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Re: Re: [PING][PATCH][RFC] Bug handling SUBREG (MEM) - MEM having side-effects?


Hi,

Could you please let me know if this is OK for 4.7 as this bug shows up on 4.7 but seems to be latent on trunk? I'd like to get this in before the release.

Thanks,
Tejas Belagod
ARM.

Tejas Belagod wrote:
PING.

Tejas Belagod wrote:
Richard Sandiford wrote:
After the discussions Richard Earnshaw had on IRC with Andrew Pinski, it was
felt that it was best to fix the standard predicate
'general_operand' to not allow SUBREG (MEM) with side-effects as it has known
issues associated with it - particularly reload not being able to deal with such
cases. 'general_operand' currently outlaws cases like paradoxical SUBREG (MEM)
on targets with insn scheduling and SUBREG (MEM) with non-zero SUBREG_BYTE. This
is another case it should not allow. Here is a patch that tightens
general_operands to not allow SUBREG (MEM) with MEM having side-effects.

I would like to hear some thoughts on this.
LGTM.

It would be good to get rid of subreg mem operands altogether at some point,
but that's a little too drastic for stage 3.  This patch looks like a strict
improvement.

Thanks for looking at this. Is this OK for 4.7 as well?

Tejas Belagod
ARM.








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