Inliner.cpp revision 6c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdf
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" 226c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth#include "llvm/Analysis/InstructionSimplify.h" 23ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner#include "llvm/Target/TargetData.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 40844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic cl::opt<int> 41f9c3b228e5579e0d2a9cd05a2191fe17b4c58b23Jakob Stoklund OlesenInlineLimit("inline-threshold", cl::Hidden, cl::init(225), cl::ZeroOrMore, 42f9c3b228e5579e0d2a9cd05a2191fe17b4c58b23Jakob Stoklund Olesen cl::desc("Control the amount of inlining to perform (default = 225)")); 43237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 44f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesenstatic cl::opt<int> 45f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund OlesenHintThreshold("inlinehint-threshold", cl::Hidden, cl::init(325), 46f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen cl::desc("Threshold for inlining functions with inline hint")); 47570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 48570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen// Threshold to use when optsize is specified (and there is no -inline-limit). 49570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesenconst int OptSizeThreshold = 75; 50570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 5190c579de5a383cee278acc3f7e7b9d0a656e6a35Owen AndersonInliner::Inliner(char &ID) 52fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier : CallGraphSCCPass(ID), InlineThreshold(InlineLimit), InsertLifetime(true) {} 53237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 54fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad RosierInliner::Inliner(char &ID, int Threshold, bool InsertLifetime) 55930f5efac0f76aa9e3772d9a36757f18b3573112Jakob Stoklund Olesen : CallGraphSCCPass(ID), InlineThreshold(InlineLimit.getNumOccurrences() > 0 ? 56fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InlineLimit : Threshold), 57fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InsertLifetime(InsertLifetime) {} 58120d053e3ba810b44047fbcb719824bed5673ca9Chris Lattner 59ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// getAnalysisUsage - For this class, we declare that we require and preserve 60ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// the call graph. If the derived class implements this method, it should 61ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// always explicitly call the implementation here. 62ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattnervoid Inliner::getAnalysisUsage(AnalysisUsage &Info) const { 63ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner CallGraphSCCPass::getAnalysisUsage(Info); 64ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner} 65ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner 66199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 67db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattnertypedef DenseMap<ArrayType*, std::vector<AllocaInst*> > 68199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerInlinedArrayAllocasTy; 69199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 70199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// InlineCallIfPossible - If it is possible to inline the specified call site, 71199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// do so and update the CallGraph for this operation. 72199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// 73199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// This function also does some basic book-keeping to update the IR. The 74cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// InlinedArrayAllocas map keeps track of any allocas that are already 75cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// available from other functions inlined into the caller. If we are able to 76cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// inline this call site we attempt to reuse already available allocas or add 77cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// any new allocas to the set if not possible. 7860915146f4d35e12f10dcdaa155596fac79184daChris Lattnerstatic bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, 796c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner InlinedArrayAllocasTy &InlinedArrayAllocas, 80fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier int InlineHistory, bool InsertLifetime) { 81befa499d45ffcc32bd9902518aec18589464e47cChris Lattner Function *Callee = CS.getCalledFunction(); 8266c75aaa028683c389c55b377ee2411b61081677Bill Wendling Function *Caller = CS.getCaller(); 8366c75aaa028683c389c55b377ee2411b61081677Bill Wendling 84199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Try to inline the function. Get the list of static allocas that were 85199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // inlined. 86fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier if (!InlineFunction(CS, IFI, InsertLifetime)) 8712f0babca4459c253675700e1d707652d5b6ba17Chris Lattner return false; 88fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 898c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // If the inlined function had a higher stack protection level than the 908c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // calling function, then bump up the caller's stack protection level. 918c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling if (Callee->hasFnAttr(Attribute::StackProtectReq)) 928c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtectReq); 938c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling else if (Callee->hasFnAttr(Attribute::StackProtect) && 948c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling !Caller->hasFnAttr(Attribute::StackProtectReq)) 958c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtect); 968c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling 97199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Look at all of the allocas that we inlined through this call site. If we 98199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // have already inlined other allocas through other calls into this function, 99199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // then we know that they have disjoint lifetimes and that we can merge them. 100199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 101199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // There are many heuristics possible for merging these allocas, and the 102199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // different options have different tradeoffs. One thing that we *really* 103199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // don't want to hurt is SRoA: once inlining happens, often allocas are no 104199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // longer address taken and so they can be promoted. 105199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 106199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Our "solution" for that is to only merge allocas whose outermost type is an 107199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // array type. These are usually not promoted because someone is using a 108199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // variable index into them. These are also often the most important ones to 109199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // merge. 