Inliner.cpp revision fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3
1cf5933a716e7eb6bd5ff49aa62f3e76379ebaf51Chris Lattner//===- Inliner.cpp - Code common to all inliners --------------------------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// The LLVM Compiler Infrastructure 4b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell// 54ee451de366474b9c228b4e5fa573795a715216dChris Lattner// This file is distributed under the University of Illinois Open Source 64ee451de366474b9c228b4e5fa573795a715216dChris Lattner// License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8b576c94c15af9a440f69d9d03c2afead7971118cJohn Criswell//===----------------------------------------------------------------------===// 9237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner// 10befa499d45ffcc32bd9902518aec18589464e47cChris Lattner// This file implements the mechanics required to implement inlining without 11befa499d45ffcc32bd9902518aec18589464e47cChris Lattner// missing any calls and updating the call graph. The decisions of which calls 12befa499d45ffcc32bd9902518aec18589464e47cChris Lattner// are profitable to inline are implemented elsewhere. 13237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner// 14237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner//===----------------------------------------------------------------------===// 15237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 1686453c52ba02e743d29c08456e51006500041456Chris Lattner#define DEBUG_TYPE "inline" 17237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner#include "llvm/Module.h" 1847b14a4a6a455c7be169cfd312fcbe796f0ad426Misha Brukman#include "llvm/Instructions.h" 191f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen#include "llvm/IntrinsicInst.h" 20237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner#include "llvm/Analysis/CallGraph.h" 21e4aeec003f82a5263ffb168e175e6fca8b6f681dDan Gohman#include "llvm/Analysis/InlineCost.h" 22ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner#include "llvm/Target/TargetData.h" 236f7426ec2e46bb19cc9f9e75f1c355b35cf12d7dTanya Lattner#include "llvm/Transforms/IPO/InlinerPass.h" 24237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner#include "llvm/Transforms/Utils/Cloning.h" 254ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner#include "llvm/Transforms/Utils/Local.h" 264ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner#include "llvm/Support/CallSite.h" 27551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/CommandLine.h" 28551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 29ce63ffb52f249b62cdf2d250c128007b13f27e71Daniel Dunbar#include "llvm/Support/raw_ostream.h" 3012f0babca4459c253675700e1d707652d5b6ba17Chris Lattner#include "llvm/ADT/SmallPtrSet.h" 31551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 32befa499d45ffcc32bd9902518aec18589464e47cChris Lattner#include <set> 33a51bcb50b0c74adc741361824ef81dbefb715c53Chris Lattnerusing namespace llvm; 34d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 3586453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumInlined, "Number of functions inlined"); 36dbab4dc942e0c3286415908762de71a9447f9dfaChris LattnerSTATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined"); 3786453c52ba02e743d29c08456e51006500041456Chris LattnerSTATISTIC(NumDeleted, "Number of functions deleted because all callers found"); 38199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerSTATISTIC(NumMergedAllocas, "Number of allocas merged together"); 3986453c52ba02e743d29c08456e51006500041456Chris Lattner 40844731a7f1909f55935e3514c9e713a62d67662eDan Gohmanstatic cl::opt<int> 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 51ae73dc1448d25b02cabc7c64c86c64371453dda8Dan GohmanInliner::Inliner(void *ID) 52ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman : CallGraphSCCPass(ID), InlineThreshold(InlineLimit) {} 53237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 54ae73dc1448d25b02cabc7c64c86c64371453dda8Dan GohmanInliner::Inliner(void *ID, int Threshold) 55ae73dc1448d25b02cabc7c64c86c64371453dda8Dan Gohman : CallGraphSCCPass(ID), InlineThreshold(Threshold) {} 56120d053e3ba810b44047fbcb719824bed5673ca9Chris Lattner 57ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// getAnalysisUsage - For this class, we declare that we require and preserve 58ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// the call graph. If the derived class implements this method, it should 59ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner/// always explicitly call the implementation here. 60ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattnervoid Inliner::getAnalysisUsage(AnalysisUsage &Info) const { 61ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner CallGraphSCCPass::getAnalysisUsage(Info); 62ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner} 63ff2dad312883e5da91fb9f4e3619b7d095867f3bChris Lattner 64199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 65199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattnertypedef DenseMap<const ArrayType*, std::vector<AllocaInst*> > 66199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris LattnerInlinedArrayAllocasTy; 67199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 68199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// InlineCallIfPossible - If it is possible to inline the specified call site, 69199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// do so and update the CallGraph for this operation. 70199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// 71199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner/// This function also does some basic book-keeping to update the IR. The 72cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// InlinedArrayAllocas map keeps track of any allocas that are already 73cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// available from other functions inlined into the caller. If we are able to 74cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// inline this call site we attempt to reuse already available allocas or add 75cc0a0299d96676e0a51e9b8f5bf617d8025f09a7Chris Lattner/// any new allocas to the set if not possible. 