379 lines
8.4 KiB
C
379 lines
8.4 KiB
C
/* Copyright (C) 2005 Jean-Marc Valin */
|
|
/**
|
|
@file pseudofloat.h
|
|
@brief Pseudo-floating point
|
|
* This header file provides a lightweight floating point type for
|
|
* use on fixed-point platforms when a large dynamic range is
|
|
* required. The new type is not compatible with the 32-bit IEEE format,
|
|
* it is not even remotely as accurate as 32-bit floats, and is not
|
|
* even guaranteed to produce even remotely correct results for code
|
|
* other than Speex. It makes all kinds of shortcuts that are acceptable
|
|
* for Speex, but may not be acceptable for your application. You're
|
|
* quite welcome to reuse this code and improve it, but don't assume
|
|
* it works out of the box. Most likely, it doesn't.
|
|
*/
|
|
/*
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
|
|
- Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
- Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
|
|
- Neither the name of the Xiph.org Foundation nor the names of its
|
|
contributors may be used to endorse or promote products derived from
|
|
this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
|
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
|
|
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
|
|
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
|
|
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef PSEUDOFLOAT_H
|
|
#define PSEUDOFLOAT_H
|
|
|
|
#include "arch.h"
|
|
#include "os_support.h"
|
|
#include "math_approx.h"
|
|
#include <math.h>
|
|
|
|
#ifdef FIXED_POINT
|
|
|
|
typedef struct {
|
|
spx_int16_t m;
|
|
spx_int16_t e;
|
|
} spx_float_t;
|
|
|
|
static const spx_float_t FLOAT_ZERO = {0,0};
|
|
static const spx_float_t FLOAT_ONE = {16384,-14};
|
|
static const spx_float_t FLOAT_HALF = {16384,-15};
|
|
|
|
#define MIN(a,b) ((a)<(b)?(a):(b))
|
|
static inline spx_float_t PSEUDOFLOAT(spx_int32_t x)
|
|
{
|
|
int e=0;
|
|
int sign=0;
|
|
if (x<0)
|
|
{
|
|
sign = 1;
|
|
x = -x;
|
|
}
|
|
if (x==0)
|
|
{
|
|
spx_float_t r = {0,0};
|
|
return r;
|
|
}
|
|
e = spx_ilog2(ABS32(x))-14;
|
|
x = VSHR32(x, e);
|
|
if (sign)
|
|
{
|
|
spx_float_t r;
|
|
r.m = -x;
|
|
r.e = e;
|
|
return r;
|
|
}
|
|
else
|
|
{
|
|
spx_float_t r;
|
|
r.m = x;
|
|
r.e = e;
|
|
return r;
|
|
}
|
|
}
|
|
|
|
|
|
static inline spx_float_t FLOAT_ADD(spx_float_t a, spx_float_t b)
|
|
{
|
|
spx_float_t r;
|
|
if (a.m==0)
|
|
return b;
|
|
else if (b.m==0)
|
|
return a;
|
|
if ((a).e > (b).e)
|
|
{
|
|
r.m = ((a).m>>1) + ((b).m>>MIN(15,(a).e-(b).e+1));
|
|
r.e = (a).e+1;
|
|
}
|
|
else
|
|
{
|
|
r.m = ((b).m>>1) + ((a).m>>MIN(15,(b).e-(a).e+1));
|
|
r.e = (b).e+1;
|
|
}
|
|
if (r.m>0)
|
|
{
|
|
if (r.m<16384)
