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64 lines
1.2 KiB
C
64 lines
1.2 KiB
C
/*
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* Copyright (C) 2016 Eistec AB
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @ingroup cpu
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* @{
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*
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* @file
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* @brief MSPGCC supplemental functions
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*
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* @author Joakim Nohlgård <joakim.nohlgard@eistec.se
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*
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* @}
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*/
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#ifdef __MSPGCC__
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/* internal GCC type for "half integer" (16 bit) */
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/* See also:
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* http://stackoverflow.com/questions/4559025/what-does-gcc-attribute-modexx-actually-do
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* http://www.delorie.com/gnu/docs/gcc/gccint_53.html
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*/
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typedef unsigned int UHItype __attribute__ ((mode (HI)));
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/**
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* @brief Count leading zeros
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*
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* Naive implementation
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*/
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int __clzhi2(UHItype x)
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{
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int i = 0;
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for (UHItype mask = (1 << 15); mask != 0; mask >>= 1) {
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if (x & mask) {
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return i;
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}
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++i;
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}
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return i; /* returns 16 if x == 0 */
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}
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/**
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* @brief Count trailing zeros
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*
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* Naive implementation
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*/
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int __ctzhi2(UHItype x)
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{
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int i = 0;
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for (UHItype mask = 1; mask != 0; mask <<= 1) {
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if (x & mask) {
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return i;
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}
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++i;
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}
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return i; /* returns 16 if x == 0 */
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}
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#endif /* __MSPGCC__ */
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