7660915146f4d35e12f10dcdaa155596fac79184daChris Lattnerstatic bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, 77199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner InlinedArrayAllocasTy &InlinedArrayAllocas) { 78befa499d45ffcc32bd9902518aec18589464e47cChris Lattner Function *Callee = CS.getCalledFunction(); 7966c75aaa028683c389c55b377ee2411b61081677Bill Wendling Function *Caller = CS.getCaller(); 8066c75aaa028683c389c55b377ee2411b61081677Bill Wendling 81199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Try to inline the function. Get the list of static allocas that were 82199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // inlined. 8360915146f4d35e12f10dcdaa155596fac79184daChris Lattner if (!InlineFunction(CS, IFI)) 8412f0babca4459c253675700e1d707652d5b6ba17Chris Lattner return false; 85fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 868c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // If the inlined function had a higher stack protection level than the 878c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling // calling function, then bump up the caller's stack protection level. 888c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling if (Callee->hasFnAttr(Attribute::StackProtectReq)) 898c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtectReq); 908c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling else if (Callee->hasFnAttr(Attribute::StackProtect) && 918c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling !Caller->hasFnAttr(Attribute::StackProtectReq)) 928c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling Caller->addFnAttr(Attribute::StackProtect); 938c1604e7d617622cb391f1c679ddf70ea03baedcBill Wendling 94199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 95199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Look at all of the allocas that we inlined through this call site. If we 96199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // have already inlined other allocas through other calls into this function, 97199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // then we know that they have disjoint lifetimes and that we can merge them. 98199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 99199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // There are many heuristics possible for merging these allocas, and the 100199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // different options have different tradeoffs. One thing that we *really* 101199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // don't want to hurt is SRoA: once inlining happens, often allocas are no 102199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // longer address taken and so they can be promoted. 103199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 104199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Our "solution" for that is to only merge allocas whose outermost type is an 105199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // array type. These are usually not promoted because someone is using a 106199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // variable index into them. These are also often the most important ones to 107199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // merge. 108199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 109199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // A better solution would be to have real memory lifetime markers in the IR 110199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // and not have the inliner do any merging of allocas at all. This would 111199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allow the backend to do proper stack slot coloring of all allocas that 112199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // *actually make it to the backend*, which is really what we want. 113199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 114199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Because we don't have this information, we do this simple and useful hack. 115199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // 116199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallPtrSet<AllocaInst*, 16> UsedAllocas; 117199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 118199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over all the allocas we have so far and see if they can be merged with 119199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // a previously inlined alloca. If not, remember that we had it. 12060915146f4d35e12f10dcdaa155596fac79184daChris Lattner for (unsigned AllocaNo = 0, e = IFI.StaticAllocas.size(); 121199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaNo != e; ++AllocaNo) { 12260915146f4d35e12f10dcdaa155596fac79184daChris Lattner AllocaInst *AI = IFI.StaticAllocas[AllocaNo]; 123199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 124199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Don't bother trying to merge array allocations (they will usually be 125199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // canonicalized to be an allocation *of* an array), or allocations whose 126199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // type is not itself an array (because we're afraid of pessimizing SRoA). 127199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner const ArrayType *ATy = dyn_cast<ArrayType>(AI->getAllocatedType()); 128199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (ATy == 0 || AI->isArrayAllocation()) 129199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 130199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 131199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Get the list of all available allocas for this array type. 132199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner std::vector<AllocaInst*> &AllocasForType = InlinedArrayAllocas[ATy]; 133199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 134199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Loop over the allocas in AllocasForType to see if we can reuse one. Note 135199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // that we have to be careful not to reuse the same "available" alloca for 136199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // multiple different allocas that we just inlined, we use the 'UsedAllocas' 137199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // set to keep track of which "available" allocas are being used by this 138199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function. Also, AllocasForType can be empty of course! 