Inliner.cpp revision fa086f1f00a8b75ab2e2208bd7a028e62f9854db
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" 32a51bcb50b0c74adc741361824ef81dbefb715c53Chris Lattnerusing namespace llvm; 33d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 3486453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumInlined, "Number of functions inlined"); 3583f66fe6144c2041f1f7897f7015b0e2e68faad3Chris LattnerSTATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined"); 3686453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumDeleted, "Number of functions deleted because all callers found"); 37199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerSTATISTIC(NumMergedAllocas, "Number of allocas merged together"); 3886453c52ba02e743d29c08456e51006500041456Chris Lattner 39844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic cl::opt<int> 40f9c3b228e5579e0d2a9cd05a2191fe17b4c58b23Jakob Stoklund OlesenInlineLimit("inline-threshold", cl::Hidden, cl::init(225), cl::ZeroOrMore, 41f9c3b228e5579e0d2a9cd05a2191fe17b4c58b23Jakob Stoklund Olesen cl::desc("Control the amount of inlining to perform (default = 225)")); 42237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 43f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesenstatic cl::opt<int> 44f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund OlesenHintThreshold("inlinehint-threshold", cl::Hidden, cl::init(325), 45f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen cl::desc("Threshold for inlining functions with inline hint")); 46570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 47570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen// Threshold to use when optsize is specified (and there is no -inline-limit). 48570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesenconst int OptSizeThreshold = 75; 49570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 5090c579de5a383cee278acc3f7e7b9d0a656e6a35Owen AndersonInliner::Inliner(char &ID) 51fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier : CallGraphSCCPass(ID), InlineThreshold(InlineLimit), InsertLifetime(true) {} 52237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 53fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad RosierInliner::Inliner(char &ID, int Threshold, bool InsertLifetime) 54930f5efac0f76aa9e3772d9a36757f18b3573112Jakob Stoklund Olesen : CallGraphSCCPass(ID), InlineThreshold(InlineLimit.getNumOccurrences() > 0 ? 55fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InlineLimit : Threshold), 56fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InsertLifetime(InsertLifetime) {} 57120d053e3ba810b44047fbcb719824bed5673ca9Chris Lattner 58ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// getAnalysisUsage - For this class, we declare that we require and preserve 59ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// the call graph. If the derived class implements this method, it should 60ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// always explicitly call the implementation here. 61ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattnervoid Inliner::getAnalysisUsage(AnalysisUsage &Info) const { 62ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner CallGraphSCCPass::getAnalysisUsage(Info); 63ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner} 64ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner 65199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 66db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattnertypedef DenseMap<ArrayType*, std::vector<AllocaInst*> > 67199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerInlinedArrayAllocasTy; 68199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 69199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// InlineCallIfPossible - If it is possible to inline the specified call site, 70199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// do so and update the CallGraph for this operation. 71199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// 72199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// This function also does some basic book-keeping to update the IR. The 73cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// InlinedArrayAllocas map keeps track of any allocas that are already 74cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// available from other functions inlined into the caller. If we are able to 75cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// inline this call site we attempt to reuse already available allocas or add 76cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// any new allocas to the set if not possible. 7760915146f4d35e12f10dcdaa155596fac79184daChris Lattnerstatic bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, 786c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner InlinedArrayAllocasTy &InlinedArrayAllocas, 79fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier int InlineHistory, bool InsertLifetime) { 80befa499d45ffcc32bd9902518aec18589464e47cChris Lattner Function *Callee = CS.getCalledFunction(); 8166c75aaa028683c389c55b377ee2411b61081677Bill Wendling Function *Caller = CS.getCaller(); 8266c75aaa028683c389c55b377ee2411b61081677Bill Wendling 83199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Try to inline the function. Get the list of static allocas that were 84199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // inlined. 85fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier if (!InlineFunction(CS, IFI, InsertLifetime)) 8612f0babca4459c253675700e1d707652d5b6ba17Chris Lattner return false; 87fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 888c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // If the inlined function had a higher stack protection level than the 898c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // calling function, then bump up the caller's stack protection level. 908c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling if (Callee->hasFnAttr(Attribute::StackProtectReq)) 918c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtectReq); 928c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling else if (Callee->hasFnAttr(Attribute::StackProtect) && 938c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling !Caller->hasFnAttr(Attribute::StackProtectReq)) 948c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtect); 958c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling 96199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Look at all of the allocas that we inlined through this call site. If we 97199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // have already inlined other allocas through other calls into this function, 98199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // then we know that they have disjoint lifetimes and that we can merge them. 99199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 100199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // There are many heuristics possible for merging these allocas, and the 101199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // different options have different tradeoffs. One thing that we *really* 102199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // don't want to hurt is SRoA: once inlining happens, often allocas are no 103199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // longer address taken and so they can be promoted. 104199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 105199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Our "solution" for that is to only merge allocas whose outermost type is an 106199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // array type. These are usually not promoted because someone is using a 107199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // variable index into them. These are also often the most important ones to 108199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // merge. 