diff options
Diffstat (limited to 'c/dec/decode.c')
-rw-r--r-- | c/dec/decode.c | 81 |
1 files changed, 45 insertions, 36 deletions
diff --git a/c/dec/decode.c b/c/dec/decode.c index 674b829..1fde329 100644 --- a/c/dec/decode.c +++ b/c/dec/decode.c @@ -347,15 +347,17 @@ static BrotliDecoderErrorCode BROTLI_NOINLINE DecodeMetaBlockLength( static BROTLI_INLINE uint32_t DecodeSymbol(uint32_t bits, const HuffmanCode* table, BrotliBitReader* br) { - table += bits & HUFFMAN_TABLE_MASK; - if (table->bits > HUFFMAN_TABLE_BITS) { - uint32_t nbits = table->bits - HUFFMAN_TABLE_BITS; + BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(table); + BROTLI_HC_ADJUST_TABLE_INDEX(table, bits & HUFFMAN_TABLE_MASK); + if (BROTLI_HC_FAST_LOAD_BITS(table) > HUFFMAN_TABLE_BITS) { + uint32_t nbits = BROTLI_HC_FAST_LOAD_BITS(table) - HUFFMAN_TABLE_BITS; BrotliDropBits(br, HUFFMAN_TABLE_BITS); - table += table->value; - table += (bits >> HUFFMAN_TABLE_BITS) & BitMask(nbits); + BROTLI_HC_ADJUST_TABLE_INDEX(table, + BROTLI_HC_FAST_LOAD_VALUE(table) + + ((bits >> HUFFMAN_TABLE_BITS) & BitMask(nbits))); } - BrotliDropBits(br, table->bits); - return table->value; + BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(table)); + return BROTLI_HC_FAST_LOAD_VALUE(table); } /* Reads and decodes the next Huffman code from bit-stream. @@ -371,19 +373,20 @@ static BROTLI_NOINLINE BROTLI_BOOL SafeDecodeSymbol( const HuffmanCode* table, BrotliBitReader* br, uint32_t* result) { uint32_t val; uint32_t available_bits = BrotliGetAvailableBits(br); + BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(table); if (available_bits == 0) { - if (table->bits == 0) { - *result = table->value; + if (BROTLI_HC_FAST_LOAD_BITS(table) == 0) { + *result = BROTLI_HC_FAST_LOAD_VALUE(table); return BROTLI_TRUE; } return BROTLI_FALSE; /* No valid bits at all. */ } val = (uint32_t)BrotliGetBitsUnmasked(br); - table += val & HUFFMAN_TABLE_MASK; - if (table->bits <= HUFFMAN_TABLE_BITS) { - if (table->bits <= available_bits) { - BrotliDropBits(br, table->bits); - *result = table->value; + BROTLI_HC_ADJUST_TABLE_INDEX(table, val & HUFFMAN_TABLE_MASK); + if (BROTLI_HC_FAST_LOAD_BITS(table) <= HUFFMAN_TABLE_BITS) { + if (BROTLI_HC_FAST_LOAD_BITS(table) <= available_bits) { + BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(table)); + *result = BROTLI_HC_FAST_LOAD_VALUE(table); return BROTLI_TRUE; } else { return BROTLI_FALSE; /* Not enough bits for the first level. */ @@ -394,15 +397,15 @@ static BROTLI_NOINLINE BROTLI_BOOL SafeDecodeSymbol( } /* Speculatively drop HUFFMAN_TABLE_BITS. */ - val = (val & BitMask(table->bits)) >> HUFFMAN_TABLE_BITS; + val = (val & BitMask(BROTLI_HC_FAST_LOAD_BITS(table))) >> HUFFMAN_TABLE_BITS; available_bits -= HUFFMAN_TABLE_BITS; - table += table->value + val; - if (available_bits < table->bits) { + BROTLI_HC_ADJUST_TABLE_INDEX(table, BROTLI_HC_FAST_LOAD_VALUE(table) + val); + if (available_bits < BROTLI_HC_FAST_LOAD_BITS(table)) { return BROTLI_FALSE; /* Not enough bits for the second level. */ } - BrotliDropBits(br, HUFFMAN_TABLE_BITS + table->bits); - *result = table->value; + BrotliDropBits(br, HUFFMAN_TABLE_BITS + BROTLI_HC_FAST_LOAD_BITS(table)); + *result = BROTLI_HC_FAST_LOAD_VALUE(table); return BROTLI_TRUE; } @@ -425,9 +428,10 @@ static BROTLI_INLINE void PreloadSymbol(int safe, if (safe) { return; } - table += BrotliGetBits(br, HUFFMAN_TABLE_BITS); - *bits = table->bits; - *value = table->value; + BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(table); + BROTLI_HC_ADJUST_TABLE_INDEX(table, BrotliGetBits(br, HUFFMAN_TABLE_BITS)); + *bits = BROTLI_HC_FAST_LOAD_BITS(table); + *value = BROTLI_HC_FAST_LOAD_VALUE(table); } /* Decodes the next Huffman code using data