ArgumentPromotion.cpp revision 992e97eed344a141ff581838cfdacb76a1e9559a
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 20bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner// by default 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 22bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner// large array or structure is unprofitable! This limit is can be configured or 23bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner// 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" 39ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Analysis/AliasAnalysis.h" 405eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner#include "llvm/Analysis/CallGraph.h" 41ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Target/TargetData.h" 42ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Support/CallSite.h" 43ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Support/CFG.h" 44551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 45551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/DepthFirstIterator.h" 46551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 47551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/StringExtras.h" 489133fe28954d498fc4de13064c7d65bd811de02cReid Spencer#include "llvm/Support/Compiler.h" 49ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include <set> 50ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattnerusing namespace llvm; 51ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5286453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumArgumentsPromoted , "Number of pointer arguments promoted"); 5386453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumAggregatesPromoted, "Number of aggregate arguments promoted"); 5410603e0c84d15f61443e8b17bc35f98cc46606d9Chris LattnerSTATISTIC(NumByValArgsPromoted , "Number of byval arguments promoted"); 5586453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumArgumentsDead , "Number of dead pointer args eliminated"); 56ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5786453c52ba02e743d29c08456e51006500041456Chris Lattnernamespace { 58ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner /// ArgPromotion - The 'by reference' to 'by value' argument promotion pass. 59ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner /// 609133fe28954d498fc4de13064c7d65bd811de02cReid Spencer struct VISIBILITY_HIDDEN ArgPromotion : public CallGraphSCCPass { 61ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 62ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner AU.addRequired<AliasAnalysis>(); 63ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner AU.addRequired<TargetData>(); 645eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner CallGraphSCCPass::getAnalysisUsage(AU); 65ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 66ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 675eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner virtual bool runOnSCC(const std::vector<CallGraphNode *> &SCC); 68ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 69a72acf938902ea8ae2776cad7327257e88a63a54Nate Begeman ArgPromotion(unsigned maxElements = 3) : CallGraphSCCPass((intptr_t)&ID), 70a72acf938902ea8ae2776cad7327257e88a63a54Nate Begeman maxElements(maxElements) {} 71794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 72ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner private: 735eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner bool PromoteArguments(CallGraphNode *CGN); 7440c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner bool isSafeToPromoteArgument(Argument *Arg, bool isByVal) const; 75a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner Function *DoPromotion(Function *F, 7610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 7710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform); 78992e97eed344a141ff581838cfdacb76a1e9559aMatthijs Kooijman /// The maximum number of elements to expand, or 0 for unlimited. 79992e97eed344a141ff581838cfdacb76a1e9559aMatthijs Kooijman unsigned maxElements; 80ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner }; 81ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 82ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 83844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanchar ArgPromotion::ID = 0; 84844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic RegisterPass<ArgPromotion> 85844731a7f1909f55935e3514c9e713a62d67662eDan GohmanX("argpromotion", "Promote 'by reference' arguments to scalars"); 86844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 87bcd203cf860269987f32b14737b200b84fc2b63eChris LattnerPass *llvm::createArgumentPromotionPass(unsigned maxElements) { 88bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner return new ArgPromotion(maxElements); 89ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 90ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 915eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattnerbool ArgPromotion::runOnSCC(const std::vector<CallGraphNode *> &SCC) { 925eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner bool Changed = false, LocalChange; 93ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 94f5afcabff887c2e9023f0c69c44f1de15b5c4347Chris Lattner do { // Iterate until we stop promoting from this SCC. 955eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner LocalChange = false; 965eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Attempt to promote arguments from all functions in this SCC. 975eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner for (unsigned i = 0, e = SCC.size(); i != e; ++i) 985eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner LocalChange |= PromoteArguments(SCC[i]); 995eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Changed |= LocalChange; // Remember that we changed something. 1005eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner } while (LocalChange); 101fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 102ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return Changed; 103ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 104ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 1059e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// PromoteArguments - This method checks the specified function to see if there 1069e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// are any promotable arguments and if it is safe to promote the function (for 1079e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// example, all callers are direct). If safe to promote some arguments, it 1089e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// calls the DoPromotion method. 1099e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// 1105eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattnerbool ArgPromotion::PromoteArguments(CallGraphNode *CGN) { 1115eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Function *F = CGN->getFunction(); 1125eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner 1135eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Make sure that it is local to this module. 