110199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 111199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // A better solution would be to have real memory lifetime markers in the IR 112199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // and not have the inliner do any merging of allocas at all. This would 113199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allow the backend to do proper stack slot coloring of all allocas that 114199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // *actually make it to the backend*, which is really what we want. 115199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 116199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Because we don't have this information, we do this simple and useful hack. 117199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 118199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallPtrSet<AllocaInst*, 16> UsedAllocas; 119199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 1206c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // When processing our SCC, check to see if CS was inlined from some other 1216c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // call site. For example, if we're processing "A" in this code: 1226c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // A() { B() } 1236c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // B() { x = alloca ... C() } 1246c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // C() { y = alloca ... } 1256c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // Assume that C was not inlined into B initially, and so we're processing A 1266c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // and decide to inline B into A. Doing this makes an alloca available for 1276c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // reuse and makes a callsite (C) available for inlining. When we process 1286c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // the C call site we don't want to do any alloca merging between X and Y 1296c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // because their scopes are not disjoint. We could make this smarter by 1306c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // keeping track of the inline history for each alloca in the 1316c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner // InlinedArrayAllocas but this isn't likely to be a significant win. 1326c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner if (InlineHistory != -1) // Only do merging for top-level call sites in SCC. 1336c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner return true; 1346c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner 135199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over all the allocas we have so far and see if they can be merged with 136199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // a previously inlined alloca. If not, remember that we had it. 13760915146f4d35e12f10dcdaa155596fac79184daChris Lattner for (unsigned AllocaNo = 0, e = IFI.StaticAllocas.size(); 138199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaNo != e; ++AllocaNo) { 13960915146f4d35e12f10dcdaa155596fac79184daChris Lattner AllocaInst *AI = IFI.StaticAllocas[AllocaNo]; 140199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 141199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Don't bother trying to merge array allocations (they will usually be 142199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // canonicalized to be an allocation *of* an array), or allocations whose 143199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // type is not itself an array (because we're afraid of pessimizing SRoA). 144db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType()); 145199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (ATy == 0 || AI->isArrayAllocation()) 146199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 147199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 148199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Get the list of all available allocas for this array type. 149199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner std::vector<AllocaInst*> &AllocasForType = InlinedArrayAllocas[ATy]; 150199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 151199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over the allocas in AllocasForType to see if we can reuse one. Note 152199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // that we have to be careful not to reuse the same "available" alloca for 153199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // multiple different allocas that we just inlined, we use the 'UsedAllocas' 154199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // set to keep track of which "available" allocas are being used by this 155199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function. Also, AllocasForType can be empty of course! 156199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner bool MergedAwayAlloca = false; 157199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) { 158199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaInst *AvailableAlloca = AllocasForType[i]; 159199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 160199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // The available alloca has to be in the right function, not in some other 161199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function in this SCC. 162199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (AvailableAlloca->getParent() != AI->getParent()) 163199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 164199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 165199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If the inlined function already uses this alloca then we can't reuse 166199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it. 167199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (!UsedAllocas.insert(AvailableAlloca)) 168199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 169199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 170199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Otherwise, we *can* reuse it, RAUW AI into AvailableAlloca and declare 171199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // success! 1727d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI << "\n\t\tINTO: " 1737d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner << *AvailableAlloca << '\n'); 174199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 175199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->replaceAllUsesWith(AvailableAlloca); 176199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->eraseFromParent(); 177199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner MergedAwayAlloca = true; 178199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumMergedAllocas; 1797d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner IFI.StaticAllocas[AllocaNo] = 0; 180199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner break; 181199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 182fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 183199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we already nuked the alloca, we're done with it. 184199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (MergedAwayAlloca) 185199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 1867d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner 187199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we were unable to merge away the alloca either because there are no 188199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allocas of the right type available or because we reused them all 189199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // already, remember that this alloca came from an inlined function and mark 190199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it used so we don't reuse it for other allocas from this inline 191199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // operation. 