Inliner.cpp revision 3574eca1b02600bac4e625297f4ecf745f4c4f32
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" 223574eca1b02600bac4e625297f4ecf745f4c4f32Micah Villmow#include "llvm/DataLayout.h" 238e0d1c03ca7fd86e6879b4e37d0d7f0e982feef6Benjamin Kramer#include "llvm/Target/TargetLibraryInfo.h" 246f7426ec2e46bb19cc9f9e75f1c355b35cf12d7dTanya Lattner#include "llvm/Transforms/IPO/InlinerPass.h" 25237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner#include "llvm/Transforms/Utils/Cloning.h" 264ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner#include "llvm/Transforms/Utils/Local.h" 274ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner#include "llvm/Support/CallSite.h" 28551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/CommandLine.h" 29551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 30ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar#include "llvm/Support/raw_ostream.h" 3112f0babca4459c253675700e1d707652d5b6ba17Chris Lattner#include "llvm/ADT/SmallPtrSet.h" 32551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 33a51bcb50b0c74adc741361824ef81dbefb715c53Chris Lattnerusing namespace llvm; 34d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 3586453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumInlined, "Number of functions inlined"); 3683f66fe6144c2041f1f7897f7015b0e2e68faad3Chris 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 40d9b0b025612992a0b724eeca8bdf10b1d7a5c355Benjamin Kramer// This weirdly named statistic tracks the number of times that, when attempting 41d6fc26217e194372cabe4ef9e2514beac511a943Chandler Carruth// to inline a function A into B, we analyze the callers of B in order to see 42d6fc26217e194372cabe4ef9e2514beac511a943Chandler Carruth// if those would be more profitable and blocked inline steps. 43d6fc26217e194372cabe4ef9e2514beac511a943Chandler CarruthSTATISTIC(NumCallerCallersAnalyzed, "Number of caller-callers analyzed"); 44d6fc26217e194372cabe4ef9e2514beac511a943Chandler Carruth 45844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic cl::opt<int> 46f9c3b228e5579e0d2a9cd05a2191fe17b4c58b23Jakob Stoklund OlesenInlineLimit("inline-threshold", cl::Hidden, cl::init(225), cl::ZeroOrMore, 47f9c3b228e5579e0d2a9cd05a2191fe17b4c58b23Jakob Stoklund Olesen cl::desc("Control the amount of inlining to perform (default = 225)")); 48237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 49f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesenstatic cl::opt<int> 50f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund OlesenHintThreshold("inlinehint-threshold", cl::Hidden, cl::init(325), 51f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen cl::desc("Threshold for inlining functions with inline hint")); 52570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 53570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen// Threshold to use when optsize is specified (and there is no -inline-limit). 54570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesenconst int OptSizeThreshold = 75; 55570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 5690c579de5a383cee278acc3f7e7b9d0a656e6a35Owen AndersonInliner::Inliner(char &ID) 57fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier : CallGraphSCCPass(ID), InlineThreshold(InlineLimit), InsertLifetime(true) {} 58237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 59fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad RosierInliner::Inliner(char &ID, int Threshold, bool InsertLifetime) 60930f5efac0f76aa9e3772d9a36757f18b3573112Jakob Stoklund Olesen : CallGraphSCCPass(ID), InlineThreshold(InlineLimit.getNumOccurrences() > 0 ? 61fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InlineLimit : Threshold), 62fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InsertLifetime(InsertLifetime) {} 63120d053e3ba810b44047fbcb719824bed5673ca9Chris Lattner 64ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// getAnalysisUsage - For this class, we declare that we require and preserve 65ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// the call graph. If the derived class implements this method, it should 66ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// always explicitly call the implementation here. 67ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattnervoid Inliner::getAnalysisUsage(AnalysisUsage &Info) const { 68ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner CallGraphSCCPass::getAnalysisUsage(Info); 69ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner} 70ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner 71199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 72db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattnertypedef DenseMap<ArrayType*, std::vector<AllocaInst*> > 73199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerInlinedArrayAllocasTy; 74199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 75199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// InlineCallIfPossible - If it is possible to inline the specified call site, 76199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// do so and update the CallGraph for this operation. 77199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// 78199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// This function also does some basic book-keeping to update the IR. The 79cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// InlinedArrayAllocas map keeps track of any allocas that are already 80cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// available from other functions inlined into the caller. If we are able to 81cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// inline this call site we attempt to reuse already available allocas or add 82cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// any new allocas to the set if not possible. 8360915146f4d35e12f10dcdaa155596fac79184daChris Lattnerstatic bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, 846c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner InlinedArrayAllocasTy &InlinedArrayAllocas, 85fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier int InlineHistory, bool InsertLifetime) { 86befa499d45ffcc32bd9902518aec18589464e47cChris Lattner Function *Callee = CS.getCalledFunction(); 8766c75aaa028683c389c55b377ee2411b61081677Bill Wendling Function *Caller = CS.getCaller(); 8866c75aaa028683c389c55b377ee2411b61081677Bill Wendling 89199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Try to inline the function. Get the list of static allocas that were 90199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // inlined. 91fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier if (!InlineFunction(CS, IFI, InsertLifetime)) 9212f0babca4459c253675700e1d707652d5b6ba17Chris Lattner return false; 93fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 948c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // If the inlined function had a higher stack protection level than the 958c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // calling function, then bump up the caller's stack protection level. 