runtime/util/endian.h

   1 /* Copyright (C) 2012 Matthew Fluet.
   2  * Copyright (C) 1999-2006 Henry Cejtin, Matthew Fluet, Suresh
   3  *    Jagannathan, and Stephen Weeks.
   4  * Copyright (C) 1997-2000 NEC Research Institute.
   5  *
   6  * MLton is released under a BSD-style license.
   7  * See the file MLton-LICENSE for details.
   8  */
   9
  10 static inline bool isBigEndian(void) {
  11   uint16_t x = 0xABCDU;
  12   uint8_t y = 0;
  13   /* gcc optimizes the following code to just return the result. */
  14   memcpy(&y, &x, sizeof(uint8_t));
  15   if (y == 0xAB) return TRUE; /* big endian */
  16   if (y == 0xCD) return FALSE; /* little endian */
  17   die ("Could not detect endian --- neither big nor little!\n");
  18   // return 0;
  19 }
  20
  21 static inline bool isLittleEndian(void) {
  22   return not (isBigEndian());
  23 }