This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Remove MISALIGNED_INDIRECT_REF
On Thu, Sep 30, 2010 at 04:29:22PM +0200, Bernd Schmidt wrote:
> On 09/30/2010 04:10 PM, Nathan Froyd wrote:
> > In a similar fashion--though GCC does not take advantage of this at the
> > moment--on E500 targets, the vector and FP instructions require
> > alignment, but integer instructions do not. E500 is a STRICT_ALIGNMENT
> > target to cover the vector bits, but it would be beneficial if we could
> > move away from that.
>
> Isn't this how it should be, however? The way I understand it is that
> STRICT_ALIGNMENT should prevent the compiler from using unaligned
> operands in all insns except movmisalign (which was introduced much
> later). The mere existence of movmisalign does not mean a target
> shouldn't set STRICT_ALIGNMENT.
Hm, maybe all that needs to be done is some experimentation with
movmisalign{hi,si} for E500, then.
> Maybe STRICT_ALIGNMENT should take a mode argument.
Well, there's SLOW_UNALIGNED_ACCESS.
-Nathan