summaryrefslogtreecommitdiffstats
path: root/apps/fixedpoint.h
diff options
context:
space:
mode:
Diffstat (limited to 'apps/fixedpoint.h')
-rw-r--r--apps/fixedpoint.h197
1 files changed, 197 insertions, 0 deletions
diff --git a/apps/fixedpoint.h b/apps/fixedpoint.h
new file mode 100644
index 0000000000..a3ca6ee6ed
--- /dev/null
+++ b/apps/fixedpoint.h
@@ -0,0 +1,197 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id: fixedpoint.h -1 $
+ *
+ * Copyright (C) 2006 Jens Arnold
+ *
+ * Fixed point library for plugins
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+/** FIXED POINT MATH ROUTINES - USAGE
+ *
+ * - x and y arguments are fixed point integers
+ * - fracbits is the number of fractional bits in the argument(s)
+ * - functions return long fixed point integers with the specified number
+ * of fractional bits unless otherwise specified
+ *
+ * Multiply two fixed point numbers:
+ * fp_mul(x, y, fracbits)
+ *
+ * Shortcut: Multiply two fixed point numbers with 31 fractional bits:
+ * fp31_mul(x, y)
+ *
+ * Shortcut: Multiply two fixed point numbers with 31 fractional bits,
+ * then shift left by z bits:
+ * fp31_mulshl(x, y, z)
+ * NOTE: z must be in the range 1-8 on Coldfire targets.
+ *
+ * Divide two fixed point numbers:
+ * fp_div(x, y, fracbits)
+ *
+ * Take square root of a fixed point number:
+ * fp_sqrt(x, fracbits)
+ *
+ * Calculate sin and cos of an angle:
+ * fp_sincos(phase, *cos)
+ * where phase is a 32 bit unsigned integer with 0 representing 0
+ * and 0xFFFFFFFF representing 2*pi, and *cos is the address to
+ * a long signed integer. Value returned is a long signed integer
+ * from LONG_MIN to LONG_MAX, representing -1 to 1 respectively.
+ * That is, value is a fixed point integer with 31 fractional bits.
+ *
+ * Calculate sin or cos of an angle (very fast, from a table):
+ * fp14_sin(angle)
+ * fp14_cos(angle)
+ * where angle is a non-fixed point integer in degrees. Value
+ * returned is a fixed point integer with 14 fractional bits.
+ *
+ * Calculate decibel equivalent of a gain factor:
+ * fp_decibels(factor, fracbits)
+ * where fracbits is in the range 12 to 22 (higher is better),
+ * and factor is a positive fixed point integer.
+ *
+ * Calculate factor equivalent of a decibel value:
+ * fp_factor(decibels, fracbits)
+ * where fracbits is in the range 12 to 22 (lower is better),
+ * and decibels is a fixed point integer.
+ */
+
+#ifndef _FIXEDPOINT_H
+#define _FIXEDPOINT_H
+
+#include <inttypes.h>
+
+/* Redefine function names, making sure legacy code is usable */
+#define fp31_mul(x, y) FRACMUL(x, y)
+#define fp31_mulshl(x, y, z) FRACMUL_SHL(x, y, z)
+#define fp_div(x, y, z) DIV64(x, y, z)
+#define fp_sqrt(x, y) fsqrt(x, y)
+#define fp_sincos(x, y) fsincos(x, y)
+#define fp14_sin(x) sin_int(x)
+#define fp14_cos(x) cos_int(x)
+#define fp16_log(x) flog(x)
+
+
+#define fp_mul(x, y, z) (long)((((long long)(x)) * ((long long)(y))) >> (z))
+#define DIV64(x, y, z) (long)((((long long)(x)) << (z)) / ((long long)(y)))
+
+/** TAKEN FROM apps/dsp.h */
+/* A bunch of fixed point assembler helper macros */
+#if defined(CPU_COLDFIRE)
+/* These macros use the Coldfire EMAC extension and need the MACSR flags set
+ * to fractional mode with no rounding.
+ */
+
+/* Multiply two S.31 fractional integers and return the sign bit and the
+ * 31 most significant bits of the result.
