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From: Terje Mathisen <terje.mathisen@tmsw.no>
Newsgroups: comp.arch
Subject: Re: Computer architects leaving Intel...
Date: Tue, 3 Sep 2024 19:52:49 +0200
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Michael S wrote:
> On Tue, 3 Sep 2024 17:41:40 +0200
> Terje Mathisen <terje.mathisen@tmsw.no> wrote:
> 
>> Michael S wrote:
>>> 3 years ago Terje Mathisen wrote that many years ago he read that
>>> behaviour of memcpy() with overlappped src/dst was defined.
>>> https://groups.google.com/g/comp.arch/c/rSk8c7Urd_Y/m/ZWEG5V1KAQAJ
>>> Mitch Alsup answered "That was true in 1983".
>>> So, two people of different age living in different parts of the
>>> world are telling the same story. May be, there exist old popular
>>> book that said that it was defined?
>>>    
>>
>> It probably wasn't written in the official C standard, which I
>> couldn't have afforded to buy/read, but in a compiler runtime doc?
>>
>> Specifying that it would always copy from beginning to end of the
>> source buffer, in increasing address order meant that it was
>> guaranteed safe when used to compact buffers.
>>
> 
> What is "compact buffers" ?

Assume a buffer consisting of records of some type, some of them marked 
as deleted. Iterating over them while removing the gaps means that you 
are always copying to a destination lower in memory, right?

Terje


-- 
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"