[fpc-devel] Policy regarding SHL/SHR under x86

J. Gareth Moreton gareth at moreton-family.com
Mon Oct 24 13:52:19 CEST 2022

That's useful - thank you.  Michael Van Canneyt mentioend he updated the 
documentation for this - where is this usually located? It's not here, 
for example: https://www.freepascal.org/docs-html/ref/refsu45.html


On 24/10/2022 11:58, Kai Burghardt via fpc-devel wrote:
> Hi there:
> On 2022‑10‑24 11:51:32 +0100, J. Gareth Moreton via fpc-devel wrote:
>> [...] I've come across one situation that I need clarity on... how
>> are SHL and SHR instructions handled if the shift value exceeds the word
>> size?
> About a half year ago I raised a documentation issue regarding that:
> https://gitlab.com/freepascal.org/fpc/documentation/-/issues/39304
> Bottom line: The behavior is _undefined_. Explanation by Jonas Maebe:
>> Such behaviour is indeed undefined (it's not implementation-defined
>> because when evaluating at compile time you may get different results
>> compared to when it gets evaluated at run time due to architecture
>> peculiarities).
>> _______________________________________________
>> fpc-devel maillist  -  fpc-devel at lists.freepascal.org
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