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Re: [PATCH 1/4, MIPS] Add r2 variant for *clear_upper32
- From: Richard Sandiford <rdsandiford at googlemail dot com>
- To: Adam Nemet <anemet at caviumnetworks dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Thu, 30 Jul 2009 21:16:52 +0100
- Subject: Re: [PATCH 1/4, MIPS] Add r2 variant for *clear_upper32
- References: <19057.62127.907350.916479@ropi.home> <o7y6q69dnu.fsf@ropi.home>
Adam Nemet <anemet@caviumnetworks.com> writes:
> In the new pattern I am using "o" for the memory operand's constraint. I am
> also changing the same thing for the *zero_extensidi2_dext pattern; these
> patterns are not applicable to mips16 and while the constraint amounts to m
> for non-mips16, there is no need for the extra checks performed by "W" (unless
> of course we want to keep the !ISA_HAS_EXT_INS and the ISA_HAS_EXT_INS
> patterns similar).
Yes, please keep "W" for "lwu" addresses. Although it's true that the
extra checks are not currently needed in this case, "o" is probably even
more expensive. And even if it isn't, there's no way this will have a
noticable effect on compilation speed. I think the consistency of using
the same constraint everywhere is more important.
OK with that change, thanks.
Richard