From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeffrey A Law To: Nick Ing-Simmons Cc: mrs@wrs.com, gcc@gcc.gnu.org, mark@codesourcery.com, rms@gnu.org, dje@watson.ibm.com, jbuck@synopsys.com Subject: Re: type based aliasing again Date: Thu, 30 Sep 1999 18:02:00 -0000 Message-ID: <13132.937411270@upchuck.cygnus.com> References: <199909151501.QAA26239@tiuk.ti.com> X-SW-Source: 1999-09n/msg00629.html Message-ID: <19990930180200.RsKlawNsg7ZXnYYbiCvyIzuWYDtUe6IthYH3ngvMnYg@z> In message < 199909151501.QAA26239@tiuk.ti.com >you write: > Jeffrey A Law writes: > > In message < 199909130757.DAA05910@psilocin.gnu.org >you write: > > > Changing the default to -fno-strict-aliasing would certainly solve the > > > immediate problem. If people are happy with that, as a more or less > > > permanent decision, I think it avoids most of the need to do anything > > > else. (An added warning might be desirable, though, even with > > > -fno-strict-aliasing.) > >I strongly feel this is the wrong approach. > > > >It penalizes those programmers who write correct code to cater to the > >programmers that do not write correct code. > > No, it allows _programmers_ that know what they are doing to get the > benefit of their knowledge by the simple expedient of adding -fstrict-alias > ing > to Makefile.in and forgetting about it. > > While protecting sys-admins and users of open-source products that just > build but do not write them from the bad habits that not-so-good/or > too-clever-for-their-own-good programmers have developed over the decades. So are you going to propose next that we turn off automatic register allocation because some programmers don't have enough of a clue to write correct code? (yes, automatic register allocation will cause programs to behave in an unexpected manner if the programmer does stupid things like not initializing automatics, or not using volatile for variables live across setjmp). Or are you going to propose that we turn off MEM_IN_STRUCT_P because some clueless programmer violated the assumptions for that optimization? Hell, while you're at it, you might as well turn off any optimization that might have a bug. jeff