prepared by PreloadSymbol. @@ -441,10 +445,11 @@ static BROTLI_INLINE uint32_t ReadPreloadedSymbol(const HuffmanCode* table, uint32_t val = BrotliGet16BitsUnmasked(br); const HuffmanCode* ext = table + (val & HUFFMAN_TABLE_MASK) + *value; uint32_t mask = BitMask((*bits - HUFFMAN_TABLE_BITS)); + BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(ext); BrotliDropBits(br, HUFFMAN_TABLE_BITS); - ext += (val >> HUFFMAN_TABLE_BITS) & mask; - BrotliDropBits(br, ext->bits); - result = ext->value; + BROTLI_HC_ADJUST_TABLE_INDEX(ext, (val >> HUFFMAN_TABLE_BITS) & mask); + BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(ext)); + result = BROTLI_HC_FAST_LOAD_VALUE(ext); } else { BrotliDropBits(br, *bits); } @@ -597,6 +602,7 @@ static BrotliDecoderErrorCode ReadSymbolCodeLengths( while (symbol < alphabet_size && space > 0) { const HuffmanCode* p = s->table; uint32_t code_len; + BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(p); if (!BrotliCheckInputAmount(br, BROTLI_SHORT_FILL_BIT_WINDOW_READ)) { s->symbol = symbol; s->repeat = repeat; @@ -606,10 +612,10 @@ static BrotliDecoderErrorCode ReadSymbolCodeLengths( return BROTLI_DECODER_NEEDS_MORE_INPUT; } BrotliFillBitWindow16(br); - p += BrotliGetBitsUnmasked(br) & - BitMask(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH); - BrotliDropBits(br, p->bits); /* Use 1..5 bits. */ - code_len = p->value; /* code_len == 0..17 */ + BROTLI_HC_ADJUST_TABLE_INDEX(p, BrotliGetBitsUnmasked(br) & + BitMask(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH)); + BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(p)); /* Use 1..5 bits. */ + code_len = BROTLI_HC_FAST_LOAD_VALUE(p); /* code_len == 0..17 */ if (code_len < BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) { ProcessSingleCodeLength(code_len, &symbol, &repeat, &space, &prev_code_len, symbol_lists, code_length_histo, next_symbol); @@ -637,31 +643,34 @@ static BrotliDecoderErrorCode SafeReadSymbolCodeLengths( uint32_t code_len; uint32_t available_bits; uint32_t bits = 0; + BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(p); if (get_byte && !BrotliPullByte(br)) return BROTLI_DECODER_NEEDS_MORE_INPUT; get_byte = BROTLI_FALSE; available_bits = BrotliGetAvailableBits(br); if (available_bits != 0) { bits = (uint32_t)BrotliGetBitsUnmasked(br); } - p += bits & BitMask(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH); - if (p->bits > available_bits) { + BROTLI_HC_ADJUST_TABLE_INDEX(p, + bits & BitMask(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH)); + if (BROTLI_HC_FAST_LOAD_BITS(p) > available_bits) { get_byte = BROTLI_TRUE; continue; } - code_len = p->value; /* code_len == 0..17 */ + code_len = BROTLI_HC_FAST_LOAD_VALUE(p); /* code_len == 0..17 */ if (code_len < BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) { - BrotliDropBits(br, p->bits); + BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(p)); ProcessSingleCodeLength(code_len, &s->symbol, &s->repeat, &s->space, &s->prev_code_len, s->symbol_lists, s->code_length_histo, s->next_symbol); } else { /* code_len == 16..17, extra_bits == 2..3 */ uint32_t extra_bits = code_len - 14U; - uint32_t repeat_delta = (bits >> p->bits) & BitMask(extra_bits); - if (available_bits < p->bits + extra_bits) { + uint32_t repeat_delta = (bits >> BROTLI_HC_FAST_LOAD_BITS(p)) & + BitMask(extra_bits); + if (available_bits < BROTLI_HC_FAST_LOAD_BITS(p) + extra_bits) { get_byte = BROTLI_TRUE; continue; } - BrotliDropBits(br, p->bits + extra_bits); + BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(p) + extra_bits); ProcessRepeatedCodeLength(code_len, repeat_delta, alphabet_size, &s->symbol, &s->repeat, &s->space, &s->prev_code_len, &s->repeat_code_len, s->symbol_lists, s->code_length_histo, |