From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Harvey J. Stein" To: "Artem Hodyush" Cc: hjstein@bfr.co.il Subject: Re: type based aliasing again Date: Thu, 30 Sep 1999 18:02:00 -0000 Message-ID: <199909211540.RAA02290@blinky.bfr.co.il> References: <00d501bf01b9$dc677b10$545a9090@uito-nt-server.duma.gov.ru> X-SW-Source: 1999-09n/msg00912.html Message-ID: <19990930180200.Go34CXC9gV2wr-3H1sB91TXe0lMTfqlaXDBGLGXo5Hg@z> "Artem Hodyush" writes: > The very idea that compiler should make an educated guess and decide > which options to apply to my code gives me shudder. The software should > do what I say, no more and no less. Then type based aliasing should make you shudder too, since it's very much the situation of the compiler *not* doing what you say, but doing substantially more work to figure out a faster way to have the same effect. For that matter, any optimization at all should make you shudder. It's really a matter of degree. In this case there seems to be a substantial amount of code that breaks when the compiler trys to do sophisticated analysis on variable usage to determine what can be stored where. This analysis is allowable by the ANSI standard, but it seems that most people haven't written their code in a manner that's portable wrt this analysis. So, the question becomes, "To what extent can the compiler help people who aren't writing code conforming to this particular aspect of the ANSI standard?" -- Harvey Stein Bloomberg LP hjstein@bfr.co.il