assembly.h

nds上大名鼎鼎的DSOrganize 2.8最新源代码。很值得研究。

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: assembly.h,v 1.8 2006/07/19 14:19:27 damann Exp $
 *
 * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.
 *
 * The contents of this file, and the files included with this file,
 * are subject to the current version of the RealNetworks Public
 * Source License (the "RPSL") available at
 * http://www.helixcommunity.org/content/rpsl unless you have licensed
 * the file under the current version of the RealNetworks Community
 * Source License (the "RCSL") available at
 * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
 * will apply. You may also obtain the license terms directly from
 * RealNetworks.  You may not use this file except in compliance with
 * the RPSL or, if you have a valid RCSL with RealNetworks applicable
 * to this file, the RCSL.  Please see the applicable RPSL or RCSL for
 * the rights, obligations and limitations governing use of the
 * contents of the file.
 *
 * This file is part of the Helix DNA Technology. RealNetworks is the
 * developer of the Original Code and owns the copyrights in the
 * portions it created.
 *
 * This file, and the files included with this file, is distributed
 * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY
 * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS
 * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET
 * ENJOYMENT OR NON-INFRINGEMENT.
 *
 * Technology Compatibility Kit Test Suite(s) Location:
 *    http://www.helixcommunity.org/content/tck
 *
 * Contributor(s):
 *
 * ***** END LICENSE BLOCK ***** */

/**************************************************************************************
 * Fixed-point HE-AAC decoder
 * Jon Recker ([e-mail])
 * February 2005
 *
 * assembly.h - inline assembly language functions and prototypes
 *
 * MULSHIFT32(x, y)             signed multiply of two 32-bit integers (x and y),
 *                            returns top 32-bits of 64-bit result
 * CLIPTOSHORT(x)                       convert 32-bit integer to 16-bit short,
 *                            clipping to [-32768, 32767]
 * FASTABS(x)               branchless absolute value of signed integer x
 * CLZ(x)                   count leading zeros on signed integer x
 * MADD64(sum64, x, y)          64-bit multiply accumulate: sum64 += (x*y)
 **************************************************************************************/

#ifndef _ASSEMBLY_H
#define _ASSEMBLY_H

/* toolchain:           MSFT Visual C++
 * target architecture: x86
 */
#if (defined (_WIN32) && !defined (_WIN32_WCE)) || (defined (__WINS__) && defined (_SYMBIAN)) || (defined (WINCE_EMULATOR)) || (defined (_OPENWAVE_SIMULATOR))

#pragma warning( disable : 4035 )       /* complains about inline asm not returning a value */

static __inline int MULSHIFT32(int x, int y)    
{
    __asm {
                mov             eax, x
            imul        y
            mov         eax, edx
            }
}

static __inline short CLIPTOSHORT(int x)
{
        int sign;

        /* clip to [-32768, 32767] */
        sign = x >> 31;
        if (sign != (x >> 15))
                x = sign ^ ((1 << 15) - 1);

        return (short)x;
}

static __inline int FASTABS(int x)
{
        int sign;

        sign = x >> (sizeof(int) * 8 - 1);
        x ^= sign;
        x -= sign;

        return x;
}

static __inline int CLZ(int x)
{
        int numZeros;

        if (!x)
                return 32;

        /* count leading zeros with binary search */
        numZeros = 1;
        if (!((unsigned int)x >> 16))   { numZeros += 16; x <<= 16; }
        if (!((unsigned int)x >> 24))   { numZeros +=  8; x <<=  8; }
        if (!((unsigned int)x >> 28))   { numZeros +=  4; x <<=  4; }
        if (!((unsigned int)x >> 30))   { numZeros +=  2; x <<=  2; }

        numZeros -= ((unsigned int)x >> 31);

        return numZeros;
}

#ifdef __CW32__
typedef long long Word64;
#else
typedef __int64 Word64;
#endif

typedef union _U64 {
        Word64 w64;
        struct {
                /* x86 = little endian */
                unsigned int lo32;
                signed int   hi32;
        } r;
} U64;

/* returns 64-bit value in [edx:eax] */
static __inline Word64 MADD64(Word64 sum64, int x, int y)
{
#if (defined (_SYMBIAN_61_) || defined (_SYMBIAN_70_)) && defined (__WINS__) && !defined (__CW32__)
/* Workaround for the Symbian emulator because of non existing longlong.lib and
 * hence __allmul not defined. */
    __asm {
        mov     eax, x
        imul    y
        add     dword ptr sum64, eax
        adc     dword ptr sum64 + 4, edx
    }
#else
    sum64 += (Word64)x * (Word64)y;
#endif

    return sum64;
}

/* toolchain:           MSFT Embedded Visual C++
 * target architecture: ARM v.4 and above (require 'M' type processor for 32x32->64 multiplier)
 */
#elif defined (_WIN32) && defined (_WIN32_WCE) && defined (ARM)

static __inline short CLIPTOSHORT(int x)
{
        int sign;

