diff options
| -rw-r--r-- | linux/lib/xz/xz_dec_lzma2.c | 124 |
1 files changed, 65 insertions, 59 deletions
diff --git a/linux/lib/xz/xz_dec_lzma2.c b/linux/lib/xz/xz_dec_lzma2.c index 0b8ddb6..ad36e29 100644 --- a/linux/lib/xz/xz_dec_lzma2.c +++ b/linux/lib/xz/xz_dec_lzma2.c @@ -130,31 +130,31 @@ struct lzma_len_dec { }; struct lzma_dec { - /* - * LZMA properties or related bit masks (number of literal - * context bits, a mask dervied from the number of literal - * position bits, and a mask dervied from the number - * position bits) - */ - uint32_t lc; - uint32_t literal_pos_mask; /* (1 << lp) - 1 */ - uint32_t pos_mask; /* (1 << pb) - 1 */ - - /* Types of the most recently seen LZMA symbols */ - enum lzma_state state; - /* Distances of latest four matches */ uint32_t rep0; uint32_t rep1; uint32_t rep2; uint32_t rep3; + /* Types of the most recently seen LZMA symbols */ + enum lzma_state state; + /* * Length of a match. This is updated so that dict_repeat can * be called again to finish repeating the whole match. */ uint32_t len; + /* + * LZMA properties or related bit masks (number of literal + * context bits, a mask dervied from the number of literal + * position bits, and a mask dervied from the number + * position bits) + */ + uint32_t lc; + uint32_t literal_pos_mask; /* (1 << lp) - 1 */ + uint32_t pos_mask; /* (1 << pb) - 1 */ + /* If 1, it's a match. Otherwise it's a single 8-bit literal. */ uint16_t is_match[STATES][POS_STATES_MAX]; @@ -211,49 +211,59 @@ struct lzma_dec { uint16_t literal[LITERAL_CODERS_MAX][LITERAL_CODER_SIZE]; }; +struct lzma2_dec { + /* Position in xz_dec_lzma2_run(). */ + enum lzma2_seq { + SEQ_CONTROL, + SEQ_UNCOMPRESSED_1, + SEQ_UNCOMPRESSED_2, + SEQ_COMPRESSED_0, + SEQ_COMPRESSED_1, + SEQ_PROPERTIES, + SEQ_LZMA_PREPARE, + SEQ_LZMA_RUN, + SEQ_COPY + } sequence; + + /* Next position after decoding the compressed size of the chunk. */ + enum lzma2_seq next_sequence; + + /* Uncompressed size of LZMA chunk (2 MiB at maximum) */ + uint32_t uncompressed; + + /* + * Compressed size of LZMA chunk or compressed/uncompressed + * size of uncompressed chunk (64 KiB at maximum) + */ + uint32_t compressed; + + /* + * True if dictionary reset is needed. This is false before + * the first chunk (LZMA or uncompressed). + */ + bool need_dict_reset; + + /* + * True if new LZMA properties are needed. This is false + * before the first LZMA chunk. + */ + bool need_props; +}; + struct xz_dec_lzma2 { - /* LZMA2 */ - struct { - /* Position in xz_dec_lzma2_run(). */ - enum lzma2_seq { - SEQ_CONTROL, - SEQ_UNCOMPRESSED_1, - SEQ_UNCOMPRESSED_2, - SEQ_COMPRESSED_0, - SEQ_COMPRESSED_1, - SEQ_PROPERTIES, - SEQ_LZMA_PREPARE, - SEQ_LZMA_RUN, - SEQ_COPY - } sequence; - - /* - * Next position after decoding the compressed size of - * the chunk. - */ - enum lzma2_seq next_sequence; - - /* Uncompressed size of LZMA chunk (2 MiB at maximum) */ - uint32_t uncompressed; - - /* - * Compressed size of LZMA chunk or compressed/uncompressed - * size of uncompressed chunk (64 KiB at maximum) - */ - uint32_t compressed; - - /* - * True if dictionary reset is needed. This is false before - * the first chunk (LZMA or uncompressed). - */ - bool need_dict_reset; - - /* - * True if new LZMA properties are needed. This is false - * before the first LZMA chunk. - */ - bool need_props; - } lzma2; + /* + * The order below is important on x86 to reduce code size and + * it shouldn't hurt on other platforms. Everything up to and + * including lzma.pos_mask are in the first 128 bytes on x86-32, + * which allows using smaller instructions to access those + * variables. On x86-64, fewer variables fit into the first 128 + * bytes, but this is still the best order without sacrificing + * the readability by splitting the structures. + */ + struct rc_dec rc; + struct dictionary dict; + struct lzma2_dec lzma2; + struct lzma_dec lzma; /* * Temporary buffer which holds small number of input bytes between @@ -263,10 +273,6 @@ struct xz_dec_lzma2 { uint32_t size; uint8_t buf[3 * LZMA_IN_REQUIRED]; } temp; - - struct dictionary dict; - struct rc_dec rc; - struct lzma_dec lzma; }; /************** |