|
|
{
|
|
r.m<<=1;
|
|
r.e-=1;
|
|
}
|
|
} else {
|
|
if (r.m>-16384)
|
|
{
|
|
r.m<<=1;
|
|
r.e-=1;
|
|
}
|
|
}
|
|
/*printf ("%f + %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/
|
|
return r;
|
|
}
|
|
|
|
static inline spx_float_t FLOAT_SUB(spx_float_t a, spx_float_t b)
|
|
{
|
|
spx_float_t r;
|
|
if (a.m==0)
|
|
return b;
|
|
else if (b.m==0)
|
|
return a;
|
|
if ((a).e > (b).e)
|
|
{
|
|
r.m = ((a).m>>1) - ((b).m>>MIN(15,(a).e-(b).e+1));
|
|
r.e = (a).e+1;
|
|
}
|
|
else
|
|
{
|
|
r.m = ((a).m>>MIN(15,(b).e-(a).e+1)) - ((b).m>>1);
|
|
r.e = (b).e+1;
|
|
}
|
|
if (r.m>0)
|
|
{
|
|
if (r.m<16384)
|
|
{
|
|
r.m<<=1;
|
|
r.e-=1;
|
|
}
|
|
} else {
|
|
if (r.m>-16384)
|
|
{
|
|
r.m<<=1;
|
|
r.e-=1;
|
|
}
|
|
}
|
|
/*printf ("%f + %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/
|
|
return r;
|
|
}
|
|
|
|
static inline int FLOAT_LT(spx_float_t a, spx_float_t b)
|
|
{
|
|
if (a.m==0)
|
|
return b.m>0;
|
|
else if (b.m==0)
|
|
return a.m<0;
|
|
if ((a).e > (b).e)
|
|
return ((a).m>>1) < ((b).m>>MIN(15,(a).e-(b).e+1));
|
|
else
|
|
return ((b).m>>1) > ((a).m>>MIN(15,(b).e-(a).e+1));
|
|
|
|
}
|
|
|
|
static inline int FLOAT_GT(spx_float_t a, spx_float_t b)
|
|
{
|
|
return FLOAT_LT(b,a);
|
|
}
|
|
|
|
static inline spx_float_t FLOAT_MULT(spx_float_t a, spx_float_t b)
|
|
{
|
|
spx_float_t r;
|
|
r.m = (spx_int16_t)((spx_int32_t)(a).m*(b).m>>15);
|
|
r.e = (a).e+(b).e+15;
|
|
if (r.m>0)
|
|
{
|
|
if (r.m<16384)
|
|
{
|
|
r.m<<=1;
|
|
r.e-=1;
|
|
}
|
|
} else {
|
|
if (r.m>-16384)
|
|
{
|
|
r.m<<=1;
|
|
r.e-=1;
|
|
}
|
|
}
|
|
/*printf ("%f * %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/
|
|
return r;
|
|
}
|
|
|
|
static inline spx_float_t FLOAT_AMULT(spx_float_t a, spx_float_t b)
|
|
{
|
|
spx_float_t r;
|
|
r.m = (spx_int16_t)((spx_int32_t)(a).m*(b).m>>15);
|
|
r.e = (a).e+(b).e+15;
|
|
return r;
|
|
}
|
|
|
|
|
|
static inline spx_float_t FLOAT_SHL(spx_float_t a, int b)
|
|
{
|
|
spx_float_t r;
|
|
r.m = a.m;
|
|
r.e = a.e+b;
|
|
return r;
|
|
}
|
|
|
|
static inline spx_int16_t FLOAT_EXTRACT16(spx_float_t a)
|
|
{
|
|
if (a.e<0)
|
|
return EXTRACT16((EXTEND32(a.m)+(EXTEND32(1)<<(-a.e-1)))>>-a.e);
|
|
else
|
|
return a.m<<a.e;
|
|
}
|
|
|
|
static inline spx_int32_t FLOAT_EXTRACT32(spx_float_t a)
|
|
{
|
|
if (a.e<0)
|
|
return (EXTEND32(a.m)+(EXTEND32(1)<<(-a.e-1)))>>-a.e;
|
|
else
|
|
return EXTEND32(a.m)<<a.e;
|
|
}
|
|
|
|
static inline spx_int32_t FLOAT_MUL32(spx_float_t a, spx_word32_t b)
|
|
{
|
|
return VSHR32(MULT16_32_Q15(a.m, b),-a.e-15);
|
|
}
|
|
|
|
static inline spx_float_t FLOAT_MUL32U(spx_word32_t a, spx_word32_t b)
|
|
{
|
|
int e1, e2;
|
|
spx_float_t r;
|
|
if (a==0 || b==0)
|
|
{
|
|
return FLOAT_ZERO;
|
|
}
|
