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Re: 32->64 bit cross compilers


David Edelsohn <dje@watson.ibm.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 <geoffk@geoffk.org>


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