Inliner.cpp revision c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0
1cf5933a716e7eb6bd5ff49aa62f3e76379ebaf51Chris Lattner//===- Inliner.cpp - Code common to all inliners --------------------------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// The LLVM Compiler Infrastructure 4b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell//===----------------------------------------------------------------------===// 9237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner// 10befa499d45ffcc32bd9902518aec18589464e47cChris Lattner// This file implements the mechanics required to implement inlining without 11befa499d45ffcc32bd9902518aec18589464e47cChris Lattner// missing any calls and updating the call graph. The decisions of which calls 12befa499d45ffcc32bd9902518aec18589464e47cChris Lattner// are profitable to inline are implemented elsewhere. 13237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner// 14237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner//===----------------------------------------------------------------------===// 15237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 1686453c52ba02e743d29c08456e51006500041456Chris Lattner#define DEBUG_TYPE "inline" 17237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner#include "llvm/Module.h" 1847b14a4a6a455c7be169cfd312fcbe796f0ad426Misha Brukman#include "llvm/Instructions.h" 191f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen#include "llvm/IntrinsicInst.h" 20237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner#include "llvm/Analysis/CallGraph.h" 21e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman#include "llvm/Analysis/InlineCost.h" 22ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner#include "llvm/Target/TargetData.h" 236f7426ec2e46bb19cc9f9e75f1c355b35cf12d7dTanya Lattner#include "llvm/Transforms/IPO/InlinerPass.h" 24237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner#include "llvm/Transforms/Utils/Cloning.h" 254ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner#include "llvm/Transforms/Utils/Local.h" 264ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner#include "llvm/Support/CallSite.h" 27551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/CommandLine.h" 28551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 29ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar#include "llvm/Support/raw_ostream.h" 3012f0babca4459c253675700e1d707652d5b6ba17Chris Lattner#include "llvm/ADT/SmallPtrSet.h" 31551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 32befa499d45ffcc32bd9902518aec18589464e47cChris Lattner#include <set> 33a51bcb50b0c74adc741361824ef81dbefb715c53Chris Lattnerusing namespace llvm; 34d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 3586453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumInlined, "Number of functions inlined"); 36dbab4dc942e0c3286415908762de71a9447f9dfaChris LattnerSTATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined"); 3786453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumDeleted, "Number of functions deleted because all callers found"); 38199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerSTATISTIC(NumMergedAllocas, "Number of allocas merged together"); 3986453c52ba02e743d29c08456e51006500041456Chris Lattner 40844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic cl::opt<int> 415fee49eff92c2ae2f70eb84d136c31a706560750Dale JohannesenInlineLimit("inline-threshold", cl::Hidden, cl::init(200), cl::ZeroOrMore, 42cbfdf9644ce38fd3404469c26ac3c8466c940b6eDale Johannesen cl::desc("Control the amount of inlining to perform (default = 200)")); 43237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 44ae73dc1448d25b02cabc7c64c86c64371453dda8Dan GohmanInliner::Inliner(void *ID) 45ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman : CallGraphSCCPass(ID), InlineThreshold(InlineLimit) {} 46237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 47ae73dc1448d25b02cabc7c64c86c64371453dda8Dan GohmanInliner::Inliner(void *ID, int Threshold) 48ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman : CallGraphSCCPass(ID), InlineThreshold(Threshold) {} 49120d053e3ba810b44047fbcb719824bed5673ca9Chris Lattner 50ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// getAnalysisUsage - For this class, we declare that we require and preserve 51ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// the call graph. If the derived class implements this method, it should 52ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// always explicitly call the implementation here. 53ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattnervoid Inliner::getAnalysisUsage(AnalysisUsage &Info) const { 54ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner CallGraphSCCPass::getAnalysisUsage(Info); 55ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner} 56ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner 57199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 58199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattnertypedef DenseMap<const ArrayType*, std::vector<AllocaInst*> > 59199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerInlinedArrayAllocasTy; 60199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 61199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// InlineCallIfPossible - If it is possible to inline the specified call site, 62199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// do so and update the CallGraph for this operation. 63199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// 64199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// This function also does some basic book-keeping to update the IR. The 65cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// InlinedArrayAllocas map keeps track of any allocas that are already 66cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// available from other functions inlined into the caller. If we are able to 67cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// inline this call site we attempt to reuse already available allocas or add 68cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// any new allocas to the set if not possible. 69199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattnerstatic bool InlineCallIfPossible(CallSite CS, CallGraph &CG, 70199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner const TargetData *TD, 71199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner InlinedArrayAllocasTy &InlinedArrayAllocas) { 72befa499d45ffcc32bd9902518aec18589464e47cChris Lattner Function *Callee = CS.getCalledFunction(); 7366c75aaa028683c389c55b377ee2411b61081677Bill Wendling Function *Caller = CS.getCaller(); 7466c75aaa028683c389c55b377ee2411b61081677Bill Wendling 75199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Try to inline the function. Get the list of static allocas that were 76199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // inlined. 77199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallVector<AllocaInst*, 16> StaticAllocas; 78199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (!InlineFunction(CS, &CG, TD, &StaticAllocas)) 7912f0babca4459c253675700e1d707652d5b6ba17Chris Lattner return false; 80fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 818c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // If the inlined function had a higher stack protection level than the 828c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // calling function, then bump up the caller's stack protection level. 838c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling if (Callee->hasFnAttr(Attribute::StackProtectReq)) 848c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtectReq); 858c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling else if (Callee->hasFnAttr(Attribute::StackProtect) && 868c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling !Caller->hasFnAttr(Attribute::StackProtectReq)) 878c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtect); 888c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling 89199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 90199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Look at all of the allocas that we inlined through this call site. If we 91199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // have already inlined other allocas through other calls into this function, 92199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // then we know that they have disjoint lifetimes and that we can merge them. 93199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 94199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // There are many heuristics possible for merging these allocas, and the 95199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // different options have different tradeoffs. One thing that we *really* 96199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // don't want to hurt is SRoA: once inlining happens, often allocas are no 97199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // longer address taken and so they can be promoted. 