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/*

 * mad - MPEG audio decoder

 * Copyright (C) 2000-2001 Robert Leslie

 *

 * This program 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * $Id: fixed.h,v 1.3 2001-11-06 17:01:28 simons Exp $

 */

# ifndef LIBMAD_FIXED_H

# define LIBMAD_FIXED_H

# if SIZEOF_INT >= 4

typedef   signed int mad_fixed_t;

typedef   signed int mad_fixed64hi_t;

typedef unsigned int mad_fixed64lo_t;

# else

typedef   signed long mad_fixed_t;

typedef   signed long mad_fixed64hi_t;

typedef unsigned long mad_fixed64lo_t;

# endif

/*

 * Fixed-point format: 0xABBBBBBB

 * A == whole part      (sign + 3 bits)

 * B == fractional part (28 bits)

 *

 * Values are signed two's complement, so the effective range is:

 * 0x80000000 to 0x7fffffff

 *       -8.0 to +7.9999999962747097015380859375

 *

 * The smallest representable value is:

 * 0x00000001 == 0.0000000037252902984619140625 (i.e. about 3.725e-9)

 *

 * 28 bits of fractional accuracy represent about

 * 8.6 digits of decimal accuracy.

 *

 * Fixed-point numbers can be added or subtracted as normal

 * integers, but multiplication requires shifting the 64-bit result

 * from 56 fractional bits back to 28 (and rounding.)

 *

 * Changing the definition of MAD_F_FRACBITS is only partially

 * supported, and must be done with care.

 */

# define MAD_F_FRACBITS         28

# if MAD_F_FRACBITS == 28

#  define MAD_F(x)              ((mad_fixed_t) (x##L))

# else

#  if MAD_F_FRACBITS < 28

#   warning "MAD_F_FRACBITS < 28"

#   define MAD_F(x)             ((mad_fixed_t)  \

                                 (((x##L) +  \

                                   (1L << (28 - MAD_F_FRACBITS - 1))) >>  \

                                  (28 - MAD_F_FRACBITS)))

#  elif MAD_F_FRACBITS > 28

#   error "MAD_F_FRACBITS > 28 not currently supported"

#   define MAD_F(x)             ((mad_fixed_t)  \

                                 ((x##L) << (MAD_F_FRACBITS - 28)))

#  endif

# endif

# define MAD_F_MIN              ((mad_fixed_t) -0x80000000L)

# define MAD_F_MAX              ((mad_fixed_t) +0x7fffffffL)

# define MAD_F_ONE              MAD_F(0x10000000)

#ifndef EMBED

# define mad_f_tofixed(x)       ((mad_fixed_t)  \

                                 ((x) * (double) (1L << MAD_F_FRACBITS) + 0.5))

# define mad_f_todouble(x)      ((double)  \

                                 ((x) / (double) (1L << MAD_F_FRACBITS)))

#endif

# define mad_f_intpart(x)       ((x) >> MAD_F_FRACBITS)

# define mad_f_fracpart(x)      ((x) & ((1L << MAD_F_FRACBITS) - 1))

                                /* (x should be positive) */

# define mad_f_fromint(x)       ((x) << MAD_F_FRACBITS)

# define mad_f_add(x, y)        ((x) + (y))

# define mad_f_sub(x, y)        ((x) - (y))

# if defined(FPM_64BIT)

/*

 * This version should be the most accurate if 64-bit (long long) types are

 * supported by the compiler, although it may not be the most efficient.

 */

#  if defined(OPT_ACCURACY)

#   define mad_f_mul(x, y)  \

    ((mad_fixed_t)  \

     ((((signed long long) (x) * (y)) +  \

       (1L << (MAD_F_SCALEBITS - 1))) >> MAD_F_SCALEBITS))

#  else

#   define mad_f_mul(x, y)  \

    ((mad_fixed_t) (((signed long long) (x) * (y)) >> MAD_F_SCALEBITS))

#  endif

#  define MAD_F_SCALEBITS  MAD_F_FRACBITS

/* --- Intel --------------------------------------------------------------- */

# elif defined(FPM_INTEL)

/*

 * This Intel version is fast and accurate; the disposition of the least

 * significant bit depends on OPT_ACCURACY via mad_f_scale64().

 */

#  define MAD_F_MLX(hi, lo, x, y)  \

    asm ("imull %3"  \

         : "=a" (lo), "=d" (hi)  \

         : "%a" (x), "rm" (y)  \

         : "cc")

#  if defined(OPT_ACCURACY)

/*

 * This gives best accuracy but is not very fast.