1145eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner if (!F || !F->hasInternalLinkage()) return false; 115ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 116ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // First check: see if there are any pointer arguments! If not, quick exit. 11740c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner SmallVector<std::pair<Argument*, unsigned>, 16> PointerArgs; 11840c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner unsigned ArgNo = 0; 11940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 12040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner I != E; ++I, ++ArgNo) 121ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (isa<PointerType>(I->getType())) 12240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner PointerArgs.push_back(std::pair<Argument*, unsigned>(I, ArgNo)); 123ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (PointerArgs.empty()) return false; 124ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 125ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Second check: make sure that all callers are direct callers. We can't 126ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // transform functions that have indirect callers. 127ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (Value::use_iterator UI = F->use_begin(), E = F->use_end(); 1287db5a6df78749bf0cd37870fcefe08b8849e38e6Chris Lattner UI != E; ++UI) { 1297db5a6df78749bf0cd37870fcefe08b8849e38e6Chris Lattner CallSite CS = CallSite::get(*UI); 1309e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (!CS.getInstruction()) // "Taking the address" of the function 1319e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner return false; 1329e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 1339e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Ensure that this call site is CALLING the function, not passing it as 1349e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // an argument. 135f1577014ddd13113c4a06d85bc75cd7b2dce71a9Chris Lattner if (UI.getOperandNo() != 0) 136f1577014ddd13113c4a06d85bc75cd7b2dce71a9Chris Lattner return false; 1377db5a6df78749bf0cd37870fcefe08b8849e38e6Chris Lattner } 138ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 13940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner // Check to see which arguments are promotable. If an argument is promotable, 14040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner // add it to ArgsToPromote. 14140c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner SmallPtrSet<Argument*, 8> ArgsToPromote; 14210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> ByValArgsToTransform; 14340c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner for (unsigned i = 0; i != PointerArgs.size(); ++i) { 14410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner bool isByVal = F->paramHasAttr(PointerArgs[i].second+1, ParamAttr::ByVal); 14510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 14610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // If this is a byval argument, and if the aggregate type is small, just 14710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // pass the elements, which is always safe. 14810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Argument *PtrArg = PointerArgs[i].first; 14910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (isByVal) { 15010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType(); 15110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (const StructType *STy = dyn_cast<StructType>(AgTy)) 152bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner if (maxElements > 0 && STy->getNumElements() > maxElements) { 153bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner DOUT << "argpromotion disable promoting argument '" 154bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner << PtrArg->getName() << "' because it would require adding more " 155bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner << "than " << maxElements << " arguments to the function.\n"; 156bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner } else { 157399101a5990621b0357009ab1852cc00f410a6c6Dan Gohman // If all the elements are single-value types, we can promote it. 15810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner bool AllSimple = true; 15910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) 160399101a5990621b0357009ab1852cc00f410a6c6Dan Gohman if (!STy->getElementType(i)->isSingleValueType()) { 16110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AllSimple = false; 16210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner break; 16310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 16410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 16510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Safe to transform, don't even bother trying to "promote" it. 16610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Passing the elements as a scalar will allow scalarrepl to hack on 16710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // the new alloca we introduce. 16810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (AllSimple) { 16910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ByValArgsToTransform.insert(PtrArg); 17010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 17110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 17210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 17310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 17410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 17510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, see if we can promote the pointer to its value. 17610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (isSafeToPromoteArgument(PtrArg, isByVal)) 17710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ArgsToPromote.insert(PtrArg); 17840c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner } 17940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner 180ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // No promotable pointer arguments. 18110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) return false; 182ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 18310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Function *NewF = DoPromotion(F, ArgsToPromote, ByValArgsToTransform); 1845eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner 185dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Update the call graph to know that the function has been transformed. 1865eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner getAnalysis<CallGraph>().changeFunction(F, NewF); 187ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return true; 188ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 189ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 19011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// IsAlwaysValidPointer - Return true if the specified pointer is always legal 19111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// to load. 19211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattnerstatic bool IsAlwaysValidPointer(Value *V) { 19311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (isa<AllocaInst>(V) || isa<GlobalVariable>(V)) return true; 19411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) 19511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return IsAlwaysValidPointer(GEP->getOperand(0)); 19611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) 19711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (CE->getOpcode() == Instruction::GetElementPtr) 19811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return IsAlwaysValidPointer(CE->getOperand(0)); 19911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; 20111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner} 20211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// AllCalleesPassInValidPointerForArgument - Return true if we can prove that 20411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// all callees pass in a valid pointer for the specified function argument. 