Displaying 3 results from an estimated 3 matches for "count_zero_msbs2".
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count_zero_msbs
2015 Dec 20
2
about word size in bitreader/bitwriter
Erik de Castro Lopo wrote:
> The think in and ideal world we would a:
>
> * Make it work correctly FLAC__BYTES_PER_WORD == 8 and compare the performance
> with FLAC__BYTES_PER_WORD == 4.
> * If there is an statistically measurable performance, keep it, otherwise
> remove the FLAC__BYTES_PER_WORD == 8 code all together.
I'll try to do it, but I don't have a deep
2016 Jan 04
0
about word size in bitreader/bitwriter
...it across two words.
In the measurements comparing 32-bit and 64-bit words you posted
later, I'm wondering why there is a slow down in decoding of 24-bit
files. Does profiling show it comes from the read_rice_signed_block()
function or something else? Could it be slower SWAP_BE_WORD_TO_HOST or
COUNT_ZERO_MSBS2?
--
Miroslav Lichvar
2008 Mar 14
2
bitreader optimizations
...ble[(word) >> 24] : \
+ !word ? 32 : \
+ word > 0xffff ? byte_to_unary_table[word >> 16] + 8 : \
+ word > 0xff ? byte_to_unary_table[(word) >> 8] + 16 : \
+ byte_to_unary_table[word] + 24 \
)
-/* this alternate might be slightly faster on some systems/compilers: */
-#define COUNT_ZERO_MSBS2(word) ( (word) <= 0xff ? byte_to_unary_table[word] + 24 : ((word) <= 0xffff ? byte_to_unary_table[(word) >> 8] + 16 : ((word) <= 0xffffff ? byte_to_unary_table[(word) >> 16] + 8 : byte_to_unary_table[(word) >> 24])) )
-
/*
* This should be at least twice as large as...