ArgumentPromotion.cpp revision d509d0b532ec2358b3f341d4a4cd1411cb8b5db2
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/Support/CallSite.h" 43ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner#include "llvm/Support/CFG.h" 44551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 45ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar#include "llvm/Support/raw_ostream.h" 46551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/DepthFirstIterator.h" 47551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 4823132b188ba651ba172380cd082cc286df73d440Chris Lattner#include "llvm/ADT/StringExtras.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 /// 606726b6d75a8b679068a58cb954ba97cf9d1690baNick Lewycky struct ArgPromotion : public CallGraphSCCPass { 61ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 62ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner AU.addRequired<AliasAnalysis>(); 635eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner CallGraphSCCPass::getAnalysisUsage(AU); 64ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 65ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 662decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner virtual bool runOnSCC(CallGraphSCC &SCC); 67ecd94c804a563f2a86572dcf1d2e81f397e19daaNick Lewycky static char ID; // Pass identification, replacement for typeid 6838deef9ce58b33dba34515f23fb7dbde02164c77Dan Gohman explicit ArgPromotion(unsigned maxElements = 3) 69081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson : CallGraphSCCPass(ID), maxElements(maxElements) { 70081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson initializeArgPromotionPass(*PassRegistry::getPassRegistry()); 71081c34b725980f995be9080eaec24cd3dfaaf065Owen Anderson } 724cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 73477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman /// A vector used to hold the indices of a single GEP instruction 74477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman typedef std::vector<uint64_t> IndicesVector; 75794fd75c67a2cdc128d67342c6d88a504d186896Devang Patel 76ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner private: 775095e3d1d1caef8d573534d369e37277c623064cChris Lattner CallGraphNode *PromoteArguments(CallGraphNode *CGN); 7840c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner bool isSafeToPromoteArgument(Argument *Arg, bool isByVal) const; 795095e3d1d1caef8d573534d369e37277c623064cChris Lattner CallGraphNode *DoPromotion(Function *F, 805095e3d1d1caef8d573534d369e37277c623064cChris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 815095e3d1d1caef8d573534d369e37277c623064cChris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform); 82992e97eed344a141ff581838cfdacb76a1e9559aMatthijs Kooijman /// The maximum number of elements to expand, or 0 for unlimited. 83992e97eed344a141ff581838cfdacb76a1e9559aMatthijs Kooijman unsigned maxElements; 84ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner }; 85ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 86ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 87844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanchar ArgPromotion::ID = 0; 882ab36d350293c77fc8941ce1023e4899df7e3a82Owen AndersonINITIALIZE_PASS_BEGIN(ArgPromotion, "argpromotion", 892ab36d350293c77fc8941ce1023e4899df7e3a82Owen Anderson "Promote 'by reference' arguments to scalars", false, false) 902ab36d350293c77fc8941ce1023e4899df7e3a82Owen AndersonINITIALIZE_AG_DEPENDENCY(AliasAnalysis) 91ae0a7bc68303ce0c8721f0e981ae602601390e68Owen AndersonINITIALIZE_AG_DEPENDENCY(CallGraph) 922ab36d350293c77fc8941ce1023e4899df7e3a82Owen AndersonINITIALIZE_PASS_END(ArgPromotion, "argpromotion", 93ce665bd2e2b581ab0858d1afe359192bac96b868Owen Anderson "Promote 'by reference' arguments to scalars", false, false) 94844731a7f1909f55935e3514c9e713a62d67662eDan Gohman 95bcd203cf860269987f32b14737b200b84fc2b63eChris LattnerPass *llvm::createArgumentPromotionPass(unsigned maxElements) { 96bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner return new ArgPromotion(maxElements); 97ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 98ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 992decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattnerbool ArgPromotion::runOnSCC(CallGraphSCC &SCC) { 1005eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner bool Changed = false, LocalChange; 101ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 102f5afcabff887c2e9023f0c69c44f1de15b5c4347Chris Lattner do { // Iterate until we stop promoting from this SCC. 1035eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner LocalChange = false; 1045eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Attempt to promote arguments from all functions in this SCC. 1052decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 1062decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner if (CallGraphNode *CGN = PromoteArguments(*I)) { 1075095e3d1d1caef8d573534d369e37277c623064cChris Lattner LocalChange = true; 1082decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner SCC.ReplaceNode(*I, CGN); 1095095e3d1d1caef8d573534d369e37277c623064cChris Lattner } 1102decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner } 1115eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Changed |= LocalChange; // Remember that we changed something. 1125eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner } while (LocalChange); 113eae220259fca393adc874ed41e3930011047beb7Chris Lattner 114ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return Changed; 115ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 116ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 1179e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// PromoteArguments - This method checks the specified function to see if there 1189e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// are any promotable arguments and if it is safe to promote the function (for 1199e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// example, all callers are direct). If safe to promote some arguments, it 1209e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// calls the DoPromotion method. 1219e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// 1225095e3d1d1caef8d573534d369e37277c623064cChris LattnerCallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) { 1235eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner Function *F = CGN->getFunction(); 1245eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner 1255eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner // Make sure that it is local to this module. 1265095e3d1d1caef8d573534d369e37277c623064cChris Lattner if (!F || !F->hasLocalLinkage()) return 0; 127ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 128ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // First check: see if there are any pointer arguments! If not, quick exit. 12940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner SmallVector<std::pair<Argument*, unsigned>, 16> PointerArgs; 13040c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner unsigned ArgNo = 0; 13140c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 13240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner I != E; ++I, ++ArgNo) 1331df9859c40492511b8aa4321eb76496005d3b75bDuncan Sands if (I->getType()->isPointerTy()) 13440c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner PointerArgs.push_back(std::pair<Argument*, unsigned>(I, ArgNo)); 1355095e3d1d1caef8d573534d369e37277c623064cChris Lattner if (PointerArgs.empty()) return 0; 136ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 137ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Second check: make sure that all callers are direct callers. We can't 13828252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // transform functions that have indirect callers. Also see if the function 13928252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // is self-recursive. 14028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner bool isSelfRecursive = false; 14128252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner for (Value::use_iterator UI = F->use_begin(), E = F->use_end(); 14228252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner UI != E; ++UI) { 14328252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner CallSite CS(*UI); 14428252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // Must be a direct call. 14528252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (CS.getInstruction() == 0 || !CS.isCallee(UI)) return 0; 14628252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner 14728252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (CS.getInstruction()->getParent()->getParent() == F) 14828252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner isSelfRecursive = true; 14928252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner } 15028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner 15140c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner // Check to see which arguments are promotable. If an argument is promotable, 15240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner // add it to ArgsToPromote. 