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patacongo
@@ -0,0 +1,43 @@
|
||||
############################################################################
|
||||
# lib/fixedmath/Make.defs
|
||||
#
|
||||
# Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
|
||||
# Author: Gregory Nutt <gnutt@nuttx.org>
|
||||
#
|
||||
# Redistribution and use in source and binary forms, with or without
|
||||
# modification, are permitted provided that the following conditions
|
||||
# are met:
|
||||
#
|
||||
# 1. Redistributions of source code must retain the above copyright
|
||||
# notice, this list of conditions and the following disclaimer.
|
||||
# 2. 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.
|
||||
# 3. Neither the name NuttX 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
|
||||
# COPYRIGHT OWNER 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.
|
||||
#
|
||||
############################################################################
|
||||
|
||||
# Add the fixed precision math C files to the build
|
||||
|
||||
CSRCS += lib_rint.c lib_fixedmath.c lib_b16sin.c lib_b16cos.c lib_b16atan2.c
|
||||
|
||||
# Add the fixed precision math directory to the build
|
||||
|
||||
DEPPATH += --dep-path fixedmath
|
||||
VPATH += :fixedmath
|
||||
@@ -0,0 +1,108 @@
|
||||
/****************************************************************************
|
||||
* lib/fixedmath/lib_b16atan2.c
|
||||
*
|
||||
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
|
||||
* Author: Gregory Nutt <gnutt@nuttx.org>
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. 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.
|
||||
* 3. Neither the name NuttX 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
|
||||
* COPYRIGHT OWNER 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.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Included Files
|
||||
****************************************************************************/
|
||||
|
||||
#include <fixedmath.h>
|
||||
|
||||
/****************************************************************************
|
||||
* Pre-processor Definitions
|
||||
****************************************************************************/
|
||||
|
||||
#define B16_C1 0x00000373 /* 0.013480470 */
|
||||
#define B16_C2 0x00000eb7 /* 0.057477314 */
|
||||
#define B16_C3 0x00001f0a /* 0.121239071 */
|
||||
#define B16_C4 0x00003215 /* 0.195635925 */
|
||||
#define B16_C5 0x0000553f /* 0.332994597 */
|
||||
#define B16_C6 0x00010000 /* 0.999995630 */
|
||||
#define B16_HALFPI 0x00019220 /* 1.570796327 */
|
||||
#define B16_PI 0x00032440 /* 3.141592654 */
|
||||
|
||||
#ifndef MAX
|
||||
# define MAX(a,b) (a > b ? a : b)
|
||||
#endif
|
||||
|
||||
#ifndef MIN
|
||||
# define MIN(a,b) (a < b ? a : b)
|
||||
#endif
|
||||
|
||||
#ifndef ABS
|
||||
# define ABS(a) (a < 0 ? -a : a)
|
||||
#endif
|
||||
|
||||
/****************************************************************************
|
||||
* Global Functions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Name: b16atan2
|
||||
*
|
||||
* Description:
|
||||
* atan2 calculates the arctangent of y/x. (Based on a algorithm I saw
|
||||
* posted on the internet... now I have lost the link -- sorry).
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
b16_t b16atan2(b16_t y, b16_t x)
|
||||
{
|
||||
b16_t t0;
|
||||
b16_t t1;
|
||||
b16_t t2;
|
||||
b16_t t3;
|
||||
|
||||
t2 = ABS(x);
|
||||
t1 = ABS(y);
|
||||
t0 = MAX(t2, t1);
|
||||
t1 = MIN(t2, t1);
|
||||
t2 = ub16inv(t0);
|
||||
t2 = b16mulb16(t1, t2);
|
||||
|
||||
t3 = b16mulb16(t2, t2);
|
||||
t0 = - B16_C1;
|
||||
t0 = b16mulb16(t0, t3) + B16_C2;
|
||||
t0 = b16mulb16(t0, t3) - B16_C3;
|
||||
t0 = b16mulb16(t0, t3) + B16_C4;
|
||||
t0 = b16mulb16(t0, t3) - B16_C5;
|
||||
t0 = b16mulb16(t0, t3) + B16_C6;
|
||||
t2 = b16mulb16(t0, t2);
|
||||
|
||||
t2 = (ABS(y) > ABS(x)) ? B16_HALFPI - t2 : t2;
|
||||
t2 = (x < 0) ? B16_PI - t2 : t2;
|
||||
t2 = (y < 0) ? -t2 : t2;
|
||||
|
||||
return t2;
|
||||
}
|
||||
@@ -0,0 +1,64 @@
|
||||
/****************************************************************************
|
||||
* lib/fixedmath/lib_b16cos.c
|
||||
*
|
||||
* Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved.
