|  | //===- 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()); | 
|  | } |