This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Who is responsible for satisfying assembler constraints?
- To: Joern Rennecke <amylaar at cygnus dot co dot uk>
- Subject: Re: Who is responsible for satisfying assembler constraints?
- From: Geoff Keating <geoffk at cygnus dot com>
- Date: 11 Jul 2000 13:11:54 -0700
- CC: gcc at gcc dot gnu dot org
- References: <200007111829.TAA08746@phal.cygnus.co.uk>
Joern Rennecke <amylaar@cygnus.co.uk> writes:
> > However I thought the whole point of constraints was that gcc would make sure
> > they would be satisfied?
>
> reload can reload objects from memory into registers, but not vice versa.
It can also put constants, or registers equivalent to constants, into
memory, and move registers into memory to move them into other
registers. I don't think it should ever need to move registers into
memory directly, because then the pseudo should not have been
allocated a hard register in the first place.
--
- Geoffrey Keating <geoffk@cygnus.com>