|
||||
* Author: Gregory Nutt <gnutt@nuttx.org>
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. 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.
|
||||
* 3. Neither the name NuttX 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
|
||||
* COPYRIGHT OWNER 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.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Included Files
|
||||
****************************************************************************/
|
||||
|
||||
#include <fixedmath.h>
|
||||
|
||||
/****************************************************************************
|
||||
* Pre-processor Definitions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Global Functions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Name: b16cos
|
||||
****************************************************************************/
|
||||
|
||||
b16_t b16cos(b16_t rad)
|
||||
{
|
||||
/* Compute cosine: sin(rad + PI/2) = cos(rad) */
|
||||
|
||||
rad += b16HALFPI;
|
||||
if (rad > b16PI)
|
||||
{
|
||||
rad -= b16TWOPI;
|
||||
}
|
||||
return b16sin(rad);
|
||||
}
|
||||
@@ -0,0 +1,110 @@
|
||||
/****************************************************************************
|
||||
* lib/fixedmath/lib_b16sin.c
|
||||
*
|
||||
* Copyright (C) 2008, 2011 Gregory Nutt. All rights reserved.
|
||||
* Author: Gregory Nutt <gnutt@nuttx.org>
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. 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.
|
||||
* 3. Neither the name NuttX 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
|
||||
* COPYRIGHT OWNER 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.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Included Files
|
||||
****************************************************************************/
|
||||
|
||||
#include <fixedmath.h>
|
||||
|
||||
/****************************************************************************
|
||||
* Pre-processor Definitions
|
||||
****************************************************************************/
|
||||
|
||||
#define b16_P225 0x0000399a
|
||||
#define b16_P405284735 0x000067c1
|
||||
#define b16_1P27323954 0x000145f3
|
||||
|
||||
/****************************************************************************
|
||||
* Global Functions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Name: b16sin
|
||||
* Ref: http://lab.polygonal.de/2007/07/18/fast-and-accurate-sinecosine-approximation/
|
||||
****************************************************************************/
|
||||
|
||||
b16_t b16sin(b16_t rad)
|
||||
{
|
||||
b16_t tmp1;
|
||||
b16_t tmp2;
|
||||
b16_t tmp3;
|
||||
|
||||
/* Force angle into the good range */
|
||||
|
||||
if (rad < -b16PI)
|
||||
{
|
||||
rad += b16TWOPI;
|
||||
}
|
||||
else if (rad > b16PI)
|
||||
{
|
||||
rad -= b16TWOPI;
|
||||
}
|
||||
|
||||
/* tmp1 = 1.27323954 * rad
|
||||
* tmp2 = .405284735 * rad * rad
|
||||
*/
|
||||
|
||||
|
||||
tmp1 = b16mulb16(b16_1P27323954, rad);
|
||||
tmp2 = b16mulb16(b16_P405284735, b16sqr(rad));
|
||||
|
||||
if (rad < 0)
|
||||
{
|
||||
/* tmp3 = 1.27323954 * rad + .405284735 * rad * rad */
|
||||
|
||||
tmp3 = tmp1 + tmp2;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* tmp3 = 1.27323954 * rad - 0.405284735 * rad * rad */
|
||||
|
||||
tmp3 = tmp1 - tmp2;
|
||||
}
|
||||
|
||||
/* tmp1 = tmp3*tmp3 */
|
||||
|
||||
tmp1 = b16sqr(tmp3);
|
||||
if (tmp3 < 0)
|
||||
{
|
||||
/* tmp1 = tmp3 * -tmp3 */
|
||||
|
||||
tmp1 = -tmp1;
|
||||
}
|
||||
|
||||
/* Return sin = .225 * (tmp3 * (+/-tmp3) - tmp3) + tmp3 */
|
||||
|
||||
return b16mulb16(b16_P225, (tmp1 - tmp3)) + tmp3;
|
||||
}
|
||||
@@ -0,0 +1,272 @@
|
||||
/****************************************************************************
|
||||
* lib/math/lib_fixedmath.c
|
||||
*
|
||||
* Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
|
||||
* Author: Gregory Nutt <gnutt@nuttx.org>
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. 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.
