/* * libmad - MPEG audio decoder library * Copyright (C) 2000-2004 Underbit Technologies, Inc. * * 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 1.38 2004/02/17 02:02:03 rob Exp $ */ #ifndef LIBMAD_FIXED_H #define LIBMAD_FIXED_H #ifdef __cplusplus extern "C" { #endif #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 #if defined(_MSC_VER) #define mad_fixed64_t signed __int64 #elif 1 || defined(__GNUC__) #define mad_fixed64_t signed long long #endif #if defined(FPM_FLOAT) typedef double mad_sample_t; #else typedef mad_fixed_t mad_sample_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) #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))) #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_FLOAT) #error "FPM_FLOAT not yet supported" #undef MAD_F #define MAD_F(x) mad_f_todouble(x) #define mad_f_mul(x, y) ((x) * (y)) #define mad_f_scale64 #undef ASO_ZEROCHECK #elif defined(FPM_64BIT) /* * This version should be the most accurate if 64-bit 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)((((mad_fixed64_t)(x) * (y)) + (1L << (MAD_F_SCALEBITS - 1))) >> MAD_F_SCALEBITS)) #else #define mad_f_mul(x, y) ((mad_fixed_t)(((mad_fixed64_t)(x) * (y)) >> MAD_F_SCALEBITS)) #endif #define MAD_F_SCALEBITS MAD_F_FRACBITS /* --- Intel --------------------------------------------------------------- */ #elif defined(FPM_INTEL) #if defined(_MSC_VER) #pragma warning(push) #pragma warning(disable : 4035) /* no return value */ static __forceinline mad_fixed_t mad_f_mul_inline(mad_fixed_t x, mad_fixed_t y) { enum { fracbits = MAD_F_FRACBITS }; __asm { mov eax, x imul y shrd eax, edx, fracbits } /* implicit return of eax */ } #pragma warning(pop) #define mad_f_mul mad_f_mul_inline #define mad_f_scale64 #else /* * 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; \ }) #elif defined(OPT_INTEL) /* * Alternate Intel scaling that may or may not perform better. */ #define mad_f_scale64(hi, lo) \ ({ \ mad_fixed_t __result; \ asm("shrl %3,%1\n\t" \ "shll %4,%2\n\t" \ "orl %2,%1" \ : "=rm"(__result) \ : "0"(lo), "r"(hi), "I"(MAD_F_SCALEBITS), "I"(32 - 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 #endif /* --- 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 /* * This is faster than the default implementation via MAD_F_MLX() and * 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_MLN(hi, lo) \ asm("rsbs %0, %2, #0\n\t" \ "rsc %1, %3, #0" \ : "=r"(lo), "=r"(hi) \ : "0"(lo), "1"(hi) \ : "cc") #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 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) \ do { \ asm("mullw %0,%1,%2" : "=r"(lo) : "%r"(x), "r"(y)); \ asm("mulhw %0,%1,%2" : "=r"(hi) : "%r"(x), "r"(y)); \ } \ while (0) #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("addc %0,%2,%3\n\t" \ "adde %1,%4,%5" \ : "=r"(lo), "=r"(hi) \ : "%r"(lo), "r"(__lo), "%r"(hi), "r"(__hi) \ : "xer"); \ }) #endif #if defined(OPT_ACCURACY) /* * This is slower than the truncating version below it. */ #define mad_f_scale64(hi, lo) \ ({ \ mad_fixed_t __result, __round; \ asm("rotrwi %0,%1,%2" : "=r"(__result) : "r"(lo), "i"(MAD_F_SCALEBITS)); \ asm("extrwi %0,%1,1,0" : "=r"(__round) : "r"(__result)); \ asm("insrwi %0,%1,%2,0" : "+r"(__result) : "r"(hi), "i"(MAD_F_SCALEBITS)); \ asm("add %0,%1,%2" : "=r"(__result) : "%r"(__result), "r"(__round)); \ __result; \ }) #else #define mad_f_scale64(hi, lo) \ ({ \ mad_fixed_t __result; \ asm("rotrwi %0,%1,%2" : "=r"(__result) : "r"(lo), "i"(MAD_F_SCALEBITS)); \ asm("insrwi %0,%1,%2,0" : "+r"(__result) : "r"(hi), "i"(MAD_F_SCALEBITS)); \ __result; \ }) #endif #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. */ #if defined(OPT_SPEED) #define mad_f_mul(x, y) (((x) >> 12) * ((y) >> 16)) #else #define mad_f_mul(x, y) ((((x) + (1L << 11)) >> 12) * (((y) + (1L << 15)) >> 16)) #endif /* ------------------------------------------------------------------------- */ #else #error "no FPM selected" #endif /* default implementations */ #if !defined(mad_f_mul) #define mad_f_mul(x, y) \ ({ \ register mad_fixed64hi_t __hi; \ register 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_MLN(hi, lo) ((lo) = -(lo)) #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_MLN) #define MAD_F_MLN(hi, lo) ((hi) = ((lo) = -(lo)) ? ~(hi) : -(hi)) #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 /* C routines */ mad_fixed_t mad_f_abs(mad_fixed_t); mad_fixed_t mad_f_div(mad_fixed_t, mad_fixed_t); #ifdef __cplusplus } #endif #endif