139199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner bool MergedAwayAlloca = false; 140199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) { 141199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocaInst *AvailableAlloca = AllocasForType[i]; 142199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 143199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // The available alloca has to be in the right function, not in some other 144199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // function in this SCC. 145199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (AvailableAlloca->getParent() != AI->getParent()) 146199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 147199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 148199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If the inlined function already uses this alloca then we can't reuse 149199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it. 150199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (!UsedAllocas.insert(AvailableAlloca)) 151199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 152199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 153199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Otherwise, we *can* reuse it, RAUW AI into AvailableAlloca and declare 154199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // success! 155c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI); 156199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 157199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->replaceAllUsesWith(AvailableAlloca); 158199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AI->eraseFromParent(); 159199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner MergedAwayAlloca = true; 160199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumMergedAllocas; 161199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner break; 162199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 163fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 164199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we already nuked the alloca, we're done with it. 165199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner if (MergedAwayAlloca) 166199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner continue; 1671f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen 168199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // If we were unable to merge away the alloca either because there are no 169199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // allocas of the right type available or because we reused them all 170199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // already, remember that this alloca came from an inlined function and mark 171199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // it used so we don't reuse it for other allocas from this inline 172199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // operation. 173199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner AllocasForType.push_back(AI); 174199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner UsedAllocas.insert(AI); 175befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } 176199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 177befa499d45ffcc32bd9902518aec18589464e47cChris Lattner return true; 178237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 179f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 180570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesenunsigned Inliner::getInlineThreshold(CallSite CS) const { 181f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen int thres = InlineThreshold; 182570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 183570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen // Listen to optsize when -inline-limit is not given. 184570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen Function *Caller = CS.getCaller(); 185f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen if (Caller && !Caller->isDeclaration() && 186f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen Caller->hasFnAttr(Attribute::OptimizeForSize) && 187f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen InlineLimit.getNumOccurrences() == 0) 188f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = OptSizeThreshold; 189f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen 190f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen // Listen to inlinehint when it would increase the threshold. 191f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen Function *Callee = CS.getCalledFunction(); 192f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen if (HintThreshold > thres && Callee && !Callee->isDeclaration() && 193f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen Callee->hasFnAttr(Attribute::InlineHint)) 194f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen thres = HintThreshold; 195570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen 196f0907fe59093753fe5a9e8fe5adc399dbdc94627Jakob Stoklund Olesen return thres; 197f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen} 198f8526cb711ec96cd2d5aff30da57f65ae8e5b7b8Jakob Stoklund Olesen 1991a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// shouldInline - Return true if the inliner should attempt to inline 2001a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar/// at the given CallSite. 2011a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbarbool Inliner::shouldInline(CallSite CS) { 202c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar InlineCost IC = getInlineCost(CS); 2031a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar 204c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isAlways()) { 205c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=always" 20684a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 207c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return true; 208c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 209c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 210c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar if (IC.isNever()) { 211c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=never" 21284a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 213c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar return false; 214c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar } 215c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar 216c5e1ec47c719806fcc882470595960512edc7441Daniel Dunbar int Cost = IC.getValue(); 217e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen Function *Caller = CS.getCaller(); 