98199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 99199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Our "solution" for that is to only merge allocas whose outermost type is an 100199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // array type. These are usually not promoted because someone is using a 101199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // variable index into them. These are also often the most important ones to 102199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // merge. 103199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 104199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // A better solution would be to have real memory lifetime markers in the IR 105199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // and not have the inliner do any merging of allocas at all. This would 106199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allow the backend to do proper stack slot coloring of all allocas that 107199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // *actually make it to the backend*, which is really what we want. 108199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 109199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Because we don't have this information, we do this simple and useful hack. 110199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 111199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallPtrSet<AllocaInst*, 16> UsedAllocas; 112199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 113199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over all the allocas we have so far and see if they can be merged with 114199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // a previously inlined alloca. If not, remember that we had it. 115199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner for (unsigned AllocaNo = 0, e = StaticAllocas.size(); 116199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaNo != e; ++AllocaNo) { 117199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaInst *AI = StaticAllocas[AllocaNo]; 118199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 119199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Don't bother trying to merge array allocations (they will usually be 120199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // canonicalized to be an allocation *of* an array), or allocations whose 121199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // type is not itself an array (because we're afraid of pessimizing SRoA). 122199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner const ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType()); 123199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (ATy == 0 || AI->isArrayAllocation()) 124199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 125199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 126199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Get the list of all available allocas for this array type. 127199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner std::vector<AllocaInst*> &AllocasForType = InlinedArrayAllocas[ATy]; 128199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 129199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over the allocas in AllocasForType to see if we can reuse one. Note 130199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // that we have to be careful not to reuse the same "available" alloca for 131199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // multiple different allocas that we just inlined, we use the 'UsedAllocas' 132199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // set to keep track of which "available" allocas are being used by this 133199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function. Also, AllocasForType can be empty of course! 134199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner bool MergedAwayAlloca = false; 135199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) { 136199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaInst *AvailableAlloca = AllocasForType[i]; 137199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 138199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // The available alloca has to be in the right function, not in some other 139199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function in this SCC. 140199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (AvailableAlloca->getParent() != AI->getParent()) 141199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 142199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 143199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If the inlined function already uses this alloca then we can't reuse 144199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it. 145199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (!UsedAllocas.insert(AvailableAlloca)) 146199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 147199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 148199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Otherwise, we *can* reuse it, RAUW AI into AvailableAlloca and declare 149199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // success! 150c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI); 151199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 152199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->replaceAllUsesWith(AvailableAlloca); 153199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->eraseFromParent(); 154199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner MergedAwayAlloca = true; 155199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumMergedAllocas; 156199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner break; 157199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 158fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 159199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we already nuked the alloca, we're done with it. 160199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (MergedAwayAlloca) 161199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 1621f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen 163199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we were unable to merge away the alloca either because there are no 164199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allocas of the right type available or because we reused them all 165199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // already, remember that this alloca came from an inlined function and mark 166199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it used so we don't reuse it for other allocas from this inline 167199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // operation. 168199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocasForType.push_back(AI); 169199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner UsedAllocas.insert(AI); 170befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } 171199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 172befa499d45ffcc32bd9902518aec18589464e47cChris Lattner return true; 173237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 1741a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar 1751a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// shouldInline - Return true if the inliner should attempt to inline 1761a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// at the given CallSite. 