109199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 110199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // A better solution would be to have real memory lifetime markers in the IR 111199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // and not have the inliner do any merging of allocas at all. This would 112199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allow the backend to do proper stack slot coloring of all allocas that 113199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // *actually make it to the backend*, which is really what we want. 114199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 115199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Because we don't have this information, we do this simple and useful hack. 116199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 117199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallPtrSet<AllocaInst*, 16> UsedAllocas; 118199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 1196c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // When processing our SCC, check to see if CS was inlined from some other 1206c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // call site. For example, if we're processing "A" in this code: 1216c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // A() { B() } 1226c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // B() { x = alloca ... C() } 1236c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // C() { y = alloca ... } 1246c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // Assume that C was not inlined into B initially, and so we're processing A 1256c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // and decide to inline B into A. Doing this makes an alloca available for 1266c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // reuse and makes a callsite (C) available for inlining. When we process 1276c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // the C call site we don't want to do any alloca merging between X and Y 1286c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // because their scopes are not disjoint. We could make this smarter by 1296c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // keeping track of the inline history for each alloca in the 1306c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // InlinedArrayAllocas but this isn't likely to be a significant win. 1316c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner if (InlineHistory != -1) // Only do merging for top-level call sites in SCC. 1326c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner return true; 1336c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner 134199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over all the allocas we have so far and see if they can be merged with 135199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // a previously inlined alloca. If not, remember that we had it. 13660915146f4d35e12f10dcdaa155596fac79184daChris Lattner for (unsigned AllocaNo = 0, e = IFI.StaticAllocas.size(); 137199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaNo != e; ++AllocaNo) { 13860915146f4d35e12f10dcdaa155596fac79184daChris Lattner AllocaInst *AI = IFI.StaticAllocas[AllocaNo]; 139199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 140199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Don't bother trying to merge array allocations (they will usually be 141199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // canonicalized to be an allocation *of* an array), or allocations whose 142199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // type is not itself an array (because we're afraid of pessimizing SRoA). 143db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType()); 144199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (ATy == 0 || AI->isArrayAllocation()) 145199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 146199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 147199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Get the list of all available allocas for this array type. 148199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner std::vector<AllocaInst*> &AllocasForType = InlinedArrayAllocas[ATy]; 149199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 150199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over the allocas in AllocasForType to see if we can reuse one. Note 151199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // that we have to be careful not to reuse the same "available" alloca for 152199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // multiple different allocas that we just inlined, we use the 'UsedAllocas' 153199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // set to keep track of which "available" allocas are being used by this 154199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function. Also, AllocasForType can be empty of course! 155199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner bool MergedAwayAlloca = false; 156199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) { 157199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaInst *AvailableAlloca = AllocasForType[i]; 158199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 159199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // The available alloca has to be in the right function, not in some other 160199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function in this SCC. 161199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (AvailableAlloca->getParent() != AI->getParent()) 162199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 163199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 164199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If the inlined function already uses this alloca then we can't reuse 165199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it. 166199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (!UsedAllocas.insert(AvailableAlloca)) 167199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 168199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 169199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Otherwise, we *can* reuse it, RAUW AI into AvailableAlloca and declare 170199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // success! 1717d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI << "\n\t\tINTO: " 1727d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner << *AvailableAlloca << '\n'); 173199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 174199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->replaceAllUsesWith(AvailableAlloca); 175199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->eraseFromParent(); 176199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner MergedAwayAlloca = true; 177199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumMergedAllocas; 1787d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner IFI.StaticAllocas[AllocaNo] = 0; 179199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner break; 180199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 181fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 182199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we already nuked the alloca, we're done with it. 183199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (MergedAwayAlloca) 184199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 1857d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner 186199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we were unable to merge away the alloca either because there are no 187199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allocas of the right type available or because we reused them all 188199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // already, remember that this alloca came from an inlined function and mark 189199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it used so we don't reuse it for other allocas from this inline 190199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // operation. 191199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocasForType.push_back(AI); 192199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner UsedAllocas.insert(AI); 193befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } 194199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 195befa499d45ffcc32bd9902518aec18589464e47cChris Lattner return true; 196237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 197f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 198570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesenunsigned Inliner::getInlineThreshold(CallSite CS) const { 199f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen int thres = InlineThreshold; 200570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 201570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen // Listen to optsize when -inline-limit is not given. 