Skip to content

[aarch64] use crc32 instructions when available #4108

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

[aarch64] use crc32 instructions when available #4108

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
50 changes: 50 additions & 0 deletions ext/standard/crc32.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,32 @@
#include "basic_functions.h"
#include "crc32.h"

#if defined(__aarch64__)
# pragma GCC target ("+nothing+crc")
# include <arm_acle.h>
# if defined(__linux__)
# include <sys/auxv.h>
# include <asm/hwcap.h>
# endif

static inline int has_crc32_insn() {
/* Only go through the runtime detection once. */
static int res = -1;
if (res != -1)
return res;
# if defined(HWCAP_CRC32)
res = getauxval(AT_HWCAP) & HWCAP_CRC32;
return res;
# elif defined(HWCAP2_CRC32)
res = getauxval(AT_HWCAP2) & HWCAP2_CRC32;
return res;
# else
res = 0;
return res;
# endif
}
#endif

/* {{{ proto string crc32(string str)
Calculate the crc32 polynomial of a string */
PHP_NAMED_FUNCTION(php_if_crc32)
Expand All @@ -35,6 +61,30 @@ PHP_NAMED_FUNCTION(php_if_crc32)

crc = crcinit^0xFFFFFFFF;

#if defined(__aarch64__)
if (has_crc32_insn()) {
while(nr >= sizeof(uint64_t)) {
crc = __crc32d(crc, *(uint64_t *)p);
p += sizeof(uint64_t);
nr -= sizeof(uint64_t);
}
if (nr >= sizeof(int32_t)) {
crc = __crc32w(crc, *(uint32_t *)p);
p += sizeof(uint32_t);
nr -= sizeof(uint32_t);
}
if (nr >= sizeof(int16_t)) {
crc = __crc32h(crc, *(uint16_t *)p);
p += sizeof(uint16_t);
nr -= sizeof(uint16_t);
}
if (nr) {
crc = __crc32b(crc, *p);
p += sizeof(uint8_t);
nr -= sizeof(uint8_t);
}
}
#endif
for (; nr--; ++p) {
crc = ((crc >> 8) & 0x00FFFFFF) ^ crc32tab[(crc ^ (*p)) & 0xFF ];
}
Expand Down