hphp/runtime/vm/jit/array-kind-profile.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #ifndef incl_HPHP_JIT_ARRAY_KIND_PROFILE_H_
  18 #define incl_HPHP_JIT_ARRAY_KIND_PROFILE_H_
  19
  20 #include "hphp/runtime/base/array-data.h"
  21
  22 namespace HPHP { namespace jit {
  23
  24 ///////////////////////////////////////////////////////////////////////////////
  25
  26 /*
  27  * Target profile for the distribution of a value's observed array kinds.
  28  *
  29  * The array kinds currently tracked are Empty, Packed, and Mixed.
  30  */
  31 struct ArrayKindProfile {
  32   static const uint32_t kNumProfiledArrayKinds = 4;
  33
  34   /*
  35    * Register an observed `kind'.
  36    */
  37   void report(ArrayData::ArrayKind kind);
  38
  39   /*
  40    * Return the fraction of the profiled arrays that had the given `kind'.
  41    */
  42   double fraction(ArrayData::ArrayKind kind) const;
  43
  44   /*
  45    * Return the total number of samples profiled so far.
  46    */
  47   uint32_t total() const {
  48     uint32_t sum = 0;
  49     for (uint32_t i = 0; i < kNumProfiledArrayKinds; ++i) {
  50       sum += m_count[i];
  51     }
  52     return sum;
  53   }
  54
  55   /*
  56    * Combine `l' and `r', summing across the kind counts.
  57    */
  58   static void reduce(ArrayKindProfile& l, const ArrayKindProfile& r) {
  59     for (uint32_t i = 0; i < kNumProfiledArrayKinds; ++i) {
  60       l.m_count[i] += r.m_count[i];
  61     }
  62   }
  63
  64   std::string toString() const;
  65
  66 private:
  67   uint32_t m_count[kNumProfiledArrayKinds];
  68 };
  69
  70 ///////////////////////////////////////////////////////////////////////////////
  71
  72 }}
  73
  74 #endif