cosmopolitan/libc/str/crc32z.c
Justine Tunney 39bf41f4eb Make numerous improvements
- Python static hello world now 1.8mb
- Python static fully loaded now 10mb
- Python HTTPS client now uses MbedTLS
- Python REPL now completes import stmts
- Increase stack size for Python for now
- Begin synthesizing posixpath and ntpath
- Restore Python \N{UNICODE NAME} support
- Restore Python NFKD symbol normalization
- Add optimized code path for Intel SHA-NI
- Get more Python unit tests passing faster
- Get Python help() pagination working on NT
- Python hashlib now supports MbedTLS PBKDF2
- Make memcpy/memmove/memcmp/bcmp/etc. faster
- Add Mersenne Twister and Vigna to LIBC_RAND
- Provide privileged __printf() for error code
- Fix zipos opendir() so that it reports ENOTDIR
- Add basic chmod() implementation for Windows NT
- Add Cosmo's best functions to Python cosmo module
- Pin function trace indent depth to that of caller
- Show memory diagram on invalid access in MODE=dbg
- Differentiate stack overflow on crash in MODE=dbg
- Add stb_truetype and tools for analyzing font files
- Upgrade to UNICODE 13 and reduce its binary footprint
- COMPILE.COM now logs resource usage of build commands
- Start implementing basic poll() support on bare metal
- Set getauxval(AT_EXECFN) to GetModuleFileName() on NT
- Add descriptions to strerror() in non-TINY build modes
- Add COUNTBRANCH() macro to help with micro-optimizations
- Make error / backtrace / asan / memory code more unbreakable
- Add fast perfect C implementation of μ-Law and a-Law audio codecs
- Make strtol() functions consistent with other libc implementations
- Improve Linenoise implementation (see also github.com/jart/bestline)
- COMPILE.COM now suppresses stdout/stderr of successful build commands
2021-09-28 01:52:34 -07:00

72 lines
3.4 KiB
C

/*-*- 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 2020 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/assert.h"
#include "libc/bits/safemacros.internal.h"
#include "libc/dce.h"
#include "libc/intrin/asan.internal.h"
#include "libc/macros.internal.h"
#include "libc/nexgen32e/crc32.h"
#include "libc/nexgen32e/x86feature.h"
#include "libc/str/str.h"
static inline noasan uint64_t WildRead64(const signed char *p) {
return (uint64_t)(255 & p[7]) << 070 | (uint64_t)(255 & p[6]) << 060 |
(uint64_t)(255 & p[5]) << 050 | (uint64_t)(255 & p[4]) << 040 |
(uint64_t)(255 & p[3]) << 030 | (uint64_t)(255 & p[2]) << 020 |
(uint64_t)(255 & p[1]) << 010 | (uint64_t)(255 & p[0]) << 000;
}
/**
* Computes Phil Katz CRC-32 used by zip/zlib/gzip/etc.
*
* x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1
* 0b100000100110000010001110110110111
* bitreverse32(0x104c11db7)
*
* This implementation takes 32 picoseconds per byte or 30 gibibyte/s.
*
* @param h is initial value
*/
uint32_t crc32_z(uint32_t h, const void *data, size_t size) {
size_t n;
static bool once;
const unsigned char *p, *e;
static uint32_t kCrc32Tab[256];
if (!once) {
crc32init(kCrc32Tab, 0xedb88320);
once = 0;
}
if (size == -1) {
size = data ? strlen(data) : 0;
}
p = data;
e = p + size;
h ^= 0xffffffff;
if (X86_HAVE(PCLMUL)) {
while (((intptr_t)p & 15) && p < e)
h = h >> 8 ^ kCrc32Tab[(h & 0xff) ^ *p++];
if ((n = ROUNDDOWN(e - p, 16)) >= 64) {
if (IsAsan()) __asan_verify(p, n);
h = crc32_pclmul(h, p, n); /* 51x faster */
p += n;
}
}
while (p < e) h = h >> 8 ^ kCrc32Tab[(h & 0xff) ^ *p++];
return h ^ 0xffffffff;
}