192199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocasForType.push_back(AI); 193199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner UsedAllocas.insert(AI); 194befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } 195199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 196befa499d45ffcc32bd9902518aec18589464e47cChris Lattner return true; 197237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 198f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 199570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesenunsigned Inliner::getInlineThreshold(CallSite CS) const { 200f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen int thres = InlineThreshold; 201570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 202570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen // Listen to optsize when -inline-limit is not given. 203570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen Function *Caller = CS.getCaller(); 204f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen if (Caller && !Caller->isDeclaration() && 205f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen Caller->hasFnAttr(Attribute::OptimizeForSize) && 206f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen InlineLimit.getNumOccurrences() == 0) 207f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = OptSizeThreshold; 208f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen 209f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen // Listen to inlinehint when it would increase the threshold. 210f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen Function *Callee = CS.getCalledFunction(); 211f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen if (HintThreshold > thres && Callee && !Callee->isDeclaration() && 212f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen Callee->hasFnAttr(Attribute::InlineHint)) 213f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = HintThreshold; 214570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 215f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen return thres; 216f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen} 217f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 2181a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// shouldInline - Return true if the inliner should attempt to inline 2191a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// at the given CallSite. 2201a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbarbool Inliner::shouldInline(CallSite CS) { 221c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar InlineCost IC = getInlineCost(CS); 2221a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar 223c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isAlways()) { 224c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=always" 22584a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 226c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return true; 227c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 228c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 229c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isNever()) { 230c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=never" 23184a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 232c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return false; 233c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 234c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 235c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar int Cost = IC.getValue(); 236e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Function *Caller = CS.getCaller(); 237570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen int CurrentThreshold = getInlineThreshold(CS); 238135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner float FudgeFactor = getInlineFudgeFactor(CS); 2392ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen int AdjThreshold = (int)(CurrentThreshold * FudgeFactor); 2402ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen if (Cost >= AdjThreshold) { 241c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=" << Cost 2422ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen << ", thres=" << AdjThreshold 24384a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 2441a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar return false; 2451a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar } 246135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 247e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // Try to detect the case where the current inlining candidate caller 248e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // (call it B) is a static function and is an inlining candidate elsewhere, 249e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // and the current candidate callee (call it C) is large enough that 250e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // inlining it into B would make B too big to inline later. In these 251e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // circumstances it may be best not to inline C into B, but to inline B 252e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // into its callers. 253e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Caller->hasLocalLinkage()) { 254e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int TotalSecondaryCost = 0; 255e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool outerCallsFound = false; 256c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // This bool tracks what happens if we do NOT inline C into B. 257c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen bool callerWillBeRemoved = true; 258c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // This bool tracks what happens if we DO inline C into B. 259c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen bool inliningPreventsSomeOuterInline = false; 260e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen for (Value::use_iterator I = Caller->use_begin(), E =Caller->use_end(); 261e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen I != E; ++I) { 2627d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS2(*I); 263e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 264e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call to Caller (it could be some other sort 265c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // of reference) skip it. Such references will prevent the caller 266c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen // from being removed. 