Re: how cast works?

On 10/08/2024 14:15, Thiago Adams wrote:

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:

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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.

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When would you choose -O2 over -O1 or vice versa? Could a similar circumstance cause you to choose -O0? Why not -O3?
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In fact, why is there a -O0 option at all?
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   (Ignore Bart's

ignorant blatherings about optimisation.)

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[To TA:]
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Yes do. But don't complaint to me when your test code results in meaningless or misleading output, or no output at all.
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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.
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I would recommend also looking at the Tiny C option on godbolt when comparing x86 code.
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   Bart, Does your compiler support the `bool` type, where the value is always either 1 or 0?

There is a bool type, but it is treated like unsigned char, so is non-conforming.