20511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattnerstatic bool AllCalleesPassInValidPointerForArgument(Argument *Arg) { 20611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner Function *Callee = Arg->getParent(); 20711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 20893e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner unsigned ArgNo = std::distance(Callee->arg_begin(), 20993e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner Function::arg_iterator(Arg)); 21011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 21111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Look at all call sites of the function. At this pointer we know we only 21211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // have direct callees. 21311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner for (Value::use_iterator UI = Callee->use_begin(), E = Callee->use_end(); 21411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner UI != E; ++UI) { 21511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner CallSite CS = CallSite::get(*UI); 21611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner assert(CS.getInstruction() && "Should only have direct calls!"); 21711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 21811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner if (!IsAlwaysValidPointer(CS.getArgument(ArgNo))) 21911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; 22011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner } 22111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return true; 22211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner} 22311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 2249e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 2259e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// isSafeToPromoteArgument - As you might guess from the name of this method, 2269e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// it checks to see if it is both safe and useful to promote the argument. 2279e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// This method limits promotion of aggregates to only promote up to three 2289e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// elements of the aggregate in order to avoid exploding the number of 2299e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// arguments passed in. 23040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattnerbool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const { 2319440db886627161a8413e823797569fc7b10beafChris Lattner // We can only promote this argument if all of the uses are loads, or are GEP 2329440db886627161a8413e823797569fc7b10beafChris Lattner // instructions (with constant indices) that are subsequently loaded. 233170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 234170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // We can also only promote the load if we can guarantee that it will happen. 235170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // Promoting a load causes the load to be unconditionally executed in the 236170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // caller, so we can't turn a conditional load into an unconditional load in 237170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // general. 238170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner bool SafeToUnconditionallyLoad = false; 239170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner if (isByVal) // ByVal arguments are always safe to load from. 240170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner SafeToUnconditionallyLoad = true; 241170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 24211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner BasicBlock *EntryBlock = Arg->getParent()->begin(); 243a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner SmallVector<LoadInst*, 16> Loads; 244a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner std::vector<SmallVector<ConstantInt*, 8> > GEPIndices; 245ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end(); 246ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner UI != E; ++UI) 247ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { 248ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (LI->isVolatile()) return false; // Don't hack volatile loads 249ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Loads.push_back(LI); 250170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 251170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // If this load occurs in the entry block, then the pointer is 252170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // unconditionally loaded. 253170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner SafeToUnconditionallyLoad |= LI->getParent() == EntryBlock; 2549440db886627161a8413e823797569fc7b10beafChris Lattner } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(*UI)) { 2559440db886627161a8413e823797569fc7b10beafChris Lattner if (GEP->use_empty()) { 2569440db886627161a8413e823797569fc7b10beafChris Lattner // Dead GEP's cause trouble later. Just remove them if we run into 2579440db886627161a8413e823797569fc7b10beafChris Lattner // them. 2589e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner getAnalysis<AliasAnalysis>().deleteValue(GEP); 25940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner GEP->eraseFromParent(); 26040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner return isSafeToPromoteArgument(Arg, isByVal); 2619440db886627161a8413e823797569fc7b10beafChris Lattner } 2629440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that all of the indices are constants. 263a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner SmallVector<ConstantInt*, 8> Operands; 2649440db886627161a8413e823797569fc7b10beafChris Lattner for (unsigned i = 1, e = GEP->getNumOperands(); i != e; ++i) 265beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner if (ConstantInt *C = dyn_cast<ConstantInt>(GEP->getOperand(i))) 2669440db886627161a8413e823797569fc7b10beafChris Lattner Operands.push_back(C); 2679440db886627161a8413e823797569fc7b10beafChris Lattner else 2689440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a constant operand GEP! 2699440db886627161a8413e823797569fc7b10beafChris Lattner 2709440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that the only users of the GEP are load instructions. 2719440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = GEP->use_begin(), E = GEP->use_end(); 2729440db886627161a8413e823797569fc7b10beafChris Lattner UI != E; ++UI) 2739440db886627161a8413e823797569fc7b10beafChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { 2749440db886627161a8413e823797569fc7b10beafChris Lattner if (LI->isVolatile()) return false; // Don't hack volatile loads 2759440db886627161a8413e823797569fc7b10beafChris Lattner Loads.push_back(LI); 276170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 277170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // If this load occurs in the entry block, then the pointer is 278170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner // unconditionally loaded. 