267c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (!CS2 || CS2.getCalledFunction() != Caller) { 268c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 269e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 270c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen } 271e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 272e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen InlineCost IC2 = getInlineCost(CS2); 273e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isNever()) 274c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 275e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isAlways() || IC2.isNever()) 276e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 277e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 278e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen outerCallsFound = true; 279e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int Cost2 = IC2.getValue(); 280570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen int CurrentThreshold2 = getInlineThreshold(CS2); 281e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen float FudgeFactor2 = getInlineFudgeFactor(CS2); 282e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 283e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 >= (int)(CurrentThreshold2 * FudgeFactor2)) 284c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen callerWillBeRemoved = false; 285e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 286bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen // See if we have this case. We subtract off the penalty 287e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // for the call instruction, which we would be deleting. 288e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 < (int)(CurrentThreshold2 * FudgeFactor2) && 289bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen Cost2 + Cost - (InlineConstants::CallPenalty + 1) >= 290bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen (int)(CurrentThreshold2 * FudgeFactor2)) { 291c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen inliningPreventsSomeOuterInline = true; 292e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost += Cost2; 293e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 294e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 295e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If all outer calls to Caller would get inlined, the cost for the last 296e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // one is set very low by getInlineCost, in anticipation that Caller will 297e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // be removed entirely. We did not account for this above unless there 298e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // is only one caller of Caller. 299c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (callerWillBeRemoved && Caller->use_begin() != Caller->use_end()) 300bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen TotalSecondaryCost += InlineConstants::LastCallToStaticBonus; 301e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 302c84e3c0c03a0dab7aea7047e7b8e38051542f7e4Dale Johannesen if (outerCallsFound && inliningPreventsSomeOuterInline && 303e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost < Cost) { 304c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: " << *CS.getInstruction() << 305e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen " Cost = " << Cost << 306e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen ", outer Cost = " << TotalSecondaryCost << '\n'); 307e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen return false; 308e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 309e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 310e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 311c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=" << Cost 3122ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen << ", thres=" << AdjThreshold 313e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen << ", Call: " << *CS.getInstruction() << '\n'); 314135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner return true; 3151a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar} 316237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 317159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner/// InlineHistoryIncludes - Return true if the specified inline history ID 318159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner/// indicates an inline history that includes the specified function. 319159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattnerstatic bool InlineHistoryIncludes(Function *F, int InlineHistoryID, 320159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner const SmallVectorImpl<std::pair<Function*, int> > &InlineHistory) { 321159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner while (InlineHistoryID != -1) { 322159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner assert(unsigned(InlineHistoryID) < InlineHistory.size() && 323159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner "Invalid inline history ID"); 324159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (InlineHistory[InlineHistoryID].first == F) 325159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner return true; 326159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistoryID = InlineHistory[InlineHistoryID].second; 327159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner } 328159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner return false; 329159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner} 330159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 3316c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// \brief Simplify arguments going into a particular callsite. 3326c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// 3336c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// This is important to do each time we add a callsite due to inlining so that 3346c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// constants and other entities which feed into inline cost estimation are 3356c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// properly recognized when analyzing the new callsite. Consider: 3366c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// void outer(int x) { 3376c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// if (x < 42) 3386c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// return inner(42 - x); 3396c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// ... 3406c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// } 3416c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// void inner(int x) { 3426c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// ... 3436c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// } 3446c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// 3456c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// The inliner gives calls to 'outer' with a constant argument a bonus because 3466c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// it will delete one side of a branch. But the resulting call to 'inner' 3476c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// will, after inlining, also have a constant operand. We need to do just 3486c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// enough constant folding to expose this for callsite arguments. The rest 3496c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth/// will be taken care of after the inliner finishes running. 3506c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruthstatic void simplifyCallSiteArguments(const TargetData *TD, CallSite CS) { 3516c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth // FIXME: It would be nice to avoid this smallvector if RAUW doesn't 3526c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth // invalidate operand iterators in any cases. 