!F->use_empty()) { 618ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner CallSite CS = CallSite::get(F->use_back()); 619ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *Call = CS.getInstruction(); 6200598866c052147c31b808391f58434ce3dbfb838Devang Patel const AttrListPtr &CallPAL = CS.getAttributes(); 6214cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 622532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 62319c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = CallPAL.getRetAttributes()) 6240598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(0, attrs)); 625532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands 6269e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Loop over the operands, inserting GEP and loads in the caller as 6279e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // appropriate. 628ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner CallSite::arg_iterator AI = CS.arg_begin(); 629ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ArgIndex = 1; 630f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 631ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner I != E; ++I, ++AI, ++ArgIndex) 63210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 633ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); // Unmodified argument 6344cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 63519c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex)) 6360598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs)); 6374cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 63810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (ByValArgsToTransform.count(I)) { 63910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Emit a GEP and load for each element of the struct. 64010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 64110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 642eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Value *Idxs[2] = { ConstantInt::get(Type::Int32Ty, 0), 0 }; 64310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 644eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Idxs[1] = ConstantInt::get(Type::Int32Ty, i); 645051a950000e21935165db56695e35bade668193bGabor Greif Value *Idx = GetElementPtrInst::Create(*AI, Idxs, Idxs+2, 646051a950000e21935165db56695e35bade668193bGabor Greif (*AI)->getName()+"."+utostr(i), 647051a950000e21935165db56695e35bade668193bGabor Greif Call); 64810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // TODO: Tell AA about the new values? 64910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Args.push_back(new LoadInst(Idx, Idx->getName()+".val", Call)); 6504cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands } 65110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!I->use_empty()) { 6529e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Non-dead argument: insert GEPs and loads as appropriate. 653beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 654477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Store the Value* version of the indices in here, but declare it now 655477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // for reuse 656477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::vector<Value*> Ops; 657beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 6589440db886627161a8413e823797569fc7b10beafChris Lattner E = ArgIndices.end(); SI != E; ++SI) { 6599440db886627161a8413e823797569fc7b10beafChris Lattner Value *V = *AI; 6609e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner LoadInst *OrigLoad = OriginalLoads[*SI]; 6619e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (!SI->empty()) { 662477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Ops.reserve(SI->size()); 663477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman const Type *ElTy = V->getType(); 6644cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands for (IndicesVector::const_iterator II = SI->begin(), 665477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IE = SI->end(); II != IE; ++II) { 666477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Use i32 to index structs, and i64 for others (pointers/arrays). 667477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This satisfies GEP constraints. 668477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman const Type *IdxTy = (isa<StructType>(ElTy) ? Type::Int32Ty : Type::Int64Ty); 669eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Ops.push_back(ConstantInt::get(IdxTy, *II)); 670477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Keep track of the type we're currently indexing 671477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ElTy = cast<CompositeType>(ElTy)->getTypeAtIndex(*II); 672477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 673477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // And create a GEP to extract those indices 674477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman V = GetElementPtrInst::Create(V, Ops.begin(), Ops.end(), 675051a950000e21935165db56695e35bade668193bGabor Greif V->getName()+".idx", Call); 676477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Ops.clear(); 6779e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad->getOperand(0), V); 6789e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } 6799440db886627161a8413e823797569fc7b10beafChris Lattner Args.push_back(new LoadInst(V, V->getName()+".val", Call)); 6809e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad, Args.back()); 6819440db886627161a8413e823797569fc7b10beafChris Lattner } 682ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 683ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 684ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (ExtraArgHack) 685e922c0201916e0b980ab3cfe91e1413e68d55647Owen Anderson Args.push_back(Context.getNullValue(Type::Int32Ty)); 686ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 687ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Push any varargs arguments on the list 688ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner for (; AI != CS.arg_end(); ++AI, ++ArgIndex) { 689ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); 69019c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex)) 6910598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs)); 692ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner } 693ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 69419c874638d9478a5d5028854817a5ee72293bb2bDevang Patel // Add any function attributes. 69519c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = CallPAL.getFnAttributes()) 69619c874638d9478a5d5028854817a5ee72293bb2bDevang Patel AttributesVec.push_back(AttributeWithIndex::get(~0, attrs)); 69719c874638d9478a5d5028854817a5ee72293bb2bDevang Patel 698ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *New; 699ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) { 700051a950000e21935165db56695e35bade668193bGabor Greif New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(), 701051a950000e21935165db56695e35bade668193bGabor Greif Args.begin(), Args.end(), "", Call); 702f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv()); 7030598866c052147c31b808391f58434ce3dbfb838Devang Patel cast<InvokeInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(), 7040598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.end())); 705ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } else { 706051a950000e21935165db56695e35bade668193bGabor Greif New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call); 707f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<CallInst>(New)->setCallingConv(CS.getCallingConv()); 7080598866c052147c31b808391f58434ce3dbfb838Devang Patel cast<CallInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(), 7090598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.end())); 7101430ef134d36888b99d2e6fedd2b025882593538Chris Lattner if (cast<CallInst>(Call)->isTailCall()) 7111430ef134d36888b99d2e6fedd2b025882593538Chris Lattner cast<CallInst>(New)->setTailCall(); 712ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 713ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.clear(); 7140598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.clear(); 715ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 7169e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Update the alias analysis implementation to know that we are replacing 7179e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // the old call with a new one. 7189e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(Call, New); 7199e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 72034c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands // Update the callgraph to know that the callsite has been transformed. 72134c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands CG[Call->getParent()->getParent()]->replaceCallSite(Call, New); 72234c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands 723ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (!Call->use_empty()) { 724ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Call->replaceAllUsesWith(New); 725046800a7125cd497613efc0e1ea15cb595666585Chris Lattner New->takeName(Call); 726ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 727fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 728ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Finally, remove the old call from the program, reducing the use-count of 729ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // F. 73040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner Call->eraseFromParent(); 731ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 732ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 733ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Since we have now created the new function, splice the body of the old 734ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function right into the new function, leaving the old rotting hulk of the 735ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function empty. 736ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList()); 737ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 738ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Loop over the argument list, transfering uses of the old arguments over to 739ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the new arguments, also transfering over the names as well. 740ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 74193e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(), 74210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2 = NF->arg_begin(); I != E; ++I) { 74310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 744ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If this is an unmodified argument, move the name and users over to the 745ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // new version. 746ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner I->replaceAllUsesWith(I2); 747046800a7125cd497613efc0e1ea15cb595666585Chris Lattner I2->takeName(I); 7489e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(I, I2); 749ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ++I2; 75010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 75110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 7524cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 75310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 75410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // In the callee, we create an alloca, and store each of the new incoming 75510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // arguments into the alloca. 75610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Instruction *InsertPt = NF->begin()->begin(); 7574cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 75810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Just add all the struct element types. 75910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 76050dead06ffc107edb7e84857baaeeb09039c631cOwen Anderson Value *TheAlloca = new AllocaInst(AgTy, 0, "", InsertPt); 76110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 762eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Value *Idxs[2] = { ConstantInt::get(Type::Int32Ty, 0), 0 }; 7634cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 76410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 765eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Idxs[1] = ConstantInt::get(Type::Int32Ty, i); 766dfd3b647839d3f944b5d8bffd6e9a2ec022d3507Daniel Dunbar Value *Idx = 767dfd3b647839d3f944b5d8bffd6e9a2ec022d3507Daniel Dunbar GetElementPtrInst::Create(TheAlloca, Idxs, Idxs+2, 768dfd3b647839d3f944b5d8bffd6e9a2ec022d3507Daniel Dunbar TheAlloca->getName()+"."+utostr(i), 769dfd3b647839d3f944b5d8bffd6e9a2ec022d3507Daniel Dunbar InsertPt); 77010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2->setName(I->getName()+"."+utostr(i)); 77110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner new StoreInst(I2++, Idx, InsertPt); 77210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 7734cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 77410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Anything that used the arg should now use the alloca. 77510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I->replaceAllUsesWith(TheAlloca); 77610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner TheAlloca->takeName(I); 77710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(I, TheAlloca); 77810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 7794cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands } 7804cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 78110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (I->use_empty()) { 7829e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.deleteValue(I); 78310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 78410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 7854cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 78610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, if we promoted this argument, then all users are load 787477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // instructions (or GEPs with only load users), and all loads should be 788477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // using the new argument that we added. 78910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 79010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 79110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!I->use_empty()) { 79210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(I->use_back())) { 79310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(ArgIndices.begin()->empty() && 79410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner "Load element should sort to front!"); 79510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2->setName(I->getName()+".val"); 79610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->replaceAllUsesWith(I2); 79710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(LI, I2); 79810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->eraseFromParent(); 799ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar DEBUG(errs() << "*** Promoted load of argument '" << I->getName() 800ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << "' in function '" << F->getName() << "'\n"); 80110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else { 80210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->use_back()); 803477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Operands; 804477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.reserve(GEP->getNumIndices()); 805477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end(); 806477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman II != IE; ++II) 807477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.push_back(cast<ConstantInt>(*II)->getSExtValue()); 808477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 809477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // GEPs with a single 0 index can be merged with direct loads 810477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Operands.size() == 1 && Operands.front() == 0) 811477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.clear(); 81210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 81310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Function::arg_iterator TheArg = I2; 81410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (ScalarizeTable::iterator It = ArgIndices.begin(); 81510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner *It != Operands; ++It, ++TheArg) { 81610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(It != ArgIndices.end() && "GEP not handled??"); 81710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 8189440db886627161a8413e823797569fc7b10beafChris Lattner 81910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner std::string NewName = I->getName(); 820477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (unsigned i = 0, e = Operands.size(); i != e; ++i) { 821477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman NewName += "." + utostr(Operands[i]); 822477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 823477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman NewName += ".val"; 824477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman TheArg->setName(NewName); 82510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 826ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar DEBUG(errs() << "*** Promoted agg argument '" << TheArg->getName() 827ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << "' of function '" << NF->getName() << "'\n"); 82810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 82910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // All of the uses must be load instructions. Replace them all with 83010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // the argument specified by ArgNo. 83110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!GEP->use_empty()) { 83210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LoadInst *L = cast<LoadInst>(GEP->use_back()); 83310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->replaceAllUsesWith(TheArg); 83410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(L, TheArg); 83510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->eraseFromParent(); 8369440db886627161a8413e823797569fc7b10beafChris Lattner } 83710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.deleteValue(GEP); 83810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GEP->eraseFromParent(); 839ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 840ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 841ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 84210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Increment I2 past all of the arguments added for this promoted pointer. 84310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = ArgIndices.size(); i != e; ++i) 84410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++I2; 84510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 84610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 8479e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Notify the alias analysis implementation that we inserted a new argument. 8489e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (ExtraArgHack) 849e922c0201916e0b980ab3cfe91e1413e68d55647Owen Anderson AA.copyValue(Context.getNullValue(Type::Int32Ty), NF->arg_begin()); 8509e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 8519e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 8529e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Tell the alias analysis that the old function is about to disappear. 8539e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(F, NF); 8549e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 855ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Now that the old function is dead, delete it. 85640c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner F->eraseFromParent(); 8575eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner return NF; 858ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 859