962c189061184925c6a8ecbb5a19e648b230a41c0eBill Wendling if (Callee->getFnAttributes().hasStackProtectReqAttr()) 978c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtectReq); 982c189061184925c6a8ecbb5a19e648b230a41c0eBill Wendling else if (Callee->getFnAttributes().hasStackProtectAttr() && 992c189061184925c6a8ecbb5a19e648b230a41c0eBill Wendling !Caller->getFnAttributes().hasStackProtectReqAttr()) 1008c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtect); 1018c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling 102199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Look at all of the allocas that we inlined through this call site. If we 103199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // have already inlined other allocas through other calls into this function, 104199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // then we know that they have disjoint lifetimes and that we can merge them. 105199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 106199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // There are many heuristics possible for merging these allocas, and the 107199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // different options have different tradeoffs. One thing that we *really* 108199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // don't want to hurt is SRoA: once inlining happens, often allocas are no 109199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // longer address taken and so they can be promoted. 110199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 111199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Our "solution" for that is to only merge allocas whose outermost type is an 112199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // array type. These are usually not promoted because someone is using a 113199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // variable index into them. These are also often the most important ones to 114199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // merge. 115199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 116199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // A better solution would be to have real memory lifetime markers in the IR 117199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // and not have the inliner do any merging of allocas at all. This would 118199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allow the backend to do proper stack slot coloring of all allocas that 119199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // *actually make it to the backend*, which is really what we want. 120199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 121199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Because we don't have this information, we do this simple and useful hack. 122199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 123199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallPtrSet<AllocaInst*, 16> UsedAllocas; 124199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 1256c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // When processing our SCC, check to see if CS was inlined from some other 1266c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // call site. For example, if we're processing "A" in this code: 1276c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // A() { B() } 1286c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // B() { x = alloca ... C() } 1296c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // C() { y = alloca ... } 1306c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // Assume that C was not inlined into B initially, and so we're processing A 1316c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // and decide to inline B into A. Doing this makes an alloca available for 1326c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // reuse and makes a callsite (C) available for inlining. When we process 1336c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // the C call site we don't want to do any alloca merging between X and Y 1346c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // because their scopes are not disjoint. We could make this smarter by 1356c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // keeping track of the inline history for each alloca in the 1366c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // InlinedArrayAllocas but this isn't likely to be a significant win. 1376c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner if (InlineHistory != -1) // Only do merging for top-level call sites in SCC. 1386c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner return true; 1396c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner 140199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over all the allocas we have so far and see if they can be merged with 141199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // a previously inlined alloca. If not, remember that we had it. 14260915146f4d35e12f10dcdaa155596fac79184daChris Lattner for (unsigned AllocaNo = 0, e = IFI.StaticAllocas.size(); 143199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaNo != e; ++AllocaNo) { 14460915146f4d35e12f10dcdaa155596fac79184daChris Lattner AllocaInst *AI = IFI.StaticAllocas[AllocaNo]; 145199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 146199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Don't bother trying to merge array allocations (they will usually be 147199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // canonicalized to be an allocation *of* an array), or allocations whose 148199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // type is not itself an array (because we're afraid of pessimizing SRoA). 149db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType()); 150199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (ATy == 0 || AI->isArrayAllocation()) 151199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 152199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 153199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Get the list of all available allocas for this array type. 154199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner std::vector<AllocaInst*> &AllocasForType = InlinedArrayAllocas[ATy]; 155199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 156199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over the allocas in AllocasForType to see if we can reuse one. Note 157199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // that we have to be careful not to reuse the same "available" alloca for 158199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // multiple different allocas that we just inlined, we use the 'UsedAllocas' 159199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // set to keep track of which "available" allocas are being used by this 160199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function. Also, AllocasForType can be empty of course! 161199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner bool MergedAwayAlloca = false; 162199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) { 163199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaInst *AvailableAlloca = AllocasForType[i]; 164199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 165199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // The available alloca has to be in the right function, not in some other 166199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function in this SCC. 167199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (AvailableAlloca->getParent() != AI->getParent()) 168199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 169199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 170199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If the inlined function already uses this alloca then we can't reuse 171199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it. 172199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (!UsedAllocas.insert(AvailableAlloca)) 173199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 174199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 175199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Otherwise, we *can* reuse it, RAUW AI into AvailableAlloca and declare 176199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // success! 