279170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner SafeToUnconditionallyLoad |= LI->getParent() == EntryBlock; 2809440db886627161a8413e823797569fc7b10beafChris Lattner } else { 2819440db886627161a8413e823797569fc7b10beafChris Lattner return false; 2829440db886627161a8413e823797569fc7b10beafChris Lattner } 283ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 2849e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // See if there is already a GEP with these indices. If not, check to 2859e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // make sure that we aren't promoting too many elements. If so, nothing 2869e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // to do. 2879440db886627161a8413e823797569fc7b10beafChris Lattner if (std::find(GEPIndices.begin(), GEPIndices.end(), Operands) == 2889440db886627161a8413e823797569fc7b10beafChris Lattner GEPIndices.end()) { 289bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner if (maxElements > 0 && GEPIndices.size() == maxElements) { 2900a81aac4b46eed130d20714af5a1c01b05d0275eBill Wendling DOUT << "argpromotion disable promoting argument '" 2910a81aac4b46eed130d20714af5a1c01b05d0275eBill Wendling << Arg->getName() << "' because it would require adding more " 292bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner << "than " << maxElements << " arguments to the function.\n"; 293bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner // We limit aggregate promotion to only promoting up to a fixed number 294a72acf938902ea8ae2776cad7327257e88a63a54Nate Begeman // of elements of the aggregate. 2959440db886627161a8413e823797569fc7b10beafChris Lattner return false; 2969440db886627161a8413e823797569fc7b10beafChris Lattner } 2979440db886627161a8413e823797569fc7b10beafChris Lattner GEPIndices.push_back(Operands); 2989440db886627161a8413e823797569fc7b10beafChris Lattner } 2999440db886627161a8413e823797569fc7b10beafChris Lattner } else { 3009440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a load or a GEP. 3019440db886627161a8413e823797569fc7b10beafChris Lattner } 302ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 3039e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (Loads.empty()) return true; // No users, this is a dead argument. 304ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 30511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // If we decide that we want to promote this argument, the value is going to 30611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // be unconditionally loaded in all callees. This is only safe to do if the 30711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // pointer was going to be unconditionally loaded anyway (i.e. there is a load 30811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // of the pointer in the entry block of the function) or if we can prove that 30911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // all pointers passed in are always to legal locations (for example, no null 31011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // pointers are passed in, no pointers to free'd memory, etc). 311170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner if (!SafeToUnconditionallyLoad && 312170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner !AllCalleesPassInValidPointerForArgument(Arg)) 31311a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; // Cannot prove that this is safe!! 31411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 31511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Okay, now we know that the argument is only used by load instructions and 31611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // it is safe to unconditionally load the pointer. Use alias analysis to 31711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // check to see if the pointer is guaranteed to not be modified from entry of 31811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // the function to each of the load instructions. 319ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 320ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Because there could be several/many load instructions, remember which 321ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // blocks we know to be transparent to the load. 322e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner SmallPtrSet<BasicBlock*, 16> TranspBlocks; 32346f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson 32446f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 3259440db886627161a8413e823797569fc7b10beafChris Lattner TargetData &TD = getAnalysis<TargetData>(); 326ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 327ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (unsigned i = 0, e = Loads.size(); i != e; ++i) { 328ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Check to see if the load is invalidated from the start of the block to 329ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the load itself. 330ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner LoadInst *Load = Loads[i]; 331ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner BasicBlock *BB = Load->getParent(); 3329440db886627161a8413e823797569fc7b10beafChris Lattner 3339440db886627161a8413e823797569fc7b10beafChris Lattner const PointerType *LoadTy = 3349440db886627161a8413e823797569fc7b10beafChris Lattner cast<PointerType>(Load->getOperand(0)->getType()); 335514ab348fddcdffa8367685dc608b2f8d5de986dDuncan Sands unsigned LoadSize = (unsigned)TD.getTypeStoreSize(LoadTy->getElementType()); 3369440db886627161a8413e823797569fc7b10beafChris Lattner 337ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (AA.canInstructionRangeModify(BB->front(), *Load, Arg, LoadSize)) 338ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; // Pointer is invalidated! 339ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 340ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Now check every path from the entry block to the load for transparency. 341ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // To do this, we perform a depth first search on the inverse CFG from the 342ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // loading block. 343ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) 344e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner for (idf_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 16> > 345e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner I = idf_ext_begin(*PI, TranspBlocks), 346ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner E = idf_ext_end(*PI, TranspBlocks); I != E; ++I) 347ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (AA.canBasicBlockModify(**I, Arg, LoadSize)) 348ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; 349ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 350ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 351ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If the path from the entry of the function to each load is free of 352ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // instructions that potentially invalidate the load, we can make the 353ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // transformation! 354ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return true; 355ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 356ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 357beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattnernamespace { 358beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner /// GEPIdxComparator - Provide a strong ordering for GEP indices. All Value* 359beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner /// elements are instances of ConstantInt. 360beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner /// 361beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner struct GEPIdxComparator { 362beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner bool operator()(const std::vector<Value*> &LHS, 363beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner const std::vector<Value*> &RHS) const { 364beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner unsigned idx = 0; 365beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (; idx < LHS.size() && idx < RHS.size(); ++idx) { 366beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner if (LHS[idx] != RHS[idx]) { 367b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer return cast<ConstantInt>(LHS[idx])->getZExtValue() < 368b83eb6447ba155342598f0fabe1f08f5baa9164aReid Spencer cast<ConstantInt>(RHS[idx])->getZExtValue(); 369beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner } 370beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner } 371beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 372beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner // Return less than if we ran out of stuff in LHS and we didn't run out of 373beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner // stuff in RHS. 374beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner return idx == LHS.size() && idx != RHS.size(); 375beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner } 376beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner }; 377beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner} 378beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 379beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 3809e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// DoPromotion - This method actually performs the promotion of the specified 3815eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// arguments, and returns the new function. At this point, we know that it's 3825eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// safe to do so. 3835eb6f6c829ddfe353f94623aa1009c72be930497Chris LattnerFunction *ArgPromotion::DoPromotion(Function *F, 38410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 38510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform) { 386fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 387ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Start by computing a new prototype for the function, which is the same as 388ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the old function, but has modified arguments. 389ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner const FunctionType *FTy = F->getFunctionType(); 390ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner std::vector<const Type*> Params; 391ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 392beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner typedef std::set<std::vector<Value*>, GEPIdxComparator> ScalarizeTable; 393beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 3949440db886627161a8413e823797569fc7b10beafChris Lattner // ScalarizedElements - If we are promoting a pointer that has elements 3959440db886627161a8413e823797569fc7b10beafChris Lattner // accessed out of it, keep track of which elements are accessed so that we 3969440db886627161a8413e823797569fc7b10beafChris Lattner // can add one argument for each. 3979440db886627161a8413e823797569fc7b10beafChris Lattner // 3989440db886627161a8413e823797569fc7b10beafChris Lattner // Arguments that are directly loaded will have a zero element value here, to 3999440db886627161a8413e823797569fc7b10beafChris Lattner // handle cases where there are both a direct load and GEP accesses. 4009440db886627161a8413e823797569fc7b10beafChris Lattner // 401beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner std::map<Argument*, ScalarizeTable> ScalarizedElements; 4029440db886627161a8413e823797569fc7b10beafChris Lattner 4039e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // OriginalLoads - Keep track of a representative load instruction from the 4049e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // original function so that we can tell the alias analysis implementation 4059e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // what the new GEP/Load instructions we are inserting look like. 4069e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner std::map<std::vector<Value*>, LoadInst*> OriginalLoads; 4079e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 408dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // ParamAttrs - Keep track of the parameter attributes for the arguments 409dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // that we are *not* promoting. For the ones that we do promote, the parameter 410dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // attributes are lost 41158d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner SmallVector<ParamAttrsWithIndex, 8> ParamAttrsVec; 41258d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner const PAListPtr &PAL = F->getParamAttrs(); 413dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 414532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 41558d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes attrs = PAL.getParamAttrs(0)) 416532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, attrs)); 417532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands 418ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner unsigned ArgIndex = 1; 419dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; 420ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ++I, ++ArgIndex) { 42110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 42210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Just add all the struct element types. 42310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 42410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 42510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) 42610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Params.push_back(STy->getElementType(i)); 42710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++NumByValArgsPromoted; 42810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!ArgsToPromote.count(I)) { 429ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Params.push_back(I->getType()); 43058d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes attrs = PAL.getParamAttrs(ArgIndex)) 43110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Params.size(), attrs)); 4329e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else if (I->use_empty()) { 4339e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner ++NumArgumentsDead; 4349e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else { 4359440db886627161a8413e823797569fc7b10beafChris Lattner // Okay, this is being promoted. Check to see if there are any GEP uses 4369440db886627161a8413e823797569fc7b10beafChris Lattner // of the argument. 437beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 4389440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; 4399440db886627161a8413e823797569fc7b10beafChris Lattner ++UI) { 4409440db886627161a8413e823797569fc7b10beafChris Lattner Instruction *User = cast<Instruction>(*UI); 44146f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson assert(isa<LoadInst>(User) || isa<GetElementPtrInst>(User)); 44246f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson std::vector<Value*> Indices(User->op_begin()+1, User->op_end()); 44346f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson ArgIndices.insert(Indices); 44446f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson LoadInst *OrigLoad; 44546f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson if (LoadInst *L = dyn_cast<LoadInst>(User)) 44646f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = L; 44746f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson else 44846f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = cast<LoadInst>(User->use_back()); 44946f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OriginalLoads[Indices] = OrigLoad; 4509440db886627161a8413e823797569fc7b10beafChris Lattner } 4519440db886627161a8413e823797569fc7b10beafChris Lattner 4529440db886627161a8413e823797569fc7b10beafChris Lattner // Add a parameter to the function for each element passed in. 453beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 4549440db886627161a8413e823797569fc7b10beafChris Lattner E = ArgIndices.end(); SI != E; ++SI) 4551ccd185cb49d81465a2901622e58ceae046d1d83Chris Lattner Params.push_back(GetElementPtrInst::getIndexedType(I->getType(), 456b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene SI->begin(), 457b8f74793b9d161bc666fe27fc92fe112b6ec169bDavid Greene SI->end())); 4589440db886627161a8413e823797569fc7b10beafChris Lattner 4599440db886627161a8413e823797569fc7b10beafChris Lattner if (ArgIndices.size() == 1 && ArgIndices.begin()->empty()) 4609440db886627161a8413e823797569fc7b10beafChris Lattner ++NumArgumentsPromoted; 4619440db886627161a8413e823797569fc7b10beafChris Lattner else 4629440db886627161a8413e823797569fc7b10beafChris Lattner ++NumAggregatesPromoted; 463ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 46410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 465ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 466ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner const Type *RetTy = FTy->getReturnType(); 467ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 468ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Work around LLVM bug PR56: the CWriter cannot emit varargs functions which 469ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // have zero fixed arguments. 470ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner bool ExtraArgHack = false; 471ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (Params.empty() && FTy->isVarArg()) { 472ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ExtraArgHack = true; 473c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Params.push_back(Type::Int32Ty); 474ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 475dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 476dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Construct the new function type using the new arguments. 477ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg()); 478fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 479dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Create the new function body and insert it into the module... 480051a950000e21935165db56695e35bade668193bGabor Greif Function *NF = Function::Create(NFTy, F->getLinkage(), F->getName()); 481f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner NF->setCallingConv(F->getCallingConv()); 482ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 483ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // Recompute the parameter attributes list based on the new arguments for 484ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // the function. 48558d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner NF->setParamAttrs(PAListPtr::get(ParamAttrsVec.begin(), ParamAttrsVec.end())); 48658d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner ParamAttrsVec.clear(); 487ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 488194c90ed2a8e74b5a1c5184835f84c572d524dadGordon Henriksen if (F->hasCollector()) 489194c90ed2a8e74b5a1c5184835f84c572d524dadGordon Henriksen NF->setCollector(F->getCollector()); 490ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner F->getParent()->getFunctionList().insert(F, NF); 4912b3407f5b3d8626b924c532bcfea15daaf1bd3c0Zhou Sheng NF->takeName(F); 4929e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 4939e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Get the alias analysis information that we need to update to reflect our 4949e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // changes. 4959e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 4969e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 497ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Loop over all of the callers of the function, transforming the call sites 498ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // to pass in the loaded pointers. 499ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 500ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner SmallVector<Value*, 16> Args; 501ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner while (!F->use_empty()) { 502ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner CallSite CS = CallSite::get(F->use_back()); 503ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *Call = CS.getInstruction(); 50458d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner const PAListPtr &CallPAL = CS.getParamAttrs(); 505ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 506532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 50758d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes attrs = CallPAL.getParamAttrs(0)) 508532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands ParamAttrsVec.push_back(ParamAttrsWithIndex::get(0, attrs)); 509532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands 5109e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Loop over the operands, inserting GEP and loads in the caller as 5119e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // appropriate. 512ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner CallSite::arg_iterator AI = CS.arg_begin(); 513ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ArgIndex = 1; 514f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 515ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner I != E; ++I, ++AI, ++ArgIndex) 51610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 517ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); // Unmodified argument 518ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 51958d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes Attrs = CallPAL.getParamAttrs(ArgIndex)) 520ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs)); 521ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 52210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (ByValArgsToTransform.count(I)) { 52310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Emit a GEP and load for each element of the struct. 52410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 52510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 52610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *Idxs[2] = { ConstantInt::get(Type::Int32Ty, 0), 0 }; 52710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 52810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Idxs[1] = ConstantInt::get(Type::Int32Ty, i); 529051a950000e21935165db56695e35bade668193bGabor Greif Value *Idx = GetElementPtrInst::Create(*AI, Idxs, Idxs+2, 530051a950000e21935165db56695e35bade668193bGabor Greif (*AI)->getName()+"."+utostr(i), 531051a950000e21935165db56695e35bade668193bGabor Greif Call); 53210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // TODO: Tell AA about the new values? 