1 files changed, 55 insertions, 45 deletions

diff --git a/include/llvm/MC/SubtargetFeature.h b/include/llvm/MC/SubtargetFeature.h
index 76c7dd560800..fc9565ceafad 100644
--- a/include/llvm/MC/SubtargetFeature.h
+++ b/include/llvm/MC/SubtargetFeature.h
@@ -1,9 +1,8 @@
 //===- llvm/MC/SubtargetFeature.h - CPU characteristics ---------*- C++ -*-===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -19,6 +18,7 @@
 #define LLVM_MC_SUBTARGETFEATURE_H
 
 #include "llvm/ADT/StringRef.h"
+#include <array>
 #include <bitset>
 #include <initializer_list>
 #include <string>
@@ -26,11 +26,12 @@
 
 namespace llvm {
 
-template <typename T> class ArrayRef;
 class raw_ostream;
 class Triple;
 
-const unsigned MAX_SUBTARGET_FEATURES = 192;
+const unsigned MAX_SUBTARGET_WORDS = 3;
+const unsigned MAX_SUBTARGET_FEATURES = MAX_SUBTARGET_WORDS * 64;
+
 /// Container class for subtarget features.
 /// This is convenient because std::bitset does not have a constructor
 /// with an initializer list of set bits.
@@ -45,38 +46,34 @@ public:
     for (auto I : Init)
       set(I);
   }
-};
-
-//===----------------------------------------------------------------------===//
-
-/// Used to provide key value pairs for feature and CPU bit flags.
-struct SubtargetFeatureKV {
-  const char *Key;                      ///< K-V key string
-  const char *Desc;                     ///< Help descriptor
-  FeatureBitset Value;                  ///< K-V integer value
-  FeatureBitset Implies;                ///< K-V bit mask
 
-  /// Compare routine for std::lower_bound
-  bool operator<(StringRef S) const {
-    return StringRef(Key) < S;
-  }
-
-  /// Compare routine for std::is_sorted.
-  bool operator<(const SubtargetFeatureKV &Other) const {
-    return StringRef(Key) < StringRef(Other.Key);
+  bool operator < (const FeatureBitset &Other) const {
+    for (unsigned I = 0, E = size(); I != E; ++I) {
+      bool LHS = test(I), RHS = Other.test(I);
+      if (LHS != RHS)
+        return LHS < RHS;
+    }
+    return false;
   }
 };
 
-//===----------------------------------------------------------------------===//
+/// Class used to store the subtarget bits in the tables created by tablegen.
+/// The std::initializer_list constructor of FeatureBitset can't be done at
+/// compile time and requires a static constructor to run at startup.
+class FeatureBitArray {
+  std::array<uint64_t, MAX_SUBTARGET_WORDS> Bits;
+
+public:
+  constexpr FeatureBitArray(const std::array<uint64_t, MAX_SUBTARGET_WORDS> &B)
+      : Bits(B) {}
 
-/// Used to provide key value pairs for CPU and arbitrary pointers.
-struct SubtargetInfoKV {
-  const char *Key;                      ///< K-V key string
-  const void *Value;                    ///< K-V pointer value
+  FeatureBitset getAsBitset() const {
+    FeatureBitset Result;
 
-  /// Compare routine for std::lower_bound
-  bool operator<(StringRef S) const {
-    return StringRef(Key) < S;
+    for (unsigned i = 0, e = Bits.size(); i != e; ++i)
+      Result |= FeatureBitset(Bits[i]) << (64 * i);
+
+    return Result;
   }
 };
 
@@ -102,19 +99,6 @@ public:
   /// Adds Features.
   void AddFeature(StringRef String, bool Enable = true);
 
-  /// Toggles a feature and update the feature bits.
-  static void ToggleFeature(FeatureBitset &Bits, StringRef String,
-                            ArrayRef<SubtargetFeatureKV> FeatureTable);
-
-  /// Applies the feature flag and update the feature bits.
-  static void ApplyFeatureFlag(FeatureBitset &Bits, StringRef Feature,
-                               ArrayRef<SubtargetFeatureKV> FeatureTable);
-
-  /// Returns feature bits of a CPU.
-  FeatureBitset getFeatureBits(StringRef CPU,
-                               ArrayRef<SubtargetFeatureKV> CPUTable,
-                               ArrayRef<SubtargetFeatureKV> FeatureTable);
-
   /// Returns the vector of individual subtarget features.
   const std::vector<std::string> &getFeatures() const { return Features; }
 
@@ -126,6 +110,32 @@ public:
 
   /// Adds the default features for the specified target triple.
   void getDefaultSubtargetFeatures(const Triple& Triple);
+
+  /// Determine if a feature has a flag; '+' or '-'
+  static bool hasFlag(StringRef Feature) {
+    assert(!Feature.empty() && "Empty string");
+    // Get first character
+    char Ch = Feature[0];
+    // Check if first character is '+' or '-' flag
+    return Ch == '+' || Ch =='-';
+  }
+
+  /// Return string stripped of flag.
+  static std::string StripFlag(StringRef Feature) {
+    return hasFlag(Feature) ? Feature.substr(1) : Feature;
+  }
+
+  /// Return true if enable flag; '+'.
+  static inline bool isEnabled(StringRef Feature) {
+    assert(!Feature.empty() && "Empty string");
+    // Get first character
+    char Ch = Feature[0];
+    // Check if first character is '+' for enabled
+    return Ch == '+';
+  }
+
+  /// Splits a string of comma separated items in to a vector of strings.
+  static void Split(std::vector<std::string> &V, StringRef S);
 };
 
 } // end namespace llvm