Re: [PATCH] pseudo-register un-optimization

[Andrew Cagney <ac131313@cygnus.com>]

> 
> 
> 2001-08-10  Michael Snyder  <msnyder@redhat.com>
> 
> * regcache.c (legacy_write_register_gen): Don't 'optimize out'
> 	a write_register to a pseudo-reg.  Target_store_pseudo_register
> 	needs to get called, because these regs may be computed and may
> 	have side-effects.


Michael, can you expand a little?  This is legacy code, so as long as 
this change is to keep an old target working, I'm not too fussed.

However, if this is for a new target then it should really be looking at 
gdbarch_register_{read,write} and bypassing the legacy mess entirely.

	Andrew


> Index: regcache.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/regcache.c,v
> retrieving revision 1.24
> diff -c -3 -p -r1.24 regcache.c
> *** regcache.c	2001/06/15 23:50:46	1.24
> --- regcache.c	2001/08/10 21:49:23
> *************** legacy_write_register_gen (int regnum, c
> *** 334,348 ****
>   
>     size = REGISTER_RAW_SIZE (regnum);
>   
> -   /* If we have a valid copy of the register, and new value == old value,
> -      then don't bother doing the actual store. */
> - 
> -   if (register_cached (regnum)
> -       && memcmp (register_buffer (regnum), myaddr, size) == 0)
> -     return;
> - 
>     if (real_register (regnum))
> !     target_prepare_to_store ();
>   
>     memcpy (register_buffer (regnum), myaddr, size);
>   
> --- 334,349 ----
>   
>     size = REGISTER_RAW_SIZE (regnum);
>   
>     if (real_register (regnum))
> !     {
> !       /* If we have a valid copy of the register, and new value == old
> ! 	 value, then don't bother doing the actual store. */
> !       if (register_cached (regnum)
> ! 	  && memcmp (register_buffer (regnum), myaddr, size) == 0)
> ! 	return;
> !       else
> ! 	target_prepare_to_store ();
> !     }
>   
>     memcpy (register_buffer (regnum), myaddr, size);
>   
>