15340c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner SmallPtrSet<Argument*, 8> ArgsToPromote; 15410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> ByValArgsToTransform; 15540c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner for (unsigned i = 0; i != PointerArgs.size(); ++i) { 1560598866c052147c31b808391f58434ce3dbfb838Devang Patel bool isByVal = F->paramHasAttr(PointerArgs[i].second+1, Attribute::ByVal); 15728252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner Argument *PtrArg = PointerArgs[i].first; 158db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType(); 1594cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 16010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // If this is a byval argument, and if the aggregate type is small, just 16110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // pass the elements, which is always safe. 16210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (isByVal) { 163db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (StructType *STy = dyn_cast<StructType>(AgTy)) { 164bcd203cf860269987f32b14737b200b84fc2b63eChris Lattner if (maxElements > 0 && STy->getNumElements() > maxElements) { 1655ededf7d42417379d230c92fc73912ebb650ede9David Greene DEBUG(dbgs() << "argpromotion disable promoting argument '" 166ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << PtrArg->getName() << "' because it would require adding more" 167ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << " than " << maxElements << " arguments to the function.\n"); 16828252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner continue; 16928252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner } 17028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner 17128252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // If all the elements are single-value types, we can promote it. 17228252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner bool AllSimple = true; 17328252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 17428252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (!STy->getElementType(i)->isSingleValueType()) { 17528252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner AllSimple = false; 17628252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner break; 17710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 17810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 17928252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner 18028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // Safe to transform, don't even bother trying to "promote" it. 18128252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // Passing the elements as a scalar will allow scalarrepl to hack on 18228252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // the new alloca we introduce. 18328252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (AllSimple) { 18428252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner ByValArgsToTransform.insert(PtrArg); 18528252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner continue; 18628252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner } 18743e2a035309f4e353a8bd5547d10125414597e74Duncan Sands } 18810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 1894cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 19028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // If the argument is a recursive type and we're in a recursive 19128252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner // function, we could end up infinitely peeling the function argument. 19228252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (isSelfRecursive) { 193db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner if (StructType *STy = dyn_cast<StructType>(AgTy)) { 19428252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner bool RecursiveType = false; 19528252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 19628252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (STy->getElementType(i) == PtrArg->getType()) { 19728252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner RecursiveType = true; 19828252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner break; 19928252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner } 20028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner } 20128252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (RecursiveType) 20228252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner continue; 20328252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner } 20428252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner } 20528252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner 20610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, see if we can promote the pointer to its value. 20710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (isSafeToPromoteArgument(PtrArg, isByVal)) 20810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ArgsToPromote.insert(PtrArg); 20940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner } 2104cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 211ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // No promotable pointer arguments. 2125095e3d1d1caef8d573534d369e37277c623064cChris Lattner if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) 2135095e3d1d1caef8d573534d369e37277c623064cChris Lattner return 0; 214ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 2155095e3d1d1caef8d573534d369e37277c623064cChris Lattner return DoPromotion(F, ArgsToPromote, ByValArgsToTransform); 216ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 217ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 21828252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner/// AllCallersPassInValidPointerForArgument - Return true if we can prove that 21911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner/// all callees pass in a valid pointer for the specified function argument. 22028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattnerstatic bool AllCallersPassInValidPointerForArgument(Argument *Arg) { 22111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner Function *Callee = Arg->getParent(); 22211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 22393e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner unsigned ArgNo = std::distance(Callee->arg_begin(), 22493e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner Function::arg_iterator(Arg)); 22511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 22611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Look at all call sites of the function. At this pointer we know we only 22711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // have direct callees. 22811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner for (Value::use_iterator UI = Callee->use_begin(), E = Callee->use_end(); 22911a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner UI != E; ++UI) { 2307d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS(*UI); 2317d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif assert(CS && "Should only have direct calls!"); 23211a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 2334d70a2949007edeaad4662d5cdcb2d272cb2b2ffDan Gohman if (!CS.getArgument(ArgNo)->isDereferenceablePointer()) 23411a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return false; 23511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner } 23611a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner return true; 23711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner} 23811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 239477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// Returns true if Prefix is a prefix of longer. That means, Longer has a size 240477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// that is greater than or equal to the size of prefix, and each of the 241477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// elements in Prefix is the same as the corresponding elements in Longer. 242477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// 243477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// This means it also returns true when Prefix and Longer are equal! 244477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijmanstatic bool IsPrefix(const ArgPromotion::IndicesVector &Prefix, 245477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman const ArgPromotion::IndicesVector &Longer) { 246477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Prefix.size() > Longer.size()) 247477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 248477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (unsigned i = 0, e = Prefix.size(); i != e; ++i) 249477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Prefix[i] != Longer[i]) 250477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 251477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return true; 252477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman} 253477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 254477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 255477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// Checks if Indices, or a prefix of Indices, is in Set. 256477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijmanstatic bool PrefixIn(const ArgPromotion::IndicesVector &Indices, 257477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector> &Set) { 258477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator Low; 259477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low = Set.upper_bound(Indices); 260477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Low != Set.begin()) 261477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low--; 262477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Low is now the last element smaller than or equal to Indices. This means 263477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // it points to a prefix of Indices (possibly Indices itself), if such 264477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // prefix exists. 