gl_impucode???

[Bob Drebin]

In article <1991Mar30.010020.6227 at riacs.edu>, lam at windchime.arc.nasa.gov writes:
|> I am trying to tune my program on the VGX and the profiling statistics
|> returns with:
|> 
|> %time     seconds  cum %   cum sec  procedure (file)
|> 
|>  34.0     79.6100   34.0     79.61 gl_impucode (impcode.c)
|>   9.8     22.9100   43.8    102.52 draw_object (sg_object.c)
|>   4.8     11.2000   48.6    113.72 v3f (./STAPUFTIP7GT.O/gl_if.s)
|>   4.4     10.3400   53.0    124.06 gl_i_n3f (sgl2.s)
|>   4.2      9.8000   57.2    133.86 gl_i_v3f (sgl2.s)
|> 
|> My question is what does "gl_impucode" do?  Can someone who knows explain?
|> 
|> Thanks,
|> 
|> Tony Lam


gl_impucode is a gl-internal subroutine to download microcode to the
Image Memory Processors (IMPs).  The subroutine is called whenever the
pixel microcode needed for the current gl mode settings is not resident
in the IMPs.

If gl_impucode REALLY is your bottleneck, then you must be changing modes
extremely often (maybe every polygon?).   It should be mentioned that
measuring the percentage of cpu tine spent in each of the gl subroutines
is generally not an effective method for tuning gl applications.  Most of
the performance critical work of the gl happens in the graphics pipeline,
not on the cpu.

--Bob Drebin