This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: i386.md splits 1
- To: Richard Henderson <rth at cygnus dot com>
- Subject: Re: i386.md splits 1
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Fri, 02 Oct 1998 01:43:49 -0600
- cc: Jan Hubicka <hubicka at atrey dot karlin dot mff dot cuni dot cz>, egcs-patches at cygnus dot com
- Reply-To: law at cygnus dot com
In message <19981001232347.B12133@dot.cygnus.com>you write:
> On Thu, Oct 01, 1998 at 01:47:29PM +0200, Jan Hubicka wrote:
> > (movdi): split the trivial (non-overlapping) case
> > (zero_extendsidi2): split it, support extending from other
> > register and to memory to avoid unnecesary moves of extended value
> > Use # in pattern and handle completely by splits.
>
> IMO, movdi and zero_extendsidi3 should both be deleted. Neither
> defines any machine-specific instructions; both can be handled
> better by the middle-end.
Don't be so hasty.
I've actually run into codegen bugs when ports haven't defined movdi :(
I've also generally seen better code when ports define double-word move
patterns -- even on register poor targets.
jeff