|
||||
* 3. Neither the name NuttX 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
|
||||
* COPYRIGHT OWNER 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.
|
||||
*
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Included Files
|
||||
****************************************************************************/
|
||||
|
||||
#include <nuttx/config.h>
|
||||
|
||||
#include <stdint.h>
|
||||
#include <stdbool.h>
|
||||
#include <fixedmath.h>
|
||||
|
||||
#ifndef CONFIG_HAVE_LONG_LONG
|
||||
|
||||
/****************************************************************************
|
||||
* Pre-processor Definitions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Private Type Declarations
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Private Function Prototypes
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Public Data
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Private Data
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Name: fixsign
|
||||
****************************************************************************/
|
||||
|
||||
static void fixsign(b16_t *parg1, b16_t *parg2, bool *pnegate)
|
||||
{
|
||||
bool negate = false;
|
||||
b16_t arg;
|
||||
|
||||
arg = *parg1;
|
||||
if (arg < 0)
|
||||
{
|
||||
*parg1 = -arg;
|
||||
negate = true;
|
||||
}
|
||||
|
||||
arg = *parg2;
|
||||
if (arg < 0)
|
||||
{
|
||||
*parg2 = -arg;
|
||||
negate ^= true;
|
||||
}
|
||||
|
||||
*pnegate = negate;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: adjustsign
|
||||
****************************************************************************/
|
||||
|
||||
static b16_t adjustsign(b16_t result, bool negate)
|
||||
{
|
||||
/* If the product is negative, then we overflowed */
|
||||
|
||||
if (result < 0)
|
||||
{
|
||||
if (result)
|
||||
{
|
||||
return b16MIN;
|
||||
}
|
||||
else
|
||||
{
|
||||
return b16MAX;
|
||||
}
|
||||
}
|
||||
|
||||
/* correct the sign of the result */
|
||||
|
||||
if (negate)
|
||||
{
|
||||
return -result;
|
||||
}
|
||||
return result;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Public Functions
|
||||
****************************************************************************/
|
||||
|
||||
/****************************************************************************
|
||||
* Name: b16mulb16
|
||||
****************************************************************************/
|
||||
|
||||
b16_t b16mulb16(b16_t m1, b16_t m2)
|
||||
{
|
||||
bool negate;
|
||||
b16_t product;
|
||||
|
||||
fixsign(&m1, &m2, &negate);
|
||||
product = (b16_t)ub16mulub16((ub16_t)m1, (ub16_t)m2);
|
||||
return adjustsign(product, negate);
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: ub16mulub16
|
||||
**************************************************************************/
|
||||
|
||||
ub16_t ub16mulub16(ub16_t m1, ub16_t m2)
|
||||
{
|
||||
/* Let:
|
||||
*
|
||||
* m1 = m1i*2**16 + m1f (b16)
|
||||
* m2 = m2i*2**16 + m2f (b16)
|
||||
*
|
||||
* Then:
|
||||
*
|
||||
* m1*m2 = (m1i*m2i)*2**32 + (m1i*m2f + m2i*m1f)*2**16 + m1f*m2f (b32)
|
||||
* = (m1i*m2i)*2**16 + (m1i*m2f + m2i*m1f) + m1f*m2f*2**-16 (b16)
|
||||
* = a*2**16 + b + c*2**-16
|
||||
*/
|
||||