218570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen int CurrentThreshold = getInlineThreshold(CS); 219135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner float FudgeFactor = getInlineFudgeFactor(CS); 2202ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen int AdjThreshold = (int)(CurrentThreshold * FudgeFactor); 2212ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen if (Cost >= AdjThreshold) { 222c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: cost=" << Cost 2232ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen << ", thres=" << AdjThreshold 22484a832f9272ed7f1a47c3e019c770b62e373cc6cBill Wendling << ", Call: " << *CS.getInstruction() << "\n"); 2251a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar return false; 2261a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar } 227135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 228e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // Try to detect the case where the current inlining candidate caller 229e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // (call it B) is a static function and is an inlining candidate elsewhere, 230e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // and the current candidate callee (call it C) is large enough that 231e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // inlining it into B would make B too big to inline later. In these 232e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // circumstances it may be best not to inline C into B, but to inline B 233e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // into its callers. 234e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Caller->hasLocalLinkage()) { 235e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int TotalSecondaryCost = 0; 236e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool outerCallsFound = false; 237e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool allOuterCallsWillBeInlined = true; 238e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen bool someOuterCallWouldNotBeInlined = false; 239e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen for (Value::use_iterator I = Caller->use_begin(), E =Caller->use_end(); 240e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen I != E; ++I) { 241e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen CallSite CS2 = CallSite::get(*I); 242e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 243e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call to Caller (it could be some other sort 244e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // of reference) skip it. 245e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (CS2.getInstruction() == 0 || CS2.getCalledFunction() != Caller) 246e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 247e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 248e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen InlineCost IC2 = getInlineCost(CS2); 249e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isNever()) 250e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen allOuterCallsWillBeInlined = false; 251e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (IC2.isAlways() || IC2.isNever()) 252e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen continue; 253e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 254e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen outerCallsFound = true; 255e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen int Cost2 = IC2.getValue(); 256570a4a5d9ca31f276a67502d1e0533d59d331feaJakob Stoklund Olesen int CurrentThreshold2 = getInlineThreshold(CS2); 257e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen float FudgeFactor2 = getInlineFudgeFactor(CS2); 258e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 259e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 >= (int)(CurrentThreshold2 * FudgeFactor2)) 260e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen allOuterCallsWillBeInlined = false; 261e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 262bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen // See if we have this case. We subtract off the penalty 263e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // for the call instruction, which we would be deleting. 264e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (Cost2 < (int)(CurrentThreshold2 * FudgeFactor2) && 265bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen Cost2 + Cost - (InlineConstants::CallPenalty + 1) >= 266bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen (int)(CurrentThreshold2 * FudgeFactor2)) { 267e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen someOuterCallWouldNotBeInlined = true; 268e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost += Cost2; 269e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 270e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 271e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If all outer calls to Caller would get inlined, the cost for the last 272e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // one is set very low by getInlineCost, in anticipation that Caller will 273e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // be removed entirely. We did not account for this above unless there 274e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // is only one caller of Caller. 275e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (allOuterCallsWillBeInlined && Caller->use_begin() != Caller->use_end()) 276bdb984bc2757114bc706026603ed40d7f508c4c1Dale Johannesen TotalSecondaryCost += InlineConstants::LastCallToStaticBonus; 277e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 278e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen if (outerCallsFound && someOuterCallWouldNotBeInlined && 279e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen TotalSecondaryCost < Cost) { 280c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " NOT Inlining: " << *CS.getInstruction() << 281e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen " Cost = " << Cost << 282e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen ", outer Cost = " << TotalSecondaryCost << '\n'); 283e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen return false; 284e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 285e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen } 286e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 287c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " Inlining: cost=" << Cost 