KasmVNC/common/rfb/cpuid.cxx

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/* Copyright (C) 2021 Kasm Web
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#include <stdint.h>
static uint32_t cpuid[4] = { 0 };
static uint32_t extcpuid[4] = { 0 };
static void getcpuid() {
if (cpuid[0])
return;
#if defined(__x86_64__) || defined(__i386__)
uint32_t eax, ecx = 0;
eax = 1; // normal feature bits
__asm__ __volatile__(
"cpuid\n\t"
: "=a"(cpuid[0]), "=b"(cpuid[1]), "=c"(cpuid[2]), "=d"(cpuid[3])
: "0"(eax), "2"(ecx)
);
eax = 7; // ext feature bits
ecx = 0;
__asm__ __volatile__(
"cpuid\n\t"
: "=a"(extcpuid[0]), "=b"(extcpuid[1]), "=c"(extcpuid[2]), "=d"(extcpuid[3])
: "0"(eax), "2"(ecx)
);
#endif
}
namespace rfb {
bool supportsSSE2() {
getcpuid();
#if defined(__x86_64__) || defined(__i386__)
#define bit_SSE2 (1 << 26)
return cpuid[3] & bit_SSE2;
#endif
return false;
}
bool supportsAVX512f() {
getcpuid();
#if defined(__x86_64__) || defined(__i386__)
#define bit_AVX512f (1 << 16)
return extcpuid[1] & bit_AVX512f;
#endif
return false;
}
}; // namespace rfb