gcc/hwint.h

/* HOST_WIDE_INT definitions for the GNU compiler.
   Copyright (C) 1998, 2002, 2004, 2008, 2009, 2010
   Free Software Foundation, Inc.

   This file is part of GCC.

   Provide definitions for macros which depend on HOST_BITS_PER_INT
   and HOST_BITS_PER_LONG.  */

#ifndef GCC_HWINT_H
#define GCC_HWINT_H

/* This describes the machine the compiler is hosted on.  */
#define HOST_BITS_PER_CHAR  CHAR_BIT
#define HOST_BITS_PER_SHORT (CHAR_BIT * SIZEOF_SHORT)
#define HOST_BITS_PER_INT   (CHAR_BIT * SIZEOF_INT)
#define HOST_BITS_PER_LONG  (CHAR_BIT * SIZEOF_LONG)

/* The string that should be inserted into a printf style format to
   indicate a "long" operand.  */
#ifndef HOST_LONG_FORMAT
#define HOST_LONG_FORMAT "l"
#endif

/* The string that should be inserted into a printf style format to
   indicate a "long long" operand.  */
#ifndef HOST_LONG_LONG_FORMAT
#define HOST_LONG_LONG_FORMAT "ll"
#endif

/* If HAVE_LONG_LONG and SIZEOF_LONG_LONG aren't defined, but
   GCC_VERSION >= 3000, assume this is the second or later stage of a
   bootstrap, we do have long long, and it's 64 bits.  (This is
   required by C99; we do have some ports that violate that assumption
   but they're all cross-compile-only.)  Just in case, force a
   constraint violation if that assumption is incorrect.  */
#if !defined HAVE_LONG_LONG
# if GCC_VERSION >= 3000
#  define HAVE_LONG_LONG 1
#  define SIZEOF_LONG_LONG 8
extern char sizeof_long_long_must_be_8[sizeof(long long) == 8 ? 1 : -1];
# endif
#endif

#ifdef HAVE_LONG_LONG
# define HOST_BITS_PER_LONGLONG (CHAR_BIT * SIZEOF_LONG_LONG)
#endif
#ifdef HAVE___INT64
# define HOST_BITS_PER___INT64 (CHAR_BIT * SIZEOF___INT64)
#endif

/* Set HOST_WIDE_INT.  This should be the widest efficient host
   integer type.  It can be 32 or 64 bits, except that if we are
   targeting a machine with 64-bit size_t then it has to be 64 bits.

   With a sane ABI, 'long' is the largest efficient host integer type.
   Thus, we use that unless we have to use 'long long' or '__int64'
   because we're targeting a 64-bit machine from a 32-bit host.  */

#if HOST_BITS_PER_LONG >= 64 || !defined NEED_64BIT_HOST_WIDE_INT
#   define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_LONG
#   define HOST_WIDE_INT long
#else
# if HOST_BITS_PER_LONGLONG >= 64
#   define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_LONGLONG
#   define HOST_WIDE_INT long long
# else
#  if HOST_BITS_PER___INT64 >= 64
#   define HOST_BITS_PER_WIDE_INT HOST_BITS_PER___INT64
#   define HOST_WIDE_INT __int64
#  else
    #error "Unable to find a suitable type for HOST_WIDE_INT"
#  endif
# endif
#endif

/* Various printf format strings for HOST_WIDE_INT.  */

#if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG
# define HOST_WIDE_INT_PRINT HOST_LONG_FORMAT
# define HOST_WIDE_INT_PRINT_C "L"
  /* 'long' might be 32 or 64 bits, and the number of leading zeroes
     must be tweaked accordingly.  */
# if HOST_BITS_PER_WIDE_INT == 64
#  define HOST_WIDE_INT_PRINT_DOUBLE_HEX \
     "0x%" HOST_LONG_FORMAT "x%016" HOST_LONG_FORMAT "x"
# else
#  define HOST_WIDE_INT_PRINT_DOUBLE_HEX \
     "0x%" HOST_LONG_FORMAT "x%08" HOST_LONG_FORMAT "x"
# endif
#else
# define HOST_WIDE_INT_PRINT HOST_LONG_LONG_FORMAT
# define HOST_WIDE_INT_PRINT_C "LL"
  /* We can assume that 'long long' is at least 64 bits.  */
# define HOST_WIDE_INT_PRINT_DOUBLE_HEX \
    "0x%" HOST_LONG_LONG_FORMAT "x%016" HOST_LONG_LONG_FORMAT "x"
#endif /* HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG */

#define HOST_WIDE_INT_PRINT_DEC "%" HOST_WIDE_INT_PRINT "d"
#define HOST_WIDE_INT_PRINT_DEC_C HOST_WIDE_INT_PRINT_DEC HOST_WIDE_INT_PRINT_C
#define HOST_WIDE_INT_PRINT_UNSIGNED "%" HOST_WIDE_INT_PRINT "u"
#define HOST_WIDE_INT_PRINT_HEX "%#" HOST_WIDE_INT_PRINT "x"

/* Set HOST_WIDEST_INT.  This is a 64-bit type unless the compiler
   in use has no 64-bit type at all; in that case it's 32 bits.  */