2882ddbf8208e0ee50cb1aeb24d509b52549a85c211Jakob Stoklund Olesen << ", thres=" << AdjThreshold 289e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen << ", Call: " << *CS.getInstruction() << '\n'); 290135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner return true; 2911a99dbfe3b70c83d3f3e4648b5868c04697cd77cDaniel Dunbar} 292237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 2932decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattnerbool Inliner::runOnSCC(CallGraphSCC &SCC) { 294237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner CallGraph &CG = getAnalysis<CallGraph>(); 29502a436c48ecff9e34d50ce0a2f861e5acdd9bf3fDan Gohman const TargetData *TD = getAnalysisIfAvailable<TargetData>(); 296237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 29716581bf931c0ccf2f8993397acfa4e1d509a68dcDale Johannesen SmallPtrSet<Function*, 8> SCCFunctions; 298c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << "Inliner visiting SCC:"); 2992decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3002decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 301befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (F) SCCFunctions.insert(F); 302c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE")); 303237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 304237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 305befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Scan through and identify all call sites ahead of time so that we only 306befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // inline call sites in the original functions, not call sites that result 307befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // from inlining other functions. 308199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner SmallVector<CallSite, 16> CallSites; 309befa499d45ffcc32bd9902518aec18589464e47cChris Lattner 3102decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { 3112decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner Function *F = (*I)->getFunction(); 312135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (!F) continue; 313135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 314135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) 315135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) { 316135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSite CS = CallSite::get(I); 317e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen // If this isn't a call, or it is a call to an intrinsic, it can 318d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // never be inlined. 319d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner if (CS.getInstruction() == 0 || isa<IntrinsicInst>(I)) 320135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 321135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 322d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // If this is a direct call to an external function, we can never inline 323d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // it. If it is an indirect call, inlining may resolve it to be a 324d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // direct call, so we keep it. 325d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner if (CS.getCalledFunction() && CS.getCalledFunction()->isDeclaration()) 326d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner continue; 327d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 328d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner CallSites.push_back(CS); 329135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 330135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 331237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 332c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n"); 333fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 3344471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner // If there are no calls in this function, exit early. 3354471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner if (CallSites.empty()) 3364471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner return false; 3374471136e4db67f5b6cf064cb3b0a7668f15bfe6cChris Lattner 338befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, move the ones to functions in the 339befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // current SCC to the end of the list. 340befa499d45ffcc32bd9902518aec18589464e47cChris Lattner unsigned FirstCallInSCC = CallSites.size(); 341befa499d45ffcc32bd9902518aec18589464e47cChris Lattner for (unsigned i = 0; i < FirstCallInSCC; ++i) 342befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (Function *F = CallSites[i].getCalledFunction()) 343befa499d45ffcc32bd9902518aec18589464e47cChris Lattner if (SCCFunctions.count(F)) 344befa499d45ffcc32bd9902518aec18589464e47cChris Lattner std::swap(CallSites[i--], CallSites[--FirstCallInSCC]); 345fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 346199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 347199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner InlinedArrayAllocasTy InlinedArrayAllocas; 34860915146f4d35e12f10dcdaa155596fac79184daChris Lattner InlineFunctionInfo InlineInfo(&CG, TD); 349199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 350befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Now that we have all of the call sites, loop over them and inline them if 351befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // it looks profitable to do so. 352befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool Changed = false; 353befa499d45ffcc32bd9902518aec18589464e47cChris Lattner bool LocalChange; 354befa499d45ffcc32bd9902518aec18589464e47cChris Lattner do { 355befa499d45ffcc32bd9902518aec18589464e47cChris Lattner LocalChange = false; 356befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // Iterate over the outer loop because inlining functions can cause indirect 357befa499d45ffcc32bd9902518aec18589464e47cChris Lattner // calls to become direct calls. 