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Re: Alias code


>>>>> "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


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