53310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Args.push_back(new LoadInst(Idx, Idx->getName()+".val", Call)); 53410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 53510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!I->use_empty()) { 5369e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Non-dead argument: insert GEPs and loads as appropriate. 537beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 538beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 5399440db886627161a8413e823797569fc7b10beafChris Lattner E = ArgIndices.end(); SI != E; ++SI) { 5409440db886627161a8413e823797569fc7b10beafChris Lattner Value *V = *AI; 5419e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner LoadInst *OrigLoad = OriginalLoads[*SI]; 5429e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (!SI->empty()) { 543051a950000e21935165db56695e35bade668193bGabor Greif V = GetElementPtrInst::Create(V, SI->begin(), SI->end(), 544051a950000e21935165db56695e35bade668193bGabor Greif V->getName()+".idx", Call); 5459e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad->getOperand(0), V); 5469e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } 5479440db886627161a8413e823797569fc7b10beafChris Lattner Args.push_back(new LoadInst(V, V->getName()+".val", Call)); 5489e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad, Args.back()); 5499440db886627161a8413e823797569fc7b10beafChris Lattner } 550ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 551ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 552ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (ExtraArgHack) 553c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer Args.push_back(Constant::getNullValue(Type::Int32Ty)); 554ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 555ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Push any varargs arguments on the list 556ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner for (; AI != CS.arg_end(); ++AI, ++ArgIndex) { 557ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); 55858d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner if (ParameterAttributes Attrs = CallPAL.getParamAttrs(ArgIndex)) 559ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ParamAttrsVec.push_back(ParamAttrsWithIndex::get(Args.size(), Attrs)); 560ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner } 561ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 562ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *New; 563ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) { 564051a950000e21935165db56695e35bade668193bGabor Greif New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(), 565051a950000e21935165db56695e35bade668193bGabor Greif Args.begin(), Args.end(), "", Call); 566f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv()); 56758d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner cast<InvokeInst>(New)->setParamAttrs(PAListPtr::get(ParamAttrsVec.begin(), 56858d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner ParamAttrsVec.end())); 569ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } else { 570051a950000e21935165db56695e35bade668193bGabor Greif New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call); 571f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<CallInst>(New)->setCallingConv(CS.getCallingConv()); 57258d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner cast<CallInst>(New)->setParamAttrs(PAListPtr::get(ParamAttrsVec.begin(), 57358d74910c6b82e622ecbb57d6644d48fec5a5c0fChris Lattner ParamAttrsVec.end())); 5741430ef134d36888b99d2e6fedd2b025882593538Chris Lattner if (cast<CallInst>(Call)->isTailCall()) 5751430ef134d36888b99d2e6fedd2b025882593538Chris Lattner cast<CallInst>(New)->setTailCall(); 576ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 577ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.clear(); 578ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ParamAttrsVec.clear(); 579ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 5809e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Update the alias analysis implementation to know that we are replacing 5819e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // the old call with a new one. 5829e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(Call, New); 5839e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 584ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (!Call->use_empty()) { 585ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Call->replaceAllUsesWith(New); 586046800a7125cd497613efc0e1ea15cb595666585Chris Lattner New->takeName(Call); 587ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 588fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 589ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Finally, remove the old call from the program, reducing the use-count of 590ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // F. 59140c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner Call->eraseFromParent(); 592ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 593ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 594ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Since we have now created the new function, splice the body of the old 595ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function right into the new function, leaving the old rotting hulk of the 596ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function empty. 597ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList()); 598ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 599ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Loop over the argument list, transfering uses of the old arguments over to 600ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the new arguments, also transfering over the names as well. 601ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 60293e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(), 60310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2 = NF->arg_begin(); I != E; ++I) { 60410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 605ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If this is an unmodified argument, move the name and users over to the 606ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // new version. 607ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner I->replaceAllUsesWith(I2); 608046800a7125cd497613efc0e1ea15cb595666585Chris Lattner I2->takeName(I); 6099e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(I, I2); 610ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ++I2; 61110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 61210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 61310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 61410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 61510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // In the callee, we create an alloca, and store each of the new incoming 61610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // arguments into the alloca. 61710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Instruction *InsertPt = NF->begin()->begin(); 61810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 61910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Just add all the struct element types. 