libfaad/fixed.h

/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
**
** 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.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** The "appropriate copyright message" mentioned in section 2c of the GPLv2
** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
**
** $Id: fixed.h,v 1.32 2007/11/01 12:33:30 menno Exp $
**/

#ifndef __FIXED_H__
#define __FIXED_H__

#ifdef __cplusplus
extern "C" {
#endif

#if defined(_WIN32_WCE) && defined(_ARM_)
#include <cmnintrin.h>
#endif


#define COEF_BITS 28
#define COEF_PRECISION (1 << COEF_BITS)
#define REAL_BITS 14 // MAXIMUM OF 14 FOR FIXED POINT SBR
#define REAL_PRECISION (1 << REAL_BITS)

    /* FRAC is the fractional only part of the fixed point number [0.0..1.0) */
#define FRAC_SIZE 32 /* frac is a 32 bit integer */
#define FRAC_BITS 31
#define FRAC_PRECISION ((uint32_t)(1 << FRAC_BITS))
#define FRAC_MAX 0x7FFFFFFF

    typedef int32_t real_t;


#define REAL_CONST(A) (((A) >= 0) ? ((real_t)((A)*(REAL_PRECISION)+0.5)) : ((real_t)((A)*(REAL_PRECISION)-0.5)))
#define COEF_CONST(A) (((A) >= 0) ? ((real_t)((A)*(COEF_PRECISION)+0.5)) : ((real_t)((A)*(COEF_PRECISION)-0.5)))
#define FRAC_CONST(A) (((A) == 1.00) ? ((real_t)FRAC_MAX) : (((A) >= 0) ? ((real_t)((A)*(FRAC_PRECISION)+0.5)) : ((real_t)((A)*(FRAC_PRECISION)-0.5))))
    //#define FRAC_CONST(A) (((A) >= 0) ? ((real_t)((A)*(FRAC_PRECISION)+0.5)) : ((real_t)((A)*(FRAC_PRECISION)-0.5)))

#define Q2_BITS 22
#define Q2_PRECISION (1 << Q2_BITS)
#define Q2_CONST(A) (((A) >= 0) ? ((real_t)((A)*(Q2_PRECISION)+0.5)) : ((real_t)((A)*(Q2_PRECISION)-0.5)))

#if defined(_WIN32) && !defined(_WIN32_WCE)

    /* multiply with real shift */
    static INLINE real_t MUL_R(real_t A, real_t B)
    {
        _asm {
            mov eax, A
            imul B
            shrd eax, edx, REAL_BITS
        }
    }

    /* multiply with coef shift */
    static INLINE real_t MUL_C(real_t A, real_t B)
    {
        _asm {
            mov eax, A
            imul B
            shrd eax, edx, COEF_BITS
        }
    }

    static INLINE real_t MUL_Q2(real_t A, real_t B)
    {
        _asm {
            mov eax, A
            imul B
            shrd eax, edx, Q2_BITS
        }
    }

    static INLINE real_t MUL_SHIFT6(real_t A, real_t B)
    {
        _asm {
            mov eax, A
            imul B
            shrd eax, edx, 6
        }
    }

    static INLINE real_t MUL_SHIFT23(real_t A, real_t B)
    {
        _asm {
            mov eax, A
            imul B
            shrd eax, edx, 23
        }
    }

#if 1
    static INLINE real_t _MulHigh(real_t A, real_t B)
    {
        _asm {
            mov eax, A
            imul B
            mov eax, edx
        }
    }

    /* multiply with fractional shift */
    static INLINE real_t MUL_F(real_t A, real_t B)
    {
        return _MulHigh(A, B) << (FRAC_SIZE - FRAC_BITS);
    }

    /* Complex multiplication */
    static INLINE void ComplexMult(real_t *y1, real_t *y2,
                                   real_t x1, real_t x2, real_t c1, real_t c2)
    {
        *y1 = (_MulHigh(x1, c1) + _MulHigh(x2, c2)) << (FRAC_SIZE - FRAC_BITS);
        *y2 = (_MulHigh(x2, c1) - _MulHigh(x1, c2)) << (FRAC_SIZE - FRAC_BITS);
    }
#else
    static INLINE real_t MUL_F(real_t A, real_t B)
    {
        _asm {
            mov eax, A
            imul B
            shrd eax, edx, FRAC_BITS
        }
    }

    /* Complex multiplication */
    static INLINE void ComplexMult(real_t *y1, real_t *y2,
                                   real_t x1, real_t x2, real_t c1, real_t c2)
    {
        *y1 = MUL_F(x1, c1) + MUL_F(x2, c2);
        *y2 = MUL_F(x2, c1) - MUL_F(x1, c2);
    }
#endif

#elif defined(__GNUC__) && defined (__arm__)