265477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // 266477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This load is safe if any prefix of its operands is safe to load. 267477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return Low != Set.end() && IsPrefix(*Low, Indices); 268477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman} 269477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 270f451cb870efcf9e0302d25ed05f4cac6bb494e42Dan Gohman/// Mark the given indices (ToMark) as safe in the given set of indices 271477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// (Safe). Marking safe usually means adding ToMark to Safe. However, if there 272477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// is already a prefix of Indices in Safe, Indices are implicitely marked safe 273477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// already. Furthermore, any indices that Indices is itself a prefix of, are 274477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman/// removed from Safe (since they are implicitely safe because of Indices now). 275477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijmanstatic void MarkIndicesSafe(const ArgPromotion::IndicesVector &ToMark, 276477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector> &Safe) { 277477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator Low; 278477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low = Safe.upper_bound(ToMark); 279477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Guard against the case where Safe is empty 280477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Low != Safe.begin()) 281477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low--; 282477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Low is now the last element smaller than or equal to Indices. This 283477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // means it points to a prefix of Indices (possibly Indices itself), if 284477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // such prefix exists. 285477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Low != Safe.end()) { 286477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (IsPrefix(*Low, ToMark)) 287477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // If there is already a prefix of these indices (or exactly these 288477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // indices) marked a safe, don't bother adding these indices 289477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return; 290477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 291477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Increment Low, so we can use it as a "insert before" hint 2924cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands ++Low; 293477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 2944cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands // Insert 295477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Low = Safe.insert(Low, ToMark); 296477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ++Low; 297477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // If there we're a prefix of longer index list(s), remove those 298477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator End = Safe.end(); 299477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman while (Low != End && IsPrefix(ToMark, *Low)) { 300477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::set<ArgPromotion::IndicesVector>::iterator Remove = Low; 301477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ++Low; 302477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Safe.erase(Remove); 303477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 304477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman} 3059e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 3069e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// isSafeToPromoteArgument - As you might guess from the name of this method, 3079e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// it checks to see if it is both safe and useful to promote the argument. 3089e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// This method limits promotion of aggregates to only promote up to three 3099e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// elements of the aggregate in order to avoid exploding the number of 3109e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// arguments passed in. 31140c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattnerbool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const { 312477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman typedef std::set<IndicesVector> GEPIndicesSet; 313477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 314477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Quick exit for unused arguments 315477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Arg->use_empty()) 316477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return true; 317477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 3189440db886627161a8413e823797569fc7b10beafChris Lattner // We can only promote this argument if all of the uses are loads, or are GEP 3199440db886627161a8413e823797569fc7b10beafChris Lattner // instructions (with constant indices) that are subsequently loaded. 320477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // 321477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Promoting the argument causes it to be loaded in the caller 322477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // unconditionally. This is only safe if we can prove that either the load 323477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // would have happened in the callee anyway (ie, there is a load in the entry 324477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // block) or the pointer passed in at every call site is guaranteed to be 325477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // valid. 326477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // In the former case, invalid loads can happen, but would have happened 327477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // anyway, in the latter case, invalid loads won't happen. This prevents us 328477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // from introducing an invalid load that wouldn't have happened in the 329477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // original code. 330477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // 331477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This set will contain all sets of indices that are loaded in the entry 332477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // block, and thus are safe to unconditionally load in the caller. 333477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman GEPIndicesSet SafeToUnconditionallyLoad; 334170b1816b2cd6f02a8d0d5f1e13d9bda2f247012Chris Lattner 335477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This set contains all the sets of indices that we are planning to promote. 336477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This makes it possible to limit the number of arguments added. 337477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman GEPIndicesSet ToPromote; 3384cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 339477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // If the pointer is always valid, any load with first index 0 is valid. 34028252b6f0a483ffb0ead991c7a1ead14e3cd2fc1Chris Lattner if (isByVal || AllCallersPassInValidPointerForArgument(Arg)) 341477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman SafeToUnconditionallyLoad.insert(IndicesVector(1, 0)); 342477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 343477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // First, iterate the entry block and mark loads of (geps of) arguments as 344477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // safe. 34511a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner BasicBlock *EntryBlock = Arg->getParent()->begin(); 346477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Declare this here so we can reuse it 347477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Indices; 348477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (BasicBlock::iterator I = EntryBlock->begin(), E = EntryBlock->end(); 349477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman I != E; ++I) 350477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (LoadInst *LI = dyn_cast<LoadInst>(I)) { 351477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Value *V = LI->getPointerOperand(); 352477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) { 353477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman V = GEP->getPointerOperand(); 354477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (V == Arg) { 355477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This load actually loads (part of) Arg? Check the indices then. 356477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.reserve(GEP->getNumIndices()); 357477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end(); 358477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman II != IE; ++II) 359477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (ConstantInt *CI = dyn_cast<ConstantInt>(*II)) 360477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.push_back(CI->getSExtValue()); 361477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman else 362477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // We found a non-constant GEP index for this argument? Bail out 363477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // right away, can't promote this argument at all. 364477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 365477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 366477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Indices checked out, mark them as safe 367477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman MarkIndicesSafe(Indices, SafeToUnconditionallyLoad); 368477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.clear(); 369477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 370477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } else if (V == Arg) { 371477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Direct loads are equivalent to a GEP with a single 0 index. 