        /* clip to [-32768, 32767] */
        sign = x >> 31;
        if (sign != (x >> 15))
                x = sign ^ ((1 << 15) - 1);

        return (short)x;
}

static __inline int FASTABS(int x)
{
        int sign;

        sign = x >> (sizeof(int) * 8 - 1);
        x ^= sign;
        x -= sign;

        return x;
}

static __inline int CLZ(int x)
{
        int numZeros;

        if (!x)
                return 32;

        /* count leading zeros with binary search (function should be 17 ARM instructions total) */
        numZeros = 1;
        if (!((unsigned int)x >> 16))   { numZeros += 16; x <<= 16; }
        if (!((unsigned int)x >> 24))   { numZeros +=  8; x <<=  8; }
        if (!((unsigned int)x >> 28))   { numZeros +=  4; x <<=  4; }
        if (!((unsigned int)x >> 30))   { numZeros +=  2; x <<=  2; }

        numZeros -= ((unsigned int)x >> 31);

        return numZeros;
}

/* implemented in asmfunc.s */
#ifdef __cplusplus
extern "C" {
#endif

typedef __int64 Word64;

typedef union _U64 {
        Word64 w64;
        struct {
                /* ARM WinCE = little endian */
                unsigned int lo32;
                signed int   hi32;
        } r;
} U64;

/* manual name mangling for just this platform (must match labels in .s file) */
#define MULSHIFT32      raac_MULSHIFT32
#define MADD64          raac_MADD64

int MULSHIFT32(int x, int y);
Word64 MADD64(Word64 sum64, int x, int y);

#ifdef __cplusplus
}
#endif

/* toolchain:           ARM ADS or RealView
 * target architecture: ARM v.4 and above (requires 'M' type processor for 32x32->64 multiplier)
 */
#elif (defined (__arm) && defined (__ARMCC_VERSION)) || defined(HELIX_CONFIG_SYMBIAN_GENERATE_MMP)

static __inline int MULSHIFT32(int x, int y)
{
    /* rules for smull RdLo, RdHi, Rm, Rs:
     *   RdHi != Rm
     *   RdLo != Rm
     *   RdHi != RdLo
     */
    int zlow;
    __asm {
        smull zlow,y,x,y
        }

    return y;
}

static __inline short CLIPTOSHORT(int x)
{
        int sign;

        /* clip to [-32768, 32767] */
        sign = x >> 31;
        if (sign != (x >> 15))
                x = sign ^ ((1 << 15) - 1);

        return (short)x;
}

static __inline int FASTABS(int x)
{
        int sign;

        sign = x >> (sizeof(int) * 8 - 1);
        x ^= sign;
        x -= sign;

        return x;
}

static __inline int CLZ(int x)
{
        int numZeros;

        if (!x)
                return 32;

        /* count leading zeros with binary search (function should be 17 ARM instructions total) */
        numZeros = 1;
        if (!((unsigned int)x >> 16))   { numZeros += 16; x <<= 16; }
        if (!((unsigned int)x >> 24))   { numZeros +=  8; x <<=  8; }
        if (!((unsigned int)x >> 28))   { numZeros +=  4; x <<=  4; }
        if (!((unsigned int)x >> 30))   { numZeros +=  2; x <<=  2; }

        numZeros -= ((unsigned int)x >> 31);

        return numZeros;

/* ARM code would look like this, but do NOT use inline asm in ADS for this,
   because you can't safely use the status register flags intermixed with C code

        __asm {
            mov         numZeros, #1
                tst             x, 0xffff0000
                addeq   numZeros, numZeros, #16
                moveq   x, x, lsl #16
                tst             x, 0xff000000
                addeq   numZeros, numZeros, #8
                moveq   x, x, lsl #8
                tst             x, 0xf0000000
                addeq   numZeros, numZeros, #4
                moveq   x, x, lsl #4
                tst             x, 0xc0000000
                addeq   numZeros, numZeros, #2
                moveq   x, x, lsl #2
                sub             numZeros, numZeros, x, lsr #31
        }
*/
/* reference:
        numZeros = 0;
        while (!(x & 0x80000000)) {
                numZeros++;
                x <<= 1;
        }
*/
}

typedef __int64 Word64;

typedef union _U64 {
        Word64 w64;
        struct {
                /* ARM ADS = little endian */
                unsigned int lo32;
                signed int   hi32;
        } r;
} U64;

static __inline Word64 MADD64(Word64 sum64, int x, int y)
{
        U64 u;
        u.w64 = sum64;
        
        __asm {
        smlal u.r.lo32, u.r.hi32, x, y
        }

        return u.w64;
}

/* toolchain:           ARM gcc
 * target architecture: ARM v.4 and above (requires 'M' type processor for 32x32->64 multiplier)
 */
#elif defined(__GNUC__) && defined(__arm__)
static __inline__ int MULSHIFT32(int x, int y)
{
    int zlow;
    __asm__ volatile ("smull %0,%1,%2,%3" : "=&r" (zlow), "=r" (y) : "r" (x), "1" (y) : "cc");
    return y;
}

static __inline short CLIPTOSHORT(int x)
{
        int sign;

