forked from nuttx/nuttx-update
Add fixed precision math support
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1304 42af7a65-404d-4744-a932-0658087f49c3
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patacongo
parent
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3 changed files with 429 additions and 1 deletions
205
include/fixedmath.h
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205
include/fixedmath.h
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@ -0,0 +1,205 @@
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/****************************************************************************
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* include/fixedmath.h
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*
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* Copyright (C) 2008 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
*
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||||
* 1. Redistributions of source code must retain the above copyright
|
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* notice, this list of conditions and the following disclaimer.
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* 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.
|
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* 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.
|
||||
*
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||||
* 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,
|
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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#ifndef __INCLUDE_FIXEDMATH_H
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#define __INCLUDE_FIXEDMATH_H
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <sys/types.h>
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/**************************************************************************
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* Definitions
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**************************************************************************/
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/* Common numbers */
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#define b8HUNDRED 0x6400 /* 100 */
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#define b8TEN 0x0a00 /* 10 */
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#define b8ONE 0x0100 /* 1 */
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#define b8HALF 0x0080 /* 0.5 */
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#define b8ONETENTH 0x001a /* 0.1 (acutally 0.1015625) */
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#define b8ONEHUNDRTH 0x0003 /* 0.01 (actualy 0.0117198765) */
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#define b8MAX 0x7fff /* Max value of b8_t */
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#define ub8MAX 0xffff /* Max value of rb8_t */
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#define b8MIN 0x8000 /* Min value of b8_t */
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#define ub8MIN 0x0000 /* Min value of ub8_t */
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#define b16THOUSAND 0x03e80000 /* 1000 */
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#define b16HUNDRED 0x00640000 /* 100 */
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#define b16TEN 0x000a0000 /* 10 */
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#define b16ONE 0x00010000 /* 1 */
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#define b16HALF 0x00008000 /* 0.5 */
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#define b16ONETENTH 0x0000199a /* 0.1 (actually 0.100006..) */
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#define b16ONEHUNDRTH 0x0000028f /* 0.01 (actually 0.0099945..) */
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#define b16ONETHOUSTH 0x00000042 /* 0.001 (actually 0.000100708..)*/
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#define b16MAX 0x7fffffff /* Max value of b16_t */
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#define ub16MAX 0xffffffff /* Max value of ub16_t */
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#define b16MIN 0x80000000 /* Min value of b16_t */
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#define ub16MIN 0x00000000 /* Min value of ub16_t */
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#define b32MILLION 0x000f424000000000 /* 1000000 */
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#define b32THOUSAND 0x000003e800000000 /* 1000 */
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#define b32HUNDRED 0x0000006400000000 /* 100 */
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#define b32TEN 0x0000000a00000000 /* 10 */
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#define b32ONE 0x0000000100000000 /* 1 */
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#define b32HALF 0x0000000080000000 /* 0.5 */
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#define b32ONETENTH 0x000000001999999a /* 0.1 */
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#define b32ONEHUNDRTH 0x00000000028f5c29 /* 0.01 */
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#define b32ONETHOUSTH 0x0000000000418937 /* 0.001 */
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#define b32ONETENTHOU 0x0000000000068db9 /* 0.0001 */
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#define b32MAX 0x7fffffffffffffff /* Max value of b16_t */
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#define ub32MAX 0xffffffffffffffff /* Max value of ub16_t */
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#define b32MIN 0x8000000000000000 /* Min value of b16_t */
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#define ub32MIN 0x0000000000000000 /* Min value of ub16_t */
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/* Conversions between b16 and b8 *****************************************/
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#define b8tob16(b) ((b16_t)(b) << 8)
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#define ub8toub16(b) ((ub16_t)(b) << 8)
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#define b16tob8(b) (b8_t)(((b)+0x0080)>>8)
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#define ub16toub8(b) (ub8_t)(((b)+0x0080)>>8)
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#ifdef CONFIG_HAVE_LONG_LONG
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# define b8tob32(b) ((b32_t)(b) << 24)
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# define ub8toub32(b) ((ub32_t)(b) << 24)
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# define b16tob32(b) ((b32_t)(b) << 16)
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# define ub16toub32(b) ((ub32_t)(b) << 16)
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# define b32tob16(b) (b16_t)(((b) + 0x0000000000008000)>>16)
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# define ub32toub16(b) (ub16_t)(((b) + 0x0000000000008000)>>16)
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# define b32tob8(b) (b8_t)(((b) + 0x0000000000000080)>>8)
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#endif
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/* 16-bit values with 8 bits of precision *********************************/
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/* Conversions */
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#define b8toi(a) ((a) >> 8) /* Conversion to integer */
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#define itob8(i) ((i) << 8) /* Conversion from integer */
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#define b8tof(b) (((float)b)/256.0) /* Conversion to float */
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#define ftob8(f) (b8_t)(((f)*256.0)) /* Conversion from float */
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#define b8trunc(a) ((a) & 0xff00) /* Truncate to integer b8 */
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#define b8round(a) (((a)+0x0080) & 0xff00) /* Round to integer b8 */
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#define b8frac(a) ((a) & 0x00ff) /* Take fractional part */
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/* Operators */
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#define ub8inv(b) (0x8000/((b)>>1)) /* Inversion (b8=b15/b7) */
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#define b8inv(b) (0x4000/((b)>>2)) /* Inversion (b8=b14/b6) */
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#define b8addb8(a,b) ((a)+(b)) /* Addition */
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#define b8addi(a,i) ((a)+itob8(i)) /* Add integer from b16 */
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#define b8subb8(a,b) ((a)-(b)) /* Subtraction */
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#define b8subi(a,i) ((a)-itob8(i)) /* Subtract integer from b8 */
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#define b8mulb8(a,b) b16tob8((b16_t)(a)*(b16_t)(b) /* Muliplication */
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#define ub8mulub8(a,b) ub16toub8((ub16_t)(a)*(ub16_t)(b) /* Muliplication */
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#define b8muli(a,i) ((a)*(i)) /* Simple multiplication by integer */
