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Diffstat (limited to 'c/dec/decode.c')
-rw-r--r--c/dec/decode.c81
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,