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Re: 32->64 bit cross compilers
- To: David Edelsohn <dje at watson dot ibm dot com>
- Subject: Re: 32->64 bit cross compilers
- From: Geoff Keating <geoffk at geoffk dot org>
- Date: 03 May 2001 23:38:25 -0700
- CC: gcc at gcc dot gnu dot org
- References: <200105040613.CAA22708@makai.watson.ibm.com>
David Edelsohn <email@example.com> writes:
> I know that Alexandre fixed the PowerPC port well enough that it
> does not break with his patches enabled, but I'm not sure how well it
> functions with the patches. These are the patches that use "long long"
> for 32->64, right?
> The PowerPC port hasn't been hosted on a 64-bit system and has not
> been tuned for 64-bit CONST_INT. I know that performance is not a
> priority for GCC 3.0, but the last time that I was working on 64-bit
> hosting, GCC was generating worse code for 64-bit PowerPC than when hosted
> in 32-bit mode. The patch of mine for rs6000_emit_move() that Alexandre
> applied along with his patches was the beginning of the fixes. If 64-bit
> PowerPC code generation takes a hit on the branch, we are going to have to
> address that before the release.
I think that a lot of those problems were fixed when Red Hat moved to
using 64-bit CONST_INT for x86 (in the past year). However, it'd be
interesting to run some benchmarks and see what the impact is.
- Geoffrey Keating <firstname.lastname@example.org>