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#define b8divb8(a,b) b8tob16(a)/(b16_t)(b) /* Division */
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#define ub8divub8(a,b) ub8toub16(a)/(ub16_t)(b) /* Division */
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#define b8divi(a,i) ((a)/(i)) /* Simple division by integer */
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#define b8idiv(i,j) (((i)<<8)/j) /* Division of integer, b8 result */
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/* 32-bit values with 16 bits of precision ********************************/
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/* Conversions */
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#define b16toi(a) ((a) >> 16) /* Conversion to integer */
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#define itob16(i) ((i) << 16) /* Conversion from integer */
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#define b16tof(b) (((float)b)/65536.0) /* Conversion to float */
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#define ftob16(f) (b16_t)(((f)*65536.0)) /* Conversion from float */
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#define b16trunc(a) ((a) & 0xffff0000) /* Truncate to integer */
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#define b16round(a) (((a)+0x00008000) & 0xffff0000)
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#define b16frac(a) ((a) & 0x0000ffff) /* Take fractional part */
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/* Operators */
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#define ub16inv(b) (0x80000000/((b)>>1)) /* Inversion (b16=b31/b15) */
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#define b16inv(b) (0x40000000/((b)>>2)) /* Inversion (b16=b30/b14) */
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#define b16addb16(a,b) ((a)+(b)) /* Addition */
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#define b16addi(a,i) ((a)+itob16(i)) /* Add integer to b16 */
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#define b16subb16(a,b) ((a)-(b)) /* Subtraction */
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#define b16subi(a,i) ((a)-itob16(i)) /* Subtract integer from b16 */
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#define b16muli(a,i) ((a)*(i)) /* Simple multiplication by integer */
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#define b16divi(a,i) ((a)/(i)) /* Simple division by integer*/
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#define b16idiv(i,j) (((i)<<16)/j) /* Division of integer, b16 result */
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#ifdef CONFIG_HAVE_LONG_LONG
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# define b16mulb16(a,b) b32tob16((b32_t)(a)*(b32_t)(b) /* Muliplication */
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# define ub16mulub16(a,b) ub32toub16((ub32_t)(a)*(ub32_t)(b)
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# define b16divb16(a,b) b16tob32(a)/(b32_t)(b) /* Division */
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# define ub16divub16(a,b) ub16toub32(a)/(ub32_t)(b)
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#endif
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/**************************************************************************
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* Public Types
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**************************************************************************/
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typedef sint16 b8_t;
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typedef uint16 ub8_t;
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typedef sint32 b16_t;
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typedef uint32 ub16_t;
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#ifdef CONFIG_HAVE_LONG_LONG
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typedef sint64 b32_t;
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typedef uint64 ub32_t;
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#endif
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/**************************************************************************
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* Global Functions
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**************************************************************************/
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#undef EXTERN
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#if defined(__cplusplus)
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#define EXTERN extern "C"
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extern "C" {
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#else
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#define EXTERN extern
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#endif
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#ifndef CONFIG_HAVE_LONG_LONG
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EXTERN b16_t b16mulb16(b16_t m1, b16_t m2);
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EXTERN ub16_t ub16mulub16(ub16_t m1, ub16_t m2);
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EXTERN b16_t b16divb16(b16_t num, b16_t denom);
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EXTERN ub16_t ub16divub16(ub16_t num, ub16_t denom);
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#endif
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#undef EXTERN
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#if defined(__cplusplus)
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}
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#endif
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#endif /* __INCLUDE_FIXEDMATH_H */
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@ -71,7 +71,7 @@ endif
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STDLIB_SRCS = lib_rand.c
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MATH_SRCS = lib_rint.c
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MATH_SRCS = lib_rint.c lib_fixedmath.c
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UNISTD_SRCS = lib_getopt.c
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ifneq ($(CONFIG_NFILE_DESCRIPTORS),0)
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223
lib/lib_fixedmath.c
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223
lib/lib_fixedmath.c
Normal file
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@ -0,0 +1,223 @@
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/****************************************************************************
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* lib/lib_fixedmath.c
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*
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* Copyright (C) 2008 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
|
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* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
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||||
* notice, this list of conditions and the following disclaimer in
|
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* the documentation and/or other materials provided with the
|
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
|
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
||||
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <fixedmath.h>
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#ifndef CONFIG_HAVE_LONG_LONG
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/****************************************************************************
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* Definitions
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****************************************************************************/
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/****************************************************************************
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* Private Type Declarations
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****************************************************************************/
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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/****************************************************************************
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* Public Data
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****************************************************************************/
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/****************************************************************************
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* Private Data
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****************************************************************************/
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/****************************************************************************
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* Name: fixsign
