74 lines
2.2 KiB
C
74 lines
2.2 KiB
C
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/****************************************************************************
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* libc/math/lib_truncf.c
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*
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* This implementation is derived from the musl library under the MIT License
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*
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* Copyright © 2005-2014 Rich Felker, et al.
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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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 <nuttx/compiler.h>
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#include <stdint.h>
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#include <math.h>
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/************************************************************************
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* Public Functions
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************************************************************************/
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float truncf(float x)
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{
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union {float f; uint32_t i;} u = {x};
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int e = (int)(u.i >> 23 & 0xff) - 0x7f + 9;
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uint32_t m;
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volatile float __x;
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if (e >= 23 + 9)
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{
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return x;
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}
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if (e < 9)
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{
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e = 1;
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}
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m = -1u >> e;
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if ((u.i & m) == 0)
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{
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return x;
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}
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/* Force Eval */
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__x = (x + 0x1p120f);
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(void)__x;
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u.i &= ~m;
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return u.f;
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}
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