/* dsp.c */ /* {{{ * * Copyright (C) 2004 Nicolas Schodet * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Contact : * Web: http://perso.efrei.fr/~schodet/ * Email: * }}} */ #include "dsp.h" /* +AutoDec */ /* -AutoDec */ /* Add two signed words and saturate. */ inline int16_t dsp_i16i16_add_sat (int16_t a, int16_t b) { asm ("add %A0, %A1\n\t" "adc %B0, %B1\n\t" /* Branch if not V. */ "brvc 1f\n\t" /* Load Max. */ "ldi %A0, 0xff\n\t" "ldi %B0, 0x7f\n\t" /* Branch if not S. */ "brlt 1f\n\t" /* Load Min. */ "ldi %A0, 0x00\n\t" "ldi %B0, 0x80\n\t" "1f" "\n\t" : "=r" a : "0" a, "r" b); return a; } /* Multiply and saturate. */ inline int16_t dsp_i16u8_mul_sat (int16_t a, uint8_t b) { asm ("mul }