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****************************************************************************/
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static void fixsign(b16_t *parg1, b16_t *parg2, boolean *pnegate)
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{
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boolean negate = FALSE;
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b16_t arg;
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arg = *parg1;
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if (arg < 0)
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{
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*parg1 = -arg;
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negate = TRUE;
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}
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arg = *parg2;
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if (arg < 0)
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{
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*parg2 = -arg;
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negate ^= TRUE;
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}
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*pnegate = negate;
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}
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/****************************************************************************
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* Name: adjustsign
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****************************************************************************/
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static b16_t adjustsign(b16_t result, boolean negate)
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{
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/* If the product is negative, then we overflowed */
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if (result < 0)
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{
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if (result)
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{
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return b16MIN;
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}
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else
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{
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return b16MAX;
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}
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}
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/* correct the sign of the result */
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if (negate)
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{
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return -result;
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}
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return result;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: b16mulb16
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****************************************************************************/
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b16_t b16mulb16(b16_t m1, b16_t m2)
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{
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boolean negate;
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b16_t product;
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fixsign(&m1, &m2, &negate);
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product = (b16_t)ub16mulub16((ub16_t)m1, (ub16_t)m2);
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return adjustsign(product, negate);
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}
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/****************************************************************************
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* Name: ub16mulub16
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**************************************************************************/
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ub16_t ub16mulub16(ub16_t m1, ub16_t m2)
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{
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/* Let:
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*
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* m1 = m1i*2**16 + m1f (b16)
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* m2 = m2i*2**16 + m2f (b16)
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*
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* Then:
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*
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* m1*m2 = (m1i*m2i)*2**32 + (m1i*m2f + m2i*m1f)*2**16 + m1f*m2f (b32)
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* = (m1i*m2i)*2**16 + (m1i*m2f + m2i*m1f) + m1f*m2f*2**-16 (b16)
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* = a*2**16 + b + c*2**-16
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*/
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uint32 m1i = ((uint32)m1 >> 16);
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uint32 m2i = ((uint32)m1 >> 16);
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uint32 m1f = ((uint32)m1 & 0x0000ffff);
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uint32 m2f = ((uint32)m2 & 0x0000ffff);
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return (m1i*m2i << 16) + m1i*m2f + m2i*m1f + (((m1f*m2f) + b16HALF) >> 16);
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}
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/****************************************************************************
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* Name: b16divb16
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**************************************************************************/
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b16_t b16divb16(b16_t num, b16_t denom)
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{
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boolean negate;
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b16_t quotient;
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fixsign(&num, &denom, &negate);
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quotient = (b16_t)ub16divub16((ub16_t)num, (ub16_t)denom);
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return adjustsign(quotient, negate);
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}
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/****************************************************************************
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* Name: ub16divub16
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**************************************************************************/
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ub16_t ub16divub16(ub16_t num, ub16_t denom)
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{
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uint32 term1;
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uint32 numf;
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uint32 product;
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/* Let:
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*
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* num = numi*2**16 + numf (b16)
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* den = deni*2**16 + denf (b16)
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*
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* Then:
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*
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* num/den = numi*2**16 / den + numf / den (b0)
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* = numi*2**32 / den + numf*2**16 /den (b16)
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*/
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/* Check for overflow in the first part of the quotient */
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term1 = ((uint32)num & 0xffff0000) / denom;
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if (term1 >= 0x00010000)
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{
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return ub16MAX; /* Will overflow */
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}
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/* Finish the division */
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numf = num - term1 * denom;
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term1 <<= 16;
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product = term1 + (numf + (denom >> 1)) / denom;
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/* Check for overflow */
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if (product < term1)
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{
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return ub16MAX; /* Overflowed */
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}
|
||||
return product;
|
||||
}
|
||||
|
||||
#endif
|
||||
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Reference in a new issue