After looking at the assembly output it became apparent that the Windows
compiler did not compile out the `getSettingsController()` function
call.
This led to an unnecessary function call in order to get the
SettingsController. Turning it into a static object in the compilation
unit scope removes this function call and turns getSettings call into a
single instruction (not counting zeroing the register for comparison and
the jump instruction afterwards).
----
Adding the following code to the `main` function:
```cpp
f ( settings::getSetting( settings::BoolSetting::UTILITY_vrcDebug ) )
{
LOG( INFO ) << "Enabled";
}
else
{
LOG( INFO ) << "Disabled";
}
```
Leads to this with the `getSettingsController` function:
```assembly
[...]
47 if ( settings::getSetting( settings::BoolSetting::UTILITY_vrcDebug ) )
0x7ff6c96819a0 <+ 1024> call AdvancedSettings!settings::getSettingsController (00007ff6`c96cd280)
0x7ff6c96819a5 <+ 1029> xorps xmm0,xmm0
0x7ff6c96819a8 <+ 1032> cmp byte ptr [rax+5FCh],0
0x7ff6c96819af <+ 1039> je AdvancedSettings!main+0x4fd (00007ff6`c9681a9d)
49 LOG( INFO ) << "Enabled";
0x7ff6c96819b5 <+ 1045> mov qword ptr
[rsp+288h],r15
0x7ff6c96819bd <+ 1053> mov qword ptr
[rsp+290h],rsi
[...]
```
And this without the function:
```assembly
[...]
47 if ( settings::getSetting( settings::BoolSetting::UTILITY_vrcDebug ) )
0x7ff7d97a19bb <+ 1019> xorps xmm0,xmm0
0x7ff7d97a19be <+ 1022> cmp byte ptr [AdvancedSettings!settings::settingController+0x5fc (00007ff7`d9854d4c)],0
0x7ff7d97a19c5 <+ 1029> je AdvancedSettings!main+0x4f3 (00007ff7`d97a1ab3)
49 LOG( INFO ) << "Enabled";
0x7ff7d97a19cb <+ 1035> mov qword ptr
[rsp+288h],r15
0x7ff7d97a19d3 <+ 1043> mov qword ptr
[rsp+290h],rsi
[...]
```
Notice the missing `call AdvancedSettings![...]` without the function
and that the settings call literally cannot be made any faster.
The details of the API are in the `/docs/specsSettings-API.md` file.
The enums do not list all available settings, more are to be added as
the settings API replaces inline QSettings calls.
Vasily