1777d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI << "\n\t\tINTO: " 1787d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner << *AvailableAlloca << '\n'); 179199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 180199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->replaceAllUsesWith(AvailableAlloca); 181199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->eraseFromParent(); 182199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner MergedAwayAlloca = true; 183199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumMergedAllocas; 1847d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner IFI.StaticAllocas[AllocaNo] = 0; 185199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner break; 186199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 187fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 188199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we already nuked the alloca, we're done with it. 189199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (MergedAwayAlloca) 190199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 1917d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner 192199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we were unable to merge away the alloca either because there are no 193199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allocas of the right type available or because we reused them all 194199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // already, remember that this alloca came from an inlined function and mark 195199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it used so we don't reuse it for other allocas from this inline 196199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // operation. 197199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocasForType.push_back(AI); 198199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner UsedAllocas.insert(AI); 199befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } 200199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 201befa499d45ffcc32bd9902518aec18589464e47cChris Lattner return true; 202237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 203f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 204570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesenunsigned Inliner::getInlineThreshold(CallSite CS) const { 205ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund int thres = InlineThreshold; // -inline-threshold or else selected by 206ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund // overall opt level 207570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 208ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund // If -inline-threshold is not given, listen to the optsize attribute when it 209ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund // would decrease the threshold. 210570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen Function *Caller = CS.getCaller(); 211ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund bool OptSize = Caller && !Caller->isDeclaration() && 2122c189061184925c6a8ecbb5a19e648b230a41c0eBill Wendling Caller->getFnAttributes().hasOptimizeForSizeAttr(); 213aa8405811ed9ad84e5afb70dac04ebfbae519316Nadav Rotem if (!(InlineLimit.getNumOccurrences() > 0) && OptSize && 214aa8405811ed9ad84e5afb70dac04ebfbae519316Nadav Rotem OptSizeThreshold < thres) 215f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = OptSizeThreshold; 216f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen 217ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund // Listen to the inlinehint attribute when it would increase the threshold. 218f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen Function *Callee = CS.getCalledFunction(); 219ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund bool InlineHint = Callee && !Callee->isDeclaration() && 2202c189061184925c6a8ecbb5a19e648b230a41c0eBill Wendling Callee->getFnAttributes().hasInlineHintAttr(); 221ab767213fdfc219384e26b8073783cb883974dcdPatrik Hägglund if (InlineHint && HintThreshold > thres) 222f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = HintThreshold; 223570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 224f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen return thres; 225f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen} 226f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 2271a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// shouldInline - Return true if the inliner should attempt to inline 2281a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// at the given CallSite. 2291a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbarbool Inliner::shouldInline(CallSite CS) { 230c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar InlineCost IC = getInlineCost(CS); 2311a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar 232c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isAlways()) { 233c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=always" 23484a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 235c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return true; 236c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 237c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 238c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isNever()) { 239c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=never" 24084a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 241c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return false; 242c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 243c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 244e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Function *Caller = CS.getCaller(); 245f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!IC) { 246f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG(dbgs() << " NOT Inlining: cost=" << IC.getCost() 247f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth << ", thres=" << (IC.getCostDelta() + IC.getCost()) 24884a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 2491a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar return false; 2501a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar } 251135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 252b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // Try to detect the case where the current inlining candidate caller (call 253b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // it B) is a static or linkonce-ODR function and is an inlining candidate 254b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // elsewhere, and the current candidate callee (call it C) is large enough 255b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // that inlining it into B would make B too big to inline later. In these 256b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // circumstances it may be best not to inline C into B, but to inline B into 257b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // its callers. 