pcsx2/common/Misc.cpp

74 lines
1.5 KiB
C++

/* PCSX2 - PS2 Emulator for PCs
* Copyright (C) 2021 PCSX2 Dev Team
*
* PCSX2 is free software: you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* PCSX2 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 PCSX2.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include "General.h"
static u32 PAUSE_TIME = 0;
static void MultiPause()
{
_mm_pause();
_mm_pause();
_mm_pause();
_mm_pause();
_mm_pause();
_mm_pause();
_mm_pause();
_mm_pause();
}
__noinline static void UpdatePauseTime()
{
u64 start = GetCPUTicks();
for (int i = 0; i < 64; i++)
{
MultiPause();
}
u64 time = GetCPUTicks() - start;
u64 nanos = (time * 1000000000) / GetTickFrequency();
PAUSE_TIME = (nanos / 64) + 1;
}
u32 ShortSpin()
{
u32 inc = PAUSE_TIME;
if (unlikely(inc == 0))
{
UpdatePauseTime();
inc = PAUSE_TIME;
}
u32 time = 0;
// Sleep for approximately 500ns
for (; time < 500; time += inc)
MultiPause();
return time;
}
static u32 GetSpinTime()
{
if (char* req = getenv("WAIT_SPIN_MICROSECONDS"))
{
return 1000 * atoi(req);
}
else
{
return 50 * 1000; // 50µs
}
}
const u32 SPIN_TIME_NS = GetSpinTime();