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-rw-r--r--src/libmad/fixed.c81
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diff --git a/src/libmad/fixed.c b/src/libmad/fixed.c
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+/*
+ * libmad - MPEG audio decoder library
+ * Copyright (C) 2000-2003 Underbit Technologies, Inc.
+ *
+ * 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
+ *
+ * $Id: fixed.c,v 1.1 2003/08/14 03:57:13 shank Exp $
+ */
+
+# ifdef HAVE_CONFIG_H
+# include "config.h"
+# endif
+
+# include "global.h"
+
+# include "fixed.h"
+
+/*
+ * NAME: fixed->abs()
+ * DESCRIPTION: return absolute value of a fixed-point number
+ */
+mad_fixed_t mad_f_abs(mad_fixed_t x)
+{
+ return x < 0 ? -x : x;
+}
+
+/*
+ * NAME: fixed->div()
+ * DESCRIPTION: perform division using fixed-point math
+ */
+mad_fixed_t mad_f_div(mad_fixed_t x, mad_fixed_t y)
+{
+ mad_fixed_t q, r;
+ unsigned int bits;
+
+ q = mad_f_abs(x / y);
+
+ if (x < 0) {
+ x = -x;
+ y = -y;
+ }
+
+ r = x % y;
+
+ if (y < 0) {
+ x = -x;
+ y = -y;
+ }
+
+ if (q > mad_f_intpart(MAD_F_MAX) &&
+ !(q == -mad_f_intpart(MAD_F_MIN) && r == 0 && (x < 0) != (y < 0)))
+ return 0;
+
+ for (bits = MAD_F_FRACBITS; bits && r; --bits) {
+ q <<= 1, r <<= 1;
+ if (r >= y)
+ r -= y, ++q;
+ }
+
+ /* round */
+ if (2 * r >= y)
+ ++q;
+
+ /* fix sign */
+ if ((x < 0) != (y < 0))
+ q = -q;
+
+ return q << bits;
+}