62010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 62110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *TheAlloca = new AllocaInst(AgTy, 0, "", InsertPt); 62210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner const StructType *STy = cast<StructType>(AgTy); 62310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Value *Idxs[2] = { ConstantInt::get(Type::Int32Ty, 0), 0 }; 62410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 62510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 62610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Idxs[1] = ConstantInt::get(Type::Int32Ty, i); 627051a950000e21935165db56695e35bade668193bGabor Greif Value *Idx = GetElementPtrInst::Create(TheAlloca, Idxs, Idxs+2, 628051a950000e21935165db56695e35bade668193bGabor Greif TheAlloca->getName()+"."+utostr(i), 629051a950000e21935165db56695e35bade668193bGabor Greif InsertPt); 63010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2->setName(I->getName()+"."+utostr(i)); 63110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner new StoreInst(I2++, Idx, InsertPt); 63210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 63310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 63410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Anything that used the arg should now use the alloca. 63510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I->replaceAllUsesWith(TheAlloca); 63610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner TheAlloca->takeName(I); 63710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(I, TheAlloca); 63810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 63910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 64010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 64110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (I->use_empty()) { 6429e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.deleteValue(I); 64310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 64410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 64510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 64610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, if we promoted this argument, then all users are load 64710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // instructions, and all loads should be using the new argument that we 64810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // added. 64910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 65010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 65110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!I->use_empty()) { 65210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(I->use_back())) { 65310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(ArgIndices.begin()->empty() && 65410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner "Load element should sort to front!"); 65510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2->setName(I->getName()+".val"); 65610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->replaceAllUsesWith(I2); 65710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(LI, I2); 65810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->eraseFromParent(); 65910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner DOUT << "*** Promoted load of argument '" << I->getName() 66010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner << "' in function '" << F->getName() << "'\n"; 66110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else { 66210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->use_back()); 66310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner std::vector<Value*> Operands(GEP->op_begin()+1, GEP->op_end()); 66410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 66510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Function::arg_iterator TheArg = I2; 66610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (ScalarizeTable::iterator It = ArgIndices.begin(); 66710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner *It != Operands; ++It, ++TheArg) { 66810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(It != ArgIndices.end() && "GEP not handled??"); 66910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 6709440db886627161a8413e823797569fc7b10beafChris Lattner 67110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner std::string NewName = I->getName(); 67210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = Operands.size(); i != e; ++i) 67310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(Operands[i])) 67410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner NewName += "." + CI->getValue().toStringUnsigned(10); 67510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner else 67610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner NewName += ".x"; 67710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner TheArg->setName(NewName+".val"); 67810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 67910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner DOUT << "*** Promoted agg argument '" << TheArg->getName() 68010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner << "' of function '" << F->getName() << "'\n"; 68110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 68210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // All of the uses must be load instructions. Replace them all with 68310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // the argument specified by ArgNo. 68410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!GEP->use_empty()) { 68510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LoadInst *L = cast<LoadInst>(GEP->use_back()); 68610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->replaceAllUsesWith(TheArg); 68710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(L, TheArg); 68810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->eraseFromParent(); 6899440db886627161a8413e823797569fc7b10beafChris Lattner } 69010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.deleteValue(GEP); 69110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GEP->eraseFromParent(); 692ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 693ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 694ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 69510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Increment I2 past all of the arguments added for this promoted pointer. 69610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = ArgIndices.size(); i != e; ++i) 69710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++I2; 69810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 69910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 7009e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Notify the alias analysis implementation that we inserted a new argument. 7019e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (ExtraArgHack) 702c5b206b6be61d0d933b98b6af5e22f42edd48ad1Reid Spencer AA.copyValue(Constant::getNullValue(Type::Int32Ty), NF->arg_begin()); 7039e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 7049e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 7059e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Tell the alias analysis that the old function is about to disappear. 7069e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(F, NF); 7079e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 708ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Now that the old function is dead, delete it. 70940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner F->eraseFromParent(); 7105eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner return NF; 711ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 712