/** * Sorts the regions vector in a linear order to be used for * translation. The goal is to obtain an order that improves locality * when the function is executed. Each region is translated separately. */ static void sortRegions(RegionVec& regions, const Func* func, const TransCFG& cfg, const ProfData* profData, const TransIDToRegionMap& headToRegion, const RegionToTransIDsMap& regionToTransIds) { RegionVec sorted; RegionSet selected; if (regions.empty()) return; // First, pick the region starting at the lowest bytecode offset. // This will normally correspond to the main function entry (for // normal, regular bytecode), but it may not be for irregular // functions written in hhas (like array_map and array_filter). If // there multiple regions starting at the lowest bytecode offset, // pick the one with the largest profile weight. RegionDescPtr entryRegion = nullptr; int64_t maxEntryWeight = -1; Offset lowestOffset = kInvalidOffset; for (const auto& pair : regionToTransIds) { auto r = pair.first; auto& tids = pair.second; TransID firstTid = tids[0]; Offset firstOffset = profData->transSrcKey(firstTid).offset(); int64_t weight = cfg.weight(firstTid); if (lowestOffset == kInvalidOffset || firstOffset < lowestOffset || (firstOffset == lowestOffset && weight > maxEntryWeight)) { entryRegion = r; maxEntryWeight = weight; lowestOffset = firstOffset; } } assert(entryRegion); sorted.push_back(entryRegion); selected.insert(entryRegion); RegionDescPtr region = entryRegion; // Select the remaining regions, iteratively picking the most likely // region to execute next. for (auto i = 1; i < regions.size(); i++) { int64_t maxWeight = -1; int64_t maxHeadWeight = -1; RegionDescPtr bestNext = nullptr; auto regionTransIds = getRegionTransIDVec(regionToTransIds, region); for (auto next : regions) { if (selected.count(next)) continue; auto nextTransIds = getRegionTransIDVec(regionToTransIds, next); int64_t weight = interRegionWeight(regionTransIds, nextTransIds[0], cfg); int64_t headWeight = cfg.weight(nextTransIds[0]); if ((weight > maxWeight) || (weight == maxWeight && headWeight > maxHeadWeight)) { maxWeight = weight; maxHeadWeight = headWeight; bestNext = next; } } assert(bestNext); sorted.push_back(bestNext); selected.insert(bestNext); region = bestNext; } assert(sorted.size() == regions.size()); regions = sorted; if (debug && Trace::moduleEnabled(HPHP::Trace::pgo, 5)) { for (size_t i = 0; i < regions.size(); i++) { auto r = regions[i]; auto tids = getRegionTransIDVec(regionToTransIds, r); std::string transIds = folly::join(", ", tids); FTRACE(6, "sortRegions: region[{}]: {}\n", i, transIds); } } }
/** * Sorts the regions vector in a linear order to be used for * translation. The goal is to obtain an order that improves locality * when the function is executed. */ static void sortRegion(RegionVec& regions, const Func* func, const TransCFG& cfg, const ProfData* profData, const TransIDToRegionMap& headToRegion, const RegionToTransIDsMap& regionToTransIds) { RegionVec sorted; RegionSet selected; // First, pick the region for the function body entry. There may be // multiple translations of the function body, so pick the one with // largest profile weight. RegionDescPtr entryRegion = nullptr; int64_t maxEntryWeight = -1; for (const auto& pair : regionToTransIds) { auto r = pair.first; auto& tids = pair.second; for (auto tid : tids) { if (profData->transSrcKey(tid).offset() == func->base()) { int64_t weight = cfg.weight(tid); if (weight > maxEntryWeight) { entryRegion = r; maxEntryWeight = weight; } } } } assert(entryRegion); sorted.push_back(entryRegion); selected.insert(entryRegion); RegionDescPtr region = entryRegion; // Select the remaining regions, iteratively picking the most likely // region to execute next. for (auto i = 1; i < regions.size(); i++) { int64_t maxWeight = -1; int64_t maxHeadWeight = -1; RegionDescPtr bestNext = nullptr; auto regionTransIds = getRegionTransIDVec(regionToTransIds, region); for (auto next : regions) { if (setContains(selected, next)) continue; auto nextTransIds = getRegionTransIDVec(regionToTransIds, next); int64_t weight = interRegionWeight(regionTransIds, nextTransIds[0], cfg); int64_t headWeight = cfg.weight(nextTransIds[0]); if ((weight > maxWeight) || (weight == maxWeight && headWeight > maxHeadWeight)) { maxWeight = weight; maxHeadWeight = headWeight; bestNext = next; } } assert(bestNext); sorted.push_back(bestNext); selected.insert(bestNext); region = bestNext; } assert(sorted.size() == regions.size()); regions = sorted; if (debug && Trace::moduleEnabled(HPHP::Trace::pgo, 5)) { for (size_t i = 0; i < regions.size(); i++) { auto r = regions[i]; auto tids = getRegionTransIDVec(regionToTransIds, r); std::string transIds = folly::join(", ", tids); FTRACE(6, "sortRegion: region[{}]: {}\n", i, transIds); } } }