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