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From: Thiago Adams <thiago.adams@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: how cast works?
Date: Sat, 10 Aug 2024 10:15:28 -0300
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Em 8/10/2024 7:17 AM, Bart escreveu:
> On 09/08/2024 21:01, David Brown wrote:
>> On 09/08/2024 20:54, Thiago Adams wrote:
> 
>> I don't know what you are referring to here.  But if you are using 
>> compiler explorer, I encourage you to look at the generated output for 
>> a wide range of targets, including 8-bit AVR, 16-bit MSP430, 32-bit 
>> ARM, and 64-bit x86.  Use gcc -O1 or -O2 in every case.
> 
> When would you choose -O2 over -O1 or vice versa? Could a similar 
> circumstance cause you to choose -O0? Why not -O3?
> 
> In fact, why is there a -O0 option at all?
> 
>    (Ignore Bart's
>> ignorant blatherings about optimisation.)
> 
> [To TA:]
> 
> Yes do. But don't complaint to me when your test code results in 
> meaningless or misleading output, or no output at all.
> 
> Actually, I would recommend looking at both (eg. -O0 and -O1) so that 
> you can see if the compiler's optimiser has been over-zealous in 
> eliminating code, or has chopped out key bits, so that you might modify 
> your test code.
> 
> I would recommend also looking at the Tiny C option on godbolt when 
> comparing x86 code.
> 



Bart, Does your compiler support the `bool` type, where the value is 
always either 1 or 0?