    /* taken from MAD */
#define arm_mul(x, y, SCALEBITS) \
({ \
    uint32_t __hi; \
    uint32_t __lo; \
    uint32_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" (SCALEBITS), "M" (32 - (SCALEBITS)) \
        : "cc"); \
        __result; \
})

    static INLINE real_t MUL_R(real_t A, real_t B)
    {
        return arm_mul(A, B, REAL_BITS);
    }

    static INLINE real_t MUL_C(real_t A, real_t B)
    {
        return arm_mul(A, B, COEF_BITS);
    }

    static INLINE real_t MUL_Q2(real_t A, real_t B)
    {
        return arm_mul(A, B, Q2_BITS);
    }

    static INLINE real_t MUL_SHIFT6(real_t A, real_t B)
    {
        return arm_mul(A, B, 6);
    }

    static INLINE real_t MUL_SHIFT23(real_t A, real_t B)
    {
        return arm_mul(A, B, 23);
    }

    static INLINE real_t _MulHigh(real_t x, real_t y)
    {
        uint32_t __lo;
        uint32_t __hi;
        asm("smull\t%0, %1, %2, %3"
            : "=&r"(__lo), "=&r"(__hi)
            : "%r"(x), "r"(y)
            : "cc");
        return __hi;
    }

    static INLINE real_t MUL_F(real_t A, real_t B)
    {
        return _MulHigh(A, B) << (FRAC_SIZE - FRAC_BITS);
    }

    /* Complex multiplication */
    static INLINE void ComplexMult(real_t *y1, real_t *y2,
                                   real_t x1, real_t x2, real_t c1, real_t c2)
    {
        int32_t tmp, yt1, yt2;
        asm("smull %0, %1, %4, %6\n\t"
            "smlal %0, %1, %5, %7\n\t"
            "rsb   %3, %4, #0\n\t"
            "smull %0, %2, %5, %6\n\t"
            "smlal %0, %2, %3, %7"
            : "=&r"(tmp), "=&r"(yt1), "=&r"(yt2), "=r"(x1)
            : "3"(x1), "r"(x2), "r"(c1), "r"(c2)
            : "cc");
        *y1 = yt1 << (FRAC_SIZE - FRAC_BITS);
        *y2 = yt2 << (FRAC_SIZE - FRAC_BITS);
    }

#else

    /* multiply with real shift */
#define MUL_R(A,B) (real_t)(((int64_t)(A)*(int64_t)(B)+(1 << (REAL_BITS-1))) >> REAL_BITS)
    /* multiply with coef shift */
#define MUL_C(A,B) (real_t)(((int64_t)(A)*(int64_t)(B)+(1 << (COEF_BITS-1))) >> COEF_BITS)
    /* multiply with fractional shift */
#if defined(_WIN32_WCE) && defined(_ARM_)
    /* eVC for PocketPC has an intrinsic function that returns only the high 32 bits of a 32x32 bit multiply */
    static INLINE real_t MUL_F(real_t A, real_t B)
    {
        return _MulHigh(A, B) << (32 - FRAC_BITS);
    }
#else
#ifdef __BFIN__
#define _MulHigh(X,Y) ({ int __xxo;                      \
     asm (                                               \
         "a1 = %2.H * %1.L (IS,M);\n\t"                  \
         "a0 = %1.H * %2.H, a1+= %1.H * %2.L (IS,M);\n\t"\
         "a1 = a1 >>> 16;\n\t"                           \
         "%0 = (a0 += a1);\n\t"                          \
         : "=d" (__xxo) : "d" (X), "d" (Y) : "A0","A1"); __xxo; })

#define MUL_F(X,Y) ({ int __xxo;                         \
     asm (                                               \
         "a1 = %2.H * %1.L (M);\n\t"                     \
         "a0 = %1.H * %2.H, a1+= %1.H * %2.L (M);\n\t"   \
         "a1 = a1 >>> 16;\n\t"                           \
         "%0 = (a0 += a1);\n\t"                          \
         : "=d" (__xxo) : "d" (X), "d" (Y) : "A0","A1"); __xxo; })
#else
#define _MulHigh(A,B) (real_t)(((int64_t)(A)*(int64_t)(B)+(1 << (FRAC_SIZE-1))) >> FRAC_SIZE)
#define MUL_F(A,B) (real_t)(((int64_t)(A)*(int64_t)(B)+(1 << (FRAC_BITS-1))) >> FRAC_BITS)
#endif
#endif
#define MUL_Q2(A,B) (real_t)(((int64_t)(A)*(int64_t)(B)+(1 << (Q2_BITS-1))) >> Q2_BITS)
#define MUL_SHIFT6(A,B) (real_t)(((int64_t)(A)*(int64_t)(B)+(1 << (6-1))) >> 6)
#define MUL_SHIFT23(A,B) (real_t)(((int64_t)(A)*(int64_t)(B)+(1 << (23-1))) >> 23)

    /* Complex multiplication */
    static INLINE void ComplexMult(real_t *y1, real_t *y2,
                                   real_t x1, real_t x2, real_t c1, real_t c2)
    {
        *y1 = (_MulHigh(x1, c1) + _MulHigh(x2, c2)) << (FRAC_SIZE - FRAC_BITS);
        *y2 = (_MulHigh(x2, c1) - _MulHigh(x1, c2)) << (FRAC_SIZE - FRAC_BITS);
    }

#endif



#ifdef __cplusplus
}
#endif
#endif