3536c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth SmallVector<std::pair<Value *, Value*>, 4> SimplifiedArgs; 3546c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); 3556c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth I != E; ++I) 3566c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth if (Instruction *Inst = dyn_cast<Instruction>(*I)) 3576c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth if (Value *SimpleArg = SimplifyInstruction(Inst, TD)) 3586c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth SimplifiedArgs.push_back(std::make_pair(Inst, SimpleArg)); 3596c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth for (unsigned Idx = 0, Size = SimplifiedArgs.size(); Idx != Size; ++Idx) 3606c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth SimplifiedArgs[Idx].first->replaceAllUsesWith(SimplifiedArgs[Idx].second); 3616c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth} 362159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 3632decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattnerbool Inliner::runOnSCC(CallGraphSCC &SCC) { 364237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner CallGraph &CG = getAnalysis<CallGraph>(); 36502a436c48ecff9e34d50ce0a2f861e5acdd9bf3fDan Gohman const TargetData *TD = getAnalysisIfAvailable<TargetData>(); 366237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 36716581bf931c0ccf2f8993397acfa4e1d509a68dcDale Johannesen SmallPtrSet<Function*, 8> SCCFunctions; 368c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << "Inliner visiting SCC:"); 3692decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3702decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 371befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (F) SCCFunctions.insert(F); 372c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); 373237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 374237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 375befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Scan through and identify all call sites ahead of time so that we only 376befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // inline call sites in the original functions, not call sites that result 377befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // from inlining other functions. 378159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner SmallVector<std::pair<CallSite, int>, 16> CallSites; 379159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 380159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // When inlining a callee produces new call sites, we want to keep track of 381159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // the fact that they were inlined from the callee. This allows us to avoid 382159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // infinite inlining in some obscure cases. To represent this, we use an 383159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // index into the InlineHistory vector. 384159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner SmallVector<std::pair<Function*, int>, 8> InlineHistory; 385befa499d45ffcc32bd9902518aec18589464e47cChris Lattner 3862decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3872decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 388135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (!F) continue; 389135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 390135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 391135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { 3927d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif CallSite CS(cast<Value>(I)); 393e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call, or it is a call to an intrinsic, it can 394d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // never be inlined. 3957d3056b16038a6a09c452c0dfcc3c8f4e421506aGabor Greif if (!CS || isa<IntrinsicInst>(I)) 396135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 397135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 398d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // If this is a direct call to an external function, we can never inline 399d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // it. If it is an indirect call, inlining may resolve it to be a 400d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // direct call, so we keep it. 401d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner if (CS.getCalledFunction() && CS.getCalledFunction()->isDeclaration()) 402d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner continue; 403d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 404159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner CallSites.push_back(std::make_pair(CS, -1)); 405135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 406135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 407237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 408c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); 409fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 4104471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner // If there are no calls in this function, exit early. 4114471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner if (CallSites.empty()) 4124471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner return false; 4134471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner 414befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, move the ones to functions in the 415befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // current SCC to the end of the list. 416befa499d45ffcc32bd9902518aec18589464e47cChris Lattner unsigned FirstCallInSCC = CallSites.size(); 417befa499d45ffcc32bd9902518aec18589464e47cChris Lattner for (unsigned i = 0; i < FirstCallInSCC; ++i) 418159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (Function *F = CallSites[i].first.getCalledFunction()) 419befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (SCCFunctions.count(F)) 420befa499d45ffcc32bd9902518aec18589464e47cChris Lattner std::swap(CallSites[i--], CallSites[--FirstCallInSCC]); 421fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 422199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 423199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner InlinedArrayAllocasTy InlinedArrayAllocas; 42460915146f4d35e12f10dcdaa155596fac79184daChris Lattner InlineFunctionInfo InlineInfo(&CG, TD); 425199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 426befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, loop over them and inline them if 427befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // it looks profitable to do so. 428befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool Changed = false; 429befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool LocalChange; 430befa499d45ffcc32bd9902518aec18589464e47cChris Lattner do { 431befa499d45ffcc32bd9902518aec18589464e47cChris Lattner LocalChange = false; 432befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Iterate over the outer loop because inlining functions can cause indirect 433befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // calls to become direct calls. 