Re: [PATCH] MIPS: Provide FPU info and decode FCSR in `info float'

["Maciej W. Rozycki" <macro at codesourcery dot com>]

On Mon, 11 Jun 2012, Joel Brobecker wrote:

> > command.  So I am asking for feedback, specifically whether it would be 
> > preferable for this change to go in as is or whether the simple dump of 
> > FPU registers should be retained.
> 
> The documentation does not explicitly say that the "info float" command
> should dump the floating point registers, but now that it does, I do not
> think it would be a good idea to remove them from the dump.  But I do not
> feel strongly enough to object.

 The command dumps floating-point registers -- decided by the appropriate 
register group assignment (we don't get it right or at least consistent 
across MIPS targets, we dump FGRs on all off them and then on some we dump 
the two control registers as well and on some we don't) -- in a generic 
way by default if the target doesn't override the handler.  So it's more 
of a historical precedent rather than a deliberate choice I presume.

 Few targets actually implement an override, x86 and ARM are among them, 
perhaps something else too.  Of these x86 dumps FGRs in a raw hex format 
in addition to various status information and ARM only provides some terse 
status information.  Both targets only have 8 FGRs.

 Then MIPS has 32 FGRs, that's lots of data and certainly more than a 
screenful in the standard 80x24 terminal.  But `info all-registers' is 
worse yet, so perhaps dumping the FGRs plus status in `info float' is the 
lesser evil.  And implementing `info all-float' for verbose output as 
opposed to condensed `info float' for MIPS only sounds like an overkill to 
me.

 Anyway, thanks for your opinion, I'll give it all a thought.  I will 
appreciate if anybody else decides to convince me either way too.

  Maciej