[LLVMdev] AVX Naming
    David Greene 
    dag at cray.com
       
    Fri Oct  7 16:02:38 PDT 2011
    
    
  
When Bruno designed the AVX spec, it looks like he created names like:
VADDPSrm
VADDPSYrm
to distinguish 128-bit and 256-bit operation.  It's sort of become a
personal hobby of mine to curse the binutils maintainers for
"vcvtpd2psy" because it's so easy to miss the trailing suffix on a quick
scan.
I find that same trouble reading dumps with the current AVX names.
Before regalloc it is harder to determine the vector length of an
instruction at a glance.
To overcome that, I started using a naming convention of:
VxADDSSrm
VxADDPSrm
VyADDPSrm
What do people think?  I realize it's "only" naming but when scannig
debug dumps I've found it really helpful to quicky determine how
something was vectorized.  From a performance debugging standpoint,
vector length is often an indication of problems or missed
opportunities.
I'm willing to do a gradual mechanical change if this seems reasonable
to people.
                             -Dave
    
    
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