On Mon, May 11, 2015 at 3:29 PM, Don Provan <dprovan at bivio.net> wrote:
> I probably shouldn't stick my nose into this, but I can't help myself. > > An experienced programmer will tend to ignore the documentation for > a routine named "blahblah_memcmp" and just assume it functions like > memcmp. Whether or not there's currently a use case in DPDK is > completely irrelevant because as soon as there *is* a use case, some > poor DPDK developer will try to use rte_memcmp for that and may or > may not have a test case that reveals their mistake. > In general I agree with you. However, comparison is a hit(equal) or miss(unequal) is generally the case in networking. I haven't seen cases where "less than" or "greater than" has mattered. > > The term "compare" suggests checking for larger or smaller. > If you want to check for equality, use "equal" or "eq" in the name > and return true if they're equal. But personally, I'd compare unless > there was a good reason not to. Indeed, I would just implement > full memcmp functionality and be done with it, even if that meant > using my fancy new assembly code for the cases I handle and then > calling memcmp itself for the cases I didn't. > > Agreed, I will look into implementing full functionality. > If a routine that appears to take an arbitrary size doesn't, the name > should in some manner reflect what sizes it takes. Better would be > for a routine that only handles specific sizes to be split into versions > that only take fixed sizes, but I don't know enough about your use > cases to say whether that makes sense here. > > Users of rte_memcmp will be existing dpdk test and library code. -don provan > dprovan at bivio.net > > -----Original Message----- > From: Ravi Kerur [mailto:rkerur at gmail.com] > Sent: Monday, May 11, 2015 1:47 PM > To: Ananyev, Konstantin > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH v2] Implement memcmp using AVX/SSE > instructions. > > ... > Following memcmp semantics is not hard but there are no use-cases for it > in DPDK currently. Keeping it specific to DPDK usage simplifies code as > well. > I can change the name to "rte_compare" and add comments to the function. > Will it work? > ... > >
