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Diffstat (limited to 'nuttx/libc/fixedmath/lib_fixedmath.c')
| -rw-r--r-- | nuttx/libc/fixedmath/lib_fixedmath.c | 272 |
1 files changed, 0 insertions, 272 deletions
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 |