hphp/runtime/base/double-to-int64.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_DOUBLE_TO_INT64_H_
  18 #define incl_HPHP_DOUBLE_TO_INT64_H_
  19
  20 #include <limits>
  21
  22 #include <folly/CPortability.h>
  23
  24 namespace HPHP {
  25
  26 ///////////////////////////////////////////////////////////////////////////////
  27
  28 inline int64_t double_to_int64(double v)
  29   FOLLY_DISABLE_UNDEFINED_BEHAVIOR_SANITIZER("float-cast-overflow") {
  30   if (v >= 0) {
  31     return v < std::numeric_limits<uint64_t>::max() ? (uint64_t)v : 0u;
  32   } else if (v < 0) {
  33     return (int64_t)v;
  34   } else {
  35     // If v >= 0 is false and v < 0 is false, then v is NaN. In PHP5, on Intel,
  36     // you get 0x800..00, a.k.a. the minimum int64_t.
  37     // We mimic that on all platforms, though this makes us sad.
  38     return std::numeric_limits<int64_t>::min();
  39   }
  40 }
  41
  42 ///////////////////////////////////////////////////////////////////////////////
  43
  44 }
  45
  46 #endif