1771a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbarbool Inliner::shouldInline(CallSite CS) { 178c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar InlineCost IC = getInlineCost(CS); 1791a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar 180c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isAlways()) { 181c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=always" 18284a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 183c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return true; 184c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 185c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 186c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isNever()) { 187c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=never" 18884a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 189c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return false; 190c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 191c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 192c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar int Cost = IC.getValue(); 1931a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar int CurrentThreshold = InlineThreshold; 194e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Function *Caller = CS.getCaller(); 195e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Caller && !Caller->isDeclaration() && 196e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Caller->hasFnAttr(Attribute::OptimizeForSize) && 197a0479e53323ade402272ddf8302c8aa2c496c775Evan Cheng InlineLimit.getNumOccurrences() == 0 && 19884a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling InlineThreshold != 50) 1991a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar CurrentThreshold = 50; 2001a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar 201135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner float FudgeFactor = getInlineFudgeFactor(CS); 2021a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar if (Cost >= (int)(CurrentThreshold * FudgeFactor)) { 203c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=" << Cost 20484a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 2051a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar return false; 2061a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar } 207135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 208e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // Try to detect the case where the current inlining candidate caller 209e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // (call it B) is a static function and is an inlining candidate elsewhere, 210e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // and the current candidate callee (call it C) is large enough that 211e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // inlining it into B would make B too big to inline later. In these 212e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // circumstances it may be best not to inline C into B, but to inline B 213e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // into its callers. 214e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Caller->hasLocalLinkage()) { 215e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int TotalSecondaryCost = 0; 216e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool outerCallsFound = false; 217e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool allOuterCallsWillBeInlined = true; 218e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool someOuterCallWouldNotBeInlined = false; 219e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen for (Value::use_iterator I = Caller->use_begin(), E =Caller->use_end(); 220e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen I != E; ++I) { 221e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen CallSite CS2 = CallSite::get(*I); 222e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 223e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call to Caller (it could be some other sort 224e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // of reference) skip it. 225e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (CS2.getInstruction() == 0 || CS2.getCalledFunction() != Caller) 226e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 227e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 228e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen InlineCost IC2 = getInlineCost(CS2); 229e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isNever()) 230e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen allOuterCallsWillBeInlined = false; 231e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isAlways() || IC2.isNever()) 232e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 233e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 234e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen outerCallsFound = true; 235e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int Cost2 = IC2.getValue(); 236e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int CurrentThreshold2 = InlineThreshold; 237e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Function *Caller2 = CS2.getCaller(); 238e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Caller2 && !Caller2->isDeclaration() && 239e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Caller2->hasFnAttr(Attribute::OptimizeForSize) && 240e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen InlineThreshold != 50) 241e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen CurrentThreshold2 = 50; 242e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 243e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen float FudgeFactor2 = getInlineFudgeFactor(CS2); 244e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 245e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 >= (int)(CurrentThreshold2 * FudgeFactor2)) 246e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen allOuterCallsWillBeInlined = false; 247e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 248bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen // See if we have this case. We subtract off the penalty 249e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // for the call instruction, which we would be deleting. 250e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 < (int)(CurrentThreshold2 * FudgeFactor2) && 251bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen Cost2 + Cost - (InlineConstants::CallPenalty + 1) >= 252bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen (int)(CurrentThreshold2 * FudgeFactor2)) { 253e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen someOuterCallWouldNotBeInlined = true; 254e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost += Cost2; 255e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 256e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 257e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If all outer calls to Caller would get inlined, the cost for the last 258e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // one is set very low by getInlineCost, in anticipation that Caller will 259e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // be removed entirely. We did not account for this above unless there 260e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // is only one caller of Caller. 261e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (allOuterCallsWillBeInlined && Caller->use_begin() != Caller->use_end()) 262bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen TotalSecondaryCost += InlineConstants::LastCallToStaticBonus; 263e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 264e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (outerCallsFound && someOuterCallWouldNotBeInlined && 265e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost < Cost) { 266c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: " << *CS.getInstruction() << 267e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen " Cost = " << Cost << 268e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen ", outer Cost = " << TotalSecondaryCost << '\n'); 269e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen return false; 270e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 271e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 272e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 273c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=" << Cost 274e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen << ", Call: " << *CS.getInstruction() << '\n'); 275135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner return true; 2761a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar} 277237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 2785095e3d1d1caef8d573534d369e37277c623064cChris Lattnerbool Inliner::runOnSCC(std::vector<CallGraphNode*> &SCC) { 279237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner CallGraph &CG = getAnalysis<CallGraph>(); 28002a436c48ecff9e34d50ce0a2f861e5acdd9bf3fDan Gohman const TargetData *TD = getAnalysisIfAvailable<TargetData>(); 281237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 28216581bf931c0ccf2f8993397acfa4e1d509a68dcDale Johannesen SmallPtrSet<Function*, 8> SCCFunctions; 283c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << "Inliner visiting SCC:"); 284237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner for (unsigned i = 0, e = SCC.size(); i != e; ++i) { 285befa499d45ffcc32bd9902518aec18589464e47cChris Lattner Function *F = SCC[i]->getFunction(); 286befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (F) SCCFunctions.insert(F); 287c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); 288237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 289237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 290befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Scan through and identify all call sites ahead of time so that we only 291befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // inline call sites in the original functions, not call sites that result 292befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // from inlining other functions. 