372477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman MarkIndicesSafe(IndicesVector(1, 0), SafeToUnconditionallyLoad); 373477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 374477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 375477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 376477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Now, iterate all uses of the argument to see if there are any uses that are 377477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // not (GEP+)loads, or any (GEP+)loads that are not safe to promote. 378a10145fdf6325c5c528689e8952ad7e4e2a1a6b5Chris Lattner SmallVector<LoadInst*, 16> Loads; 379477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Operands; 380ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end(); 381477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman UI != E; ++UI) { 382a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif User *U = *UI; 383477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.clear(); 384a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif if (LoadInst *LI = dyn_cast<LoadInst>(U)) { 3853d30b435e2b3d0e7480019577f48472b51133c21Eli Friedman // Don't hack volatile/atomic loads 3863d30b435e2b3d0e7480019577f48472b51133c21Eli Friedman if (!LI->isSimple()) return false; 387ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Loads.push_back(LI); 388477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Direct loads are equivalent to a GEP with a zero index and then a load. 389477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.push_back(0); 390a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) { 3919440db886627161a8413e823797569fc7b10beafChris Lattner if (GEP->use_empty()) { 3929440db886627161a8413e823797569fc7b10beafChris Lattner // Dead GEP's cause trouble later. Just remove them if we run into 3939440db886627161a8413e823797569fc7b10beafChris Lattner // them. 3949e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner getAnalysis<AliasAnalysis>().deleteValue(GEP); 39540c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner GEP->eraseFromParent(); 396a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif // TODO: This runs the above loop over and over again for dead GEPs 397477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Couldn't we just do increment the UI iterator earlier and erase the 398477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // use? 39940c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner return isSafeToPromoteArgument(Arg, isByVal); 4009440db886627161a8413e823797569fc7b10beafChris Lattner } 401477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 4029440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that all of the indices are constants. 403477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator i = GEP->idx_begin(), e = GEP->idx_end(); 404477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman i != e; ++i) 4055e46321d665d6b1f445aff70d8eabb4870a6cf0eGabor Greif if (ConstantInt *C = dyn_cast<ConstantInt>(*i)) 406477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.push_back(C->getSExtValue()); 4079440db886627161a8413e823797569fc7b10beafChris Lattner else 4089440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a constant operand GEP! 4099440db886627161a8413e823797569fc7b10beafChris Lattner 4109440db886627161a8413e823797569fc7b10beafChris Lattner // Ensure that the only users of the GEP are load instructions. 4119440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = GEP->use_begin(), E = GEP->use_end(); 4129440db886627161a8413e823797569fc7b10beafChris Lattner UI != E; ++UI) 4139440db886627161a8413e823797569fc7b10beafChris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) { 4143d30b435e2b3d0e7480019577f48472b51133c21Eli Friedman // Don't hack volatile/atomic loads 4153d30b435e2b3d0e7480019577f48472b51133c21Eli Friedman if (!LI->isSimple()) return false; 4169440db886627161a8413e823797569fc7b10beafChris Lattner Loads.push_back(LI); 4179440db886627161a8413e823797569fc7b10beafChris Lattner } else { 418477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Other uses than load? 4199440db886627161a8413e823797569fc7b10beafChris Lattner return false; 4209440db886627161a8413e823797569fc7b10beafChris Lattner } 4219440db886627161a8413e823797569fc7b10beafChris Lattner } else { 4229440db886627161a8413e823797569fc7b10beafChris Lattner return false; // Not a load or a GEP. 4239440db886627161a8413e823797569fc7b10beafChris Lattner } 4244cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 425477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Now, see if it is safe to promote this load / loads of this GEP. Loading 426477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // is safe if Operands, or a prefix of Operands, is marked as safe. 427477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (!PrefixIn(Operands, SafeToUnconditionallyLoad)) 428477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 429ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 430477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // See if we are already promoting a load with these indices. If not, check 431477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // to make sure that we aren't promoting too many elements. If so, nothing 432477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // to do. 433477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (ToPromote.find(Operands) == ToPromote.end()) { 434477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (maxElements > 0 && ToPromote.size() == maxElements) { 4355ededf7d42417379d230c92fc73912ebb650ede9David Greene DEBUG(dbgs() << "argpromotion not promoting argument '" 436ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << Arg->getName() << "' because it would require adding more " 437ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << "than " << maxElements << " arguments to the function.\n"); 438477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // We limit aggregate promotion to only promoting up to a fixed number 439477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // of elements of the aggregate. 440477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman return false; 441477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 442477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ToPromote.insert(Operands); 443477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 444477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 445ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 446477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Loads.empty()) return true; // No users, this is a dead argument. 44711a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner 44811a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // Okay, now we know that the argument is only used by load instructions and 449477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // it is safe to unconditionally perform all of them. Use alias analysis to 45011a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // check to see if the pointer is guaranteed to not be modified from entry of 45111a3d7b7ddd10659b72ed248d878fa0d90ddcb45Chris Lattner // the function to each of the load instructions. 452ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 453ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Because there could be several/many load instructions, remember which 454ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // blocks we know to be transparent to the load. 455e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner SmallPtrSet<BasicBlock*, 16> TranspBlocks; 45646f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson 45746f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 458ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 459ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner for (unsigned i = 0, e = Loads.size(); i != e; ++i) { 460ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Check to see if the load is invalidated from the start of the block to 461ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the load itself. 462ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner LoadInst *Load = Loads[i]; 463ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner BasicBlock *BB = Load->getParent(); 4649440db886627161a8413e823797569fc7b10beafChris Lattner 4656d8eb156e6be727570b300bac7712f745a318c7dDan Gohman AliasAnalysis::Location Loc = AA.getLocation(Load); 46656653f0df85f8e4ee60941a6ca31c17ca6f936ffDan Gohman if (AA.canInstructionRangeModify(BB->front(), *Load, Loc)) 467ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; // Pointer is invalidated! 468ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 469ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Now check every path from the entry block to the load for transparency. 470ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // To do this, we perform a depth first search on the inverse CFG from the 471ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // loading block. 472a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) { 473a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif BasicBlock *P = *PI; 474e027efa21816dbd2350d137fdfa181c24cbe8c49Chris Lattner for (idf_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 16> > 475a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif I = idf_ext_begin(P, TranspBlocks), 476a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif E = idf_ext_end(P, TranspBlocks); I != E; ++I) 47756653f0df85f8e4ee60941a6ca31c17ca6f936ffDan Gohman if (AA.canBasicBlockModify(**I, Loc)) 478ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return false; 479a53029b1fcc71b1482863a7031ddb0c48d7a1177Gabor Greif } 480ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 481ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 482ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If the path from the entry of the function to each load is free of 483ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // instructions that potentially invalidate the load, we can make the 484ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // transformation! 485ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner return true; 486ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 487ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 4889e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner/// DoPromotion - This method actually performs the promotion of the specified 4895eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// arguments, and returns the new function. At this point, we know that it's 4905eb6f6c829ddfe353f94623aa1009c72be930497Chris Lattner/// safe to do so. 4915095e3d1d1caef8d573534d369e37277c623064cChris LattnerCallGraphNode *ArgPromotion::DoPromotion(Function *F, 4925095e3d1d1caef8d573534d369e37277c623064cChris Lattner SmallPtrSet<Argument*, 8> &ArgsToPromote, 49310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner SmallPtrSet<Argument*, 8> &ByValArgsToTransform) { 494fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 495ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Start by computing a new prototype for the function, which is the same as 496ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // the old function, but has modified arguments. 497db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner FunctionType *FTy = F->getFunctionType(); 4985fdd6c8793462549e3593890ec61573da06e3346Jay Foad std::vector<Type*> Params; 499ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 500477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman typedef std::set<IndicesVector> ScalarizeTable; 501beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner 5029440db886627161a8413e823797569fc7b10beafChris Lattner // ScalarizedElements - If we are promoting a pointer that has elements 5039440db886627161a8413e823797569fc7b10beafChris Lattner // accessed out of it, keep track of which elements are accessed so that we 5049440db886627161a8413e823797569fc7b10beafChris Lattner // can add one argument for each. 5059440db886627161a8413e823797569fc7b10beafChris Lattner // 5069440db886627161a8413e823797569fc7b10beafChris Lattner // Arguments that are directly loaded will have a zero element value here, to 5079440db886627161a8413e823797569fc7b10beafChris Lattner // handle cases where there are both a direct load and GEP accesses. 5089440db886627161a8413e823797569fc7b10beafChris Lattner // 509beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner std::map<Argument*, ScalarizeTable> ScalarizedElements; 5109440db886627161a8413e823797569fc7b10beafChris Lattner 5119e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // OriginalLoads - Keep track of a representative load instruction from the 5129e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // original function so that we can tell the alias analysis implementation 5139e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // what the new GEP/Load instructions we are inserting look like. 514477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::map<IndicesVector, LoadInst*> OriginalLoads; 5159e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 5160598866c052147c31b808391f58434ce3dbfb838Devang Patel // Attributes - Keep track of the parameter attributes for the arguments 517dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // that we are *not* promoting. For the ones that we do promote, the parameter 518dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // attributes are lost 5190598866c052147c31b808391f58434ce3dbfb838Devang Patel SmallVector<AttributeWithIndex, 8> AttributesVec; 5200598866c052147c31b808391f58434ce3dbfb838Devang Patel const AttrListPtr &PAL = F->getAttributes(); 521dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 522532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 52319c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = PAL.getRetAttributes()) 5240598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(0, attrs)); 5254cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 526477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // First, determine the new argument list 527ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner unsigned ArgIndex = 1; 528dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; 529ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ++I, ++ArgIndex) { 53010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 531477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Simple byval argument? Just add all the struct element types. 532db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 533db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner StructType *STy = cast<StructType>(AgTy); 53410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) 53510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Params.push_back(STy->getElementType(i)); 53610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++NumByValArgsPromoted; 53710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!ArgsToPromote.count(I)) { 538477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Unchanged argument 539ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Params.push_back(I->getType()); 54019c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = PAL.getParamAttributes(ArgIndex)) 5410598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(Params.size(), attrs)); 5429e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else if (I->use_empty()) { 543477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Dead argument (which are always marked as promotable) 5449e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner ++NumArgumentsDead; 5459e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } else { 546477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Okay, this is being promoted. This means that the only uses are loads 547477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // or GEPs which are only used by loads 548477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 549477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // In this table, we will track which indices are loaded from the argument 550477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // (where direct loads are tracked as no indices). 551beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 5529440db886627161a8413e823797569fc7b10beafChris Lattner for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; 5539440db886627161a8413e823797569fc7b10beafChris Lattner ++UI) { 5549440db886627161a8413e823797569fc7b10beafChris Lattner Instruction *User = cast<Instruction>(*UI); 55546f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson assert(isa<LoadInst>(User) || isa<GetElementPtrInst>(User)); 556477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Indices; 557477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.reserve(User->getNumOperands() - 1); 558477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Since loads will only have a single operand, and GEPs only a single 559477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // non-index operand, this will record direct loads without any indices, 560477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // and gep+loads with the GEP indices. 