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Re: Alias code
- To: law at cygnus dot com
- Subject: Re: Alias code
- From: Mark Mitchell <mark at markmitchell dot com>
- Date: Mon, 29 Jun 1998 09:49:05 -0700
- CC: egcs at cygnus dot com, egcs-patches at cygnus dot com
- References: <13462.899137606@hurl.cygnus.com>
- Reply-to: mark at markmitchell dot com
>>>>> "Jeffrey" == Jeffrey A Law <law@hurl.cygnus.com> writes:
Jeffrey> One more thought -- we might want to check
Jeffrey> flag_strict_aliasing in DIFFERENT_ALIAS_SETS_P. It
Jeffrey> shouldn't matter after your patch, but I don't think it
Jeffrey> hurts in any significant way.
I don't have a strong feeling about this. I think it amounts to
activating the CHECK_ALIAS_SETS_FOR_CONSISTENCY macro that is
presently only on with --enable-checking. If you want to enable that
all the time, it's fine with me; it should be only a small overhead
per use of DIFFERENT_ALIAS_SETS_P.
Jeffrey> Looks good. Presumably we've defined gen_rtx (MEM) and
Jeffrey> gen_rtx_MEM as explicitly unable to set the alias set.
Jeffrey> That has to be done on the return value from those
Jeffrey> functions. Right?
Right. These functions still take only one argument (the address for
the MEM), but explicitly set the MEM_ALIAS_SET to zero before
returning. It's up to the caller to change the value, if desired.
--
Mark Mitchell mark@markmitchell.com
Mark Mitchell Consulting http://www.markmitchell.com