 */

#   define MAD_F_MLA(hi, lo, x, y)  \

    ({ mad_fixed64hi_t __hi;  \

       mad_fixed64lo_t __lo;  \

       MAD_F_MLX(__hi, __lo, (x), (y));  \

       asm ("addl %2,%0\n\t"  \

            "adcl %3,%1"  \

            : "=rm" (lo), "=rm" (hi)  \

            : "r" (__lo), "r" (__hi), "0" (lo), "1" (hi)  \

            : "cc");  \

    })

#  endif  /* OPT_ACCURACY */

#  if defined(OPT_ACCURACY)

/*

 * Surprisingly, this is faster than SHRD followed by ADC.

 */

#   define mad_f_scale64(hi, lo)  \

    ({ mad_fixed64hi_t __hi_;  \

       mad_fixed64lo_t __lo_;  \

       mad_fixed_t __result;  \

       asm ("addl %4,%2\n\t"  \

            "adcl %5,%3"  \

            : "=rm" (__lo_), "=rm" (__hi_)  \

            : "0" (lo), "1" (hi),  \

              "ir" (1L << (MAD_F_SCALEBITS - 1)), "ir" (0)  \

            : "cc");  \

       asm ("shrdl %3,%2,%1"  \

            : "=rm" (__result)  \

            : "0" (__lo_), "r" (__hi_), "I" (MAD_F_SCALEBITS)  \

            : "cc");  \

       __result;  \

    })

#  else

#   define mad_f_scale64(hi, lo)  \

    ({ mad_fixed_t __result;  \

       asm ("shrdl %3,%2,%1"  \

            : "=rm" (__result)  \

            : "0" (lo), "r" (hi), "I" (MAD_F_SCALEBITS)  \

            : "cc");  \

       __result;  \

    })

#  endif  /* OPT_ACCURACY */

#  define MAD_F_SCALEBITS  MAD_F_FRACBITS

/* --- ARM ----------------------------------------------------------------- */

# elif defined(FPM_ARM)

/*

 * This ARM V4 version is as accurate as FPM_64BIT but much faster. The

 * least significant bit is properly rounded at no CPU cycle cost!

 */

# if 1

/*

 * There's a bug somewhere, possibly in the compiler, that sometimes makes

 * this necessary instead of the default implementation via MAD_F_MLX and

 * mad_f_scale64. It may be related to the use (or lack) of

 * -finline-functions and/or -fstrength-reduce.

 *

 * This is also apparently faster than MAD_F_MLX/mad_f_scale64.

 */

#  define mad_f_mul(x, y)  \

    ({ mad_fixed64hi_t __hi;  \

       mad_fixed64lo_t __lo;  \

       mad_fixed_t __result;  \

       asm ("smull      %0, %1, %3, %4\n\t"  \

            "movs       %0, %0, lsr %5\n\t"  \

            "adc        %2, %0, %1, lsl %6"  \

            : "=&r" (__lo), "=&r" (__hi), "=r" (__result)  \

            : "%r" (x), "r" (y),  \

              "M" (MAD_F_SCALEBITS), "M" (32 - MAD_F_SCALEBITS)  \

            : "cc");  \

       __result;  \

    })

# endif

#  define MAD_F_MLX(hi, lo, x, y)  \

    asm ("smull %0, %1, %2, %3"  \

         : "=&r" (lo), "=&r" (hi)  \

         : "%r" (x), "r" (y))

#  define MAD_F_MLA(hi, lo, x, y)  \

    asm ("smlal %0, %1, %2, %3"  \

         : "+r" (lo), "+r" (hi)  \

         : "%r" (x), "r" (y))

#  define mad_f_scale64(hi, lo)  \

    ({ mad_fixed_t __result;  \

       asm ("movs       %0, %1, lsr %3\n\t"  \

            "adc        %0, %0, %2, lsl %4"  \

            : "=r" (__result)  \

            : "r" (lo), "r" (hi),  \

              "M" (MAD_F_SCALEBITS), "M" (32 - MAD_F_SCALEBITS)  \

            : "cc");  \

       __result;  \

    })

#  define MAD_F_SCALEBITS  MAD_F_FRACBITS

/* --- MIPS ---------------------------------------------------------------- */

# elif defined(FPM_MIPS)

/*

 * This MIPS version is fast and accurate; the disposition of the least

 * significant bit depends on OPT_ACCURACY via mad_f_scale64().