434135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { 435159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner CallSite CS = CallSites[CSi].first; 436199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 437dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner Function *Caller = CS.getCaller(); 438199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner Function *Callee = CS.getCalledFunction(); 439dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner 440dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If this call site is dead and it is to a readonly function, we should 441dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // just delete the call instead of trying to inline it, regardless of 442dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // size. This happens because IPSCCP propagates the result out of the 443dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // call and then we're left with the dead call. 4444ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner if (isInstructionTriviallyDead(CS.getInstruction())) { 445c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead call: " 446dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner << *CS.getInstruction() << "\n"); 447dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // Update the call graph by deleting the edge from Callee to Caller. 448dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CG[Caller]->removeCallEdgeFor(CS); 449dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CS.getInstruction()->eraseFromParent(); 450dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumCallsDeleted; 451f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen // Update the cached cost info with the missing call 452f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen growCachedCostInfo(Caller, NULL); 453dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } else { 454dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // We can only inline direct calls to non-declarations. 455dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee == 0 || Callee->isDeclaration()) continue; 456135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 457f0193ed8decb2e78d8d5ec4a4eaeed8f3036bf6eEric Christopher // If this call site was obtained by inlining another function, verify 458159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // that the include path for the function did not include the callee 4597d32b8032d7ec2472b994aab2ac3459e8d47c496Chris Lattner // itself. If so, we'd be recursively inlining the same function, 460159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // which would provide the same callsites, which would cause us to 461159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // infinitely inline. 462159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner int InlineHistoryID = CallSites[CSi].second; 463159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner if (InlineHistoryID != -1 && 464159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistoryIncludes(Callee, InlineHistoryID, InlineHistory)) 465159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner continue; 466159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 467159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 468dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If the policy determines that we should inline this function, 469dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // try to do so. 470dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (!shouldInline(CS)) 471dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 472e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 473fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // Attempt to inline the function. 4746c3ee0f3c9684e588c8852d90c891d6354175c9eChris Lattner if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas, 475fa086f1f00a8b75ab2e2208bd7a028e62f9854dbChad Rosier InlineHistoryID, InsertLifetime)) 476dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 477dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumInlined; 478159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 4790ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner // If inlining this function gave us any new call sites, throw them 480fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // onto our worklist to process. They are useful inline candidates. 4810ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner if (!InlineInfo.InlinedCalls.empty()) { 482159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // Create a new inline history entry for this, so that we remember 483159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner // that these new callsites came about due to inlining Callee. 484159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner int NewHistoryID = InlineHistory.size(); 485159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner InlineHistory.push_back(std::make_pair(Callee, InlineHistoryID)); 486159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner 4870ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner for (unsigned i = 0, e = InlineInfo.InlinedCalls.size(); 488159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner i != e; ++i) { 4890ca2f28458ae9122f413a4092ddcee33a9dd21c6Chris Lattner Value *Ptr = InlineInfo.InlinedCalls[i]; 4906c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth CallSite NewCS = Ptr; 4916c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth simplifyCallSiteArguments(TD, NewCS); 4926c0b3ac8ea51d35bbd2565f17f1a73c3bfcb5cdfChandler Carruth CallSites.push_back(std::make_pair(NewCS, NewHistoryID)); 493159528702aed7222cb30c3e8b55287e4ca8068cfChris Lattner } 494076863225ce070345ff7048f48b3550e00598a10Chris Lattner } 495fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner 496f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen // Update the cached cost info with the inlined call. 497f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen growCachedCostInfo(Caller, Callee); 498dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } 499135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 500dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If we inlined or deleted the last possible call site to the function, 501dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // delete the function body now. 502dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && 503d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // TODO: Can remove if in SCC now. 504b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner !SCCFunctions.count(Callee) && 505d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 506b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // The function may be apparently dead, but if there are indirect 507b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // callgraph references to the node, we cannot delete it yet, this 508b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // could invalidate the CGSCC iterator. 509b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner CG[Callee]->getNumReferences() == 0) { 510c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead function: " 511199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner << Callee->getName() << "\n"); 512199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CallGraphNode *CalleeNode = CG[Callee]; 513199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 514199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Remove any call graph edges from the callee to its callees. 