Re: GCC optimizes integer overflow: bug or feature?

[Matthew Woehlke]

Andreas Schwab wrote:
> Matthew Woehlke <address@hidden> writes:
>
> > That said, I've seen even stranger things, too. For example:
> >
> > foo->bar = make_a_bar();
> > foo->bar->none = value;
> >
> > being rendered as:
> >
> > call make_a_bar
> > foo->bar->none = value
> > foo->bar = <result of make_a_bar()>
>
> You are not describing a C compiler.

Um, I'm describing what gcc did? I gave C code first (names changed, but 
almost exactly what I was doing), then described the assembly that was 
emitted. The resulting assembly called the function that is supposed to 
provide the value of 'foo->bar', and then dereferenced members of 
foo->bar /before/ assigning the return value to foo->bar. Trust me, I 
looked at the assembly, and that's what it was doing.

--
Matthew
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