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From: Kaz Kylheku <643-408-1753@kylheku.com>
Newsgroups: comp.lang.c
Subject: Re: Baby X is bor nagain
Date: Fri, 28 Jun 2024 03:23:47 -0000 (UTC)
Organization: A noiseless patient Spider
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Message-ID: <20240627201830.854@kylheku.com>
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On 2024-06-27, bart <bc@freeuk.com> wrote:
> And for most of /my/ compiles, the code produced by gcc-O0 is fast 
> enough. It also about the same speed as code produced by one of my 
> compilers.
>
> So I tend to use it when I want the extra speed, or other compilers 
> don't work, or when a particular app only builds with that compiler.
>
> Otherwise the extra overheads are not worth the bother.

How good are your diagnostics compared to GCC -O2, plus -Wall and -W?

Some diagnostics are not produced or don't work well without
optimization, because the the same analysis that goes into optimization
also goes into proofs connected to diagnostics.

For instance, some code look like might use a variable without
initializing it, under some conditions. The optimizer can rule out of
those conditions (e.g. by transforming the code in a way that
makes it obvious that the use of the variable is not reached
without crossing an assignment to it.)

-- 
TXR Programming Language: http://nongnu.org/txr
Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
Mastodon: @Kazinator@mstdn.ca