#if HOST_BITS_PER_WIDE_INT >= 64 \
    || (HOST_BITS_PER_LONGLONG < 64 && HOST_BITS_PER___INT64 < 64)
# define HOST_WIDEST_INT		      HOST_WIDE_INT
# define HOST_BITS_PER_WIDEST_INT	      HOST_BITS_PER_WIDE_INT
# define HOST_WIDEST_INT_PRINT                HOST_WIDE_INT_PRINT
# define HOST_WIDEST_INT_PRINT_DEC	      HOST_WIDE_INT_PRINT_DEC
# define HOST_WIDEST_INT_PRINT_DEC_C	      HOST_WIDE_INT_PRINT_DEC_C
# define HOST_WIDEST_INT_PRINT_UNSIGNED	      HOST_WIDE_INT_PRINT_UNSIGNED
# define HOST_WIDEST_INT_PRINT_HEX	      HOST_WIDE_INT_PRINT_HEX
# define HOST_WIDEST_INT_PRINT_DOUBLE_HEX     HOST_WIDE_INT_PRINT_DOUBLE_HEX
#else
# if HOST_BITS_PER_LONGLONG >= 64
#  define HOST_BITS_PER_WIDEST_INT	      HOST_BITS_PER_LONGLONG
#  define HOST_WIDEST_INT		      long long
# else
#  if HOST_BITS_PER___INT64 >= 64
#   define HOST_BITS_PER_WIDEST_INT	      HOST_BITS_PER___INT64
#   define HOST_WIDEST_INT		      __int64
#  else
    #error "This line should be impossible to reach"
#  endif
# endif
# define HOST_WIDEST_INT_PRINT                HOST_LONG_LONG_FORMAT
# define HOST_WIDEST_INT_PRINT_DEC	      "%" HOST_LONG_LONG_FORMAT "d"
# define HOST_WIDEST_INT_PRINT_DEC_C	      "%" HOST_LONG_LONG_FORMAT "dLL"
# define HOST_WIDEST_INT_PRINT_UNSIGNED	      "%" HOST_LONG_LONG_FORMAT "u"
# define HOST_WIDEST_INT_PRINT_HEX	      "%#" HOST_LONG_LONG_FORMAT "x"
# define HOST_WIDEST_INT_PRINT_DOUBLE_HEX     \
    "0x%" HOST_LONG_LONG_FORMAT "x%016" HOST_LONG_LONG_FORMAT "x"
#endif

/* Define HOST_WIDEST_FAST_INT to the widest integer type supported
   efficiently in hardware.  (That is, the widest integer type that fits
   in a hardware register.)  Normally this is "long" but on some hosts it
   should be "long long" or "__int64".  This is no convenient way to
   autodetect this, so such systems must set a flag in config.host; see there
   for details.  */

#ifdef USE_LONG_LONG_FOR_WIDEST_FAST_INT
#  ifdef HAVE_LONG_LONG
#    define HOST_WIDEST_FAST_INT long long
#    define HOST_BITS_PER_WIDEST_FAST_INT HOST_BITS_PER_LONGLONG
#  elif defined (HAVE___INT64)
#    define HOST_WIDEST_FAST_INT __int64
#    define HOST_BITS_PER_WIDEST_FAST_INT HOST_BITS_PER___INT64
#  else
#    error "Your host said it wanted to use long long or __int64 but neither"
#    error "exist"
#  endif
#else
#  define HOST_WIDEST_FAST_INT long
#  define HOST_BITS_PER_WIDEST_FAST_INT HOST_BITS_PER_LONG
#endif

/* Inline functions operating on HOST_WIDE_INT.  */
#if GCC_VERSION < 3004

extern int clz_hwi (unsigned HOST_WIDE_INT x);
extern int ctz_hwi (unsigned HOST_WIDE_INT x);
extern int ffs_hwi (unsigned HOST_WIDE_INT x);

/* Return log2, or -1 if not exact.  */
extern int exact_log2                  (unsigned HOST_WIDE_INT);

/* Return floor of log2, with -1 for zero.  */
extern int floor_log2                  (unsigned HOST_WIDE_INT);

#else /* GCC_VERSION >= 3004 */

/* For convenience, define 0 -> word_size.  */
static inline int
clz_hwi (unsigned HOST_WIDE_INT x)
{
  if (x == 0)
    return HOST_BITS_PER_WIDE_INT;
# if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG
  return __builtin_clzl (x);
# elif HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONGLONG
  return __builtin_clzll (x);
# else
  return __builtin_clz (x);
# endif
}

static inline int
ctz_hwi (unsigned HOST_WIDE_INT x)
{
  if (x == 0)
    return HOST_BITS_PER_WIDE_INT;
# if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG
  return __builtin_ctzl (x);
# elif HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONGLONG
  return __builtin_ctzll (x);
# else
  return __builtin_ctz (x);
# endif
}

static inline int
ffs_hwi (unsigned HOST_WIDE_INT x)
{
# if HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG
  return __builtin_ffsl (x);
# elif HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONGLONG
  return __builtin_ffsll (x);
# else
  return __builtin_ffs (x);
# endif
}

static inline int
floor_log2 (unsigned HOST_WIDE_INT x)
{
  return HOST_BITS_PER_WIDE_INT - 1 - clz_hwi (x);
}

static inline int
exact_log2 (unsigned HOST_WIDE_INT x)
{
  return x == (x & -x) && x ? ctz_hwi (x) : -1;
}

#endif /* GCC_VERSION >= 3004 */

/* Compute the greatest common divisor of two numbers using
   Euclid's algorithm.  */

static inline int
gcd (int a, int b)
{
  int x, y, z;

  x = abs (a);
  y = abs (b);

  while (x > 0)
    {
      z = y % x;
      y = x;
      x = z;
    }

  return y;
}

/* Compute the least common multiple of two numbers A and B .  */

static inline int
least_common_multiple (int a, int b)
{
  return (abs (a) * abs (b) / gcd (a, b));
}

#endif /* ! GCC_HWINT_H */