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bzip2: have two separate "store bit 0" and "store bit 1" functions

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function                                             old     new   delta
sendMTFValues                                       2051    2085     +34
bsW1_0                                                 -      33     +33
BZ2_compressBlock                                    225     223      -2
bsW1                                                  52       -     -52
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 1/1 up/down: 67/-54)             Total: 13 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-02-03 14:56:43 +01:00
parent feafb3423e
commit fc228b48c9
1 changed files with 22 additions and 9 deletions
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31
archival/libarchive/bz/compress.c
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@ -90,10 +90,8 @@ void bsW16(EState* s, uint32_t v)
}
/* Same with n == 1: */
static
#if CONFIG_BZIP2_FAST >= 5
ALWAYS_INLINE
#endif
void bsW1(EState* s, uint32_t v)
ALWAYS_INLINE /* one callsite */
void bsW1_1(EState* s)
{
/* need space for only 1 bit, no need for loop freeing > 8 bits */
if (s->bsLive >= 8) {
@ -101,7 +99,22 @@ void bsW1(EState* s, uint32_t v)
s->bsBuff <<= 8;
s->bsLive -= 8;
}
s->bsBuff |= (v << (31 - s->bsLive));
s->bsBuff |= (1 << (31 - s->bsLive));
s->bsLive += 1;
}
static
#if CONFIG_BZIP2_FAST >= 5
ALWAYS_INLINE
#endif
void bsW1_0(EState* s)
{
/* need space for only 1 bit, no need for loop freeing > 8 bits */
if (s->bsLive >= 8) {
*s->posZ++ = (uint8_t)(s->bsBuff >> 24);
s->bsBuff <<= 8;
s->bsLive -= 8;
}
//s->bsBuff |= (0 << (31 - s->bsLive));
s->bsLive += 1;
}
@ -573,8 +586,8 @@ void sendMTFValues(EState* s)
for (i = 0; i < nSelectors; i++) {
unsigned j;
for (j = 0; j < s->selectorMtf[i]; j++)
bsW1(s, 1);
bsW1(s, 0);
bsW1_1(s);
bsW1_0(s);
}
/*--- Now the coding tables. ---*/
@ -584,7 +597,7 @@ void sendMTFValues(EState* s)
for (i = 0; i < alphaSize; i++) {
while (curr < s->len[t][i]) { bsW(s, 2, 2); curr++; /* 10 */ };
while (curr > s->len[t][i]) { bsW(s, 2, 3); curr--; /* 11 */ };
bsW1(s, 0);
bsW1_0(s);
}
}
@ -698,7 +711,7 @@ void BZ2_compressBlock(EState* s, int is_last_block)
* so as to maintain backwards compatibility with
* older versions of bzip2.
*/
bsW1(s, 0);
bsW1_0(s);
bsW(s, 24, s->origPtr);
generateMTFValues(s);