Messages in this thread | | | From | Vineet Gupta <> | Subject | Re: [PATCH 5/5] Lib: sort.h: replace int size with size_t size in the swap function | Date | Mon, 1 Apr 2019 18:01:51 +0000 |
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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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