bfffo.h

#line 2 "../src/kernel/none/bfffo.h"
/* Copyright (C) 2000  The PARI group.

This file is part of the PARI/GP package.

PARI/GP is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version. It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY WHATSOEVER.

Check the License for details. You should have received a copy of it, along
with the package; see the file 'COPYING'. If not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */

#if !defined(INLINE)
extern int  bfffo(ulong x);
#else

#if defined(__GNUC__) && !defined(DISABLE_INLINE)

#ifdef LONG_IS_64BIT
#  define bfffo(x) \
__extension__ ({ \
  static int __bfffo_tabshi[16]={4,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};\
  int __value = BITS_IN_LONG - 4; \
  ulong __arg1=(x); \
  if (__arg1 & ~0xffffffffUL) {__value -= 32; __arg1 >>= 32;}\
  if (__arg1 & ~0xffffUL) {__value -= 16; __arg1 >>= 16;} \
  if (__arg1 & ~0x00ffUL) {__value -= 8; __arg1 >>= 8;} \
  if (__arg1 & ~0x000fUL) {__value -= 4; __arg1 >>= 4;} \
  __value + __bfffo_tabshi[__arg1]; \
})
#else
#  define bfffo(x) \
__extension__ ({ \
  static int __bfffo_tabshi[16]={4,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};\
  int __value = BITS_IN_LONG - 4; \
  ulong __arg1=(x); \
  if (__arg1 & ~0xffffUL) {__value -= 16; __arg1 >>= 16;} \
  if (__arg1 & ~0x00ffUL) {__value -= 8; __arg1 >>= 8;} \
  if (__arg1 & ~0x000fUL) {__value -= 4; __arg1 >>= 4;} \
  __value + __bfffo_tabshi[__arg1]; \
})
#endif

#else

INLINE int
bfffo(ulong x)
{
  static int tabshi[16]={4,3,2,2,1,1,1,1,0,0,0,0,0,0,0,0};
  int value = BITS_IN_LONG - 4;
  ulong arg1=x;
#ifdef LONG_IS_64BIT
  if (arg1 & ~0xffffffffUL) {value -= 32; arg1 >>= 32;}
#endif
  if (arg1 & ~0xffffUL) {value -= 16; arg1 >>= 16;}
  if (arg1 & ~0x00ffUL) {value -= 8; arg1 >>= 8;}
  if (arg1 & ~0x000fUL) {value -= 4; arg1 >>= 4;}
  return value + tabshi[arg1];
}
#endif

#endif