 */

#  define MAD_F_MLX(hi, lo, x, y)  \

    asm ("mult  %2,%3"  \

         : "=l" (lo), "=h" (hi)  \

         : "%r" (x), "r" (y))

# if defined(HAVE_MADD_ASM)

#  define MAD_F_MLA(hi, lo, x, y)  \

    asm ("madd  %2,%3"  \

         : "+l" (lo), "+h" (hi)  \

         : "%r" (x), "r" (y))

# elif defined(HAVE_MADD16_ASM)

/*

 * This loses significant accuracy due to the 16-bit integer limit in the

 * multiply/accumulate instruction.

 */

#  define MAD_F_ML0(hi, lo, x, y)  \

    asm ("mult  %2,%3"  \

         : "=l" (lo), "=h" (hi)  \

         : "%r" ((x) >> 12), "r" ((y) >> 16))

#  define MAD_F_MLA(hi, lo, x, y)  \

    asm ("madd16        %2,%3"  \

         : "+l" (lo), "+h" (hi)  \

         : "%r" ((x) >> 12), "r" ((y) >> 16))

#  define MAD_F_MLZ(hi, lo)  ((mad_fixed_t) (lo))

# endif

# if defined(OPT_SPEED)

#  define mad_f_scale64(hi, lo)  \

    ((mad_fixed_t) ((hi) << (32 - MAD_F_SCALEBITS)))

#  define MAD_F_SCALEBITS  MAD_F_FRACBITS

# endif

/* --- SPARC --------------------------------------------------------------- */

# elif defined(FPM_SPARC)

/*

 * This SPARC V8 version is fast and accurate; the disposition of the least

 * significant bit depends on OPT_ACCURACY via mad_f_scale64().

 */

#  define MAD_F_MLX(hi, lo, x, y)  \

    asm ("smul %2, %3, %0\n\t"  \

         "rd %%y, %1"  \

         : "=r" (lo), "=r" (hi)  \

         : "%r" (x), "rI" (y))

/* --- PowerPC ------------------------------------------------------------- */

# elif defined(FPM_PPC)

/*

 * This PowerPC version is tuned for the 4xx embedded processors. It is

 * effectively a tuned version of FPM_64BIT. It is a little faster and just

 * as accurate. The disposition of the least significant bit depends on

 * OPT_ACCURACY via mad_f_scale64().

 */

#  define MAD_F_MLX(hi, lo, x, y)  \

    asm ("mulhw %1, %2, %3\n\t"  \

         "mullw %0, %2, %3"  \

         : "=&r" (lo), "=&r" (hi)  \

         : "%r" (x), "r" (y))

#  define MAD_F_MLA(hi, lo, x, y)  \

    ({ mad_fixed64hi_t __hi;  \

       mad_fixed64lo_t __lo;  \

       MAD_F_MLX(__hi, __lo, (x), (y));  \

       asm ("addc %0, %2, %3\n\t"  \

            "adde %1, %4, %5"  \

            : "=r" (lo), "=r" (hi)  \

            : "%r" (__lo), "0" (lo), "%r" (__hi), "1" (hi));  \

    })

#  if defined(OPT_ACCURACY)

/*

 * This is accurate and ~2 - 2.5 times slower than the unrounded version.

 *

 * The __volatile__ improves the generated code by another 5% (fewer spills

 * to memory); eventually they should be removed.

 */

#   define mad_f_scale64(hi, lo)  \

    ({ mad_fixed_t __result;  \

       mad_fixed64hi_t __hi_;  \

       mad_fixed64lo_t __lo_;  \

       asm __volatile__ ("addc %0, %2, %4\n\t"  \

                         "addze %1, %3"  \

            : "=r" (__lo_), "=r" (__hi_)  \

            : "r" (lo), "r" (hi), "r" (1 << (MAD_F_SCALEBITS - 1)));  \

       asm __volatile__ ("rlwinm %0, %2,32-%3,0,%3-1\n\t"  \

                         "rlwimi %0, %1,32-%3,%3,31"  \

            : "=&r" (__result)  \

            : "r" (__lo_), "r" (__hi_), "I" (MAD_F_SCALEBITS));  \

            __result;  \

    })

#  else

#   define mad_f_scale64(hi, lo)  \

    ({ mad_fixed_t __result;  \

       asm ("rlwinm %0, %2,32-%3,0,%3-1\n\t"  \

            "rlwimi %0, %1,32-%3,%3,31"  \

            : "=r" (__result)  \

            : "r" (lo), "r" (hi), "I" (MAD_F_SCALEBITS));  \

            __result;  \

    })

#  endif  /* OPT_ACCURACY */

#  define MAD_F_SCALEBITS  MAD_F_FRACBITS

/* ------ OR32 ------------------------------------------------------------- */

# elif defined(FPM_OR32)

/* We assume here that we always call macros in following sequence:

 MAD_F_ML0

 MAD_F_MLA

 ...

