1 //===- BranchIslandFactory.cpp --------------------------------------------===// 2 // 3 // The MCLinker Project 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 #include "mcld/LD/BranchIslandFactory.h" 10 11 #include "mcld/Fragment/Fragment.h" 12 #include "mcld/LD/LDSection.h" 13 #include "mcld/LD/SectionData.h" 14 #include "mcld/Module.h" 15 16 namespace mcld { 17 18 //===----------------------------------------------------------------------===// 19 // BranchIslandFactory 20 //===----------------------------------------------------------------------===// 21 22 /// ctor 23 /// @param pMaxFwdBranchRange - the max forward branch range of the target 24 /// @param pMaxBwdBranchRange - the max backward branch range of the target 25 /// @param pMaxIslandSize - the predefined value for the max size of a island 26 BranchIslandFactory::BranchIslandFactory(int64_t pMaxFwdBranchRange, 27 int64_t pMaxBwdBranchRange, 28 size_t pMaxIslandSize) 29 : GCFactory<BranchIsland, 0>(1u), // magic number 30 m_MaxFwdBranchRange(pMaxFwdBranchRange - pMaxIslandSize), 31 m_MaxBwdBranchRange(pMaxBwdBranchRange + pMaxIslandSize), 32 m_MaxIslandSize(pMaxIslandSize) { 33 } 34 35 BranchIslandFactory::~BranchIslandFactory() { 36 } 37 38 /// group - group fragments and create islands when needed 39 /// @param pSectionData - the SectionData holds fragments need to be grouped 40 void BranchIslandFactory::group(Module& pModule) { 41 for (Module::iterator sect = pModule.begin(), sectEnd = pModule.end(); 42 sect != sectEnd; ++sect) { 43 if (((*sect)->kind() == LDFileFormat::TEXT) && (*sect)->hasSectionData()) { 44 SectionData& sd = *((*sect)->getSectionData()); 45 uint64_t group_end = m_MaxFwdBranchRange; 46 for (SectionData::iterator it = sd.begin(), ie = sd.end(); it != ie; 47 ++it) { 48 if ((*it).getOffset() + (*it).size() > group_end) { 49 Fragment* frag = (*it).getPrevNode(); 50 while (frag != NULL && frag->getKind() == Fragment::Alignment) { 51 frag = frag->getPrevNode(); 52 } 53 if (frag != NULL) { 54 produce(*frag); 55 group_end = (*it).getOffset() + m_MaxFwdBranchRange; 56 } 57 } 58 } 59 if (getIslands(sd.back()).first == NULL) 60 produce(sd.back()); 61 } 62 } 63 } 64 65 /// produce - produce a island for the given fragment 66 /// @param pFragment - the fragment needs a branch island 67 BranchIsland* BranchIslandFactory::produce(Fragment& pFragment) { 68 BranchIsland* island = allocate(); 69 new (island) BranchIsland(pFragment, // entry fragment to the island 70 m_MaxIslandSize, // the max size of the island 71 size() - 1u); // index in the island factory 72 return island; 73 } 74 75 /// getIsland - find fwd and bwd islands for the fragment 76 /// @param pFragment - the fragment needs a branch island 77 std::pair<BranchIsland*, BranchIsland*> BranchIslandFactory::getIslands( 78 const Fragment& pFragment) { 79 BranchIsland* fwd = NULL; 80 BranchIsland* bwd = NULL; 81 for (iterator it = begin(), ie = end(), prev = ie; it != ie; 82 prev = it, ++it) { 83 if (pFragment.getParent() != (*it).getParent()) { 84 continue; 85 } 86 87 if ((pFragment.getOffset() < (*it).offset()) && 88 ((pFragment.getOffset() + m_MaxFwdBranchRange) >= (*it).offset())) { 89 fwd = &*it; 90 91 if ((prev != ie) && (pFragment.getParent() == (*prev).getParent())) { 92 int64_t bwd_off = (int64_t)pFragment.getOffset() + m_MaxBwdBranchRange; 93 if ((pFragment.getOffset() > (*prev).offset()) && 94 (bwd_off <= (int64_t)(*prev).offset())) { 95 bwd = &*prev; 96 } 97 } 98 break; 99 } 100 } 101 return std::make_pair(fwd, bwd); 102 } 103 104 } // namespace mcld 105