|
||||
uint32_t m1i = ((uint32_t)m1 >> 16);
|
||||
uint32_t m2i = ((uint32_t)m1 >> 16);
|
||||
uint32_t m1f = ((uint32_t)m1 & 0x0000ffff);
|
||||
uint32_t m2f = ((uint32_t)m2 & 0x0000ffff);
|
||||
|
||||
return (m1i*m2i << 16) + m1i*m2f + m2i*m1f + (((m1f*m2f) + b16HALF) >> 16);
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: b16sqr
|
||||
**************************************************************************/
|
||||
|
||||
b16_t b16sqr(b16_t a)
|
||||
{
|
||||
b16_t sq;
|
||||
|
||||
/* The result is always positive. Just take the absolute value */
|
||||
|
||||
if (a < 0)
|
||||
{
|
||||
a = -a;
|
||||
}
|
||||
|
||||
/* Overflow occurred if the result is negative */
|
||||
|
||||
sq = (b16_t)ub16sqr(a);
|
||||
if (sq < 0)
|
||||
{
|
||||
sq = b16MAX;
|
||||
}
|
||||
return sq;
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: b16divb16
|
||||
**************************************************************************/
|
||||
|
||||
ub16_t ub16sqr(ub16_t a)
|
||||
{
|
||||
/* Let:
|
||||
*
|
||||
* m = mi*2**16 + mf (b16)
|
||||
*
|
||||
* Then:
|
||||
*
|
||||
* m*m = (mi*mi)*2**32 + 2*(m1*m2)*2**16 + mf*mf (b32)
|
||||
* = (mi*mi)*2**16 + 2*(mi*mf) + mf*mf*2**-16 (b16)
|
||||
*/
|
||||
|
||||
uint32_t mi = ((uint32_t)a >> 16);
|
||||
uint32_t mf = ((uint32_t)a & 0x0000ffff);
|
||||
|
||||
return (mi*mi << 16) + (mi*mf << 1) + ((mf*mf + b16HALF) >> 16);
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: b16divb16
|
||||
**************************************************************************/
|
||||
|
||||
b16_t b16divb16(b16_t num, b16_t denom)
|
||||
{
|
||||
bool negate;
|
||||
b16_t quotient;
|
||||
|
||||
fixsign(&num, &denom, &negate);
|
||||
quotient = (b16_t)ub16divub16((ub16_t)num, (ub16_t)denom);
|
||||
return adjustsign(quotient, negate);
|
||||
}
|
||||
|
||||
/****************************************************************************
|
||||
* Name: ub16divub16
|
||||
**************************************************************************/
|
||||
|
||||
ub16_t ub16divub16(ub16_t num, ub16_t denom)
|
||||
{
|
||||
uint32_t term1;
|
||||
uint32_t numf;
|
||||
uint32_t product;
|
||||
|
||||
/* Let:
|
||||
*
|
||||
* num = numi*2**16 + numf (b16)
|
||||
* den = deni*2**16 + denf (b16)
|
||||
*
|
||||
* Then:
|
||||
*
|
||||
* num/den = numi*2**16 / den + numf / den (b0)
|
||||
* = numi*2**32 / den + numf*2**16 /den (b16)
|
||||
*/
|
||||
|
||||
/* Check for overflow in the first part of the quotient */
|
||||
|
||||
term1 = ((uint32_t)num & 0xffff0000) / denom;
|
||||
if (term1 >= 0x00010000)
|
||||
{
|
||||
return ub16MAX; /* Will overflow */
|
||||
}
|
||||
|
||||
/* Finish the division */
|
||||
|
||||
numf = num - term1 * denom;
|
||||
term1 <<= 16;
|
||||
product = term1 + (numf + (denom >> 1)) / denom;
|
||||
|
||||
/* Check for overflow */
|
||||
|
||||
if (product < term1)
|
||||
{
|
||||
return ub16MAX; /* Overflowed */
|
||||
}
|
||||
return product;
|
||||
}
|
||||
|
||||
#endif
|
||||
@@ -0,0 +1,135 @@
|
||||
/************************************************************
|
||||
* lib/fixedmath/lib_rint.c
|
||||
*
|
||||
* Copyright (C) 2007, 2011 Gregory Nutt. All rights reserved.