|
e1 = spx_ilog2(ABS32(a));
|
|
a = VSHR32(a, e1-14);
|
|
e2 = spx_ilog2(ABS32(b));
|
|
b = VSHR32(b, e2-14);
|
|
r.m = MULT16_16_Q15(a,b);
|
|
r.e = e1+e2-13;
|
|
return r;
|
|
}
|
|
|
|
/* Do NOT attempt to divide by a negative number */
|
|
static inline spx_float_t FLOAT_DIV32_FLOAT(spx_word32_t a, spx_float_t b)
|
|
{
|
|
int e=0;
|
|
spx_float_t r;
|
|
if (a==0)
|
|
{
|
|
return FLOAT_ZERO;
|
|
}
|
|
e = spx_ilog2(ABS32(a))-spx_ilog2(b.m-1)-15;
|
|
a = VSHR32(a, e);
|
|
if (ABS32(a)>=SHL32(EXTEND32(b.m-1),15))
|
|
{
|
|
a >>= 1;
|
|
e++;
|
|
}
|
|
r.m = DIV32_16(a,b.m);
|
|
r.e = e-b.e;
|
|
return r;
|
|
}
|
|
|
|
|
|
/* Do NOT attempt to divide by a negative number */
|
|
static inline spx_float_t FLOAT_DIV32(spx_word32_t a, spx_word32_t b)
|
|
{
|
|
int e0=0,e=0;
|
|
spx_float_t r;
|
|
if (a==0)
|
|
{
|
|
return FLOAT_ZERO;
|
|
}
|
|
if (b>32767)
|
|
{
|
|
e0 = spx_ilog2(b)-14;
|
|
b = VSHR32(b, e0);
|
|
e0 = -e0;
|
|
}
|
|
e = spx_ilog2(ABS32(a))-spx_ilog2(b-1)-15;
|
|
a = VSHR32(a, e);
|
|
if (ABS32(a)>=SHL32(EXTEND32(b-1),15))
|
|
{
|
|
a >>= 1;
|
|
e++;
|
|
}
|
|
e += e0;
|
|
r.m = DIV32_16(a,b);
|
|
r.e = e;
|
|
return r;
|
|
}
|
|
|
|
/* Do NOT attempt to divide by a negative number */
|
|
static inline spx_float_t FLOAT_DIVU(spx_float_t a, spx_float_t b)
|
|
{
|
|
int e=0;
|
|
spx_int32_t num;
|
|
spx_float_t r;
|
|
if (b.m<=0)
|
|
{
|
|
speex_warning_int("Attempted to divide by", b.m);
|
|
return FLOAT_ONE;
|
|
}
|
|
num = a.m;
|
|
a.m = ABS16(a.m);
|
|
while (a.m >= b.m)
|
|
{
|
|
e++;
|
|
a.m >>= 1;
|
|
}
|
|
num = num << (15-e);
|
|
r.m = DIV32_16(num,b.m);
|
|
r.e = a.e-b.e-15+e;
|
|
return r;
|
|
}
|
|
|
|
static inline spx_float_t FLOAT_SQRT(spx_float_t a)
|
|
{
|
|
spx_float_t r;
|
|
spx_int32_t m;
|
|
m = SHL32(EXTEND32(a.m), 14);
|
|
r.e = a.e - 14;
|
|
if (r.e & 1)
|
|
{
|
|
r.e -= 1;
|
|
m <<= 1;
|
|
}
|
|
r.e >>= 1;
|
|
r.m = spx_sqrt(m);
|
|
return r;
|
|
}
|
|
|
|
#else
|
|
|
|
#define spx_float_t float
|
|
#define FLOAT_ZERO 0.f
|
|
#define FLOAT_ONE 1.f
|
|
#define FLOAT_HALF 0.5f
|
|
#define PSEUDOFLOAT(x) (x)
|
|
#define FLOAT_MULT(a,b) ((a)*(b))
|
|
#define FLOAT_AMULT(a,b) ((a)*(b))
|
|
#define FLOAT_MUL32(a,b) ((a)*(b))
|
|
#define FLOAT_DIV32(a,b) ((a)/(b))
|
|
#define FLOAT_EXTRACT16(a) (a)
|
|
#define FLOAT_EXTRACT32(a) (a)
|
|
#define FLOAT_ADD(a,b) ((a)+(b))
|
|
#define FLOAT_SUB(a,b) ((a)-(b))
|
|
#define REALFLOAT(x) (x)
|
|
#define FLOAT_DIV32_FLOAT(a,b) ((a)/(b))
|
|
#define FLOAT_MUL32U(a,b) ((a)*(b))
|
|
#define FLOAT_SHL(a,b) (a)
|
|
#define FLOAT_LT(a,b) ((a)<(b))
|
|
#define FLOAT_GT(a,b) ((a)>(b))
|
|
#define FLOAT_DIVU(a,b) ((a)/(b))
|
|
#define FLOAT_SQRT(a) (spx_sqrt(a))
|
|
|
|
#endif
|
|
|
|
#endif
|