202570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen Function *Caller = CS.getCaller(); 203f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen if (Caller && !Caller->isDeclaration() && 204f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen Caller->hasFnAttr(Attribute::OptimizeForSize) && 205f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen InlineLimit.getNumOccurrences() == 0) 206f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = OptSizeThreshold; 207f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen 208f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen // Listen to inlinehint when it would increase the threshold. 209f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen Function *Callee = CS.getCalledFunction(); 210f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen if (HintThreshold > thres && Callee && !Callee->isDeclaration() && 211f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen Callee->hasFnAttr(Attribute::InlineHint)) 212f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = HintThreshold; 213570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 214f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen return thres; 215f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen} 216f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 2171a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// shouldInline - Return true if the inliner should attempt to inline 2181a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// at the given CallSite. 2191a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbarbool Inliner::shouldInline(CallSite CS) { 220c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar InlineCost IC = getInlineCost(CS); 2211a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar 222c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isAlways()) { 223c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=always" 22484a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 225c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return true; 226c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 227c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 228c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isNever()) { 229c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=never" 23084a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 231c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return false; 232c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 233c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 234c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar int Cost = IC.getValue(); 235e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Function *Caller = CS.getCaller(); 236570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen int CurrentThreshold = getInlineThreshold(CS); 237135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner float FudgeFactor = getInlineFudgeFactor(CS); 2382ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen int AdjThreshold = (int)(CurrentThreshold * FudgeFactor); 2392ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen if (Cost >= AdjThreshold) { 240c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=" << Cost 2412ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen << ", thres=" << AdjThreshold 24284a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 2431a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar return false; 2441a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar } 245135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 246e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // Try to detect the case where the current inlining candidate caller 247e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // (call it B) is a static function and is an inlining candidate elsewhere, 248e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // and the current candidate callee (call it C) is large enough that 249e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // inlining it into B would make B too big to inline later. In these 250e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // circumstances it may be best not to inline C into B, but to inline B 251e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // into its callers. 252e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Caller->hasLocalLinkage()) { 253e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int TotalSecondaryCost = 0; 254e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool outerCallsFound = false; 255c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // This bool tracks what happens if we do NOT inline C into B. 256c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen bool callerWillBeRemoved = true; 257c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // This bool tracks what happens if we DO inline C into B. 258c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen bool inliningPreventsSomeOuterInline = false; 259e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen for (Value::use_iterator I = Caller->use_begin(), E =Caller->use_end(); 260e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen I != E; ++I) { 2617d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS2(*I); 262e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 263e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call to Caller (it could be some other sort 264c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // of reference) skip it. Such references will prevent the caller 265c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // from being removed. 266c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (!CS2 || CS2.getCalledFunction() != Caller) { 267c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 268e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 269c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen } 270e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 271e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen InlineCost IC2 = getInlineCost(CS2); 272e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isNever()) 273c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 274e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isAlways() || IC2.isNever()) 275e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 276e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 277e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen outerCallsFound = true; 278e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int Cost2 = IC2.getValue(); 279570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen int CurrentThreshold2 = getInlineThreshold(CS2); 280e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen float FudgeFactor2 = getInlineFudgeFactor(CS2); 281e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 282e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 >= (int)(CurrentThreshold2 * FudgeFactor2)) 283c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 284e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 285bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen // See if we have this case. We subtract off the penalty 286e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // for the call instruction, which we would be deleting. 