From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeffrey A Law To: Marc Espie Cc: egcs@egcs.cygnus.com Subject: Re: type based aliasing again Date: Thu, 09 Sep 1999 20:35:00 -0000 Message-id: <6417.936934353@upchuck.cygnus.com> References: <199909091415.QAA30861@quatramaran.ens.fr> X-SW-Source: 1999-09/msg00391.html In message < 199909091415.QAA30861@quatramaran.ens.fr >you write: > In article < 199909090211.TAA03202@kankakee.wrs.com > you write: > >Is it less confusing to a user to have the compiler predictably > >generate wrong code, or for it to almost always generate right code, > >even for bad code, except in really obscure and hard to understand > >cases? > > As far as aliasing goes, what would do wonders would be to have a > thorough section of the documentation explaining what goes on, in > understandable english, not standards legalese. This has alwasy been the plan. I'd like see this on the web page handled in a manner similar to the asm issue. Ie, we discuss the issue in some general terms, maybe give some code fragments that are invalid, and a valid translation of those fragments. Then a separate faq entry which discusses instances where strict aliasing breaks high visibility software such as the Linux kernel. Starting with Joe Buck's nice simple summary is probably the way to go. If someone wants to make a contribution, but isn't a compiler guru, writing up some of this stuff for an FAQ entry would be an excellent contribution. jeff From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeffrey A Law To: Marc Espie Cc: egcs@egcs.cygnus.com Subject: Re: type based aliasing again Date: Thu, 30 Sep 1999 18:02:00 -0000 Message-ID: <6417.936934353@upchuck.cygnus.com> References: <199909091415.QAA30861@quatramaran.ens.fr> X-SW-Source: 1999-09n/msg00391.html Message-ID: <19990930180200.GGHu3pFhKeAW2695YGDe7_MczGmxbnGTFORNmwHa_HY@z> In message < 199909091415.QAA30861@quatramaran.ens.fr >you write: > In article < 199909090211.TAA03202@kankakee.wrs.com > you write: > >Is it less confusing to a user to have the compiler predictably > >generate wrong code, or for it to almost always generate right code, > >even for bad code, except in really obscure and hard to understand > >cases? > > As far as aliasing goes, what would do wonders would be to have a > thorough section of the documentation explaining what goes on, in > understandable english, not standards legalese. This has alwasy been the plan. I'd like see this on the web page handled in a manner similar to the asm issue. Ie, we discuss the issue in some general terms, maybe give some code fragments that are invalid, and a valid translation of those fragments. Then a separate faq entry which discusses instances where strict aliasing breaks high visibility software such as the Linux kernel. Starting with Joe Buck's nice simple summary is probably the way to go. If someone wants to make a contribution, but isn't a compiler guru, writing up some of this stuff for an FAQ entry would be an excellent contribution. jeff