Re: [wip/rfc] Merge REGISTER_TO_VALUE and REGISTER_TO_TYPE

[Mark Kettenis <kettenis@chello.nl>]

Andrew Cagney <ac131313@redhat.com> writes:

  [snip]

> With this in mind, I'm thinking that REGISTER_TO_TYPE and 
> REGISTER_TO_VALUE should be merged.  To that end, I can see several ways 
> of doing it:
> 
> - Don't merge - add REGISTER_TO_TYPE to the architecture vector
> 
> - Retain the current logic - just apply REGISTER_TO_VALUE to values 
> stored across multiple registers
> 
> - Add a frame parameter to REGISTER_TO_VALUE and make it responsible for 
> both extracting the bytes from the register[s] and then storing them in 
> the ``struct value''.
> 
> The last option is interesting, it would let the target draw the value 
> from any register based on REGNUM.  The i386 with its long-long problem 
> might be interested in this (you'll notice in the patch I made an 
> attempt at doing this only I didn't see it affect the test results).
> 
> Thoughts?

The last option is certainly attractive.  The fact that this doesn't
show any improvements in the testsuite, is because there is no test
for `long long' in store.exp.  There are tests for small structs there
that will still fail since your implementation of
i386_register_to_value isn't complete; it should also handle 8-byte
strcutures stored in registers.  Not just integers.

Anyway, you can leave the i386-specific details to me if you prefer.

Mark