258b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // 259b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // This only applies to static and linkonce-ODR functions because those are 260b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // expected to be available for inlining in the translation units where they 261b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // are used. Thus we will always have the opportunity to make local inlining 262b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // decisions. Importantly the linkonce-ODR linkage covers inline functions 263b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth // and templates in C++. 264f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // 265f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // FIXME: All of this logic should be sunk into getInlineCost. It relies on 266f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // the internal implementation of the inline cost metrics rather than 267f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // treating them as truly abstract units etc. 268b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth if (Caller->hasLocalLinkage() || 269b16117c368ad4e6d004ac912549b2c6ed06731a5Chandler Carruth Caller->getLinkage() == GlobalValue::LinkOnceODRLinkage) { 270e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int TotalSecondaryCost = 0; 271f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // The candidate cost to be imposed upon the current function. 272f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth int CandidateCost = IC.getCost() - (InlineConstants::CallPenalty + 1); 273c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // This bool tracks what happens if we do NOT inline C into B. 274dacffb6679ff99fec4cc9c54f4257d2913870d01Chandler Carruth bool callerWillBeRemoved = Caller->hasLocalLinkage(); 275c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // This bool tracks what happens if we DO inline C into B. 276c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen bool inliningPreventsSomeOuterInline = false; 277e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen for (Value::use_iterator I = Caller->use_begin(), E =Caller->use_end(); 278e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen I != E; ++I) { 2797d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS2(*I); 280e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 281e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call to Caller (it could be some other sort 282c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // of reference) skip it. Such references will prevent the caller 283c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // from being removed. 284c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (!CS2 || CS2.getCalledFunction() != Caller) { 285c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 286e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 287c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen } 288e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 289e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen InlineCost IC2 = getInlineCost(CS2); 290d6fc26217e194372cabe4ef9e2514beac511a943Chandler Carruth ++NumCallerCallersAnalyzed; 291f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (!IC2) { 292c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 293f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth continue; 294f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth } 295f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (IC2.isAlways()) 296e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 297e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 298f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // See if inlining or original callsite would erase the cost delta of 299f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // this callsite. We subtract off the penalty for the call instruction, 300f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth // which we would be deleting. 301f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (IC2.getCostDelta() <= CandidateCost) { 302c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen inliningPreventsSomeOuterInline = true; 303f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth TotalSecondaryCost += IC2.getCost(); 304e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 305e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 306e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If all outer calls to Caller would get inlined, the cost for the last 307e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // one is set very low by getInlineCost, in anticipation that Caller will 308e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // be removed entirely. We did not account for this above unless there 309e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // is only one caller of Caller. 310c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (callerWillBeRemoved && Caller->use_begin() != Caller->use_end()) 311bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen TotalSecondaryCost += InlineConstants::LastCallToStaticBonus; 312e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 313f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth if (inliningPreventsSomeOuterInline && TotalSecondaryCost < IC.getCost()) { 314f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG(dbgs() << " NOT Inlining: " << *CS.getInstruction() << 315f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth " Cost = " << IC.getCost() << 316e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen ", outer Cost = " << TotalSecondaryCost << '\n'); 317e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen return false; 318e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 319e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 320e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 321f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth DEBUG(dbgs() << " Inlining: cost=" << IC.getCost() 322f2286b0152f0b942e82d8e809186e5cc0d247131Chandler Carruth << ", thres=" << (IC.getCostDelta() + IC.getCost()) 323e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen << ", Call: " << *CS.getInstruction() << '\n'); 324135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner return true; 3251a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar} 326237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 327159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner/// InlineHistoryIncludes - Return true if the specified inline history ID 328159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner/// indicates an inline history that includes the specified function. 