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gzip: code shrink

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huft_build() has way too many params

function                                             old     new   delta
inflate_block                                       1293    1281     -12
huft_build                                          1085    1058     -27
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-39)             Total: -39 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2019-10-19 18:33:49 +02:00
parent 95867147f5
commit c763392458
1 changed files with 26 additions and 27 deletions
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53
archival/libarchive/decompress_gunzip.c
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@ -277,22 +277,19 @@ static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current
/* Given a list of code lengths and a maximum table size, make a set of
* tables to decode that set of codes. Return zero on success, one if
* the given code set is incomplete (the tables are still built in this
* case), two if the input is invalid (an oversubscribed set of lengths)
* - in this case stores NULL in *t.
* tables to decode that set of codes.
*
* b: code lengths in bits (all assumed <= BMAX)
* n: number of codes (assumed <= N_MAX)
* s: number of simple-valued codes (0..s-1)
* d: list of base values for non-simple codes
* e: list of extra bits for non-simple codes
* t: result: starting table
* m: maximum lookup bits, returns actual
* result: starting table
*/
static int huft_build(const unsigned *b, const unsigned n,
const unsigned s, const unsigned short *d,
const unsigned char *e, huft_t **t, unsigned *m)
static huft_t* huft_build(const unsigned *b, const unsigned n,
const unsigned s, const uint16_t *d,
const uint8_t *e, unsigned *m)
{
unsigned a; /* counter for codes of length k */
unsigned c[BMAX + 1]; /* bit length count table */
@ -314,12 +311,12 @@ static int huft_build(const unsigned *b, const unsigned n,
unsigned *xp; /* pointer into x */
int y; /* number of dummy codes added */
unsigned z; /* number of entries in current table */
huft_t *result;
huft_t **t;
/* Length of EOB code, if any */
eob_len = n > 256 ? b[256] : BMAX;
*t = NULL;
/* Generate counts for each bit length */
memset(c, 0, sizeof(c));
p = b;
@ -335,9 +332,8 @@ static int huft_build(const unsigned *b, const unsigned n,
q[1].b = 1;
q[2].e = 99; /* invalid code marker */
q[2].b = 1;
*t = q + 1;
*m = 1;
return 0;
return q + 1;
}
/* Find minimum and maximum length, bound *m by those */
@ -353,11 +349,11 @@ static int huft_build(const unsigned *b, const unsigned n,
for (y = 1 << j; j < i; j++, y <<= 1) {
y -= c[j];
if (y < 0)
return 2; /* bad input: more codes than bits */
return NULL; /* bad input: more codes than bits */
}
y -= c[i];
if (y < 0)
return 2;
return NULL;
c[i] += y;
/* Generate starting offsets into the value table for each length */
@ -384,6 +380,8 @@ static int huft_build(const unsigned *b, const unsigned n,
} while (++i < n);
/* Generate the Huffman codes and for each, make the table entries */
result = NULL;
t = &result;
x[0] = i = 0; /* first Huffman code is zero */
p = v; /* grab values in bit order */
htl = -1; /* no tables yet--level -1 */
@ -475,8 +473,10 @@ static int huft_build(const unsigned *b, const unsigned n,
/* return actual size of base table */
*m = ws[1];
/* Return 1 if we were given an incomplete table */
return y != 0 && g != 1;
if (y != 0 && g != 1) /* we were given an incomplete table */
return NULL;
return result;
}
@ -777,14 +777,14 @@ static int inflate_block(STATE_PARAM smallint *e)
for (; i < 288; i++) /* make a complete, but wrong code set */
ll[i] = 8;
bl = 7;
huft_build(ll, 288, 257, cplens, cplext, &inflate_codes_tl, &bl);
/* huft_build() never return nonzero - we use known data */
inflate_codes_tl = huft_build(ll, 288, 257, cplens, cplext, &bl);
/* huft_build() never returns error here - we use known data */
/* set up distance table */
for (i = 0; i < 30; i++) /* make an incomplete code set */
ll[i] = 5;
bd = 5;
huft_build(ll, 30, 0, cpdist, cpdext, &inflate_codes_td, &bd);
inflate_codes_td = huft_build(ll, 30, 0, cpdist, cpdext, &bd);
/* set up data for inflate_codes() */
inflate_codes_setup(PASS_STATE bl, bd);
@ -850,9 +850,9 @@ static int inflate_block(STATE_PARAM smallint *e)
/* build decoding table for trees - single level, 7 bit lookup */
bl = 7;
i = huft_build(ll, 19, 19, NULL, NULL, &inflate_codes_tl, &bl);
if (i != 0) {
abort_unzip(PASS_STATE_ONLY); //return i; /* incomplete code set */
inflate_codes_tl = huft_build(ll, 19, 19, NULL, NULL, &bl);
if (!inflate_codes_tl) {
abort_unzip(PASS_STATE_ONLY); /* incomplete code set */
}
/* read in literal and distance code lengths */
@ -915,14 +915,13 @@ static int inflate_block(STATE_PARAM smallint *e)
/* build the decoding tables for literal/length and distance codes */
bl = lbits;
i = huft_build(ll, nl, 257, cplens, cplext, &inflate_codes_tl, &bl);
if (i != 0) {
inflate_codes_tl = huft_build(ll, nl, 257, cplens, cplext, &bl);
if (!inflate_codes_tl) {
abort_unzip(PASS_STATE_ONLY);
}
bd = dbits;
i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &inflate_codes_td, &bd);
if (i != 0) {
inflate_codes_td = huft_build(ll + nl, nd, 0, cpdist, cpdext, &bd);
if (!inflate_codes_td) {
abort_unzip(PASS_STATE_ONLY);
}