|
||||
* Author: Gregory Nutt <gnutt@nuttx.org>
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. 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.
|
||||
* 3. Neither the name NuttX 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
|
||||
* COPYRIGHT OWNER 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.
|
||||
*
|
||||
************************************************************/
|
||||
|
||||
/************************************************************
|
||||
* Compilation Switches
|
||||
************************************************************/
|
||||
|
||||
/************************************************************
|
||||
* Included Files
|
||||
************************************************************/
|
||||
|
||||
#include <nuttx/config.h>
|
||||
#include <sys/types.h>
|
||||
#include <stdlib.h>
|
||||
|
||||
/************************************************************
|
||||
* Definitions
|
||||
************************************************************/
|
||||
|
||||
/************************************************************
|
||||
* Private Type Declarations
|
||||
************************************************************/
|
||||
|
||||
/************************************************************
|
||||
* Private Function Prototypes
|
||||
************************************************************/
|
||||
|
||||
/**********************************************************
|
||||
* Global Constant Data
|
||||
**********************************************************/
|
||||
|
||||
/************************************************************
|
||||
* Global Variables
|
||||
************************************************************/
|
||||
|
||||
/**********************************************************
|
||||
* Private Constant Data
|
||||
**********************************************************/
|
||||
|
||||
/************************************************************
|
||||
* Private Variables
|
||||
************************************************************/
|
||||
|
||||
double_t rint(double_t x)
|
||||
{
|
||||
double_t ret;
|
||||
|
||||
/* If the current rounding mode rounds toward negative
|
||||
* infinity, rint() is identical to floor(). If the current
|
||||
* rounding mode rounds toward positive infinity, rint() is
|
||||
* identical to ceil().
|
||||
*/
|
||||
|
||||
#if defined(CONFIG_FP_ROUND_POSITIVE) && CONFIG_FP_ROUNDING_POSITIVE != 0
|
||||
|
||||
ret = ceil(x);
|
||||
|
||||
#elif defined(CONFIG_FP_ROUND_NEGATIVE) && CONFIG_FP_ROUNDING_NEGATIVE != 0
|
||||
|
||||
ret = floor(x);
|
||||
|
||||
#else
|
||||
|
||||
/* In the default rounding mode (round to nearest), rint(x) is the
|
||||
* integer nearest x with the additional stipulation that if
|
||||
* |rint(x)-x|=1/2, then rint(x) is even.
|
||||
*/
|
||||
|
||||
long dwinteger = (long)x;
|
||||
double_t fremainder = x - (double_t)dwinteger;
|
||||
|
||||
if (x < 0.0)
|
||||
{
|
||||
/* fremainder should be in range 0 .. -1 */
|
||||
|
||||
if (fremainder == -0.5)
|
||||
{
|
||||
dwinteger = ((dwinteger+1)&~1);
|
||||
}
|
||||
else if (fremainder < -0.5)
|
||||
{
|
||||
dwinteger--;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/* fremainder should be in range 0 .. 1 */
|
||||
|
||||
if (fremainder == 0.5)
|
||||
{
|
||||
dwinteger = ((dwinteger+1)&~1);
|
||||
}
|
||||
else if (fremainder > 0.5)
|
||||
{
|
||||
dwinteger++;
|
||||
}
|
||||
}
|
||||
|
||||
ret = (double_t)dwinteger;
|
||||
#endif
|
||||
|
||||
return ret;
|
||||
}
|
||||
Reference in New Issue
Block a user