Subject: Re: gcc optimizer bug in netbsd-1-6 on alpha (gcc 2.95.3 20010315 (release) (NetBSD nb3))
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Nathan J. Williams <firstname.lastname@example.org>
Date: 08/15/2003 17:18:52
Jonathan Stone <jonathan@DSG.Stanford.EDU> writes:
> >We want the better optimizations that "new C" enables more than we
> >want the semantics of "traditional C". Thus, anything that depends on
> >"traditional C" should be fixed.
> Huh? Thats a damn-fool thing to say. Doing, say
> find /sys -name '*.[ch]' -print |xargs grep mtod
Mostly what that tells me is that the network stack is full of code
that I want to stay far, far away from.
> might be instructive. Changing all those usages to copy to an
> appropriately-typed intermediate struct? Just Say No.
A good compiler should be able to see a copy to an intermediate
structure and a subsequent use of that structure and elide the copy
entirely, accomplishing the type-punning in the implementation rather
than in the expression. This seems like a good goal to work towards.