php-src/Zend/zend_cpuinfo.c
2020-11-27 17:04:17 +01:00

153 lines
4.5 KiB
C

/*
+----------------------------------------------------------------------+
| Zend Engine |
+----------------------------------------------------------------------+
| Copyright (c) Zend Technologies Ltd. (http://www.zend.com) |
+----------------------------------------------------------------------+
| This source file is subject to version 2.00 of the Zend license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.zend.com/license/2_00.txt. |
| If you did not receive a copy of the Zend license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@zend.com so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Xinchen Hui <xinchen.h@zend.com> |
+----------------------------------------------------------------------+
*/
#include "zend_cpuinfo.h"
typedef struct _zend_cpu_info {
uint32_t eax;
uint32_t ebx;
uint32_t ecx;
uint32_t edx;
uint32_t initialized;
} zend_cpu_info;
static zend_cpu_info cpuinfo = {0};
#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
# if defined(HAVE_CPUID_H) && defined(HAVE_CPUID_COUNT)
# include <cpuid.h>
static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
__cpuid_count(func, subfunc, cpuinfo->eax, cpuinfo->ebx, cpuinfo->ecx, cpuinfo->edx);
}
# else
static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
#if defined(__i386__) && (defined(__pic__) || defined(__PIC__))
/* PIC on i386 uses %ebx, so preserve it. */
__asm__ __volatile__ (
"pushl %%ebx\n"
"cpuid\n"
"mov %%ebx,%1\n"
"popl %%ebx"
: "=a"(cpuinfo->eax), "=r"(cpuinfo->ebx), "=c"(cpuinfo->ecx), "=d"(cpuinfo->edx)
: "a"(func), "c"(subfunc)
);
#else
__asm__ __volatile__ (
"cpuid"
: "=a"(cpuinfo->eax), "=b"(cpuinfo->ebx), "=c"(cpuinfo->ecx), "=d"(cpuinfo->edx)
: "a"(func), "c"(subfunc)
);
#endif
}
# endif
#elif defined(ZEND_WIN32) && !defined(__clang__)
# include <intrin.h>
static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
int regs[4];
__cpuidex(regs, func, subfunc);
cpuinfo->eax = regs[0];
cpuinfo->ebx = regs[1];
cpuinfo->ecx = regs[2];
cpuinfo->edx = regs[3];
}
#else
static void __zend_cpuid(uint32_t func, uint32_t subfunc, zend_cpu_info *cpuinfo) {
cpuinfo->eax = 0;
}
#endif
#if defined(__i386__) || defined(__x86_64__)
/* Function based on compiler-rt implementation. */
static unsigned get_xcr0_eax() {
# if defined(__GNUC__) || defined(__clang__)
// Check xgetbv; this uses a .byte sequence instead of the instruction
// directly because older assemblers do not include support for xgetbv and
// there is no easy way to conditionally compile based on the assembler used.
unsigned eax, edx;
__asm__(".byte 0x0f, 0x01, 0xd0" : "=a"(eax), "=d"(edx) : "c"(0));
return eax;
# elif defined(ZEND_WIN32) && defined(_XCR_XFEATURE_ENABLED_MASK)
return _xgetbv(_XCR_XFEATURE_ENABLED_MASK);
# else
return 0;
# endif
}
static zend_bool is_avx_supported() {
if (!(cpuinfo.ecx & ZEND_CPU_FEATURE_AVX)) {
/* No support for AVX */
return 0;
}
if (!(cpuinfo.ecx & ZEND_CPU_FEATURE_OSXSAVE)) {
/* The operating system does not support XSAVE. */
return 0;
}
if ((get_xcr0_eax() & 0x6) != 0x6) {
/* XCR0 SSE and AVX bits must be set. */
return 0;
}
return 1;
}
#else
static zend_bool is_avx_supported() {
return 0;
}
#endif
void zend_cpu_startup(void)
{
if (!cpuinfo.initialized) {
zend_cpu_info ebx;
int max_feature;
cpuinfo.initialized = 1;
__zend_cpuid(0, 0, &cpuinfo);
max_feature = cpuinfo.eax;
if (max_feature == 0) {
return;
}
__zend_cpuid(1, 0, &cpuinfo);
/* for avx2 */
if (max_feature >= 7) {
__zend_cpuid(7, 0, &ebx);
cpuinfo.ebx = ebx.ebx;
} else {
cpuinfo.ebx = 0;
}
if (!is_avx_supported()) {
cpuinfo.edx &= ~ZEND_CPU_FEATURE_AVX;
cpuinfo.ebx &= ~(ZEND_CPU_FEATURE_AVX2 & ~ZEND_CPU_EBX_MASK);
}
}
}
ZEND_API int zend_cpu_supports(zend_cpu_feature feature) {
if (feature & ZEND_CPU_EDX_MASK) {
return (cpuinfo.edx & (feature & ~ZEND_CPU_EDX_MASK));
} else if (feature & ZEND_CPU_EBX_MASK) {
return (cpuinfo.ebx & (feature & ~ZEND_CPU_EBX_MASK));
} else {
return (cpuinfo.ecx & feature);
}
}