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From: Bart <bc@freeuk.com>
Newsgroups: comp.lang.c
Subject: Re: else ladders practice
Date: Mon, 25 Nov 2024 23:20:04 +0000
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On 25/11/2024 21:29, Scott Lurndal wrote:
> Bart <bc@freeuk.com> writes:
>> On 25/11/2024 18:49, Tim Rentsch wrote:
> 
>>
>> I'm trying to think of some computationally intensive app that would run
>> non-stop for several hours without interaction.
> 
> I can think of several - HDL simulators (vcs, et al), system simulators
> like Simh, Qemu, Synopsys Virutalizer, SIMICS, most HPC codes (e.g. fluid dynamics)
> Machine Learning training, et alia.

OK, good.

So the only preparation you have to do to get those running at maximum 
speed is just to use -O3 on your compilers instead of -O0.

Understood. You don't need to need to worry about anything else.


However I assume that has already been done when building products like 
LLVM (which apparently takes somewhat longer then one second to build), 
however I keep seeing comments about it like this:

"I think the biggest complaint is compile time."

"but if you want fast compile times or just "O1" instead of "O3" level 
performance, it can feel like overkill."

"ah this seems like two very different use cases. Stating the obvious: 
when debugging I want as fast builds as possible. When shipping I want 
as fast software as possible."

Apparently this is not obvious to anybody here except me!