Apply fixes and speedups

This commit is contained in:
Justine Tunney 2021-10-04 03:23:31 -07:00
parent 7521bf9e73
commit 725f4d79f6
36 changed files with 682 additions and 334 deletions

43
libc/bits/bextra.c Normal file
View file

@ -0,0 +1,43 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2021 Justine Alexandra Roberts Tunney
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/bits/bits.h"
/**
* Extracts bit field from array.
*/
unsigned bextra(const unsigned *p, size_t i, char b) {
unsigned k, r, w;
w = sizeof(unsigned) * CHAR_BIT;
if (b) {
b &= w - 1;
i *= b;
k = i & (w - 1);
i /= w;
if (k <= w - b) {
return (p[i] >> k) & ((1u << (b - 1)) | ((1u << (b - 1)) - 1));
} else {
r = p[i] >> k;
r |= p[i + 1] << (w - k);
r &= (1ul << b) - 1;
return r;
}
} else {
return 0;
}
}

View file

@ -26,6 +26,7 @@ bool cmpxchg(void *, intptr_t, intptr_t, size_t);
bool lockcmpxchg(void *, intptr_t, intptr_t, size_t);
intptr_t atomic_load(void *, size_t);
intptr_t atomic_store(void *, intptr_t, size_t);
unsigned bextra(const unsigned *, size_t, char);
/*───────────────────────────────────────────────────────────────────────────│─╗
cosmopolitan § bits » no assembly required

View file

@ -97,7 +97,29 @@ void *memmove(void *dst, const void *src, size_t n) {
d = dst;
s = src;
if (IsTiny()) {
if (d <= s) {
uint16_t w1, w2;
uint32_t l1, l2;
uint64_t q1, q2;
if (n <= 16) {
if (n >= 8) {
__builtin_memcpy(&q1, s, 8);
__builtin_memcpy(&q2, s + n - 8, 8);
__builtin_memcpy(d, &q1, 8);
__builtin_memcpy(d + n - 8, &q2, 8);
} else if (n >= 4) {
__builtin_memcpy(&l1, s, 4);
__builtin_memcpy(&l2, s + n - 4, 4);
__builtin_memcpy(d, &l1, 4);
__builtin_memcpy(d + n - 4, &l2, 4);
} else if (n >= 2) {
__builtin_memcpy(&w1, s, 2);
__builtin_memcpy(&w2, s + n - 2, 2);
__builtin_memcpy(d, &w1, 2);
__builtin_memcpy(d + n - 2, &w2, 2);
} else if (n) {
*d = *s;
}
} else if (d <= s) {
asm("rep movsb"
: "+D"(d), "+S"(s), "+c"(n), "=m"(*(char(*)[n])dst)
: "m"(*(char(*)[n])src));

View file

@ -28,7 +28,7 @@
relegated wontreturn void __assert_fail(const char *expr, const char *file,
int line) {
static bool noreentry;
__printf("%s:%d: assert(%s) failed\r\n", file, line, expr);
__printf("\r\n%s:%d: assert(%s) failed\r\n", file, line, expr);
if (cmpxchg(&noreentry, false, true)) {
if (weaken(__die)) {
weaken(__die)();

74
libc/runtime/longsort.c Normal file
View file

@ -0,0 +1,74 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2021 Justine Alexandra Roberts Tunney
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/nexgen32e/bsr.h"
#include "libc/nexgen32e/x86feature.h"
#include "libc/runtime/runtime.h"
forceinline void longsorter(long *x, size_t n, size_t t) {
long a, b, c, p, q, i;
for (p = t; p > 0; p >>= 1) {
for (i = 0; i < n - p; ++i) {
if (!(i & p)) {
a = x[i + 0];
b = x[i + p];
if (a > b) c = a, a = b, b = c;
x[i + 0] = a;
x[i + p] = b;
}
}
for (q = t; q > p; q >>= 1) {
for (i = 0; i < n - q; ++i) {
if (!(i & p)) {
a = x[i + p];
b = x[i + q];
if (a > b) c = a, a = b, b = c;
x[i + p] = a;
x[i + q] = b;
}
}
}
}
}
static microarchitecture("avx2") optimizespeed noasan
void longsort_avx2(long *x, size_t n, size_t t) {
longsorter(x, n, t);
}
static optimizesize noasan void longsort_pure(long *x, size_t n, size_t t) {
longsorter(x, n, t);
}
/**
* Sorting algorithm for longs that doesn't take long.
*/
void longsort(long *x, size_t n) {
size_t t, m;
if (IsAsan()) {
if (__builtin_mul_overflow(n, sizeof(long), &m)) m = -1;
__asan_check(x, m);
}
if (n > 1) {
t = 1ul << bsrl(n - 1);
if (X86_HAVE(AVX2)) return longsort_avx2(x, n, t);
return longsort_pure(x, n, t);
}
}

