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SubjectRe: [PATCH 5/5] Lib: sort.h: replace int size with size_t size in the swap function
Date
On 4/1/19 7:46 AM, David Laight wrote:
> From: gregkh@linuxfoundation.org
>> Sent: 31 March 2019 11:54
> ...
>> Yes, "int" is a very nice variable for "size", you need to explain why
>> it is better to use size_t here please.
> Actually, on x86_64 you probably want 'unsigned int' to avoid the
> compiler having to generate a sign-extending register move if the
> value is ever used in a 64bit expression (eg an address calculation).

Thats likely true for non x86 arches too (for certain on ARC). That is also the
reason I dislike "bool", despite its "software engineering" benefits. Per ARC ABI
(and likely others too) it is signed 8 bits and any use thereof, requires the
compiler to generate an additional EXTB instruction to promote to 32-bit int with
sign extension before using the value.

-Vineet

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