lld/ELF/SyntheticSections.cpp

1653   // groups. Each relocation group starts with a header consisting of the
1656   // - the number of relocations in the relocation group
1657   // - flags for the relocation group
1659   //   for each relocation in the group.
1661   //   field for each relocation in the group.
1664   //   each relocation in the group.
1666   // Following the relocation group header are descriptions of each of the
1667   // relocations in the group. They consist of the following elements:
1684   // offset (we set this to zero because the first relocation group will
1708   // encoding, but each group will cost 7 bytes in addition to the offset from
1709   // the previous group, so it is only profitable to do this for groups of
1714     std::vector<Elf_Rela> group;
1716       group.push_back(*i++);
1719     if (group.size() < 8)
1720       ungroupedRelatives.insert(ungroupedRelatives.end(), group.begin(),
1721                                 group.end());
1723       relativeGroups.emplace_back(std::move(group));
1736   // enables us to group by r_addend as well.
1745   // Group relocations with the same r_info. Note that each group emits a group
1747   // estimate the size of a group header as the encoded size of that varies
1749   // of values encoded. Each group header contains 3 values, and each relocation
1750   // in a group encodes one less value, as compared to when it is not grouped.
1751   // Therefore, we only group relocations if there are 3 or more of them with
1755   // can usually get a smaller relocation section if we group relocations with 0
1783   // relocations. Each group is represented using two groups in the packed
1785   // group (and also encodes the first relocation), and the second encodes the
1788     // The first relocation in the group.
2040   // We want to group the local symbols by file. For that we rebuild the local
2042   // symbols, they are already naturally placed first in each group. That