329159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattnerstatic bool InlineHistoryIncludes(Function *F, int InlineHistoryID, 330159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner const SmallVectorImpl<std::pair<Function*, int> > &InlineHistory) { 331159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner while (InlineHistoryID != -1) { 332159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner assert(unsigned(InlineHistoryID) < InlineHistory.size() && 333159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner "Invalid inline history ID"); 334159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (InlineHistory[InlineHistoryID].first == F) 335159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner return true; 336159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistoryID = InlineHistory[InlineHistoryID].second; 337159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner } 338159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner return false; 339159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner} 340159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 3412decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattnerbool Inliner::runOnSCC(CallGraphSCC &SCC) { 342237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner CallGraph &CG = getAnalysis<CallGraph>(); 3433574eca1b02600bac4e625297f4ecf745f4c4f32Micah Villmow const DataLayout *TD = getAnalysisIfAvailable<DataLayout>(); 3448e0d1c03ca7fd86e6879b4e37d0d7f0e982feef6Benjamin Kramer const TargetLibraryInfo *TLI = getAnalysisIfAvailable<TargetLibraryInfo>(); 345237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 34616581bf931c0ccf2f8993397acfa4e1d509a68dcDale Johannesen SmallPtrSet<Function*, 8> SCCFunctions; 347c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << "Inliner visiting SCC:"); 3482decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3492decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 350befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (F) SCCFunctions.insert(F); 351c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); 352237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 353237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 354befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Scan through and identify all call sites ahead of time so that we only 355befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // inline call sites in the original functions, not call sites that result 356befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // from inlining other functions. 357159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner SmallVector<std::pair<CallSite, int>, 16> CallSites; 358159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 359159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // When inlining a callee produces new call sites, we want to keep track of 360159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // the fact that they were inlined from the callee. This allows us to avoid 361159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // infinite inlining in some obscure cases. To represent this, we use an 362159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // index into the InlineHistory vector. 363159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner SmallVector<std::pair<Function*, int>, 8> InlineHistory; 364befa499d45ffcc32bd9902518aec18589464e47cChris Lattner 3652decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3662decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 367135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (!F) continue; 368135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 369135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 370135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { 3717d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS(cast<Value>(I)); 372e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call, or it is a call to an intrinsic, it can 373d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // never be inlined. 3747d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif if (!CS || isa<IntrinsicInst>(I)) 375135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 376135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 377d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // If this is a direct call to an external function, we can never inline 378d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // it. If it is an indirect call, inlining may resolve it to be a 379d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // direct call, so we keep it. 380d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner if (CS.getCalledFunction() && CS.getCalledFunction()->isDeclaration()) 381d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner continue; 382d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 383159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner CallSites.push_back(std::make_pair(CS, -1)); 384135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 385135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 386237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 387c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); 388fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 3894471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner // If there are no calls in this function, exit early. 3904471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner if (CallSites.empty()) 3914471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner return false; 3924471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner 393befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, move the ones to functions in the 394befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // current SCC to the end of the list. 395befa499d45ffcc32bd9902518aec18589464e47cChris Lattner unsigned FirstCallInSCC = CallSites.size(); 396befa499d45ffcc32bd9902518aec18589464e47cChris Lattner for (unsigned i = 0; i < FirstCallInSCC; ++i) 397159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (Function *F = CallSites[i].first.getCalledFunction()) 398befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (SCCFunctions.count(F)) 399befa499d45ffcc32bd9902518aec18589464e47cChris Lattner std::swap(CallSites[i--], CallSites[--FirstCallInSCC]); 400fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 401199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 402199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner InlinedArrayAllocasTy InlinedArrayAllocas; 40360915146f4d35e12f10dcdaa155596fac79184daChris Lattner InlineFunctionInfo InlineInfo(&CG, TD); 404199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 405befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, loop over them and inline them if 406befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // it looks profitable to do so. 407befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool Changed = false; 408befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool LocalChange; 409befa499d45ffcc32bd9902518aec18589464e47cChris Lattner do { 410befa499d45ffcc32bd9902518aec18589464e47cChris Lattner LocalChange = false; 411befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Iterate over the outer loop because inlining functions can cause indirect 412befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // calls to become direct calls. 