From 8d4d4610b6814c0c4a4abe9523b4b6b2b80ac9a4 Mon Sep 17 00:00:00 2001 From: Maurus Cuelenaere Date: Tue, 7 Jul 2009 13:36:34 +0000 Subject: [PATCH] * FS#10411 - Fixed point math code is bloated by Jeffrey Goode * Set svn:keywords properties git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21701 a1c6a512-1295-4272-9138-f99709370657 --- apps/codecs/lib/fixedpoint.h | 2 +- apps/fixedpoint.c | 131 +++++++++++------------------------ apps/fixedpoint.h | 2 +- 3 files changed, 43 insertions(+), 92 deletions(-) diff --git a/apps/codecs/lib/fixedpoint.h b/apps/codecs/lib/fixedpoint.h index e6ed5208ca..b912cbe66b 100644 --- a/apps/codecs/lib/fixedpoint.h +++ b/apps/codecs/lib/fixedpoint.h @@ -5,7 +5,7 @@ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ - * $Id: fixedpoint.h -1 $ + * $Id$ * * Copyright (C) 2006 Jens Arnold * diff --git a/apps/fixedpoint.c b/apps/fixedpoint.c index 917f624258..f9903f301f 100644 --- a/apps/fixedpoint.c +++ b/apps/fixedpoint.c @@ -5,7 +5,7 @@ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ - * $Id: fixedpoint.c -1 $ + * $Id$ * * Copyright (C) 2006 Jens Arnold * @@ -261,24 +261,18 @@ long fp16_log(int x) { #if (!defined(PLUGIN) && !defined(CODEC)) /** MODIFIED FROM replaygain.c */ -/* These math routines have 64-bit internal precision to avoid overflows. - * Arguments and return values are 32-bit (long) precision. - */ -#define FP_MUL64(x, y) (((x) * (y)) >> (fracbits)) -#define FP_DIV64(x, y) (((x) << (fracbits)) / (y)) - -static long long fp_exp10(long long x, unsigned int fracbits); -/* static long long fp_log10(long long n, unsigned int fracbits); */ +#define FP_MUL_FRAC(x, y) fp_mul(x, y, fracbits) +#define FP_DIV_FRAC(x, y) fp_div(x, y, fracbits) /* constants in fixed point format, 28 fractional bits */ -#define FP28_LN2 (186065279LL) /* ln(2) */ -#define FP28_LN2_INV (387270501LL) /* 1/ln(2) */ -#define FP28_EXP_ZERO (44739243LL) /* 1/6 */ -#define FP28_EXP_ONE (-745654LL) /* -1/360 */ -#define FP28_EXP_TWO (12428LL) /* 1/21600 */ -#define FP28_LN10 (618095479LL) /* ln(10) */ -#define FP28_LOG10OF2 (80807124LL) /* log10(2) */ +#define FP28_LN2 (186065279L) /* ln(2) */ +#define FP28_LN2_INV (387270501L) /* 1/ln(2) */ +#define FP28_EXP_ZERO (44739243L) /* 1/6 */ +#define FP28_EXP_ONE (-745654L) /* -1/360 */ +#define FP28_EXP_TWO (12428L) /* 1/21600 */ +#define FP28_LN10 (618095479L) /* ln(10) */ +#define FP28_LOG10OF2 (80807124L) /* log10(2) */ #define TOL_BITS 2 /* log calculation tolerance */ @@ -290,24 +284,24 @@ static long long fp_exp10(long long x, unsigned int fracbits); /** FIXED POINT EXP10 * Return 10^x as FP integer. Argument is FP integer. */ -static long long fp_exp10(long long x, unsigned int fracbits) +static long fp_exp10(long x, unsigned int fracbits) { - long long k; - long long z; - long long R; - long long xp; + long k; + long z; + long R; + long xp; /* scale constants */ - const long long fp_one = (1 << fracbits); - const long long fp_half = (1 << (fracbits - 1)); - const long long fp_two = (2 << fracbits); - const long long fp_mask = (fp_one - 1); - const long long fp_ln2_inv = (FP28_LN2_INV >> (28 - fracbits)); - const long long fp_ln2 = (FP28_LN2 >> (28 - fracbits)); - const long long fp_ln10 = (FP28_LN10 >> (28 - fracbits)); - const long long fp_exp_zero = (FP28_EXP_ZERO >> (28 - fracbits)); - const long long fp_exp_one = (FP28_EXP_ONE >> (28 - fracbits)); - const long long fp_exp_two = (FP28_EXP_TWO >> (28 - fracbits)); + const long fp_one = (1 << fracbits); + const long fp_half = (1 << (fracbits - 1)); + const long fp_two = (2 << fracbits); + const long fp_mask = (fp_one - 1); + const long fp_ln2_inv = (FP28_LN2_INV >> (28 - fracbits)); + const long fp_ln2 = (FP28_LN2 >> (28 - fracbits)); + const long fp_ln10 = (FP28_LN10 >> (28 - fracbits)); + const long fp_exp_zero = (FP28_EXP_ZERO >> (28 - fracbits)); + const long fp_exp_one = (FP28_EXP_ONE >> (28 - fracbits)); + const long