RFC -- update_equiv_regs and friends

[Richard Henderson]

On Tue, Feb 27, 2001 at 11:58:41PM -0700, Jeffrey A Law wrote:
>   C. Prune equivalences which refer to dying registers.  Will hinder
>      local-alloc's rematerialization efforts somewhat.
> 
>   E. Prune the bogus equivalences after local-alloc is finished
>      with them, possibly by hacking up the code in reload which
>      searches for equivalences.

I would do a very simple variant of C and E.  Namely, limit
equivalence finding to non-register general_operand's.

This new equivalence finding code has caused a number of problems,
some of which have been hacked around.


r~