413135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { 414159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner CallSite CS = CallSites[CSi].first; 415199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 416dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner Function *Caller = CS.getCaller(); 417199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner Function *Callee = CS.getCalledFunction(); 418dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner 419dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If this call site is dead and it is to a readonly function, we should 420dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // just delete the call instead of trying to inline it, regardless of 421dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // size. This happens because IPSCCP propagates the result out of the 422dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // call and then we're left with the dead call. 4238e0d1c03ca7fd86e6879b4e37d0d7f0e982feef6Benjamin Kramer if (isInstructionTriviallyDead(CS.getInstruction(), TLI)) { 424c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead call: " 425dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner << *CS.getInstruction() << "\n"); 426dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // Update the call graph by deleting the edge from Callee to Caller. 427dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CG[Caller]->removeCallEdgeFor(CS); 428dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CS.getInstruction()->eraseFromParent(); 429dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumCallsDeleted; 430dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } else { 431dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // We can only inline direct calls to non-declarations. 432dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee == 0 || Callee->isDeclaration()) continue; 433135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 434f0193ed8decb2e78d8d5ec4a4eaeed8f3036bf6eEric Christopher // If this call site was obtained by inlining another function, verify 435159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // that the include path for the function did not include the callee 4367d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner // itself. If so, we'd be recursively inlining the same function, 437159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // which would provide the same callsites, which would cause us to 438159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // infinitely inline. 439159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner int InlineHistoryID = CallSites[CSi].second; 440159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (InlineHistoryID != -1 && 441159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistoryIncludes(Callee, InlineHistoryID, InlineHistory)) 442159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner continue; 443159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 444159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 445dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If the policy determines that we should inline this function, 446dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // try to do so. 447dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (!shouldInline(CS)) 448dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 449e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 450fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // Attempt to inline the function. 4516c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas, 452fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InlineHistoryID, InsertLifetime)) 453dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 454dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumInlined; 455159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 4560ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner // If inlining this function gave us any new call sites, throw them 457fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // onto our worklist to process. They are useful inline candidates. 4580ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner if (!InlineInfo.InlinedCalls.empty()) { 459159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // Create a new inline history entry for this, so that we remember 460159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // that these new callsites came about due to inlining Callee. 461159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner int NewHistoryID = InlineHistory.size(); 462159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistory.push_back(std::make_pair(Callee, InlineHistoryID)); 463159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 4640ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner for (unsigned i = 0, e = InlineInfo.InlinedCalls.size(); 465159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner i != e; ++i) { 4660ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner Value *Ptr = InlineInfo.InlinedCalls[i]; 467d54f9a4c3bcdb247ea4aa311251c19242b03be63Chandler Carruth CallSites.push_back(std::make_pair(CallSite(Ptr), NewHistoryID)); 468159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner } 469076863225ce070345ff7048f48b3550e00598a10Chris Lattner } 470dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } 471135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 472dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If we inlined or deleted the last possible call site to the function, 473dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // delete the function body now. 474dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && 475d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // TODO: Can remove if in SCC now. 476b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner !SCCFunctions.count(Callee) && 477d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 478b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // The function may be apparently dead, but if there are indirect 479b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // callgraph references to the node, we cannot delete it yet, this 480b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // could invalidate the CGSCC iterator. 481b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner CG[Callee]->getNumReferences() == 0) { 482c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead function: " 483199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner << Callee->getName() << "\n"); 484199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CallGraphNode *CalleeNode = CG[Callee]; 485199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 486199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Remove any call graph edges from the callee to its callees. 487199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CalleeNode->removeAllCalledFunctions(); 488199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 489199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Removing the node for callee from the call graph and delete it. 490199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner delete CG.removeFunctionFromModule(CalleeNode); 491199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumDeleted; 492199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 493135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 494135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove this call site from the list. If possible, use 495135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // swap/pop_back for efficiency, but do not use it if doing so would 496135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // move a call site to a function in this SCC before the 497135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 'FirstCallInSCC' barrier. 