View file

@ -17,15 +17,14 @@
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/alg/alg.h"
#include "libc/assert.h"
#include "libc/bits/bits.h"
#include "libc/calls/calls.h"
#include "libc/dce.h"
#include "libc/elf/def.h"
#include "libc/elf/elf.h"
#include "libc/errno.h"
#include "libc/intrin/asan.internal.h"
#include "libc/limits.h"
#include "libc/log/libfatal.internal.h"
#include "libc/macros.internal.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/runtime.h"
@ -44,14 +43,15 @@
struct SymbolTable *OpenSymbolTable(const char *filename) {
int fd;
void *map;
long *stp;
struct stat st;
size_t n, m, tsz;
unsigned i, j, k, x;
unsigned i, j, x;
const Elf64_Ehdr *elf;
const char *name_base;
struct SymbolTable *t;
const Elf64_Sym *symtab, *sym;
ptrdiff_t names_offset, name_base_offset, extra_offset;
ptrdiff_t names_offset, name_base_offset, stp_offset;
map = MAP_FAILED;
if ((fd = open(filename, O_RDONLY)) == -1) return 0;
if (fstat(fd, &st) == -1) goto SystemError;
@ -69,21 +69,20 @@ struct SymbolTable *OpenSymbolTable(const char *filename) {
tsz += sizeof(unsigned) * n;
name_base_offset = tsz;
tsz += m;
extra_offset = tsz;
tsz = ROUNDUP(tsz, FRAMESIZE);
stp_offset = tsz;
tsz += sizeof(const Elf64_Sym *) * n;
tsz = ROUNDUP(tsz, FRAMESIZE);
t = mmap(0, tsz, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
if (t == MAP_FAILED) goto SystemError;
if (IsAsan()) {
__asan_poison((intptr_t)((char *)t + extra_offset), tsz - extra_offset,
kAsanHeapOverrun);
}
t->mapsize = tsz;
t->names = (const unsigned *)((const char *)t + names_offset);
t->name_base = (const char *)((const char *)t + name_base_offset);
t->names = (unsigned *)((char *)t + names_offset);
t->name_base = (char *)((char *)t + name_base_offset);
GetElfVirtualAddressRange(elf, st.st_size, &t->addr_base, &t->addr_end);
memcpy(t->name_base, name_base, m);
--t->addr_end;
for (j = i = 0; i < n; ++i) {
stp = (long *)((char *)t + stp_offset);
for (m = i = 0; i < n; ++i) {
sym = symtab + i;
if (!(sym->st_size > 0 && (ELF64_ST_TYPE(sym->st_info) == STT_FUNC ||
ELF64_ST_TYPE(sym->st_info) == STT_OBJECT))) {
@ -92,23 +91,25 @@ struct SymbolTable *OpenSymbolTable(const char *filename) {
if (sym->st_value > t->addr_end) continue;
if (sym->st_value < t->addr_base) continue;
x = sym->st_value - t->addr_base;
for (k = j; k && x <= t->symbols[k - 1].x; --k) {
t->symbols[k] = t->symbols[k - 1];
t->names[k] = t->names[k - 1];
}
if (k && t->symbols[k - 1].y >= x) {
t->symbols[k - 1].y = x - 1;
}
t->names[k] = sym->st_name;
t->symbols[k].x = x;
stp[m++] = (unsigned long)x << 32 | i;
}
longsort(stp, m);
for (j = i = 0; i < m; ++i) {
sym = symtab + (stp[i] & 0x7fffffff);
x = stp[i] >> 32;
if (j && x == t->symbols[j - 1].x) --j;
if (j && t->symbols[j - 1].y >= x) t->symbols[j - 1].y = x - 1;
t->names[j] = sym->st_name;
t->symbols[j].x = x;
if (sym->st_size) {
t->symbols[k].y = x + sym->st_size - 1;
t->symbols[j].y = x + sym->st_size - 1;
} else {
t->symbols[k].y = t->addr_end - t->addr_base;
t->symbols[j].y = t->addr_end - t->addr_base;
}
j++;
++j;
}
t->count = j;
munmap(stp, ROUNDUP(sizeof(const Elf64_Sym *) * n, FRAMESIZE));
munmap(map, st.st_size);
close(fd);
return t;

