hphp/runtime/vm/jit/vasm-text.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_VASM_TEXT_H_
  18 #define incl_HPHP_JIT_VASM_TEXT_H_
  19
  20 #include "hphp/runtime/vm/jit/types.h"
  21 #include "hphp/runtime/vm/jit/containers.h"
  22
  23 #include "hphp/util/data-block.h"
  24
  25 namespace HPHP { namespace jit {
  26
  27 ///////////////////////////////////////////////////////////////////////////////
  28
  29 /*
  30  * An area into which code is emitted.
  31  *
  32  * This is a light wrapper around CodeBlock, which additionally saves the
  33  * original `start' address to measure the size of code emitted.
  34  *
  35  * All Vareas are instantiated by gen-time, so `start' (or `code.base()`) can
  36  * be used to detect aliased CodeBlocks when we emit.
  37  */
  38 struct Varea {
  39   /* implicit */ Varea(CodeBlock& cb)
  40     : code(cb)
  41     , start(cb.frontier())
  42   {}
  43
  44   bool operator==(const Varea& area) const { return start == area.start; }
  45   bool operator!=(const Varea& area) const { return start != area.start; }
  46
  47   CodeBlock& code;
  48   CodeAddress start;
  49 };
  50
  51 ///////////////////////////////////////////////////////////////////////////////
  52
  53 /*
  54  * Represents all the code areas to emit to.
  55  *
  56  * Vtext is a lightweight container for Vareas.
  57  */
  58 struct Vtext {
  59   explicit Vtext(CodeBlock& main, DataBlock& data)
  60     : m_areas{main}
  61     , m_data(data)
  62   {}
  63   Vtext(CodeBlock& main, CodeBlock& cold, DataBlock& data)
  64     : m_areas{main, cold}
  65     , m_data(data)
  66   {}
  67   Vtext(CodeBlock& main, CodeBlock& cold, CodeBlock& frozen, DataBlock& data)
  68     : m_areas{main, cold, frozen}
  69     , m_data(data)
  70   {
  71     // Main and frozen aren't allowed to alias each other unless cold is /also/
  72     // the same code region.
  73     assertx(this->main() != this->frozen() ||
  74             this->main() == this->cold());
  75   }
  76
  77   /*
  78    * Get an existing area.
  79    */
  80   const Varea& area(AreaIndex i) const;
  81         Varea& area(AreaIndex i);
  82   Varea& main() { return area(AreaIndex::Main); }
  83   Varea& cold() { return area(AreaIndex::Cold); }
  84   Varea& frozen() { return area(AreaIndex::Frozen); }
  85
  86   DataBlock& data() { return m_data; }
  87
  88   /*
  89    * The vector of areas.
  90    */
  91   const jit::vector<Varea>& areas() const { return m_areas; }
  92
  93 private:
  94   jit::vector<Varea> m_areas; // indexed by AreaIndex
  95   DataBlock& m_data;
  96 };
  97
  98 ///////////////////////////////////////////////////////////////////////////////
  99
 100 }}
 101
 102 #include "hphp/runtime/vm/jit/vasm-text-inl.h"
 103
 104 #endif