4982decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner if (SCC.isSingular()) { 499c29df3cac735bc85d16e4ef3186cb50e41bec7bbBenjamin Kramer CallSites[CSi] = CallSites.back(); 500135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.pop_back(); 501135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } else { 502135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.erase(CallSites.begin()+CSi); 503237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 504135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner --CSi; 505135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 506135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Changed = true; 507135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner LocalChange = true; 508135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 509befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } while (LocalChange); 510237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 511775cbdd51a3b33dd5eb343689f65ab5cc8ac7118Chris Lattner return Changed; 512237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 513d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 51468d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// doFinalization - Remove now-dead linkonce functions at the end of 51568d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// processing to avoid breaking the SCC traversal. 51668d57e7ae80044401efd889270a12c71b3efb9abChris Lattnerbool Inliner::doFinalization(CallGraph &CG) { 517b7c6bf1e073088635951435acedff793add1cefdDevang Patel return removeDeadFunctions(CG); 518b7c6bf1e073088635951435acedff793add1cefdDevang Patel} 519b7c6bf1e073088635951435acedff793add1cefdDevang Patel 520135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// removeDeadFunctions - Remove dead functions that are not included in 521135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// DNR (Do Not Remove) list. 522f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruthbool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) { 523f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth SmallVector<CallGraphNode*, 16> FunctionsToRemove; 5243e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 5253e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Scan for all of the functions, looking for ones that should now be removed 5263e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // from the program. Insert the dead ones in the FunctionsToRemove set. 5273e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) { 5283e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner CallGraphNode *CGN = I->second; 529135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Function *F = CGN->getFunction(); 530f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth if (!F || F->isDeclaration()) 531f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth continue; 532f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth 533f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth // Handle the case when this function is called and we only want to care 534f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth // about always-inline functions. This is a bit of a hack to share code 535f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth // between here and the InlineAlways pass. 5362c189061184925c6a8ecbb5a19e648b230a41c0eBill Wendling if (AlwaysInlineOnly && !F->getFnAttributes().hasAlwaysInlineAttr()) 537f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth continue; 538f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth 539135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // If the only remaining users of the function are dead constants, remove 540135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // them. 541135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner F->removeDeadConstantUsers(); 542135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 543c66330504c3f433430a28cd7f7f981e555c51bceEli Friedman if (!F->isDefTriviallyDead()) 544135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 545135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 546135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any call graph edges from the function to its callees. 547135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CGN->removeAllCalledFunctions(); 548135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 549135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any edges from the external node to the function's call graph 550135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // node. These edges might have been made irrelegant due to 551135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // optimization of the program. 552135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); 553fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 554135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Removing the node for callee from the call graph and delete it. 555f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth FunctionsToRemove.push_back(CGN); 55668d57e7ae80044401efd889270a12c71b3efb9abChris Lattner } 557f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth if (FunctionsToRemove.empty()) 558f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth return false; 5593e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 5603e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Now that we know which functions to delete, do so. We didn't want to do 5613e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // this inline, because that would invalidate our CallGraph::iterator 5623e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // objects. :( 563135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 564f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth // Note that it doesn't matter that we are iterating over a non-stable order 565135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // here to do this, it doesn't matter which order the functions are deleted 566135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // in. 567dafe48e230916ce0de4228d81dece732159994f1Chandler Carruth array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end()); 568f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth FunctionsToRemove.erase(std::unique(FunctionsToRemove.begin(), 569f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth FunctionsToRemove.end()), 570f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth FunctionsToRemove.end()); 571f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth for (SmallVectorImpl<CallGraphNode *>::iterator I = FunctionsToRemove.begin(), 572f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth E = FunctionsToRemove.end(); 573f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth I != E; ++I) { 5743e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner delete CG.removeFunctionFromModule(*I); 5753e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner ++NumDeleted; 5763e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner } 577f91f5af802bd4487c49ee17cd0d3e46c6456263eChandler Carruth return true; 57868d57e7ae80044401efd889270a12c71b3efb9abChris Lattner} 579