561477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator II = User->op_begin() + 1, IE = User->op_end(); 562477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman II != IE; ++II) 563477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.push_back(cast<ConstantInt>(*II)->getSExtValue()); 564477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // GEPs with a single 0 index can be merged with direct loads 565477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Indices.size() == 1 && Indices.front() == 0) 566477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Indices.clear(); 56746f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson ArgIndices.insert(Indices); 56846f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson LoadInst *OrigLoad; 56946f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson if (LoadInst *L = dyn_cast<LoadInst>(User)) 57046f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = L; 57146f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson else 572477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Take any load, we will use it only to update Alias Analysis 57346f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OrigLoad = cast<LoadInst>(User->use_back()); 57446f022a7f105211d5ea2c394e406d1943b80908cOwen Anderson OriginalLoads[Indices] = OrigLoad; 5759440db886627161a8413e823797569fc7b10beafChris Lattner } 5769440db886627161a8413e823797569fc7b10beafChris Lattner 5779440db886627161a8413e823797569fc7b10beafChris Lattner // Add a parameter to the function for each element passed in. 578beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 579477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman E = ArgIndices.end(); SI != E; ++SI) { 580b079a391c8b85d088dabce715d99be5917af88faTorok Edwin // not allowed to dereference ->begin() if size() is 0 581a9203109f4ac95aa7e9624f2838e3d89623ec902Jay Foad Params.push_back(GetElementPtrInst::getIndexedType(I->getType(), *SI)); 582477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman assert(Params.back()); 583477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 5849440db886627161a8413e823797569fc7b10beafChris Lattner 5859440db886627161a8413e823797569fc7b10beafChris Lattner if (ArgIndices.size() == 1 && ArgIndices.begin()->empty()) 5869440db886627161a8413e823797569fc7b10beafChris Lattner ++NumArgumentsPromoted; 5879440db886627161a8413e823797569fc7b10beafChris Lattner else 5889440db886627161a8413e823797569fc7b10beafChris Lattner ++NumAggregatesPromoted; 589ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 59010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 591ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 59219c874638d9478a5d5028854817a5ee72293bb2bDevang Patel // Add any function attributes. 59319c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = PAL.getFnAttributes()) 59419c874638d9478a5d5028854817a5ee72293bb2bDevang Patel AttributesVec.push_back(AttributeWithIndex::get(~0, attrs)); 59519c874638d9478a5d5028854817a5ee72293bb2bDevang Patel 596db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *RetTy = FTy->getReturnType(); 597ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 598ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Work around LLVM bug PR56: the CWriter cannot emit varargs functions which 599ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // have zero fixed arguments. 600ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner bool ExtraArgHack = false; 601ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (Params.empty() && FTy->isVarArg()) { 602ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ExtraArgHack = true; 6031d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Params.push_back(Type::getInt32Ty(F->getContext())); 604ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 605dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands 606dc024674ff96820d6020757b48d47f46d4c07db2Duncan Sands // Construct the new function type using the new arguments. 607debcb01b0f0a15f568ca69e8f288fade4bfc7297Owen Anderson FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg()); 608fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 609a51c39cc3265f5d0d5de87b4a3ef9332c83556e1Chris Lattner // Create the new function body and insert it into the module. 610051a950000e21935165db56695e35bade668193bGabor Greif Function *NF = Function::Create(NFTy, F->getLinkage(), F->getName()); 61128c3cff8250b3fe2adc6479306fe7dbdb48a1bdbDuncan Sands NF->copyAttributesFrom(F); 612ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner 613a3512bd589ad9269ddaa4e9c008da43c36b4a1b8Chris Lattner 6145ededf7d42417379d230c92fc73912ebb650ede9David Greene DEBUG(dbgs() << "ARG PROMOTION: Promoting to:" << *NF << "\n" 615a3512bd589ad9269ddaa4e9c008da43c36b4a1b8Chris Lattner << "From: " << *F); 616a3512bd589ad9269ddaa4e9c008da43c36b4a1b8Chris Lattner 617ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // Recompute the parameter attributes list based on the new arguments for 618ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner // the function. 619d509d0b532ec2358b3f341d4a4cd1411cb8b5db2Chris Lattner NF->setAttributes(AttrListPtr::get(AttributesVec)); 6200598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.clear(); 62128c3cff8250b3fe2adc6479306fe7dbdb48a1bdbDuncan Sands 622ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner F->getParent()->getFunctionList().insert(F, NF); 6232b3407f5b3d8626b924c532bcfea15daaf1bd3c0Zhou Sheng NF->takeName(F); 6249e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 6259e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Get the alias analysis information that we need to update to reflect our 6269e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // changes. 6279e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 6289e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 62934c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands // Get the callgraph information that we need to update to reflect our 63034c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands // changes. 63134c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands CallGraph &CG = getAnalysis<CallGraph>(); 6325095e3d1d1caef8d573534d369e37277c623064cChris Lattner 6335095e3d1d1caef8d573534d369e37277c623064cChris Lattner // Get a new callgraph node for NF. 6345095e3d1d1caef8d573534d369e37277c623064cChris Lattner CallGraphNode *NF_CGN = CG.getOrInsertFunction(NF); 63534c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands 636ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Loop over all of the callers of the function, transforming the call sites 637ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // to pass in the loaded pointers. 638ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 639ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner SmallVector<Value*, 16> Args; 640ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner while (!F->use_empty()) { 6417d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS(F->use_back()); 6420054c7a867f85f52fdcc11279d696160de92c9f8Gabor Greif assert(CS.getCalledFunction() == F); 643ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *Call = CS.getInstruction(); 6440598866c052147c31b808391f58434ce3dbfb838Devang Patel const AttrListPtr &CallPAL = CS.getAttributes(); 6454cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 646532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands // Add any return attributes. 64719c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = CallPAL.getRetAttributes()) 6480598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(0, attrs)); 649532d022794beabceae09c7fcc222a6e4e929c748Duncan Sands 6509e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Loop over the operands, inserting GEP and loads in the caller as 6519e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // appropriate. 652ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner CallSite::arg_iterator AI = CS.arg_begin(); 653ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner ArgIndex = 1; 654f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); 655ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner I != E; ++I, ++AI, ++ArgIndex) 65610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 657ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); // Unmodified argument 6584cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 65919c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex)) 6600598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs)); 6614cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 66210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (ByValArgsToTransform.count(I)) { 66310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Emit a GEP and load for each element of the struct. 664db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 665db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner StructType *STy = cast<StructType>(AgTy); 6661d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Value *Idxs[2] = { 6671d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), 0 }; 66810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 6691d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i); 670a9203109f4ac95aa7e9624f2838e3d89623ec902Jay Foad Value *Idx = GetElementPtrInst::Create(*AI, Idxs, 671051a950000e21935165db56695e35bade668193bGabor Greif (*AI)->getName()+"."+utostr(i), 672051a950000e21935165db56695e35bade668193bGabor Greif Call); 67310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // TODO: Tell AA about the new values? 67410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Args.push_back(new LoadInst(Idx, Idx->getName()+".val", Call)); 6754cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands } 67610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else if (!I->use_empty()) { 6779e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Non-dead argument: insert GEPs and loads as appropriate. 678beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 679477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Store the Value* version of the indices in here, but declare it now 6800054c7a867f85f52fdcc11279d696160de92c9f8Gabor Greif // for reuse. 