287e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 < (int)(CurrentThreshold2 * FudgeFactor2) && 288bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen Cost2 + Cost - (InlineConstants::CallPenalty + 1) >= 289bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen (int)(CurrentThreshold2 * FudgeFactor2)) { 290c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen inliningPreventsSomeOuterInline = true; 291e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost += Cost2; 292e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 293e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 294e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If all outer calls to Caller would get inlined, the cost for the last 295e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // one is set very low by getInlineCost, in anticipation that Caller will 296e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // be removed entirely. We did not account for this above unless there 297e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // is only one caller of Caller. 298c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (callerWillBeRemoved && Caller->use_begin() != Caller->use_end()) 299bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen TotalSecondaryCost += InlineConstants::LastCallToStaticBonus; 300e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 301c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (outerCallsFound && inliningPreventsSomeOuterInline && 302e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost < Cost) { 303c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: " << *CS.getInstruction() << 304e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen " Cost = " << Cost << 305e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen ", outer Cost = " << TotalSecondaryCost << '\n'); 306e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen return false; 307e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 308e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 309e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 310c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=" << Cost 3112ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen << ", thres=" << AdjThreshold 312e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen << ", Call: " << *CS.getInstruction() << '\n'); 313135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner return true; 3141a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar} 315237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 316159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner/// InlineHistoryIncludes - Return true if the specified inline history ID 317159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner/// indicates an inline history that includes the specified function. 318159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattnerstatic bool InlineHistoryIncludes(Function *F, int InlineHistoryID, 319159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner const SmallVectorImpl<std::pair<Function*, int> > &InlineHistory) { 320159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner while (InlineHistoryID != -1) { 321159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner assert(unsigned(InlineHistoryID) < InlineHistory.size() && 322159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner "Invalid inline history ID"); 323159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (InlineHistory[InlineHistoryID].first == F) 324159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner return true; 325159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistoryID = InlineHistory[InlineHistoryID].second; 326159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner } 327159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner return false; 328159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner} 329159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 330159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 3312decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattnerbool Inliner::runOnSCC(CallGraphSCC &SCC) { 332237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner CallGraph &CG = getAnalysis<CallGraph>(); 33302a436c48ecff9e34d50ce0a2f861e5acdd9bf3fDan Gohman const TargetData *TD = getAnalysisIfAvailable<TargetData>(); 334237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 33516581bf931c0ccf2f8993397acfa4e1d509a68dcDale Johannesen SmallPtrSet<Function*, 8> SCCFunctions; 336c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << "Inliner visiting SCC:"); 3372decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3382decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 339befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (F) SCCFunctions.insert(F); 340c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); 341237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 342237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 343befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Scan through and identify all call sites ahead of time so that we only 344befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // inline call sites in the original functions, not call sites that result 345befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // from inlining other functions. 346159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner SmallVector<std::pair<CallSite, int>, 16> CallSites; 347159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 348159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // When inlining a callee produces new call sites, we want to keep track of 349159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // the fact that they were inlined from the callee. This allows us to avoid 350159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // infinite inlining in some obscure cases. To represent this, we use an 351159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // index into the InlineHistory vector. 352159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner SmallVector<std::pair<Function*, int>, 8> InlineHistory; 353befa499d45ffcc32bd9902518aec18589464e47cChris Lattner 3542decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3552decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 356135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (!F) continue; 357135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 358135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 359135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { 3607d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS(cast<Value>(I)); 361e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call, or it is a call to an intrinsic, it can 362d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // never be inlined. 3637d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif if (!CS || isa<IntrinsicInst>(I)) 364135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 365135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 366d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // If this is a direct call to an external function, we can never inline 367d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // it. If it is an indirect call, inlining may resolve it to be a 368d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // direct call, so we keep it. 369d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner if (CS.getCalledFunction() && CS.getCalledFunction()->isDeclaration()) 370d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner continue; 371d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 372159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner CallSites.push_back(std::make_pair(CS, -1)); 373135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 374135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 375237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 376c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); 377fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 3784471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner // If there are no calls in this function, exit early. 