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Diffstat (limited to 'contrib/llvm/lib/MC/SubtargetFeature.cpp')
-rw-r--r-- | contrib/llvm/lib/MC/SubtargetFeature.cpp | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/SubtargetFeature.cpp b/contrib/llvm/lib/MC/SubtargetFeature.cpp new file mode 100644 index 0000000..be41579 --- /dev/null +++ b/contrib/llvm/lib/MC/SubtargetFeature.cpp @@ -0,0 +1,395 @@ +//===- 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/MC/SubtargetFeature.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/Format.h" +#include "llvm/Support/raw_ostream.h" +#include <algorithm> +#include <cassert> +#include <cctype> +#include <cstdlib> +using namespace llvm; + +//===----------------------------------------------------------------------===// +// Static Helper Functions +//===----------------------------------------------------------------------===// + +/// hasFlag - Determine if a feature has a flag; '+' or '-' +/// +static inline bool hasFlag(const StringRef 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 StringRef Feature) { + return hasFlag(Feature) ? Feature.substr(1) : Feature; +} + +/// isEnabled - Return true if enable flag; '+'. +/// +static inline bool isEnabled(const StringRef 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 StringRef Feature, + bool IsEnabled) { + assert(!Feature.empty() && "Empty string"); + if (hasFlag(Feature)) + return Feature; + std::string Prefix = IsEnabled ? "+" : "-"; + Prefix += Feature; + return Prefix; +} + +/// Split - Splits a string of comma separated items in to a vector of strings. +/// +static void Split(std::vector<std::string> &V, const StringRef S) { + if (S.empty()) + return; + + // 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 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 first 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 StringRef String, + bool IsEnabled) { + // Don't add empty features + if (!String.empty()) { + // Convert to lowercase, prepend flag and add to vector + Features.push_back(PrependFlag(String.lower(), IsEnabled)); + } +} + +/// Find KV in array using binary search. +template<typename T> const T *Find(const StringRef S, const T *A, size_t L) { + // Make the lower bound element we're looking for + T KV; + KV.Key = S.data(); + // 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 || StringRef(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. + errs() << "Available CPUs for this target:\n\n"; + for (size_t i = 0; i != CPUTableSize; i++) + errs() << format(" %-*s - %s.\n", + MaxCPULen, CPUTable[i].Key, CPUTable[i].Desc); + errs() << '\n'; + + // Print the Feature table. + errs() << "Available features for this target:\n\n"; + for (size_t i = 0; i != FeatTableSize; i++) + errs() << format(" %-*s - %s.\n", + MaxFeatLen, FeatTable[i].Key, FeatTable[i].Desc); + errs() << '\n'; + + errs() << "Use +feature to enable a feature, or -feature to disable it.\n" + "For example, llc -mcpu=mycpu -mattr=+feature1,-feature2\n"; + std::exit(1); +} + +//===----------------------------------------------------------------------===// +// SubtargetFeatures Implementation +//===----------------------------------------------------------------------===// + +SubtargetFeatures::SubtargetFeatures(const StringRef Initial) { + // Break up string into separate features + Split(Features, Initial); +} + + +std::string SubtargetFeatures::getString() const { + return Join(Features); +} + +/// SetImpliedBits - For each feature that is (transitively) implied by this +/// feature, set it. +/// +static +void SetImpliedBits(uint64_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(uint64_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); + } + } +} + +/// ToggleFeature - Toggle a feature and returns the newly updated feature +/// bits. +uint64_t +SubtargetFeatures::ToggleFeature(uint64_t Bits, const StringRef Feature, + const SubtargetFeatureKV *FeatureTable, + size_t FeatureTableSize) { + // Find feature in table. + const SubtargetFeatureKV *FeatureEntry = + Find(StripFlag(Feature), FeatureTable, FeatureTableSize); + // If there is a match + if (FeatureEntry) { + if ((Bits & FeatureEntry->Value) == FeatureEntry->Value) { + Bits &= ~FeatureEntry->Value; + + // For each feature that implies this, clear it. + ClearImpliedBits(Bits, FeatureEntry, FeatureTable, FeatureTableSize); + } else { + Bits |= FeatureEntry->Value; + + // For each feature that this implies, set it. + SetImpliedBits(Bits, FeatureEntry, FeatureTable, FeatureTableSize); + } + } else { + errs() << "'" << Feature + << "' is not a recognized feature for this target" + << " (ignoring feature)\n"; + } + + return Bits; +} + + +/// getFeatureBits - Get feature bits a CPU. +/// +uint64_t SubtargetFeatures::getFeatureBits(const StringRef CPU, + const SubtargetFeatureKV *CPUTable, + size_t CPUTableSize, + const SubtargetFeatureKV *FeatureTable, + size_t FeatureTableSize) { + if (!FeatureTableSize || !CPUTableSize) + return 0; + +#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 + uint64_t Bits = 0; // Resulting bits + + // Check if help is needed + if (CPU == "help") + Help(CPUTable, CPUTableSize, FeatureTable, FeatureTableSize); + + // Find CPU entry if CPU name is specified. + if (!CPU.empty()) { + const SubtargetFeatureKV *CPUEntry = Find(CPU, 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 { + errs() << "'" << CPU + << "' is not a recognized processor for this target" + << " (ignoring processor)\n"; + } + } + + // Iterate through each feature + for (size_t i = 0, E = Features.size(); i < E; i++) { + const StringRef 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 { + errs() << "'" << Feature + << "' is not a recognized feature for this target" + << " (ignoring feature)\n"; + } + } + + return Bits; +} + +/// Get scheduling itinerary of a CPU. +void *SubtargetFeatures::getItinerary(const StringRef CPU, + 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(CPU, Table, TableSize); + + if (Entry) { + return Entry->Value; + } else { + errs() << "'" << CPU + << "' is not a recognized processor for this target" + << " (ignoring processor)\n"; + return NULL; + } +} + +/// print - Print feature string. +/// +void SubtargetFeatures::print(raw_ostream &OS) const { + for (size_t i = 0, e = Features.size(); i != e; ++i) + OS << Features[i] << " "; + OS << "\n"; +} + +/// dump - Dump feature info. +/// +void SubtargetFeatures::dump() const { + print(dbgs()); +} + +/// getDefaultSubtargetFeatures - Return a string listing the features +/// associated with the target triple. +/// +/// FIXME: This is an inelegant way of specifying the features of a +/// subtarget. It would be better if we could encode this information +/// into the IR. See <rdar://5972456>. +/// +void SubtargetFeatures::getDefaultSubtargetFeatures(const Triple& Triple) { + if (Triple.getVendor() == Triple::Apple) { + if (Triple.getArch() == Triple::ppc) { + // powerpc-apple-* + AddFeature("altivec"); + } else if (Triple.getArch() == Triple::ppc64) { + // powerpc64-apple-* + AddFeature("64bit"); + AddFeature("altivec"); + } + } +} |