358135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) { 359199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CallSite CS = CallSites[CSi]; 360199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 361dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner Function *Caller = CS.getCaller(); 362199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner Function *Callee = CS.getCalledFunction(); 363dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner 364dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If this call site is dead and it is to a readonly function, we should 365dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // just delete the call instead of trying to inline it, regardless of 366dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // size. This happens because IPSCCP propagates the result out of the 367dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // call and then we're left with the dead call. 3684ff4141a9ee9ce705f2a709f3372acaf58d86ea3Chris Lattner if (isInstructionTriviallyDead(CS.getInstruction())) { 369c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead call: " 370dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner << *CS.getInstruction() << "\n"); 371dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // Update the call graph by deleting the edge from Callee to Caller. 372dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CG[Caller]->removeCallEdgeFor(CS); 373dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner CS.getInstruction()->eraseFromParent(); 374dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumCallsDeleted; 375f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen // Update the cached cost info with the missing call 376f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen growCachedCostInfo(Caller, NULL); 377dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } else { 378dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // We can only inline direct calls to non-declarations. 379dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee == 0 || Callee->isDeclaration()) continue; 380135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 381dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If the policy determines that we should inline this function, 382dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // try to do so. 383dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (!shouldInline(CS)) 384dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 385e91b9a3b59688023e20cee8441179300b87c844eDale Johannesen 386fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // Attempt to inline the function. 38760915146f4d35e12f10dcdaa155596fac79184daChris Lattner if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas)) 388dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner continue; 389dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner ++NumInlined; 390f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen 391fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // If inlining this function devirtualized any call sites, throw them 392fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner // onto our worklist to process. They are useful inline candidates. 393fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner for (unsigned i = 0, e = InlineInfo.DevirtualizedCalls.size(); 394fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner i != e; ++i) 395fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner CallSites.push_back(CallSite(InlineInfo.DevirtualizedCalls[i])); 396fe9af3b1f7e5d68ecc330bdf4f047d76838f8cc3Chris Lattner 397f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen // Update the cached cost info with the inlined call. 398f7477470d37ee2ab9075eaee4745fa084d424ab8Jakob Stoklund Olesen growCachedCostInfo(Caller, Callee); 399dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner } 400135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 401dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // If we inlined or deleted the last possible call site to the function, 402dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner // delete the function body now. 403dbab4dc942e0c3286415908762de71a9447f9dfaChris Lattner if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() && 404d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner // TODO: Can remove if in SCC now. 405b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner !SCCFunctions.count(Callee) && 406d43d5e832f756c9d2c0c8ff4d2f51807a27cab8dChris Lattner 407b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // The function may be apparently dead, but if there are indirect 408b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // callgraph references to the node, we cannot delete it yet, this 409b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner // could invalidate the CGSCC iterator. 410b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner CG[Callee]->getNumReferences() == 0) { 411c0aa67950ae0f6e9611240d8f0e3ac49dc8195c0David Greene DEBUG(dbgs() << " -> Deleting dead function: " 412199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner << Callee->getName() << "\n"); 413199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CallGraphNode *CalleeNode = CG[Callee]; 414199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 415199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Remove any call graph edges from the callee to its callees. 416199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner CalleeNode->removeAllCalledFunctions(); 417199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 418199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner resetCachedCostInfo(Callee); 419199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner 420199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner // Removing the node for callee from the call graph and delete it. 421199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner delete CG.removeFunctionFromModule(CalleeNode); 422199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner ++NumDeleted; 423199ba42cbf56b2fc9c708edb4f08f97dd99ddd49Chris Lattner } 424135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 425135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove this call site from the list. If possible, use 426135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // swap/pop_back for efficiency, but do not use it if doing so would 427135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // move a call site to a function in this SCC before the 428135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 'FirstCallInSCC' barrier. 