681477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman std::vector<Value*> Ops; 682beabf45a6923b1748edae40d53e2b2c4362cc32fChris Lattner for (ScalarizeTable::iterator SI = ArgIndices.begin(), 6839440db886627161a8413e823797569fc7b10beafChris Lattner E = ArgIndices.end(); SI != E; ++SI) { 6849440db886627161a8413e823797569fc7b10beafChris Lattner Value *V = *AI; 6859e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner LoadInst *OrigLoad = OriginalLoads[*SI]; 6869e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (!SI->empty()) { 687477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Ops.reserve(SI->size()); 688db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ElTy = V->getType(); 6894cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands for (IndicesVector::const_iterator II = SI->begin(), 690477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IE = SI->end(); II != IE; ++II) { 691477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // Use i32 to index structs, and i64 for others (pointers/arrays). 692477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // This satisfies GEP constraints. 693db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *IdxTy = (ElTy->isStructTy() ? 6941d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Type::getInt32Ty(F->getContext()) : 6951d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Type::getInt64Ty(F->getContext())); 696eed707b1e6097aac2bb6b3d47271f6300ace7f2eOwen Anderson Ops.push_back(ConstantInt::get(IdxTy, *II)); 6970054c7a867f85f52fdcc11279d696160de92c9f8Gabor Greif // Keep track of the type we're currently indexing. 698477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman ElTy = cast<CompositeType>(ElTy)->getTypeAtIndex(*II); 699477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 7000054c7a867f85f52fdcc11279d696160de92c9f8Gabor Greif // And create a GEP to extract those indices. 701a9203109f4ac95aa7e9624f2838e3d89623ec902Jay Foad V = GetElementPtrInst::Create(V, Ops, V->getName()+".idx", Call); 702477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Ops.clear(); 7039e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad->getOperand(0), V); 7049e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner } 7056fde0bd39b1b431b7be30aaf9221ce6c60b0a5f0Eric Christopher // Since we're replacing a load make sure we take the alignment 7066fde0bd39b1b431b7be30aaf9221ce6c60b0a5f0Eric Christopher // of the previous load. 7076fde0bd39b1b431b7be30aaf9221ce6c60b0a5f0Eric Christopher LoadInst *newLoad = new LoadInst(V, V->getName()+".val", Call); 7086fde0bd39b1b431b7be30aaf9221ce6c60b0a5f0Eric Christopher newLoad->setAlignment(OrigLoad->getAlignment()); 70956653f0df85f8e4ee60941a6ca31c17ca6f936ffDan Gohman // Transfer the TBAA info too. 71056653f0df85f8e4ee60941a6ca31c17ca6f936ffDan Gohman newLoad->setMetadata(LLVMContext::MD_tbaa, 71156653f0df85f8e4ee60941a6ca31c17ca6f936ffDan Gohman OrigLoad->getMetadata(LLVMContext::MD_tbaa)); 7126fde0bd39b1b431b7be30aaf9221ce6c60b0a5f0Eric Christopher Args.push_back(newLoad); 7139e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.copyValue(OrigLoad, Args.back()); 7149440db886627161a8413e823797569fc7b10beafChris Lattner } 715ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 716ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 717ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (ExtraArgHack) 7181d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Args.push_back(Constant::getNullValue(Type::getInt32Ty(F->getContext()))); 719ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 7200054c7a867f85f52fdcc11279d696160de92c9f8Gabor Greif // Push any varargs arguments on the list. 721ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner for (; AI != CS.arg_end(); ++AI, ++ArgIndex) { 722ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.push_back(*AI); 72319c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex)) 7240598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs)); 725ab04e13a1f017c2b0a82344b4c083d92139ee2ccChris Lattner } 726ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 72719c874638d9478a5d5028854817a5ee72293bb2bDevang Patel // Add any function attributes. 72819c874638d9478a5d5028854817a5ee72293bb2bDevang Patel if (Attributes attrs = CallPAL.getFnAttributes()) 72919c874638d9478a5d5028854817a5ee72293bb2bDevang Patel AttributesVec.push_back(AttributeWithIndex::get(~0, attrs)); 73019c874638d9478a5d5028854817a5ee72293bb2bDevang Patel 731ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Instruction *New; 732ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) { 733051a950000e21935165db56695e35bade668193bGabor Greif New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(), 734a3efbb15ddd5aa9006564cd79086723640084878Jay Foad Args, "", Call); 735f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv()); 736d509d0b532ec2358b3f341d4a4cd1411cb8b5db2Chris Lattner cast<InvokeInst>(New)->setAttributes(AttrListPtr::get(AttributesVec)); 737ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } else { 738a3efbb15ddd5aa9006564cd79086723640084878Jay Foad New = CallInst::Create(NF, Args, "", Call); 739f201dbc1a4a638659ec3916785196e2c204c7755Chris Lattner cast<CallInst>(New)->setCallingConv(CS.getCallingConv()); 740d509d0b532ec2358b3f341d4a4cd1411cb8b5db2Chris Lattner cast<CallInst>(New)->setAttributes(AttrListPtr::get(AttributesVec)); 7411430ef134d36888b99d2e6fedd2b025882593538Chris Lattner if (cast<CallInst>(Call)->isTailCall()) 7421430ef134d36888b99d2e6fedd2b025882593538Chris Lattner cast<CallInst>(New)->setTailCall(); 743ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 744ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Args.clear(); 7450598866c052147c31b808391f58434ce3dbfb838Devang Patel AttributesVec.clear(); 746ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 7479e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Update the alias analysis implementation to know that we are replacing 7489e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // the old call with a new one. 7499e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(Call, New); 7509e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 75134c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands // Update the callgraph to know that the callsite has been transformed. 752da230cb876edf0d4fa8eefc289b8addfb722cd07Chris Lattner CallGraphNode *CalleeNode = CG[Call->getParent()->getParent()]; 753a51c39cc3265f5d0d5de87b4a3ef9332c83556e1Chris Lattner CalleeNode->replaceCallEdge(Call, New, NF_CGN); 75434c8847b2d27433ec7b81c824b66771e7665873aDuncan Sands 755ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner if (!Call->use_empty()) { 756ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner Call->replaceAllUsesWith(New); 757046800a7125cd497613efc0e1ea15cb595666585Chris Lattner New->takeName(Call); 758ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 759fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 760ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Finally, remove the old call from the program, reducing the use-count of 761ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // F. 76240c14be5bc9ba900f01c408b65aca57e053788e1Chris Lattner Call->eraseFromParent(); 763ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 764ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 765ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // Since we have now created the new function, splice the body of the old 766ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function right into the new function, leaving the old rotting hulk of the 767ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // function empty. 768ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList()); 769ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 7707a2bdde0a0eebcd2125055e0eacaca040f0b766cChris Lattner // Loop over the argument list, transferring uses of the old arguments over to 7717a2bdde0a0eebcd2125055e0eacaca040f0b766cChris Lattner // the new arguments, also transferring over the names as well. 772ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // 77393e985f1b17aef62d58e3198a4604f9f6cfe8d19Chris Lattner for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(), 77410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2 = NF->arg_begin(); I != E; ++I) { 77510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) { 776ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // If this is an unmodified argument, move the name and users over to the 777ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner // new version. 778ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner I->replaceAllUsesWith(I2); 779046800a7125cd497613efc0e1ea15cb595666585Chris Lattner I2->takeName(I); 7809e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(I, I2); 781ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner ++I2; 78210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 78310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 7844cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 78510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (ByValArgsToTransform.count(I)) { 78610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // In the callee, we create an alloca, and store each of the new incoming 78710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // arguments into the alloca. 78810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Instruction *InsertPt = NF->begin()->begin(); 7894cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 79010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Just add all the struct element types. 