View file

@ -34,185 +34,177 @@ asm(".include \"libc/disclaimer.inc\"");
typedef int (*cmpfun)(const void *, const void *, void *);
forceinline unsigned bsfz0(unsigned x) {
if (x) {
return bsf(x);
} else {
return 0;
}
struct SmoothSort {
size_t lp[12 * sizeof(size_t)];
unsigned char *ar[14 * sizeof(size_t) + 1];
unsigned char tmp[256];
};
static inline int ntz(unsigned long x) {
return __builtin_ctzl(x);
}
forceinline unsigned pntz(unsigned p[2]) {
unsigned r;
assert(p[0] != 0);
r = bsfz0(p[0] - 1);
if (r != 0 ||
(r = 8 * sizeof(unsigned) + bsfz0(p[1])) != 8 * sizeof(unsigned)) {
static inline int pntz(size_t p[2]) {
int r = ntz(p[0] - 1);
if (r != 0 || (r = CHAR_BIT * sizeof(size_t) + ntz(p[1])) !=
CHAR_BIT * sizeof(size_t)) {
return r;
}
return 0;
}
static void cycle(size_t width, unsigned char *ar[], size_t n) {
unsigned i, l;
unsigned char tmp[256];
if (n < 2) return;
ar[n] = tmp;
/* smoothsort_shl() and smoothsort_shr() need n > 0 */
static inline void smoothsort_shl(size_t p[2], int n) {
if (n >= CHAR_BIT * sizeof(size_t)) {
n -= CHAR_BIT * sizeof(size_t);
p[1] = p[0];
p[0] = 0;
}
p[1] <<= n;
p[1] |= p[0] >> (sizeof(size_t) * CHAR_BIT - n);
p[0] <<= n;
}
static inline void smoothsort_shr(size_t p[2], int n) {
if (n >= CHAR_BIT * sizeof(size_t)) {
n -= CHAR_BIT * sizeof(size_t);
p[0] = p[1];
p[1] = 0;
}
p[0] >>= n;
p[0] |= p[1] << (sizeof(size_t) * CHAR_BIT - n);
p[1] >>= n;
}
static void smoothsort_cycle(struct SmoothSort *s, size_t width, int n) {
size_t l;
int i;
if (n < 2) {
return;
}
s->ar[n] = s->tmp;
while (width) {
l = sizeof(tmp) < width ? sizeof(tmp) : width;
memcpy(ar[n], ar[0], l);
l = sizeof(s->tmp) < width ? sizeof(s->tmp) : width;
memcpy(s->ar[n], s->ar[0], l);
for (i = 0; i < n; i++) {
memcpy(ar[i], ar[i + 1], l);
ar[i] += l;
memcpy(s->ar[i], s->ar[i + 1], l);
s->ar[i] += l;
}
width -= l;
}
}
forceinline void shl(unsigned p[2], size_t n) {
assert(n > 0);
if (n >= CHAR_BIT * sizeof(unsigned)) {
n -= CHAR_BIT * sizeof(unsigned);
p[1] = p[0];
p[0] = 0;
}
p[1] <<= n;
p[1] |= p[0] >> (sizeof(unsigned) * CHAR_BIT - n);
p[0] <<= n;
}
forceinline void shr(unsigned p[2], size_t n) {
assert(n > 0);
if (n >= CHAR_BIT * sizeof(unsigned)) {
n -= CHAR_BIT * sizeof(unsigned);
p[0] = p[1];
p[1] = 0;
}
p[0] >>= n;
p[0] |= p[1] << (sizeof(unsigned) * CHAR_BIT - n);
p[1] >>= n;
}
static void sift(unsigned char *head, cmpfun cmp, void *arg, int pshift,
unsigned char *ar[hasatleast 14 * sizeof(unsigned) + 1],
unsigned lp[hasatleast 12 * sizeof(unsigned)], size_t width) {
unsigned i;
static void smoothsort_sift(struct SmoothSort *s, unsigned char *head,
size_t width, cmpfun cmp, void *arg, int pshift) {
unsigned char *rt, *lf;
i = 1;
ar[0] = head;
int i = 1;
s->ar[0] = head;
while (pshift > 1) {
rt = head - width;
lf = head - width - lp[pshift - 2];
if ((*cmp)(ar[0], lf, arg) >= 0 && (*cmp)(ar[0], rt, arg) >= 0) {
lf = head - width - s->lp[pshift - 2];
if (cmp(s->ar[0], lf, arg) >= 0 && cmp(s->ar[0], rt, arg) >= 0) {
break;
}
if ((*cmp)(lf, rt, arg) >= 0) {
ar[i++] = lf;
if (cmp(lf, rt, arg) >= 0) {
s->ar[i++] = lf;
head = lf;
pshift -= 1;
} else {
ar[i++] = rt;
s->ar[i++] = rt;
head = rt;
pshift -= 2;
}
}
cycle(width, ar, i);
smoothsort_cycle(s, width, i);
}
static void trinkle(unsigned char *head, cmpfun cmp, void *arg, unsigned pp[2],
unsigned char *ar[hasatleast 14 * sizeof(unsigned) + 1],
unsigned lp[hasatleast 12 * sizeof(unsigned)], size_t width,
int pshift, int trusty) {
unsigned p[2];
unsigned i, trail;
static void smoothsort_trinkle(struct SmoothSort *s, unsigned char *head,
size_t width, cmpfun cmp, void *arg,
size_t pp[2], int pshift, int trusty) {
unsigned char *stepson, *rt, *lf;
i = 1;
size_t p[2];
int i = 1;
int trail;
p[0] = pp[0];
p[1] = pp[1];
ar[0] = head;
s->ar[0] = head;
while (p[0] != 1 || p[1] != 0) {
stepson = head - lp[pshift];
if ((*cmp)(stepson, ar[0], arg) <= 0) {
