AAL: feature flags

src/aal/aal.h

@@ -11,6 +11,19 @@
 
 namespace snmalloc
 {
+  /**
+   * Flags in a bitfield of attributes of this architecture, much like
+   * PalFeatures.
+   */
+  enum AalFeatures : uint64_t
+  {
+    /**
+     * This architecture does not discriminate between integers and pointers,
+     * and so may use bit operations on pointer values.
+     */
+    IntegerPointers = (1 << 0),
+  };
+
   /**
    * Architecture Abstraction Layer. Includes default implementations of some
    * functions using compiler builtins.  Falls back to the definitions in the
@@ -64,6 +77,9 @@ namespace snmalloc
 namespace snmalloc
 {
   using Aal = AAL_Generic<AAL_Arch>;
+
+  template<AalFeatures F, typename AAL = Aal>
+  constexpr static bool aal_supports = (AAL::aal_features & F) == F;
 } // namespace snmalloc
 
 #if defined(_MSC_VER) && defined(SNMALLOC_VA_BITS_32)

src/aal/aal_x86.h

@@ -55,6 +55,11 @@ namespace snmalloc
     }
 
   public:
+    /**
+     * Bitmap of AalFeature flags
+     */
+    static constexpr uint64_t aal_features = IntegerPointers;
+
     /**
      * On pipelined processors, notify the core that we are in a spin loop and
      * that speculative execution past this point may not be a performance gain.