Common: Purge CPU frequency measurement

It's not accurate, and we can query the registry for the TSC frequency
for thread timers.

Also replaces InitCPUTicks() with a global constructor.

common/Darwin/DarwinMisc.cpp

@@ -1,5 +1,5 @@
 /*  PCSX2 - PS2 Emulator for PCs
- *  Copyright (C) 2002-2014  PCSX2 Dev Team
+ *  Copyright (C) 2002-2023 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-
@@ -52,15 +52,12 @@ u64 GetPhysicalMemory()
 	return getmem;
 }
 
-static u64 tickfreq;
 static mach_timebase_info_data_t s_timebase_info;
-
-void InitCPUTicks()
-{
+static const u64 tickfreq = []() {
 	if (mach_timebase_info(&s_timebase_info) != KERN_SUCCESS)
 		abort();
-	tickfreq = (u64)1e9 * (u64)s_timebase_info.denom / (u64)s_timebase_info.numer;
-}
+	return (u64)1e9 * (u64)s_timebase_info.denom / (u64)s_timebase_info.numer;
+}();
 
 // returns the performance-counter frequency: ticks per second (Hz)
 //

common/General.h

@@ -196,7 +196,6 @@ private:
 #define SafeSysMunmap(ptr, size) \
 	((void)(HostSys::Munmap(ptr, size), (ptr) = 0))
 
-extern void InitCPUTicks();
 extern u64 GetTickFrequency();
 extern u64 GetCPUTicks();
 extern u64 GetPhysicalMemory();

common/Linux/LnxMisc.cpp

@@ -47,11 +47,6 @@ u64 GetPhysicalMemory()
 	return pages * getpagesize();
 }
 
-
-void InitCPUTicks()
-{
-}
-
 u64 GetTickFrequency()
 {
 	return 1000000000; // unix measures in nanoseconds

common/Windows/WinMisc.cpp

@@ -29,7 +29,12 @@
 #include <timeapi.h>
 #include <VersionHelpers.h>
 
-alignas(16) static LARGE_INTEGER lfreq;
+// If anything tries to read this as an initializer, we're in trouble.
+static const LARGE_INTEGER lfreq = []() {
+	LARGE_INTEGER ret = {};
+	QueryPerformanceFrequency(&ret);
+	return ret;
+}();
 
 // This gets leaked... oh well.
 static thread_local HANDLE s_sleep_timer;
@@ -48,11 +53,6 @@ static HANDLE GetSleepTimer()
 	return s_sleep_timer;
 }
 
-void InitCPUTicks()
-{
-	QueryPerformanceFrequency(&lfreq);
-}
-
 u64 GetTickFrequency()
 {
 	return lfreq.QuadPart;

common/Windows/WinThreads.cpp

@@ -217,7 +217,20 @@ u64 Threading::GetThreadTicksPerSecond()
 	// So, the frequency is our base clock speed (and stable regardless of power management).
 	static u64 frequency = 0;
 	if (unlikely(frequency == 0))
-		frequency = x86caps.CachedMHz() * u64(1000000);
+	{
+		HKEY key;
+		LSTATUS res =
+			RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", 0, KEY_READ, &key);
+		if (res == ERROR_SUCCESS)
+		{
+			DWORD mhz;
+			DWORD size = sizeof(mhz);
+			res = RegQueryValueExW(key, L"~MHz", nullptr, nullptr, reinterpret_cast<LPBYTE>(&mhz), &size);
+			if (res == ERROR_SUCCESS)
+				frequency = static_cast<u64>(mhz) * static_cast<u64>(1000000);
+			RegCloseKey(key);
+		}
+	}
 	return frequency;
 }
 

common/emitter/cpudetect.cpp

@@ -106,49 +106,6 @@ void x86capabilities::SIMD_EstablishMXCSRmask()
 		MXCSR_Mask.bitmask = result;
 }
 
