linux/arch/tile/lib/string-endian.h
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   1/*
   2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
   3 *
   4 *   This program is free software; you can redistribute it and/or
   5 *   modify it under the terms of the GNU General Public License
   6 *   as published by the Free Software Foundation, version 2.
   7 *
   8 *   This program is distributed in the hope that it will be useful, but
   9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11 *   NON INFRINGEMENT.  See the GNU General Public License for
  12 *   more details.
  13 *
  14 * Provide a mask based on the pointer alignment that
  15 * sets up non-zero bytes before the beginning of the string.
  16 * The MASK expression works because shift counts are taken mod 64.
  17 * Also, specify how to count "first" and "last" bits
  18 * when the bits have been read as a word.
  19 */
  20
  21#include <asm/byteorder.h>
  22
  23#ifdef __LITTLE_ENDIAN
  24#define MASK(x) (__insn_shl(1ULL, (x << 3)) - 1)
  25#define NULMASK(x) ((2ULL << x) - 1)
  26#define CFZ(x) __insn_ctz(x)
  27#define REVCZ(x) __insn_clz(x)
  28#else
  29#define MASK(x) (__insn_shl(-2LL, ((-x << 3) - 1)))
  30#define NULMASK(x) (-2LL << (63 - x))
  31#define CFZ(x) __insn_clz(x)
  32#define REVCZ(x) __insn_ctz(x)
  33#endif
  34