 MAD_F_MLA

 MAD_F_MLX

*/

#  define MAD_F_MLX(hi, lo, x, y)  \

    asm volatile ("l.mac %0,%1" : : "%r" (x), "r" (y))

#  define MAD_F_MLA(hi, lo, x, y) MAX_F_MLX(hi, lo, x, y)

#  define MAX_F_ML0(hi, lo, x, y) MAX_F_MLX(hi, lo, x, y)

#  define MAX_F_MLZ(hi, lo, x, y)  \

    asm volatile ("l.macrc %0" : "=r" (lo))

#  define MAD_F_SCALEBITS  MAD_F_FRACBITS

/* --- Default ------------------------------------------------------------- */

# elif defined(FPM_DEFAULT)

/*

 * This version is the most portable but it loses significant accuracy.

 * Furthermore, accuracy is biased against the second argument, so care

 * should be taken when ordering operands.

 *

 * The scale factors are constant as this is not used with SSO.

 *

 * Pre-rounding is required to stay within the limits of compliance.

 */

#  define mad_f_mul(x, y)       ( (((x) + (1L << 11)) >> 12) * \

  (((y) + (1L << 15)) >> 16) )

/*#  define mad_f_mul(x, y) ((x)+(y))*/

/* --- Default 16 ------------------------------------------------------------- */

# elif defined(FPM_DEFAULT16)

/*

 * This version is the most portable but it loses significant accuracy.

 * Furthermore, accuracy is biased against the second argument, so care

 * should be taken when ordering operands.

 *

 * The scale factors are constant as this is not used with SSO.

 *

 * Pre-rounding is required to stay within the limits of compliance.

 */

#  define mad_f_mul(x, y)       (( (((x) + (1L << 15)) >> 16) *  \

                                   (((y) + (1L << 15)) >> 16) ) << 4)

/* ------------------------------------------------------------------------- */

# else

#  error "no FPM selected"

# endif

/* default implementations */

# if !defined(mad_f_mul)

#  define mad_f_mul(x, y)  \

    ({ mad_fixed64hi_t __hi;  \

       mad_fixed64lo_t __lo;  \

       MAD_F_MLX(__hi, __lo, (x), (y));  \

       mad_f_scale64(__hi, __lo);  \

    })

# endif

# if !defined(MAD_F_MLA)

#  define MAD_F_ML0(hi, lo, x, y)       ((lo)  = mad_f_mul((x), (y)))

#  define MAD_F_MLA(hi, lo, x, y)       ((lo) += mad_f_mul((x), (y)))

#  define MAD_F_MLZ(hi, lo)             ((void) (hi), (mad_fixed_t) (lo))

# endif

# if !defined(MAD_F_ML0)

#  define MAD_F_ML0(hi, lo, x, y)       MAD_F_MLX((hi), (lo), (x), (y))

# endif

# if !defined(MAD_F_MLZ)

#  define MAD_F_MLZ(hi, lo)             mad_f_scale64((hi), (lo))

# endif

# if !defined(mad_f_scale64)

#  if defined(OPT_ACCURACY)

#   define mad_f_scale64(hi, lo)  \

    ((((mad_fixed_t)  \

       (((hi) << (32 - (MAD_F_SCALEBITS - 1))) |  \

        ((lo) >> (MAD_F_SCALEBITS - 1)))) + 1) >> 1)

#  else

#   define mad_f_scale64(hi, lo)  \

    ((mad_fixed_t)  \

     (((hi) << (32 - MAD_F_SCALEBITS)) |  \

      ((lo) >> MAD_F_SCALEBITS)))

#  endif

#  define MAD_F_SCALEBITS  MAD_F_FRACBITS

# endif

/* miscellaneous C routines */

mad_fixed_t mad_f_abs(mad_fixed_t);

# endif