+ */
+#define FRACMUL(x, y) \
+({ \
+ long t; \
+ asm ("mac.l %[a], %[b], %%acc0\n\t" \
+ "movclr.l %%acc0, %[t]\n\t" \
+ : [t] "=r" (t) : [a] "r" (x), [b] "r" (y)); \
+ t; \
+})
+
+/* Multiply two S.31 fractional integers, and return the 32 most significant
+ * bits after a shift left by the constant z. NOTE: Only works for shifts of
+ * 1 to 8 on Coldfire!
+ */
+#define FRACMUL_SHL(x, y, z) \
+({ \
+ long t, t2; \
+ asm ("mac.l %[a], %[b], %%acc0\n\t" \
+ "moveq.l %[d], %[t]\n\t" \
+ "move.l %%accext01, %[t2]\n\t" \
+ "and.l %[mask], %[t2]\n\t" \
+ "lsr.l %[t], %[t2]\n\t" \
+ "movclr.l %%acc0, %[t]\n\t" \
+ "asl.l %[c], %[t]\n\t" \
+ "or.l %[t2], %[t]\n\t" \
+ : [t] "=&d" (t), [t2] "=&d" (t2) \
+ : [a] "r" (x), [b] "r" (y), [mask] "d" (0xff), \
+ [c] "i" ((z)), [d] "i" (8 - (z))); \
+ t; \
+})
+
+#elif defined(CPU_ARM)
+
+/* Multiply two S.31 fractional integers and return the sign bit and the
+ * 31 most significant bits of the result.
+ */
+#define FRACMUL(x, y) \
+({ \
+ long t, t2; \
+ asm ("smull %[t], %[t2], %[a], %[b]\n\t" \
+ "mov %[t2], %[t2], asl #1\n\t" \
+ "orr %[t], %[t2], %[t], lsr #31\n\t" \
+ : [t] "=&r" (t), [t2] "=&r" (t2) \
+ : [a] "r" (x), [b] "r" (y)); \
+ t; \
+})
+
+/* Multiply two S.31 fractional integers, and return the 32 most significant
+ * bits after a shift left by the constant z.
+ */
+#define FRACMUL_SHL(x, y, z) \
+({ \
+ long t, t2; \
+ asm ("smull %[t], %[t2], %[a], %[b]\n\t" \
+ "mov %[t2], %[t2], asl %[c]\n\t" \
+ "orr %[t], %[t2], %[t], lsr %[d]\n\t" \
+ : [t] "=&r" (t), [t2] "=&r" (t2) \
+ : [a] "r" (x), [b] "r" (y), \
+ [c] "M" ((z) + 1), [d] "M" (31 - (z))); \
+ t; \
+})
+
+#else
+
+#define FRACMUL(x, y) (long) (((((long long) (x)) * ((long long) (y))) >> 31))
+#define FRACMUL_SHL(x, y, z) \
+((long)(((((long long) (x)) * ((long long) (y))) >> (31 - (z)))))
+
+#endif
+
+/** TAKEN FROM ORIGINAL fixedpoint.h */
+/* fast unsigned multiplication (16x16bit->32bit or 32x32bit->32bit,
+ * whichever is faster for the architecture) */
+#ifdef CPU_ARM
+#define FMULU(a, b) ((uint32_t) (((uint32_t) (a)) * ((uint32_t) (b))))
+#else /* SH1, coldfire */
+#define FMULU(a, b) ((uint32_t) (((uint16_t) (a)) * ((uint16_t) (b))))
+#endif
+
+long fsincos(unsigned long phase, long *cos);
+long fsqrt(long x, unsigned int fracbits);
+long sin_int(int val);
+long cos_int(int val);
+long flog(int x);
+
+
+/** MODIFIED FROM replaygain.c */
+#define FP_INF (0x7fffffff)
+#define FP_NEGINF -(0x7fffffff)
+
+/* fracbits in range 12 - 22 work well. Higher is better for
+ * calculating dB, lower is better for calculating ratio.
+ */
+long fp_decibels(unsigned long factor, unsigned int fracbits);
+long fp_factor(long decibels, unsigned int fracbits);
+
+#endif