515199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CalleeNode->removeAllCalledFunctions(); 516199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 517199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner resetCachedCostInfo(Callee); 518199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 519199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Removing the node for callee from the call graph and delete it. 520199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner delete CG.removeFunctionFromModule(CalleeNode); 521199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumDeleted; 522199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 523135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 524135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove this call site from the list. If possible, use 525135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // swap/pop_back for efficiency, but do not use it if doing so would 526135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // move a call site to a function in this SCC before the 527135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 'FirstCallInSCC' barrier. 5282decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner if (SCC.isSingular()) { 529c29df3cac735bc85d16e4ef3186cb50e41bec7bbBenjamin Kramer CallSites[CSi] = CallSites.back(); 530135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.pop_back(); 531135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } else { 532135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.erase(CallSites.begin()+CSi); 533237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 534135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner --CSi; 535135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 536135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Changed = true; 537135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner LocalChange = true; 538135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 539befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } while (LocalChange); 540237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 541775cbdd51a3b33dd5eb343689f65ab5cc8ac7118Chris Lattner return Changed; 542237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 543d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 54468d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// doFinalization - Remove now-dead linkonce functions at the end of 54568d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// processing to avoid breaking the SCC traversal. 54668d57e7ae80044401efd889270a12c71b3efb9abChris Lattnerbool Inliner::doFinalization(CallGraph &CG) { 547b7c6bf1e073088635951435acedff793add1cefdDevang Patel return removeDeadFunctions(CG); 548b7c6bf1e073088635951435acedff793add1cefdDevang Patel} 549b7c6bf1e073088635951435acedff793add1cefdDevang Patel 550135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// removeDeadFunctions - Remove dead functions that are not included in 551135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// DNR (Do Not Remove) list. 552b7c6bf1e073088635951435acedff793add1cefdDevang Patelbool Inliner::removeDeadFunctions(CallGraph &CG, 553135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<const Function *, 16> *DNR) { 554135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<CallGraphNode*, 16> FunctionsToRemove; 5553e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 5563e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Scan for all of the functions, looking for ones that should now be removed 5573e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // from the program. Insert the dead ones in the FunctionsToRemove set. 5583e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) { 5593e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner CallGraphNode *CGN = I->second; 560b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner if (CGN->getFunction() == 0) 561135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 562135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 563135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Function *F = CGN->getFunction(); 564135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 565135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // If the only remaining users of the function are dead constants, remove 566135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // them. 567135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner F->removeDeadConstantUsers(); 568135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 569135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (DNR && DNR->count(F)) 570135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 571c66330504c3f433430a28cd7f7f981e555c51bceEli Friedman if (!F->isDefTriviallyDead()) 572135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 573135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 574135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any call graph edges from the function to its callees. 575135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CGN->removeAllCalledFunctions(); 576135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 577135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any edges from the external node to the function's call graph 578135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // node. These edges might have been made irrelegant due to 579135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // optimization of the program. 580135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); 581fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 582135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Removing the node for callee from the call graph and delete it. 583135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner FunctionsToRemove.insert(CGN); 58468d57e7ae80044401efd889270a12c71b3efb9abChris Lattner } 5853e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 5863e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Now that we know which functions to delete, do so. We didn't want to do 5873e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // this inline, because that would invalidate our CallGraph::iterator 5883e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // objects. :( 589135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 590135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Note that it doesn't matter that we are iterating over a non-stable set 591135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // here to do this, it doesn't matter which order the functions are deleted 592135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // in. 5933e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner bool Changed = false; 594135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (SmallPtrSet<CallGraphNode*, 16>::iterator I = FunctionsToRemove.begin(), 595135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner E = FunctionsToRemove.end(); I != E; ++I) { 5961f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen resetCachedCostInfo((*I)->getFunction()); 5973e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner delete CG.removeFunctionFromModule(*I); 5983e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner ++NumDeleted; 5993e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner Changed = true; 6003e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner } 6013e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 60268d57e7ae80044401efd889270a12c71b3efb9abChris Lattner return Changed; 60368d57e7ae80044401efd889270a12c71b3efb9abChris Lattner} 604