[hcoop/debian/mlton.git] / runtime / util / endian.h

/* Copyright (C) 2012 Matthew Fluet.
 * Copyright (C) 1999-2006 Henry Cejtin, Matthew Fluet, Suresh
 *    Jagannathan, and Stephen Weeks.
 * Copyright (C) 1997-2000 NEC Research Institute.
 *
 * MLton is released under a BSD-style license.
 * See the file MLton-LICENSE for details.
 */

static inline bool isBigEndian(void) {
  uint16_t x = 0xABCDU;
  uint8_t y = 0;
  /* gcc optimizes the following code to just return the result. */
  memcpy(&y, &x, sizeof(uint8_t));
  if (y == 0xAB) return TRUE; /* big endian */
  if (y == 0xCD) return FALSE; /* little endian */
  die ("Could not detect endian --- neither big nor little!\n");
  // return 0;
}

static inline bool isLittleEndian(void) {
  return not (isBigEndian());
}
Commit	Line	Data
7f918cf1 CE	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	}