llvm dev - Jan 2013 - [LLVMdev] [cfe-dev] RFC: Codifying (but not formalizing) the optimization levels in LLVM and Clang

Renato Golin Linaro <renato.golin at linaro.org> writes:
> I don't think you really need a performing debug image, though.
Oh, you'd be surprised.  We have hit many cases where debugging a
completely unoptimized program is so slow it's not worth doing.  Think
about large parallel codes with millions of threads running on hundreds
of thousands of sockets.

Debugging even minimally optimized code can be a huge productivity win.
Plus optimization tends to expose things like race conditions in
parallel codes.

                             -David

On 14 January 2013 18:38, <dag at cray.com> wrote:
> Debugging even minimally optimized code can be a huge productivity win.
> Plus optimization tends to expose things like race conditions in
> parallel codes.
>
That's what -O1 is for, isn't it?

What I meant is that there is little need for an -O3-no-reorder
optimization level. Maybe in extreme cases, but I wouldn't bet on it.

cheers,
--renato
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Renato Golin Linaro <renato.golin at linaro.org> writes:
> What I meant is that there is little need for an -O3-no-reorder
> optimization level. Maybe in extreme cases, but I wouldn't bet on it.
Ah, I misunderstood.  I completely agree with this.

                           -David