        /* clip to [-32768, 32767] */
        sign = x >> 31;
        if (sign != (x >> 15))
                x = sign ^ ((1 << 15) - 1);

        return (short)x;
}

static __inline int FASTABS(int x)
{
        int sign;

        sign = x >> (sizeof(int) * 8 - 1);
        x ^= sign;
        x -= sign;

        return x;
}

static __inline int CLZ(int x)
{
        int numZeros;

        if (!x)
                return (sizeof(int) * 8);

        numZeros = 0;
        while (!(x & 0x80000000)) {
                numZeros++;
                x <<= 1;
        }

        return numZeros;
}

typedef long long Word64;

typedef union _U64 {
        Word64 w64;
        struct {
                /* ARM ADS = little endian */
                unsigned int lo32;
                signed int   hi32;
        } r;
} U64;

static __inline Word64 MADD64(Word64 sum64, int x, int y)
{
        U64 u;
        u.w64 = sum64;
        
        __asm__ volatile ("smlal %0,%1,%2,%3" : "+&r" (u.r.lo32), "+&r" (u.r.hi32) : "r" (x), "r" (y) : "cc");
        
        return u.w64;
}

/* toolchain:           x86 gcc
 * target architecture: x86
 */
#elif defined(__GNUC__) && (defined(__i386__) || defined(__amd64__)) || (defined (_SOLARIS) && !defined (__GNUC__) && defined(_SOLARISX86))

typedef long long Word64;

static __inline__ int MULSHIFT32(int x, int y)
{
    int z;

    z = (Word64)x * (Word64)y >> 32;

        return z;
}

static __inline short CLIPTOSHORT(int x)
{
        int sign;

        /* clip to [-32768, 32767] */
        sign = x >> 31;
        if (sign != (x >> 15))
                x = sign ^ ((1 << 15) - 1);

        return (short)x;
}

static __inline int FASTABS(int x)
{
        int sign;

        sign = x >> (sizeof(int) * 8 - 1);
        x ^= sign;
        x -= sign;

        return x;
}

static __inline int CLZ(int x)
{
        int numZeros;

        if (!x)
                return 32;

        /* count leading zeros with binary search (function should be 17 ARM instructions total) */
        numZeros = 1;
        if (!((unsigned int)x >> 16))   { numZeros += 16; x <<= 16; }
        if (!((unsigned int)x >> 24))   { numZeros +=  8; x <<=  8; }
        if (!((unsigned int)x >> 28))   { numZeros +=  4; x <<=  4; }
        if (!((unsigned int)x >> 30))   { numZeros +=  2; x <<=  2; }

        numZeros -= ((unsigned int)x >> 31);

        return numZeros;
}

typedef union _U64 {
        Word64 w64;
        struct {
                /* x86 = little endian */
                unsigned int lo32;
                signed int   hi32;
        } r;
} U64;

static __inline Word64 MADD64(Word64 sum64, int x, int y)
{
        sum64 += (Word64)x * (Word64)y;

        return sum64;
}

#elif defined(__GNUC__) && (defined(__powerpc__) || defined(__POWERPC__)) || (defined (_SOLARIS) && !defined (__GNUC__) && !defined (_SOLARISX86))

typedef long long Word64;

static __inline__ int MULSHIFT32(int x, int y)
{
    int z;

    z = (Word64)x * (Word64)y >> 32;

        return z;
}

static __inline short CLIPTOSHORT(int x)
{
        int sign;

        /* clip to [-32768, 32767] */
        sign = x >> 31;
        if (sign != (x >> 15))
                x = sign ^ ((1 << 15) - 1);

        return (short)x;
}

static __inline int FASTABS(int x)
{
        int sign;

        sign = x >> (sizeof(int) * 8 - 1);
        x ^= sign;
        x -= sign;

        return x;
}

static __inline int CLZ(int x)
{
        int numZeros;

        if (!x)
                return 32;

        /* count leading zeros with binary search (function should be 17 ARM instructions total) */
        numZeros = 1;
        if (!((unsigned int)x >> 16))   { numZeros += 16; x <<= 16; }
        if (!((unsigned int)x >> 24))   { numZeros +=  8; x <<=  8; }
        if (!((unsigned int)x >> 28))   { numZeros +=  4; x <<=  4; }
        if (!((unsigned int)x >> 30))   { numZeros +=  2; x <<=  2; }

        numZeros -= ((unsigned int)x >> 31);

        return numZeros;
}

typedef union _U64 {
        Word64 w64;
        struct {
                /* PowerPC = big endian */
                signed int   hi32;
                unsigned int lo32;
        } r;
} U64;

static __inline Word64 MADD64(Word64 sum64, int x, int y)
{
        sum64 += (Word64)x * (Word64)y;

        return sum64;
}

#else

#error Unsupported platform in assembly.h

#endif  /* platforms */

#endif /* _ASSEMBLY_H */