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author | Lasse Collin <lasse.collin@tukaani.org> | 2024-02-14 14:58:36 +0200 |
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committer | Lasse Collin <lasse.collin@tukaani.org> | 2024-02-14 18:31:16 +0200 |
commit | 0668907ff736e4cd16738c10d39a2bc9e851aefb (patch) | |
tree | 0dfe725f1a8c94f69e39946f160afb5aedc249da /src/liblzma/rangecoder | |
parent | Scripts: Add lz4 support to xzgrep and xzdiff. (diff) | |
download | xz-0668907ff736e4cd16738c10d39a2bc9e851aefb.tar.xz |
liblzma: Add comments.
Diffstat (limited to 'src/liblzma/rangecoder')
-rw-r--r-- | src/liblzma/rangecoder/range_decoder.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/src/liblzma/rangecoder/range_decoder.h b/src/liblzma/rangecoder/range_decoder.h index ffec7bf2..ddac1060 100644 --- a/src/liblzma/rangecoder/range_decoder.h +++ b/src/liblzma/rangecoder/range_decoder.h @@ -305,8 +305,15 @@ do { \ } while (0) -// Decode one bit from variable-sized reverse bittree. -// The loop is done in the code that uses this macro. +// Decode one bit from variable-sized reverse bittree. The loop is done +// in the code that uses this macro. This could be changed if the assembly +// version benefited from having the loop done in assembly but it didn't +// seem so in early 2024. +// +// Also, if the loop was done here, the loop counter would likely be local +// to the macro so that it wouldn't modify yet another input variable. +// If a _safe version of a macro with a loop was done then a modifiable +// input variable couldn't be avoided though. #define rc_bit_add_if_1(probs, dest, value_to_add_if_1) \ rc_bit(probs[symbol], \ , \ |