791db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *AgTy = cast<PointerType>(I->getType())->getElementType(); 79250dead06ffc107edb7e84857baaeeb09039c631cOwen Anderson Value *TheAlloca = new AllocaInst(AgTy, 0, "", InsertPt); 793db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner StructType *STy = cast<StructType>(AgTy); 7941d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Value *Idxs[2] = { 7951d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), 0 }; 7964cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 79710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { 7981d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i); 799dfd3b647839d3f944b5d8bffd6e9a2ec022d3507Daniel Dunbar Value *Idx = 800a9203109f4ac95aa7e9624f2838e3d89623ec902Jay Foad GetElementPtrInst::Create(TheAlloca, Idxs, 801fe09b2098ac483f6d6ce6ea4ab237a9539bdb6b9Daniel Dunbar TheAlloca->getName()+"."+Twine(i), 802dfd3b647839d3f944b5d8bffd6e9a2ec022d3507Daniel Dunbar InsertPt); 803fe09b2098ac483f6d6ce6ea4ab237a9539bdb6b9Daniel Dunbar I2->setName(I->getName()+"."+Twine(i)); 80410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner new StoreInst(I2++, Idx, InsertPt); 80510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 8064cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 80710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Anything that used the arg should now use the alloca. 80810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I->replaceAllUsesWith(TheAlloca); 80910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner TheAlloca->takeName(I); 81010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(I, TheAlloca); 81110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 8124cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands } 8134cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 81410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (I->use_empty()) { 8159e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.deleteValue(I); 81610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner continue; 81710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 8184cddaf77c4f2482e7d3e7cc1c80895523dcfb68eDuncan Sands 81910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Otherwise, if we promoted this argument, then all users are load 820477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // instructions (or GEPs with only load users), and all loads should be 821477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // using the new argument that we added. 82210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ScalarizeTable &ArgIndices = ScalarizedElements[I]; 82310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 82410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!I->use_empty()) { 82510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner if (LoadInst *LI = dyn_cast<LoadInst>(I->use_back())) { 82610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(ArgIndices.begin()->empty() && 82710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner "Load element should sort to front!"); 82810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner I2->setName(I->getName()+".val"); 82910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->replaceAllUsesWith(I2); 83010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(LI, I2); 83110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LI->eraseFromParent(); 8325ededf7d42417379d230c92fc73912ebb650ede9David Greene DEBUG(dbgs() << "*** Promoted load of argument '" << I->getName() 833ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << "' in function '" << F->getName() << "'\n"); 83410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } else { 83510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->use_back()); 836477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman IndicesVector Operands; 837477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.reserve(GEP->getNumIndices()); 838477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end(); 839477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman II != IE; ++II) 840477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.push_back(cast<ConstantInt>(*II)->getSExtValue()); 841477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman 842477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman // GEPs with a single 0 index can be merged with direct loads 843477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman if (Operands.size() == 1 && Operands.front() == 0) 844477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman Operands.clear(); 84510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 84610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner Function::arg_iterator TheArg = I2; 84710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (ScalarizeTable::iterator It = ArgIndices.begin(); 84810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner *It != Operands; ++It, ++TheArg) { 84910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner assert(It != ArgIndices.end() && "GEP not handled??"); 85010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 8519440db886627161a8413e823797569fc7b10beafChris Lattner 85210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner std::string NewName = I->getName(); 853477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman for (unsigned i = 0, e = Operands.size(); i != e; ++i) { 854477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman NewName += "." + utostr(Operands[i]); 855477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman } 856477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman NewName += ".val"; 857477f5a2f11a0383b4ecfcb0db2913027ed38ee39Matthijs Kooijman TheArg->setName(NewName); 85810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 8595ededf7d42417379d230c92fc73912ebb650ede9David Greene DEBUG(dbgs() << "*** Promoted agg argument '" << TheArg->getName() 860ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar << "' of function '" << NF->getName() << "'\n"); 86110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 86210603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // All of the uses must be load instructions. Replace them all with 86310603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // the argument specified by ArgNo. 86410603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner while (!GEP->use_empty()) { 86510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner LoadInst *L = cast<LoadInst>(GEP->use_back()); 86610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->replaceAllUsesWith(TheArg); 86710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.replaceWithNewValue(L, TheArg); 86810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner L->eraseFromParent(); 8699440db886627161a8413e823797569fc7b10beafChris Lattner } 87010603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner AA.deleteValue(GEP); 87110603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner GEP->eraseFromParent(); 872ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 873ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner } 874ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner 87510603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner // Increment I2 past all of the arguments added for this promoted pointer. 87610603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner for (unsigned i = 0, e = ArgIndices.size(); i != e; ++i) 87710603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner ++I2; 87810603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner } 87910603e0c84d15f61443e8b17bc35f98cc46606d9Chris Lattner 8809e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Notify the alias analysis implementation that we inserted a new argument. 8819e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner if (ExtraArgHack) 8821d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson AA.copyValue(Constant::getNullValue(Type::getInt32Ty(F->getContext())), 8831d0be15f89cb5056e20e2d24faa8d6afb1573bcaOwen Anderson NF->arg_begin()); 8849e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 8859e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 8869e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner // Tell the alias analysis that the old function is about to disappear. 8879e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner AA.replaceWithNewValue(F, NF); 8889e7cc2f0d42aa4127e3b8406e25907a96ce9ada0Chris Lattner 8895095e3d1d1caef8d573534d369e37277c623064cChris Lattner 8905095e3d1d1caef8d573534d369e37277c623064cChris Lattner NF_CGN->stealCalledFunctionsFrom(CG[F]); 8915095e3d1d1caef8d573534d369e37277c623064cChris Lattner 892eae220259fca393adc874ed41e3930011047beb7Chris Lattner // Now that the old function is dead, delete it. If there is a dangling 893eae220259fca393adc874ed41e3930011047beb7Chris Lattner // reference to the CallgraphNode, just leave the dead function around for 894eae220259fca393adc874ed41e3930011047beb7Chris Lattner // someone else to nuke. 895eae220259fca393adc874ed41e3930011047beb7Chris Lattner CallGraphNode *CGN = CG[F]; 896eae220259fca393adc874ed41e3930011047beb7Chris Lattner if (CGN->getNumReferences() == 0) 897eae220259fca393adc874ed41e3930011047beb7Chris Lattner delete CG.removeFunctionFromModule(CGN); 898eae220259fca393adc874ed41e3930011047beb7Chris Lattner else 899eae220259fca393adc874ed41e3930011047beb7Chris Lattner F->setLinkage(Function::ExternalLinkage); 9005095e3d1d1caef8d573534d369e37277c623064cChris Lattner 9015095e3d1d1caef8d573534d369e37277c623064cChris Lattner return NF_CGN; 902ed570a7dca45e001a6223e2a25d034b838934f88Chris Lattner} 903