3794471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner if (CallSites.empty()) 3804471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner return false; 3814471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner 382befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, move the ones to functions in the 383befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // current SCC to the end of the list. 384befa499d45ffcc32bd9902518aec18589464e47cChris Lattner unsigned FirstCallInSCC = CallSites.size(); 385befa499d45ffcc32bd9902518aec18589464e47cChris Lattner for (unsigned i = 0; i < FirstCallInSCC; ++i) 386159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (Function *F = CallSites[i].first.getCalledFunction()) 387befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (SCCFunctions.count(F)) 388befa499d45ffcc32bd9902518aec18589464e47cChris Lattner std::swap(CallSites[i--], CallSites[--FirstCallInSCC]); 389fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 390199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 391199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner InlinedArrayAllocasTy InlinedArrayAllocas; 39260915146f4d35e12f10dcdaa155596fac79184daChris Lattner InlineFunctionInfo InlineInfo(&CG, TD); 393199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 394befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, loop over them and inline them if 395befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // it looks profitable to do so. 396befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool Changed = false; 397befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool LocalChange; 398befa499d45ffcc32bd9902518aec18589464e47cChris Lattner do { 399befa499d45ffcc32bd9902518aec18589464e47cChris Lattner LocalChange = false; 400befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Iterate over the outer loop because inlining functions can cause indirect 401befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // calls to become direct calls. 402135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { 403159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner CallSite CS = CallSites[CSi].first; 404199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 405dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner Function *Caller = CS.getCaller(); 406199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner Function *Callee = CS.getCalledFunction(); 407dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner 408dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If this call site is dead and it is to a readonly function, we should 409dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // just delete the call instead of trying to inline it, regardless of 410dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // size. This happens because IPSCCP propagates the result out of the 411dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // call and then we're left with the dead call. 4124ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner if (isInstructionTriviallyDead(CS.getInstruction())) { 413c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead call: " 414dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner << *CS.getInstruction() << "\n"); 415dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // Update the call graph by deleting the edge from Callee to Caller. 416dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CG[Caller]->removeCallEdgeFor(CS); 417dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CS.getInstruction()->eraseFromParent(); 418dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumCallsDeleted; 419f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen // Update the cached cost info with the missing call 420f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen growCachedCostInfo(Caller, NULL); 421dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } else { 422dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // We can only inline direct calls to non-declarations. 423dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee == 0 || Callee->isDeclaration()) continue; 424135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 425f0193ed8decb2e78d8d5ec4a4eaeed8f3036bf6eEric Christopher // If this call site was obtained by inlining another function, verify 426159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // that the include path for the function did not include the callee 4277d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner // itself. If so, we'd be recursively inlining the same function, 428159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // which would provide the same callsites, which would cause us to 429159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // infinitely inline. 430159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner int InlineHistoryID = CallSites[CSi].second; 431159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (InlineHistoryID != -1 && 432159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistoryIncludes(Callee, InlineHistoryID, InlineHistory)) 433159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner continue; 434159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 435159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 436dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If the policy determines that we should inline this function, 437dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // try to do so. 438dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (!shouldInline(CS)) 439dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 440e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 441fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // Attempt to inline the function. 4426c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas, 443fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InlineHistoryID, InsertLifetime)) 444dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 445dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumInlined; 446159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 4470ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner // If inlining this function gave us any new call sites, throw them 448fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // onto our worklist to process. They are useful inline candidates. 4490ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner if (!InlineInfo.InlinedCalls.empty()) { 450159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // Create a new inline history entry for this, so that we remember 451159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // that these new callsites came about due to inlining Callee. 452159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner int NewHistoryID = InlineHistory.size(); 453159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistory.push_back(std::make_pair(Callee, InlineHistoryID)); 454159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 4550ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner for (unsigned i = 0, e = InlineInfo.InlinedCalls.size(); 456159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner i != e; ++i) { 4570ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner Value *Ptr = InlineInfo.InlinedCalls[i]; 458159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner CallSites.push_back(std::make_pair(CallSite(Ptr), NewHistoryID)); 459159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner } 460076863225ce070345ff7048f48b3550e00598a10Chris Lattner } 461fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner 462f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen // Update the cached cost info with the inlined call. 463f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen growCachedCostInfo(Caller, Callee); 464dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } 465135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 466dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If we inlined or deleted the last possible call site to the function, 467dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // delete the function body now. 468dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && 469d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // TODO: Can remove if in SCC now. 470b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner !SCCFunctions.count(Callee) && 471d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 472b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // The function may be apparently dead, but if there are indirect 473b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // callgraph references to the node, we cannot delete it yet, this 474b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // could invalidate the CGSCC iterator. 