stepson = head - s->lp[pshift];
if (cmp(stepson, s->ar[0], arg) <= 0) {
break;
}
if (!trusty && pshift > 1) {
rt = head - width;
lf = head - width - lp[pshift - 2];
if ((*cmp)(rt, stepson, arg) >= 0 || (*cmp)(lf, stepson, arg) >= 0) {
lf = head - width - s->lp[pshift - 2];
if (cmp(rt, stepson, arg) >= 0 || cmp(lf, stepson, arg) >= 0) {
break;
}
}
ar[i++] = stepson;
s->ar[i++] = stepson;
head = stepson;
trail = pntz(p);
shr(p, trail);
smoothsort_shr(p, trail);
pshift += trail;
trusty = 0;
}
if (!trusty) {
cycle(width, ar, i);
sift(head, cmp, arg, pshift, ar, lp, width);
smoothsort_cycle(s, width, i);
smoothsort_sift(s, head, width, cmp, arg, pshift);
}
}
/**
* Smoothsort is an adaptive linearithmic sorting algorithm that's
* nearly linear on mostly-sorted data, and consumes constant memory.
*/
static noinline void smoothsort(
void *base, size_t count, size_t width, cmpfun cmp, void *arg,
unsigned lp[hasatleast 12 * sizeof(unsigned)],
unsigned char *ar[hasatleast 14 * sizeof(unsigned) + 1]) {
unsigned i, size = width * count;
static void smoothsort(struct SmoothSort *s, void *base, size_t nel,
size_t width, cmpfun cmp, void *arg) {
size_t i, size = width * nel;
unsigned char *head, *high;
unsigned p[2] = {1, 0};
unsigned pshift = 1;
unsigned trail;
size_t p[2] = {1, 0};
int pshift = 1;
int trail;
if (!size) return;
head = (unsigned char *)base;
head = base;
high = head + size - width;
/* Precompute Leonardo numbers, scaled by element width */
for (lp[0] = lp[1] = width, i = 2;
(lp[i] = lp[i - 2] + lp[i - 1] + width) < size; i++) {
for (s->lp[0] = s->lp[1] = width, i = 2;
(s->lp[i] = s->lp[i - 2] + s->lp[i - 1] + width) < size; i++) {
}
while (head < high) {
if ((p[0] & 3) == 3) {
sift(head, cmp, arg, pshift, ar, lp, width);
shr(p, 2);
smoothsort_sift(s, head, width, cmp, arg, pshift);
smoothsort_shr(p, 2);
pshift += 2;
} else {
if (lp[pshift - 1] >= high - head) {
trinkle(head, cmp, arg, p, ar, lp, width, pshift, 0);
if (s->lp[pshift - 1] >= high - head) {
smoothsort_trinkle(s, head, width, cmp, arg, p, pshift, 0);
} else {
sift(head, cmp, arg, pshift, ar, lp, width);
smoothsort_sift(s, head, width, cmp, arg, pshift);
}
if (pshift == 1) {
shl(p, 1);
smoothsort_shl(p, 1);
pshift = 0;
} else {
shl(p, pshift - 1);
smoothsort_shl(p, pshift - 1);
pshift = 1;
}
}
p[0] |= 1;
head += width;
}
trinkle(head, cmp, arg, p, ar, lp, width, pshift, 0);
smoothsort_trinkle(s, head, width, cmp, arg, p, pshift, 0);
while (pshift != 1 || p[0] != 1 || p[1] != 0) {
if (pshift <= 1) {
trail = pntz(p);
shr(p, trail);
smoothsort_shr(p, trail);
pshift += trail;
} else {
shl(p, 2);
smoothsort_shl(p, 2);
pshift -= 2;
p[0] ^= 7;
shr(p, 1);
trinkle(head - lp[pshift] - width, cmp, arg, p, ar, lp, width, pshift + 1,
1);
shl(p, 1);
smoothsort_shr(p, 1);
smoothsort_trinkle(s, head - s->lp[pshift] - width, width, cmp, arg, p,
pshift + 1, 1);
smoothsort_shl(p, 1);
p[0] |= 1;
trinkle(head - width, cmp, arg, p, ar, lp, width, pshift, 1);
smoothsort_trinkle(s, head - width, width, cmp, arg, p, pshift, 1);
}
head -= width;
}
@ -229,9 +221,8 @@ static noinline void smoothsort(
* @see qsort()
*/
void qsort_r(void *base, size_t count, size_t width, cmpfun cmp, void *arg) {
unsigned lp[12 * sizeof(unsigned)];
unsigned char *ar[14 * sizeof(unsigned) + 1];
smoothsort(base, count, width, (cmpfun)cmp, arg, lp, ar);
struct SmoothSort s;
smoothsort(&s, base, count, width, cmp, arg);
}
/**
@ -241,9 +232,10 @@ void qsort_r(void *base, size_t count, size_t width, cmpfun cmp, void *arg) {
* @param count is the item count
* @param width is the size of each item
* @param cmp is a callback returning <0, 0, or >0
* @see qsort_r()
* @see longsort(), djbsort()
*/
void qsort(void *base, size_t count, size_t width,
int cmp(const void *, const void *)) {
qsort_r(base, count, width, (cmpfun)cmp, NULL);
struct SmoothSort s;
smoothsort(&s, base, count, width, (cmpfun)cmp, 0);
}

