diff options
Diffstat (limited to 'nuttx/libc/fixedmath')
| -rw-r--r-- | nuttx/libc/fixedmath/Make.defs | 43 | ||||
| -rw-r--r-- | nuttx/libc/fixedmath/lib_b16atan2.c | 108 | ||||
| -rw-r--r-- | nuttx/libc/fixedmath/lib_b16cos.c | 64 | ||||
| -rw-r--r-- | nuttx/libc/fixedmath/lib_b16sin.c | 110 | ||||
| -rw-r--r-- | nuttx/libc/fixedmath/lib_fixedmath.c | 272 | ||||
| -rw-r--r-- | nuttx/libc/fixedmath/lib_rint.c | 135 |
6 files changed, 0 insertions, 732 deletions
diff --git a/nuttx/libc/fixedmath/Make.defs b/nuttx/libc/fixedmath/Make.defs deleted file mode 100644 index b53df2b2c..000000000 --- a/nuttx/libc/fixedmath/Make.defs +++ /dev/null @@ -1,43 +0,0 @@ -############################################################################ -# libc/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 diff --git a/nuttx/libc/fixedmath/lib_b16atan2.c b/nuttx/libc/fixedmath/lib_b16atan2.c deleted file mode 100644 index 443ab7be3..000000000 --- a/nuttx/libc/fixedmath/lib_b16atan2.c +++ /dev/null @@ -1,108 +0,0 @@ -/**************************************************************************** - * libc/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; -} diff --git a/nuttx/libc/fixedmath/lib_b16cos.c b/nuttx/libc/fixedmath/lib_b16cos.c deleted file mode 100644 index 0ebe48262..000000000 --- a/nuttx/libc/fixedmath/lib_b16cos.c +++ /dev/null @@ -1,64 +0,0 @@ -/**************************************************************************** - * libc/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); -} diff --git a/nuttx/libc/fixedmath/lib_b16sin.c b/nuttx/libc/fixedmath/lib_b16sin.c deleted file mode 100644 index 9cd2f0da3..000000000 --- a/nuttx/libc/fixedmath/lib_b16sin.c +++ /dev/null @@ -1,110 +0,0 @@ -/**************************************************************************** - * libc/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; -} diff --git a/nuttx/libc/fixedmath/lib_fixedmath.c b/nuttx/libc/fixedmath/lib_fixedmath.c deleted file mode 100644 index 9e9213b4f..000000000 --- a/nuttx/libc/fixedmath/lib_fixedmath.c +++ /dev/null @@ -1,272 +0,0 @@ -/**************************************************************************** - * libc/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 diff --git a/nuttx/libc/fixedmath/lib_rint.c b/nuttx/libc/fixedmath/lib_rint.c deleted file mode 100644 index a1212c970..000000000 --- a/nuttx/libc/fixedmath/lib_rint.c +++ /dev/null @@ -1,135 +0,0 @@ -/************************************************************ - * libc/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; -} |