}
/* Read into @dst_buffer an array of literal bytes embedded in the bitstream.
- * Return either a pointer to the byte past the last written, or NULL if the
- * read overflows the input buffer. */
-static inline void *
+ * Return 0 if there were enough bytes remaining in the input, otherwise -1. */
+static inline int
bitstream_read_bytes(struct input_bitstream *is, void *dst_buffer, size_t count)
{
if (unlikely(is->end - is->next < count))
- return NULL;
+ return -1;
memcpy(dst_buffer, is->next, count);
is->next += count;
- return (u8 *)dst_buffer + count;
+ return 0;
}
/* Align the input bitstream on a coding-unit boundary. */
{
machine_word_t v;
- STATIC_ASSERT(WORDSIZE == 4 || WORDSIZE == 8);
+ STATIC_ASSERT(WORDBITS == 32 || WORDBITS == 64);
v = b;
v |= v << 8;
v |= v << 16;
- v |= v << ((WORDSIZE == 8) ? 32 : 0);
+ v |= v << ((WORDBITS == 64) ? 32 : 0);
return v;
}
* example, if a word is 8 bytes and the match is of length 5, then
* we'll simply copy 8 bytes. This is okay as long as we don't write
* beyond the end of the output buffer, hence the check for (winend -
- * end >= WORDSIZE - 1).
+ * end >= WORDBYTES - 1).
*/
- if (UNALIGNED_ACCESS_IS_FAST &&
- likely(winend - end >= WORDSIZE - 1))
- {
+ if (UNALIGNED_ACCESS_IS_FAST && likely(winend - end >= WORDBYTES - 1)) {
- if (offset >= WORDSIZE) {
+ if (offset >= WORDBYTES) {
/* The source and destination words don't overlap. */
/* To improve branch prediction, one iteration of this
* and we'll need to continue copying. */
copy_word_unaligned(src, dst);
- src += WORDSIZE;
- dst += WORDSIZE;
+ src += WORDBYTES;
+ dst += WORDBYTES;
if (dst < end) {
do {
copy_word_unaligned(src, dst);
- src += WORDSIZE;
- dst += WORDSIZE;
+ src += WORDBYTES;
+ dst += WORDBYTES;
} while (dst < end);
}
return;
machine_word_t v = repeat_byte(*(dst - 1));
do {
store_word_unaligned(v, dst);
- src += WORDSIZE;
- dst += WORDSIZE;
+ src += WORDBYTES;
+ dst += WORDBYTES;
} while (dst < end);
return;
}
/*
* We don't bother with special cases for other 'offset <
- * WORDSIZE', which are usually rarer than 'offset == 1'. Extra
- * checks will just slow things down. Actually, it's possible
- * to handle all the 'offset < WORDSIZE' cases using the same
- * code, but it still becomes more complicated doesn't seem any
- * faster overall; it definitely slows down the more common
- * 'offset == 1' case.
+ * WORDBYTES', which are usually rarer than 'offset == 1'.
+ * Extra checks will just slow things down. Actually, it's
+ * possible to handle all the 'offset < WORDBYTES' cases using
+ * the same code, but it still becomes more complicated doesn't
+ * seem any faster overall; it definitely slows down the more
+ * common 'offset == 1' case.
*/
}