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-rw-r--r--contrib/llvm/lib/MC/SubtargetFeature.cpp397
1 files changed, 397 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/SubtargetFeature.cpp b/contrib/llvm/lib/MC/SubtargetFeature.cpp
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+//===- 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/raw_ostream.h"
+#include "llvm/ADT/StringExtras.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(LowercaseString(String), 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() << " " << CPUTable[i].Key
+ << std::string(MaxCPULen - std::strlen(CPUTable[i].Key), ' ')
+ << " - " << CPUTable[i].Desc << ".\n";
+ errs() << "\n";
+
+ // Print the Feature table.
+ errs() << "Available features for this target:\n\n";
+ for (size_t i = 0; i != FeatTableSize; i++)
+ errs() << " " << FeatTable[i].Key
+ << std::string(MaxFeatLen - std::strlen(FeatTable[i].Key), ' ')
+ << " - " << FeatTable[i].Desc << ".\n";
+ 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");
+ }
+ }
+}
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