4292decb22222cac46bb1d9163e7b89d7e5be8ef65fChris Lattner if (SCC.isSingular()) { 430135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner std::swap(CallSites[CSi], CallSites.back()); 431135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.pop_back(); 432135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } else { 433135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CallSites.erase(CallSites.begin()+CSi); 434237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner } 435135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner --CSi; 436135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 437135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Changed = true; 438135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner LocalChange = true; 439135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner } 440befa499d45ffcc32bd9902518aec18589464e47cChris Lattner } while (LocalChange); 441237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner 442775cbdd51a3b33dd5eb343689f65ab5cc8ac7118Chris Lattner return Changed; 443237ef567f6764f24a47c63121cc0a599ddc8f56dChris Lattner} 444d0fde30ce850b78371fd1386338350591f9ff494Brian Gaeke 44568d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// doFinalization - Remove now-dead linkonce functions at the end of 44668d57e7ae80044401efd889270a12c71b3efb9abChris Lattner// processing to avoid breaking the SCC traversal. 44768d57e7ae80044401efd889270a12c71b3efb9abChris Lattnerbool Inliner::doFinalization(CallGraph &CG) { 448b7c6bf1e073088635951435acedff793add1cefdDevang Patel return removeDeadFunctions(CG); 449b7c6bf1e073088635951435acedff793add1cefdDevang Patel} 450b7c6bf1e073088635951435acedff793add1cefdDevang Patel 451135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// removeDeadFunctions - Remove dead functions that are not included in 452135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner/// DNR (Do Not Remove) list. 453b7c6bf1e073088635951435acedff793add1cefdDevang Patelbool Inliner::removeDeadFunctions(CallGraph &CG, 454135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<const Function *, 16> *DNR) { 455135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner SmallPtrSet<CallGraphNode*, 16> FunctionsToRemove; 4563e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 4573e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Scan for all of the functions, looking for ones that should now be removed 4583e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // from the program. Insert the dead ones in the FunctionsToRemove set. 4593e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) { 4603e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner CallGraphNode *CGN = I->second; 461b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner if (CGN->getFunction() == 0) 462135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 463135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 464135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner Function *F = CGN->getFunction(); 465135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 466135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // If the only remaining users of the function are dead constants, remove 467135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // them. 468135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner F->removeDeadConstantUsers(); 469135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 470135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (DNR && DNR->count(F)) 471135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 472b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner if (!F->hasLinkOnceLinkage() && !F->hasLocalLinkage() && 473b374b90e81d0ce6b5d02041ba4f7b15a945b38d8Chris Lattner !F->hasAvailableExternallyLinkage()) 474135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 475135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner if (!F->use_empty()) 476135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner continue; 477135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 478135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any call graph edges from the function to its callees. 479135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CGN->removeAllCalledFunctions(); 480135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner 481135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Remove any edges from the external node to the function's call graph 482135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // node. These edges might have been made irrelegant due to 483135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // optimization of the program. 484135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN); 485fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 486135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Removing the node for callee from the call graph and delete it. 487135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner FunctionsToRemove.insert(CGN); 48868d57e7ae80044401efd889270a12c71b3efb9abChris Lattner } 4893e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 4903e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // Now that we know which functions to delete, do so. We didn't want to do 4913e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // this inline, because that would invalidate our CallGraph::iterator 4923e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner // objects. :( 493135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // 494135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // Note that it doesn't matter that we are iterating over a non-stable set 495135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // here to do this, it doesn't matter which order the functions are deleted 496135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner // in. 4973e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner bool Changed = false; 498135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner for (SmallPtrSet<CallGraphNode*, 16>::iterator I = FunctionsToRemove.begin(), 499135755dae4c3fa8003b76150689d5064aa4612eeChris Lattner E = FunctionsToRemove.end(); I != E; ++I) { 5001f67ce4aa3f65619f54c8a3072539da5b0022841Dale Johannesen resetCachedCostInfo((*I)->getFunction()); 5013e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner delete CG.removeFunctionFromModule(*I); 5023e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner ++NumDeleted; 5033e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner Changed = true; 5043e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner } 5053e1358a9fa1ebd3f51c94eb69da55d693895fe7cChris Lattner 50668d57e7ae80044401efd889270a12c71b3efb9abChris Lattner return Changed; 50768d57e7ae80044401efd889270a12c71b3efb9abChris Lattner} 508