fp_exp_two = (FP28_EXP_TWO >> (28 - fracbits)); /* exp(0) = 1 */ if (x == 0) @@ -316,21 +310,21 @@ static long long fp_exp10(long long x, unsigned int fracbits) } /* convert from base 10 to base e */ - x = FP_MUL64(x, fp_ln10); + x = FP_MUL_FRAC(x, fp_ln10); /* calculate exp(x) */ - k = (FP_MUL64(abs(x), fp_ln2_inv) + fp_half) & ~fp_mask; + k = (FP_MUL_FRAC(abs(x), fp_ln2_inv) + fp_half) & ~fp_mask; if (x < 0) { k = -k; } - x -= FP_MUL64(k, fp_ln2); - z = FP_MUL64(x, x); - R = fp_two + FP_MUL64(z, fp_exp_zero + FP_MUL64(z, fp_exp_one - + FP_MUL64(z, fp_exp_two))); - xp = fp_one + FP_DIV64(FP_MUL64(fp_two, x), R - x); + x -= FP_MUL_FRAC(k, fp_ln2); + z = FP_MUL_FRAC(x, x); + R = fp_two + FP_MUL_FRAC(z, fp_exp_zero + FP_MUL_FRAC(z, fp_exp_one + + FP_MUL_FRAC(z, fp_exp_two))); + xp = fp_one + FP_DIV_FRAC(FP_MUL_FRAC(fp_two, x), R - x); if (k < 0) { @@ -341,7 +335,7 @@ static long long fp_exp10(long long x, unsigned int fracbits) k = fp_one << (k >> fracbits); } - return FP_MUL64(k, xp); + return FP_MUL_FRAC(k, xp); } @@ -349,13 +343,13 @@ static long long fp_exp10(long long x, unsigned int fracbits) /** FIXED POINT LOG10 * Return log10(x) as FP integer. Argument is FP integer. */ -static long long fp_log10(long long n, unsigned int fracbits) +static long fp_log10(long n, unsigned int fracbits) { /* Calculate log2 of argument */ - long long log2, frac; - const long long fp_one = (1 << fracbits); - const long long fp_two = (2 << fracbits); + long log2, frac; + const long fp_one = (1 << fracbits); + const long fp_two = (2 << fracbits); const long tolerance = (1 << ((fracbits / 2) + 2)); if (n <=0) return FP_NEGINF; @@ -378,7 +372,7 @@ static long long fp_log10(long long n, unsigned int fracbits) while (frac > tolerance) { frac >>= 1; - n = FP_MUL64(n, n); + n = FP_MUL_FRAC(n, n); if (n >= fp_two) { n >>= 1; @@ -387,31 +381,15 @@ static long long fp_log10(long long n, unsigned int fracbits) } /* convert log2 to log10 */ - return FP_MUL64(log2, (FP28_LOG10OF2 >> (28 - fracbits))); + return FP_MUL_FRAC(log2, (FP28_LOG10OF2 >> (28 - fracbits))); } /** CONVERT FACTOR TO DECIBELS */ long fp_decibels(unsigned long factor, unsigned int fracbits) { - long long decibels; - long long f = (long long)factor; - bool neg; - - /* keep factor in signed long range */ - if (f >= (1LL << 31)) - f = (1LL << 31) - 1; - /* decibels = 20 * log10(factor) */ - decibels = FP_MUL64((20LL << fracbits), fp_log10(f, fracbits)); - - /* keep result in signed long range */ - if ((neg = (decibels < 0))) - decibels = -decibels; - if (decibels >= (1LL << 31)) - return neg ? FP_NEGINF : FP_INF; - - return neg ? (long)-decibels : (long)decibels; + return FP_MUL_FRAC((20L << fracbits), fp_log10(factor, fracbits)); } #endif /* unused code */ @@ -419,34 +397,7 @@ long fp_decibels(unsigned long factor, unsigned int fracbits) /** CONVERT DECIBELS TO FACTOR */ long fp_factor(long decibels, unsigned int fracbits) { - bool neg; - long long factor; - long long db = (long long)decibels; - - /* if decibels is 0, factor is 1 */ - if (db == 0) - return (1L << fracbits); - - /* calculate for positive decibels only */ - if ((neg = (db < 0))) - db = -db; - /* factor = 10 ^ (decibels / 20) */ - factor = fp_exp10(FP_DIV64(db, (20LL << fracbits)), fracbits); - - /* keep result in signed long range, return 0 if very small */ - if (factor >= (1LL << 31)) - { - if (neg) - return 0; - else - return FP_INF; - } - - /* if negative argument, factor is 1 / result */ - if (neg) - factor = FP_DIV64((1LL << fracbits), factor); - - return (long)factor; + return fp_exp10(FP_DIV_FRAC(decibels, (20L << fracbits)), fracbits); } #endif /* !PLUGIN and !CODEC */ diff --git a/apps/fixedpoint.h b/apps/fixedpoint.h index 49292f3417..fd68fc162c 100644 --- a/apps/fixedpoint.h +++ b/apps/fixedpoint.h @@ -5,7 +5,7 @@ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ - * $Id: fixedpoint.h -1 $ + * $Id$ * * Copyright (C) 2006 Jens Arnold *