Use golang.org/x/sys/cpu for CPU feature detection?

We can use https://godoc.org/golang.org/x/sys/cpu .

Thanks for filing this issue. There are two reasons why I didn't do this.

Firstly I need to check for CPUID flags that are unsupported by x/sys/cpu.

Lines 5 to 16 in 871e507

    
           // cpu contains feature flags relevant to selecting a Meow implementation. 
        
           var cpu struct { 
        
           	HasOSXSAVE    bool 
        
           	HasAES        bool 
        
           	HasVAES       bool 
        
           	HasAVX        bool 
        
           	HasAVX512F    bool 
        
           	HasAVX512VL   bool 
        
           	HasAVX512DQ   bool 
        
           	EnabledAVX    bool 
        
           	EnabledAVX512 bool 
        
           }

Second, for a library such as this, I prefer to avoid dependencies unless strictly necessary.

I see.
I'm trying porting meow's ARMv8( arm64 ).
However it will be painful that implement arm64's CPU feature detection on its own.

I would welcome an ARMv8 pull request. If golang.org/x/sys/cpu provides the feature detection you need, it would be fine to use it. We would still need to use custom code for x86.

	// cpu contains feature flags relevant to selecting a Meow implementation.
	var cpu struct {
	HasOSXSAVE bool
	HasAES bool
	HasVAES bool
	HasAVX bool
	HasAVX512F bool
	HasAVX512VL bool
	HasAVX512DQ bool
	EnabledAVX bool
	EnabledAVX512 bool
	}