mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-06-27 14:58:30 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Improve Python tree-shaking

Browse source
This commit is contained in:
Justine Tunney 2021-09-06 19:24:10 -07:00
parent 5bb2275788
commit 4f41f2184d
169 changed files with 4182 additions and 2411 deletions
Download patch file Download diff file Expand all files Collapse all files

121
libc/str/memcmp.c
View file

@ -16,6 +16,8 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/bits.h"
#include "libc/dce.h"
#include "libc/intrin/pcmpeqb.h"
#include "libc/intrin/pmovmskb.h"
#include "libc/nexgen32e/bsf.h"
@ -29,25 +31,116 @@
*/
int memcmp(const void *a, const void *b, size_t n) {
int c;
size_t i;
uint64_t w;
unsigned m;
uint8_t *p1, *p2;
uint8_t v1[16], v2[16];
if (n) {
for (p1 = a, p2 = b, i = 0; i + 16 <= n; i += 16) {
memcpy(v1, p1 + i, 16);
memcpy(v2, p2 + i, 16);
pcmpeqb(v1, v1, v2);
if ((m = pmovmskb(v1) - 0xffff)) {
i += bsf(m);
return p1[i] - p2[i];
uint8_t A[16], B[16];
const uint8_t *p = a, *q = b;
if (p == q) return 0;
if (IsTiny()) {
for (; n >= 8; p += 8, q += 8, n -= 8) {
w = READ64LE(p) ^ READ64LE(q);
if (w) {
m = bsfl(w) >> 3;
return p[m] - q[m];
}
}
for (; i < n; ++i) {
if ((c = p1[i] - p2[i])) {
for (; n; ++p, ++q, --n) {
if ((c = *p - *q)) {
return c;
}
}
return 0;
}
return 0;
StartOver:
switch (n) {
case 0:
return 0;
case 1:
return *p - *q;
case 2:
w = (p[0] << 000 | p[1] << 010) ^ (q[0] << 000 | q[1] << 010);
break;
case 3:
w = (p[0] << 000 | p[1] << 010 | p[2] << 020) ^
(q[0] << 000 | q[1] << 010 | q[2] << 020);
break;
case 4:
w = ((uint32_t)p[0] << 000 | (uint32_t)p[1] << 010 |
(uint32_t)p[2] << 020 | (uint32_t)p[3] << 030) ^
((uint32_t)q[0] << 000 | (uint32_t)q[1] << 010 |
(uint32_t)q[2] << 020 | (uint32_t)q[3] << 030);
break;
case 5:
w = ((uint64_t)p[0] << 000 | (uint64_t)p[1] << 010 |
(uint64_t)p[2] << 020 | (uint64_t)p[3] << 030 |
(uint64_t)p[4] << 040) ^
((uint64_t)q[0] << 000 | (uint64_t)q[1] << 010 |
(uint64_t)q[2] << 020 | (uint64_t)q[3] << 030 |
(uint64_t)q[4] << 040);
break;
case 6:
w = ((uint64_t)p[0] << 000 | (uint64_t)p[1] << 010 |
(uint64_t)p[2] << 020 | (uint64_t)p[3] << 030 |
(uint64_t)p[4] << 040 | (uint64_t)p[5] << 050) ^
((uint64_t)q[0] << 000 | (uint64_t)q[1] << 010 |
(uint64_t)q[2] << 020 | (uint64_t)q[3] << 030 |
(uint64_t)q[4] << 040 | (uint64_t)q[5] << 050);
break;
case 7:
w = ((uint64_t)p[0] << 000 | (uint64_t)p[1] << 010 |
(uint64_t)p[2] << 020 | (uint64_t)p[3] << 030 |
(uint64_t)p[4] << 040 | (uint64_t)p[5] << 050 |
(uint64_t)p[6] << 060) ^
((uint64_t)q[0] << 000 | (uint64_t)q[1] << 010 |
(uint64_t)q[2] << 020 | (uint64_t)q[3] << 030 |
(uint64_t)q[4] << 040 | (uint64_t)q[5] << 050 |
(uint64_t)q[6] << 060);
break;
case 8:
w = ((uint64_t)p[0] << 000 | (uint64_t)p[1] << 010 |
(uint64_t)p[2] << 020 | (uint64_t)p[3] << 030 |
(uint64_t)p[4] << 040 | (uint64_t)p[5] << 050 |
(uint64_t)p[6] << 060 | (uint64_t)p[7] << 070) ^
((uint64_t)q[0] << 000 | (uint64_t)q[1] << 010 |
(uint64_t)q[2] << 020 | (uint64_t)q[3] << 030 |
(uint64_t)q[4] << 040 | (uint64_t)q[5] << 050 |
(uint64_t)q[6] << 060 | (uint64_t)q[7] << 070);
break;
default:
for (; n >= 16; p += 16, q += 16, n -= 16) {
memcpy(A, p, 16);
memcpy(B, q, 16);
pcmpeqb(A, A, B);
if ((m = pmovmskb(A) - 0xffff)) {
m = bsf(m);
return p[m] - q[m];
}
}
if (n > 8) {
case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
w = ((uint64_t)p[0] << 000 | (uint64_t)p[1] << 010 |
(uint64_t)p[2] << 020 | (uint64_t)p[3] << 030 |
(uint64_t)p[4] << 040 | (uint64_t)p[5] << 050 |
(uint64_t)p[6] << 060 | (uint64_t)p[7] << 070) ^
((uint64_t)q[0] << 000 | (uint64_t)q[1] << 010 |
(uint64_t)q[2] << 020 | (uint64_t)q[3] << 030 |
(uint64_t)q[4] << 040 | (uint64_t)q[5] << 050 |
(uint64_t)q[6] << 060 | (uint64_t)q[7] << 070);
if (w) goto ItsDifferent;
p += 8;
q += 8;
n -= 8;
}
goto StartOver;
}
if (!w) return 0;
ItsDifferent:
m = bsfl(w) >> 3;
return p[m] - q[m];
}