The content of src/archutils/Darwin/VectorHelper.cpp is very old, these are AltiVec and SSE2 instructions. This is only actually used in RageSoundMixBuffer.cpp. This level of micro-optimization is not needed since platforms this old are not supported by ITGm.
NTpad is a driver for Windows 2000/XP which enables the use of a controller via the parallel port. This is not needed anymore and is just causing lag by constantly scanning the list of input devices on Windows.
Summary of changes
1) Fix issues in RageTimer and RageSoundPosMap
2) Calculate seconds from microseconds more accurately
3) Replace lrint(x) with static_cast<int>(x+0.5) for better performance
4) Replace C style casting with C++ style casting
5) Make important values 64-bit wide
6) Update RageUtil.cpp (timer conversion RStrings had some math which needed to be fixed after fixing RageTimer's math)
7) Ensure floating point math is done as floating point
8) Improve code commentary all around
9) Improve clarity and efficiency of RageSoundPosMap "return closest position" error logging
Enforcing HIGH_PRIORITY_CLASS is best for Win10+ where Windows Update can interrupt the game and it also prevents streaming apps (OBS/Discord) from causing stutter by taking rendering priority away from ITGMania.
Update ArchHooks_Win32.cpp
Update ArchHooks_Win32Static.cpp
This code provided a 7x accuracy improvement over timeGetTime(). (0.2ms vs 1.4ms std dev*3)
Rename variables to fit with existing naming mechanism
sukibaby