View file

@ -77,6 +77,7 @@ int vhangup(void);
int getdtablesize(void);
int sethostname(const char *, size_t);
int acct(const char *);
void longsort(long *, size_t);
bool _isheap(void *);
int NtGetVersion(void);

View file

@ -88,6 +88,10 @@ o/$(MODE)/libc/runtime/mman.greg.o: \
-ffreestanding \
-mgeneral-regs-only
o/$(MODE)/libc/runtime/qsort.o: \
OVERRIDE_CFLAGS += \
-Og
o/$(MODE)/libc/runtime/ftrace.greg.o: \
OVERRIDE_CFLAGS += \
-mgeneral-regs-only

View file

@ -24,7 +24,7 @@ struct SymbolTable {
struct SymbolTable *GetSymbolTable(void);
const char *FindComBinary(void);
const char *FindDebugBinary(void);
struct SymbolTable *OpenSymbolTable(const char *) nodiscard;
struct SymbolTable *OpenSymbolTable(const char *);
int CloseSymbolTable(struct SymbolTable **);
void __hook(void *, struct SymbolTable *);

View file

@ -16,8 +16,13 @@
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/bits/bits.h"
#include "libc/zip.h"
typedef char v16qi __attribute__((__vector_size__(16)));
typedef short v8hi __attribute__((__vector_size__(16)));
typedef long long v2di __attribute__((__vector_size__(16), __aligned__(1)));
/**
* Locates End Of Central Directory record in ZIP file.
*
@ -32,9 +37,23 @@
* @return pointer to EOCD64 or EOCD, or NULL if not found
*/
void *GetZipCdir(const uint8_t *p, size_t n) {
v2di x;
size_t i, j;
v8hi pk = {READ16LE("PK"), READ16LE("PK"), READ16LE("PK"), READ16LE("PK"),
READ16LE("PK"), READ16LE("PK"), READ16LE("PK"), READ16LE("PK")};
i = n - 4;
asm("" : "+x"(pk));
do {
if (i >= 14) {
x = *(const v2di *)(p + i - 14);
if (!(__builtin_ia32_pmovmskb128(
(v16qi)__builtin_ia32_pcmpeqw128((v8hi)x, pk)) |
__builtin_ia32_pmovmskb128((v16qi)__builtin_ia32_pcmpeqw128(
(v8hi)__builtin_ia32_psrldqi128(x, 8), pk)))) {
i -= 13;
continue;
}
}
if (READ32LE(p + i) == kZipCdir64LocatorMagic &&
i + kZipCdir64LocatorSize <= n &&
IsZipCdir64(p, n, ZIP_LOCATE64_OFFSET(p + i))) {