475b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner CG[Callee]->getNumReferences() == 0) { 476c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead function: " 477199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner << Callee->getName() << "\n"); 478199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CallGraphNode *CalleeNode = CG[Callee]; 479199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 480199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Remove any call graph edges from the callee to its callees. 481199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CalleeNode->removeAllCalledFunctions(); 482199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 483199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner resetCachedCostInfo(Callee); 484199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 485199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Removing the node for callee from the call graph and delete it. 486199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner delete CG.removeFunctionFromModule(CalleeNode); 487199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumDeleted; 488199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 489135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 490135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove this call site from the list. If possible, use 491135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // swap/pop_back for efficiency, but do not use it if doing so would 492135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // move a call site to a function in this SCC before the 493135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 'FirstCallInSCC' barrier. 4942decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner if (SCC.isSingular()) { 495c29df3cac735bc85d16e4ef3186cb50e41bec7bbBenjamin Kramer CallSites[CSi] = CallSites.back(); 496135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.pop_back(); 497135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } else { 498135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.erase(CallSites.begin()+CSi); 499237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 500135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner --CSi; 501135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 502135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Changed = true; 503135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner LocalChange = true; 504135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 505befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } while (LocalChange); 506237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 507775cbdd51a3b33dd5eb343689f65ab5cc8ac7118Chris Lattner return Changed; 508237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 509d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 51068d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// doFinalization - Remove now-dead linkonce functions at the end of 51168d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// processing to avoid breaking the SCC traversal. 51268d57e7ae80044401efd889270a12c71b3efb9abChris Lattnerbool Inliner::doFinalization(CallGraph &CG) { 513b7c6bf1e073088635951435acedff793add1cefdDevang Patel return removeDeadFunctions(CG); 514b7c6bf1e073088635951435acedff793add1cefdDevang Patel} 515b7c6bf1e073088635951435acedff793add1cefdDevang Patel 516135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// removeDeadFunctions - Remove dead functions that are not included in 517135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// DNR (Do Not Remove) list. 518b7c6bf1e073088635951435acedff793add1cefdDevang Patelbool Inliner::removeDeadFunctions(CallGraph &CG, 519135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<const Function *, 16> *DNR) { 520135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<CallGraphNode*, 16> FunctionsToRemove; 5213e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 5223e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Scan for all of the functions, looking for ones that should now be removed 5233e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // from the program. Insert the dead ones in the FunctionsToRemove set. 5243e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) { 5253e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner CallGraphNode *CGN = I->second; 526b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner if (CGN->getFunction() == 0) 527135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 528135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 529135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Function *F = CGN->getFunction(); 530135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 531135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // If the only remaining users of the function are dead constants, remove 532135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // them. 533135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner F->removeDeadConstantUsers(); 534135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 535135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (DNR && DNR->count(F)) 536135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 537c66330504c3f433430a28cd7f7f981e555c51bceEli Friedman if (!F->isDefTriviallyDead()) 538135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 539135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 540135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any call graph edges from the function to its callees. 541135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CGN->removeAllCalledFunctions(); 542135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 543135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any edges from the external node to the function's call graph 544135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // node. These edges might have been made irrelegant due to 545135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // optimization of the program. 546135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); 547fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 548135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Removing the node for callee from the call graph and delete it. 549135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner FunctionsToRemove.insert(CGN); 55068d57e7ae80044401efd889270a12c71b3efb9abChris Lattner } 5513e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 5523e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Now that we know which functions to delete, do so. We didn't want to do 5533e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // this inline, because that would invalidate our CallGraph::iterator 5543e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // objects. :( 555135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 556135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Note that it doesn't matter that we are iterating over a non-stable set 557135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // here to do this, it doesn't matter which order the functions are deleted 558135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // in. 5593e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner bool Changed = false; 560135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (SmallPtrSet<CallGraphNode*, 16>::iterator I = FunctionsToRemove.begin(), 561135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner E = FunctionsToRemove.end(); I != E; ++I) { 5621f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen resetCachedCostInfo((*I)->getFunction()); 5633e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner delete CG.removeFunctionFromModule(*I); 5643e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner ++NumDeleted; 5653e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner Changed = true; 5663e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner } 5673e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 56868d57e7ae80044401efd889270a12c71b3efb9abChris Lattner return Changed; 56968d57e7ae80044401efd889270a12c71b3efb9abChris Lattner} 570