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-rw-r--r--src/liblzma/lzma/lzma_decoder.c52
1 files changed, 30 insertions, 22 deletions
diff --git a/src/liblzma/lzma/lzma_decoder.c b/src/liblzma/lzma/lzma_decoder.c
index fd57ac82..04fae74e 100644
--- a/src/liblzma/lzma/lzma_decoder.c
+++ b/src/liblzma/lzma/lzma_decoder.c
@@ -425,13 +425,7 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in,
// Not a repeated match
//
// We will decode a new distance and store
- // the value to rep0.
-
- // The latest three match distances are kept in
- // memory in case there are repeated matches.
- rep3 = rep2;
- rep2 = rep1;
- rep1 = rep0;
+ // the value to distance.
// Decode the length of the match.
length_decode(len, coder->len_decoder, pos_state);
@@ -447,36 +441,36 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in,
if (pos_slot >= START_POS_MODEL_INDEX) {
uint32_t direct_bits = (pos_slot >> 1) - 1;
assert(direct_bits >= 1 && direct_bits <= 30);
- rep0 = 2 | (pos_slot & 1);
+ uint32_t distance = 2 | (pos_slot & 1);
if (pos_slot < END_POS_MODEL_INDEX) {
assert(direct_bits <= 5);
- rep0 <<= direct_bits;
- assert(rep0 <= 96);
+ distance <<= direct_bits;
+ assert(distance <= 96);
// -1 is fine, because
// bittree_reverse_decode()
// starts from table index [1]
// (not [0]).
- assert((int32_t)(rep0 - pos_slot - 1) >= -1);
- assert((int32_t)(rep0 - pos_slot - 1) <= 82);
- // We add the result to rep0, so rep0
+ assert((int32_t)(distance - pos_slot - 1) >= -1);
+ assert((int32_t)(distance - pos_slot - 1) <= 82);
+ // We add the result to distance, so distance
// must not be part of second argument
// of the macro.
- const int32_t offset = rep0 - pos_slot - 1;
- bittree_reverse_decode(rep0, coder->pos_decoders + offset,
+ const int32_t offset = distance - pos_slot - 1;
+ bittree_reverse_decode(distance, coder->pos_decoders + offset,
direct_bits);
} else {
assert(pos_slot >= 14);
assert(direct_bits >= 6);
direct_bits -= ALIGN_BITS;
assert(direct_bits >= 2);
- rc_decode_direct(rep0, direct_bits);
- rep0 <<= ALIGN_BITS;
+ rc_decode_direct(distance, direct_bits);
+ distance <<= ALIGN_BITS;
- bittree_reverse_decode(rep0, coder->pos_align_decoder,
+ bittree_reverse_decode(distance, coder->pos_align_decoder,
ALIGN_BITS);
- if (rep0 == UINT32_MAX) {
+ if (distance == UINT32_MAX) {
if (len == LEN_SPECIAL_EOPM) {
// End of Payload Marker found.
coder->lz.eopm_detected = true;
@@ -501,16 +495,31 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in,
rc_reset(rc);
// If we don't have enough input here, we jump
- // out of the loop without calling rc_normalize().
+ // out of the loop. Note that while there is a
+ // useless call to rc_normalize(), it does nothing
+ // since we have just reset the range decoder.
if (!rc_read_init(&rc, in, &in_pos_local, in_size))
- goto out;
+ break;
+
+ continue;
} else {
return true;
}
}
}
+
+ // The latest three match distances are kept in
+ // memory in case there are repeated matches.
+ rep3 = rep2;
+ rep2 = rep1;
+ rep1 = rep0;
+ rep0 = distance;
+
} else {
+ rep3 = rep2;
+ rep2 = rep1;
+ rep1 = rep0;
rep0 = pos_slot;
}
@@ -630,7 +639,6 @@ decode_real(lzma_coder *restrict coder, const uint8_t *restrict in,
// Update the *data structure. //
/////////////////////////////////
-out:
// Range decoder
rc_from_local(coder->rc);