//===- SubtargetFeature.cpp - CPU characteristics Implementation ----------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements the SubtargetFeature interface. // //===----------------------------------------------------------------------===// #include "llvm/Target/SubtargetFeature.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Support/Streams.h" #include <algorithm> #include <ostream> #include <cassert> #include <cctype> using namespace llvm; //===----------------------------------------------------------------------===// // Static Helper Functions //===----------------------------------------------------------------------===// /// hasFlag - Determine if a feature has a flag; '+' or '-' /// static inline bool hasFlag(const std::string &Feature) { assert(!Feature.empty() && "Empty string"); // Get first character char Ch = Feature[0]; // Check if first character is '+' or '-' flag return Ch == '+' || Ch =='-'; } /// StripFlag - Return string stripped of flag. /// static inline std::string StripFlag(const std::string &Feature) { return hasFlag(Feature) ? Feature.substr(1) : Feature; } /// isEnabled - Return true if enable flag; '+'. /// static inline bool isEnabled(const std::string &Feature) { assert(!Feature.empty() && "Empty string"); // Get first character char Ch = Feature[0]; // Check if first character is '+' for enabled return Ch == '+'; } /// PrependFlag - Return a string with a prepended flag; '+' or '-'. /// static inline std::string PrependFlag(const std::string &Feature, bool IsEnabled) { assert(!Feature.empty() && "Empty string"); if (hasFlag(Feature)) return Feature; return std::string(IsEnabled ? "+" : "-") + Feature; } /// Split - Splits a string of comma separated items in to a vector of strings. /// static void Split(std::vector<std::string> &V, const std::string &S) { // Start at beginning of string. size_t Pos = 0; while (true) { // Find the next comma size_t Comma = S.find(',', Pos); // If no comma found then the the rest of the string is used if (Comma == std::string::npos) { // Add string to vector V.push_back(S.substr(Pos)); break; } // Otherwise add substring to vector V.push_back(S.substr(Pos, Comma - Pos)); // Advance to next item Pos = Comma + 1; } } /// Join a vector of strings to a string with a comma separating each element. /// static std::string Join(const std::vector<std::string> &V) { // Start with empty string. std::string Result; // If the vector is not empty if (!V.empty()) { // Start with the CPU feature Result = V[0]; // For each successive feature for (size_t i = 1; i < V.size(); i++) { // Add a comma Result += ","; // Add the feature Result += V[i]; } } // Return the features string return Result; } /// Adding features. void SubtargetFeatures::AddFeature(const std::string &String, bool IsEnabled) { // Don't add empty features if (!String.empty()) { // Convert to lowercase, prepend flag and add to vector Features.push_back(PrependFlag(LowercaseString(String), IsEnabled)); } } /// Find KV in array using binary search. template<typename T> const T *Find(const std::string &S, const T *A, size_t L) { // Make the lower bound element we're looking for T KV; KV.Key = S.c_str(); // Determine the end of the array const T *Hi = A + L; // Binary search the array const T *F = std::lower_bound(A, Hi, KV); // If not found then return NULL if (F == Hi || std::string(F->Key) != S) return NULL; // Return the found array item return F; } /// getLongestEntryLength - Return the length of the longest entry in the table. /// static size_t getLongestEntryLength(const SubtargetFeatureKV *Table, size_t Size) { size_t MaxLen = 0; for (size_t i = 0; i < Size; i++) MaxLen = std::max(MaxLen, std::strlen(Table[i].Key)); return MaxLen; } /// Display help for feature choices. /// static void Help(const SubtargetFeatureKV *CPUTable, size_t CPUTableSize, const SubtargetFeatureKV *FeatTable, size_t FeatTableSize) { // Determine the length of the longest CPU and Feature entries. unsigned MaxCPULen = getLongestEntryLength(CPUTable, CPUTableSize); unsigned MaxFeatLen = getLongestEntryLength(FeatTable, FeatTableSize); // Print the CPU table. cerr << "Available CPUs for this target:\n\n"; for (size_t i = 0; i != CPUTableSize; i++) cerr << " " << CPUTable[i].Key << std::string(MaxCPULen - std::strlen(CPUTable[i].Key), ' ') << " - " << CPUTable[i].Desc << ".\n"; cerr << "\n"; // Print the Feature table. cerr << "Available features for this target:\n\n"; for (size_t i = 0; i != FeatTableSize; i++) cerr << " " << FeatTable[i].Key << std::string(MaxFeatLen - std::strlen(FeatTable[i].Key), ' ') << " - " << FeatTable[i].Desc << ".\n"; cerr << "\n"; cerr << "Use +feature to enable a feature, or -feature to disable it.