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Full precision synth_full and dct32. Replaced all multiplications with proper 64 bit EMAC multiplications, which yields improved sound.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6638 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Thom Johansen 2005-06-09 14:13:09 +00:00
parent 7c54b3ad4b
commit cc518c5f32
4 changed files with 65 additions and 20 deletions
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23
apps/codecs/libmad/fixed.h
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@ -420,6 +420,29 @@ mad_fixed_t mad_f_mul_inline(mad_fixed_t x, mad_fixed_t y)
# define MAD_F_SCALEBITS MAD_F_FRACBITS
# elif defined(FPM_COLDFIRE_EMAC)
/* mad_f_mul using the Coldfire MCF5249 EMAC unit. Loses 3 bits of accuracy.
Note that we don't define any of the libmad accumulator macros, as
any functions that use these should have the relevant sections rewritten
in assembler to utilise the EMAC accumulators properly.
Assumes the default +/- 3.28 fixed point format
*/
#define mad_f_mul(x, y) \
({ \
mad_fixed64hi_t hi; \
asm volatile("mac.l %[a], %[b], %%acc0\n\t" \
"movclr.l %%acc0, %[hi]\n\t" \
"asl.l #3, %[hi]" \
: [hi] "=d" (hi) \
: [a] "r" ((x)), [b] "r" ((y))); \
hi; \
})
/* Define dummy mad_f_scale64 to prevent libmad from defining MAD_F_SCALEBITS
below. Having MAD_F_SCALEBITS defined screws up the PRESHIFT macro in synth.h
*/
#define mad_f_scale64(hi, lo) (lo)
/* --- Default ------------------------------------------------------------- */
# elif defined(FPM_DEFAULT)