-// Counts the number of cpu cycles executed over the requested number of PerformanceCounter
-// ticks. Returns that exact count.
-// For best results you should pick a period of time long enough to get a reading that won't
-// be prone to rounding error; but short enough that it'll be highly unlikely to be interrupted
-// by the operating system task switches.
-s64 x86capabilities::_CPUSpeedHz(u64 time) const
-{
-	u64 timeStart, timeStop;
-	s64 startCycle, endCycle;
-
-	if (!hasTimeStampCounter)
-		return 0;
-
-	SingleCoreAffinity affinity_lock;
-
-	// Align the cpu execution to a cpuTick boundary.
-
-	do
-	{
-		timeStart = GetCPUTicks();
-		startCycle = __rdtsc();
-	} while (GetCPUTicks() == timeStart);
-
-	do
-	{
-		timeStop = GetCPUTicks();
-		endCycle = __rdtsc();
-	} while ((timeStop - timeStart) < time);
-
-	s64 cycleCount = endCycle - startCycle;
-	s64 timeCount = timeStop - timeStart;
-	s64 overrun = timeCount - time;
-	if (!overrun)
-		return cycleCount;
-
-	// interference could cause us to overshoot the target time, compensate:
-
-	double cyclesPerTick = (double)cycleCount / (double)timeCount;
-	double newCycleCount = (double)cycleCount - (cyclesPerTick * overrun);
-
-	return (s64)newCycleCount;
-}
-
 const char* x86capabilities::GetTypeName() const
 {
 	switch (TypeID)
@@ -307,28 +264,3 @@ void x86capabilities::Identify()
 
 	isIdentified = true;
 }
-
-u32 x86capabilities::CalculateMHz() const
-{
-	InitCPUTicks();
-	u64 span = GetTickFrequency();
-
-	if ((span % 1000) < 400) // helps minimize rounding errors
-		return (u32)(_CPUSpeedHz(span / 1000) / 1000);
-	else
-		return (u32)(_CPUSpeedHz(span / 500) / 2000);
-}
-
-u32 x86capabilities::CachedMHz()
-{
-	static std::atomic<u32> cached{0};
-	u32 local = cached.load(std::memory_order_relaxed);
-	if (unlikely(local == 0))
-	{
-		x86capabilities caps;
-		caps.Identify();
-		local = caps.CalculateMHz();
-		cached.store(local, std::memory_order_relaxed);
-	}
-	return local;
-}

common/emitter/tools.h

@@ -116,13 +116,9 @@ public:
 	void CountCores();
 	const char* GetTypeName() const;
 
-	static u32 CachedMHz();
-	u32 CalculateMHz() const;
-
 	void SIMD_EstablishMXCSRmask();
 
 protected:
-	s64 _CPUSpeedHz(u64 time) const;
 	void CountLogicalCores();
 };
 

pcsx2/System.cpp

@@ -103,19 +103,17 @@ void SysLogMachineCaps()
 		GetOSVersionString().c_str(),
 		(u32)(GetPhysicalMemory() / _1mb));
 
-	u32 speed = x86caps.CalculateMHz();
 
 	Console.Indent().WriteLn(
 		"CPU name         =  %s\n"
 		"Vendor/Model     =  %s (stepping %02X)\n"
-		"CPU speed        =  %u.%03u ghz (%u logical thread%ls)\n"
+		"Logical Cores    =  %u\n"
 		"x86PType         =  %s\n"
 		"x86Flags         =  %08x %08x\n"
 		"x86EFlags        =  %08x",
 		x86caps.FamilyName,
 		x86caps.VendorName, x86caps.StepID,
-		speed / 1000, speed % 1000,
-		x86caps.LogicalCores, (x86caps.LogicalCores == 1) ? L"" : L"s",
+		x86caps.LogicalCores,
 		x86caps.GetTypeName(),
 		x86caps.Flags, x86caps.Flags2,
 		x86caps.EFlags);

pcsx2/VMManager.cpp

@@ -306,7 +306,6 @@ bool VMManager::Internal::CPUThreadInitialize()
 	x86caps.Identify();
 	x86caps.CountCores();
 	x86caps.SIMD_EstablishMXCSRmask();
-	x86caps.CalculateMHz();
 	SysLogMachineCaps();
 
 	pxAssert(!s_vm_memory && !s_cpu_provider_pack);