293199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallVector<CallSite, 16> CallSites; 294befa499d45ffcc32bd9902518aec18589464e47cChris Lattner 295135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (unsigned i = 0, e = SCC.size(); i != e; ++i) { 296135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Function *F = SCC[i]->getFunction(); 297135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (!F) continue; 298135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 299135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 300135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { 301135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSite CS = CallSite::get(I); 302e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call, or it is a call to an intrinsic, it can 303d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // never be inlined. 304d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner if (CS.getInstruction() == 0 || isa<IntrinsicInst>(I)) 305135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 306135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 307d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // If this is a direct call to an external function, we can never inline 308d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // it. If it is an indirect call, inlining may resolve it to be a 309d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // direct call, so we keep it. 310d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner if (CS.getCalledFunction() && CS.getCalledFunction()->isDeclaration()) 311d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner continue; 312d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 313d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner CallSites.push_back(CS); 314135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 315135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 316237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 317c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); 318fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 319befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, move the ones to functions in the 320befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // current SCC to the end of the list. 321befa499d45ffcc32bd9902518aec18589464e47cChris Lattner unsigned FirstCallInSCC = CallSites.size(); 322befa499d45ffcc32bd9902518aec18589464e47cChris Lattner for (unsigned i = 0; i < FirstCallInSCC; ++i) 323befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (Function *F = CallSites[i].getCalledFunction()) 324befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (SCCFunctions.count(F)) 325befa499d45ffcc32bd9902518aec18589464e47cChris Lattner std::swap(CallSites[i--], CallSites[--FirstCallInSCC]); 326fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 327199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 328199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner InlinedArrayAllocasTy InlinedArrayAllocas; 329199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 330befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, loop over them and inline them if 331befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // it looks profitable to do so. 332befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool Changed = false; 333befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool LocalChange; 334befa499d45ffcc32bd9902518aec18589464e47cChris Lattner do { 335befa499d45ffcc32bd9902518aec18589464e47cChris Lattner LocalChange = false; 336befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Iterate over the outer loop because inlining functions can cause indirect 337befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // calls to become direct calls. 338135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { 339199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CallSite CS = CallSites[CSi]; 340199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 341dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner Function *Caller = CS.getCaller(); 342199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner Function *Callee = CS.getCalledFunction(); 343dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner 344dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If this call site is dead and it is to a readonly function, we should 345dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // just delete the call instead of trying to inline it, regardless of 346dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // size. This happens because IPSCCP propagates the result out of the 347dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // call and then we're left with the dead call. 3484ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner if (isInstructionTriviallyDead(CS.getInstruction())) { 349c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead call: " 350dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner << *CS.getInstruction() << "\n"); 351dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // Update the call graph by deleting the edge from Callee to Caller. 352dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CG[Caller]->removeCallEdgeFor(CS); 353dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CS.getInstruction()->eraseFromParent(); 354dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumCallsDeleted; 355dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } else { 356dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // We can only inline direct calls to non-declarations. 357dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee == 0 || Callee->isDeclaration()) continue; 358135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 359dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If the policy determines that we should inline this function, 360dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // try to do so. 361dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (!shouldInline(CS)) 362dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 363e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 364dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // Attempt to inline the function... 365dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (!InlineCallIfPossible(CS, CG, TD, InlinedArrayAllocas)) 366dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 367dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumInlined; 368dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } 369135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 370dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If we inlined or deleted the last possible call site to the function, 371dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // delete the function body now. 372dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && 373d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // TODO: Can remove if in SCC now. 374b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner !SCCFunctions.count(Callee) && 375d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 376b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // The function may be apparently dead, but if there are indirect 377b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // callgraph references to the node, we cannot delete it yet, this 378b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // could invalidate the CGSCC iterator. 379b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner CG[Callee]->getNumReferences() == 0) { 380c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead function: " 381199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner << Callee->getName() << "\n"); 382199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CallGraphNode *CalleeNode = CG[Callee]; 383199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 384199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Remove any call graph edges from the callee to its callees. 