1 files changed, 397 insertions, 0 deletions
diff --git a/lib/MC/SubtargetFeature.cpp b/lib/MC/SubtargetFeature.cpp
new file mode 100644
index 000000000000..348cd4c9ab1b
--- /dev/null
+++ b/lib/MC/SubtargetFeature.cpp
@@ -0,0 +1,397 @@
+//===- 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");
+    }
+  }
+}