\n" << "For example, llc -mcpu=mycpu -mattr=+feature1,-feature2\n"; exit(1); } //===----------------------------------------------------------------------===// // SubtargetFeatures Implementation //===----------------------------------------------------------------------===// SubtargetFeatures::SubtargetFeatures(const std::string &Initial) { // Break up string into separate features Split(Features, Initial); } std::string SubtargetFeatures::getString() const { return Join(Features); } void SubtargetFeatures::setString(const std::string &Initial) { // Throw out old features Features.clear(); // Break up string into separate features Split(Features, LowercaseString(Initial)); } /// setCPU - Set the CPU string. Replaces previous setting. Setting to "" /// clears CPU. void SubtargetFeatures::setCPU(const std::string &String) { Features[0] = LowercaseString(String); } /// setCPUIfNone - Setting CPU string only if no string is set. /// void SubtargetFeatures::setCPUIfNone(const std::string &String) { if (Features[0].empty()) setCPU(String); } /// SetImpliedBits - For each feature that is (transitively) implied by this /// feature, set it. /// static void SetImpliedBits(uint32_t &Bits, const SubtargetFeatureKV *FeatureEntry, const SubtargetFeatureKV *FeatureTable, size_t FeatureTableSize) { for (size_t i = 0; i < FeatureTableSize; ++i) { const SubtargetFeatureKV &FE = FeatureTable[i]; if (FeatureEntry->Value == FE.Value) continue; if (FeatureEntry->Implies & FE.Value) { Bits |= FE.Value; SetImpliedBits(Bits, &FE, FeatureTable, FeatureTableSize); } } } /// ClearImpliedBits - For each feature that (transitively) implies this /// feature, clear it. /// static void ClearImpliedBits(uint32_t &Bits, const SubtargetFeatureKV *FeatureEntry, const SubtargetFeatureKV *FeatureTable, size_t FeatureTableSize) { for (size_t i = 0; i < FeatureTableSize; ++i) { const SubtargetFeatureKV &FE = FeatureTable[i]; if (FeatureEntry->Value == FE.Value) continue; if (FE.Implies & FeatureEntry->Value) { Bits &= ~FE.Value; ClearImpliedBits(Bits, &FE, FeatureTable, FeatureTableSize); } } } /// getBits - Get feature bits. /// uint32_t SubtargetFeatures::getBits(const SubtargetFeatureKV *CPUTable, size_t CPUTableSize, const SubtargetFeatureKV *FeatureTable, size_t FeatureTableSize) { assert(CPUTable && "missing CPU table"); assert(FeatureTable && "missing features table"); #ifndef NDEBUG for (size_t i = 1; i < CPUTableSize; i++) { assert(strcmp(CPUTable[i - 1].Key, CPUTable[i].Key) < 0 && "CPU table is not sorted"); } for (size_t i = 1; i < FeatureTableSize; i++) { assert(strcmp(FeatureTable[i - 1].Key, FeatureTable[i].Key) < 0 && "CPU features table is not sorted"); } #endif uint32_t Bits = 0; // Resulting bits // Check if help is needed if (Features[0] == "help") Help(CPUTable, CPUTableSize, FeatureTable, FeatureTableSize); // Find CPU entry const SubtargetFeatureKV *CPUEntry = Find(Features[0], CPUTable, CPUTableSize); // If there is a match if (CPUEntry) { // Set base feature bits Bits = CPUEntry->Value; // Set the feature implied by this CPU feature, if any. for (size_t i = 0; i < FeatureTableSize; ++i) { const SubtargetFeatureKV &FE = FeatureTable[i]; if (CPUEntry->Value & FE.Value) SetImpliedBits(Bits, &FE, FeatureTable, FeatureTableSize); } } else { cerr << "'" << Features[0] << "' is not a recognized processor for this target" << " (ignoring processor)" << "\n"; } // Iterate through each feature for (size_t i = 1; i < Features.size(); i++) { const std::string &Feature = Features[i]; // Check for help if (Feature == "+help") Help(CPUTable, CPUTableSize, FeatureTable, FeatureTableSize); // Find feature in table. const SubtargetFeatureKV *FeatureEntry = Find(StripFlag(Feature), FeatureTable, FeatureTableSize); // If there is a match if (FeatureEntry) { // Enable/disable feature in bits if (isEnabled(Feature)) { Bits |= FeatureEntry->Value; // For each feature that this implies, set it. SetImpliedBits(Bits, FeatureEntry, FeatureTable, FeatureTableSize); } else { Bits &= ~FeatureEntry->Value; // For each feature that implies this, clear it. ClearImpliedBits(Bits, FeatureEntry, FeatureTable, FeatureTableSize); } } else { cerr << "'" << Feature << "' is not a recognized feature for this target" << " (ignoring feature)" << "\n"; } } return Bits; } /// Get info pointer void *SubtargetFeatures::getInfo(const SubtargetInfoKV *Table, size_t TableSize) { assert(Table && "missing table"); #ifndef NDEBUG for (size_t i = 1; i < TableSize; i++) { assert(strcmp(Table[i - 1].Key, Table[i].Key) < 0 && "Table is not sorted"); } #endif // Find entry const SubtargetInfoKV *Entry = Find(Features[0], Table, TableSize); if (Entry) { return Entry->Value; } else { cerr << "'" << Features[0] << "' is not a recognized processor for this target" << " (ignoring processor)" << "\n"; return NULL; } } /// print - Print feature string. /// void SubtargetFeatures::print(std::ostream &OS) const { for (size_t i = 0; i < Features.size(); i++) { OS << Features[i] << " "; } OS << "\n"; } /// dump - Dump feature info. /// void SubtargetFeatures::dump() const { print(*cerr.stream()); }