385199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CalleeNode->removeAllCalledFunctions(); 386199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 387199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner resetCachedCostInfo(Callee); 388199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 389199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Removing the node for callee from the call graph and delete it. 390199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner delete CG.removeFunctionFromModule(CalleeNode); 391199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumDeleted; 392199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 393199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 394135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any cached cost info for this caller, as inlining the 395135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // callee has increased the size of the caller (which may be the 396135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // same as the callee). 397135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner resetCachedCostInfo(Caller); 398135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 399135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove this call site from the list. If possible, use 400135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // swap/pop_back for efficiency, but do not use it if doing so would 401135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // move a call site to a function in this SCC before the 402135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 'FirstCallInSCC' barrier. 403135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (SCC.size() == 1) { 404135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner std::swap(CallSites[CSi], CallSites.back()); 405135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.pop_back(); 406135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } else { 407135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.erase(CallSites.begin()+CSi); 408237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 409135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner --CSi; 410135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 411135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Changed = true; 412135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner LocalChange = true; 413135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 414befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } while (LocalChange); 415237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 416775cbdd51a3b33dd5eb343689f65ab5cc8ac7118Chris Lattner return Changed; 417237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 418d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 41968d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// doFinalization - Remove now-dead linkonce functions at the end of 42068d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// processing to avoid breaking the SCC traversal. 42168d57e7ae80044401efd889270a12c71b3efb9abChris Lattnerbool Inliner::doFinalization(CallGraph &CG) { 422b7c6bf1e073088635951435acedff793add1cefdDevang Patel return removeDeadFunctions(CG); 423b7c6bf1e073088635951435acedff793add1cefdDevang Patel} 424b7c6bf1e073088635951435acedff793add1cefdDevang Patel 425135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// removeDeadFunctions - Remove dead functions that are not included in 426135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// DNR (Do Not Remove) list. 427b7c6bf1e073088635951435acedff793add1cefdDevang Patelbool Inliner::removeDeadFunctions(CallGraph &CG, 428135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<const Function *, 16> *DNR) { 429135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<CallGraphNode*, 16> FunctionsToRemove; 4303e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 4313e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Scan for all of the functions, looking for ones that should now be removed 4323e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // from the program. Insert the dead ones in the FunctionsToRemove set. 4333e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) { 4343e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner CallGraphNode *CGN = I->second; 435b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner if (CGN->getFunction() == 0) 436135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 437135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 438135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Function *F = CGN->getFunction(); 439135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 440135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // If the only remaining users of the function are dead constants, remove 441135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // them. 442135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner F->removeDeadConstantUsers(); 443135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 444135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (DNR && DNR->count(F)) 445135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 446b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner if (!F->hasLinkOnceLinkage() && !F->hasLocalLinkage() && 447b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner !F->hasAvailableExternallyLinkage()) 448135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 449135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (!F->use_empty()) 450135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 451135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 452135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any call graph edges from the function to its callees. 453135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CGN->removeAllCalledFunctions(); 454135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 455135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any edges from the external node to the function's call graph 456135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // node. These edges might have been made irrelegant due to 457135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // optimization of the program. 458135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); 459fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 460135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Removing the node for callee from the call graph and delete it. 461135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner FunctionsToRemove.insert(CGN); 46268d57e7ae80044401efd889270a12c71b3efb9abChris Lattner } 4633e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 4643e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Now that we know which functions to delete, do so. We didn't want to do 4653e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // this inline, because that would invalidate our CallGraph::iterator 4663e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // objects. :( 467135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 468135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Note that it doesn't matter that we are iterating over a non-stable set 469135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // here to do this, it doesn't matter which order the functions are deleted 470135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // in. 4713e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner bool Changed = false; 472135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (SmallPtrSet<CallGraphNode*, 16>::iterator I = FunctionsToRemove.begin(), 473135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner E = FunctionsToRemove.end(); I != E; ++I) { 4741f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen resetCachedCostInfo((*I)->getFunction()); 4753e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner delete CG.removeFunctionFromModule(*I); 4763e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner ++NumDeleted; 4773e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner Changed = true; 4783e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner } 4793e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 48068d57e7ae80044401efd889270a12c71b3efb9abChris Lattner return Changed; 48168d57e7ae80044401efd889270a12c71b3efb9abChris Lattner} 482