* GNAT.CRC32.Get_Value @ 2017-07-15 19:56 Aurele 2017-07-15 20:06 ` GNAT.CRC32.Get_Value Simon Wright 0 siblings, 1 reply; 4+ messages in thread From: Aurele @ 2017-07-15 19:56 UTC (permalink / raw) Hi all, can someone explain the use of the GNAT.CRC32.Get_Value function as it would apply in a typical CRC32 or Checksum application. The function returns CRC32 XOR 16FFFF_FFFF# without changing the CRC32 value. Hence, I'm not grasping its full meaning/purpose. Thanks in advance o7 ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: GNAT.CRC32.Get_Value 2017-07-15 19:56 GNAT.CRC32.Get_Value Aurele @ 2017-07-15 20:06 ` Simon Wright 2017-07-15 22:32 ` GNAT.CRC32.Get_Value Aurele 0 siblings, 1 reply; 4+ messages in thread From: Simon Wright @ 2017-07-15 20:06 UTC (permalink / raw) Aurele <aurele.vitali@gmail.com> writes: > Hi all, can someone explain the use of the GNAT.CRC32.Get_Value > function as it would apply in a typical CRC32 or Checksum > application. The function returns CRC32 XOR 16FFFF_FFFF# without > changing the CRC32 value. Hence, I'm not grasping its full > meaning/purpose. Thanks in advance o7 Probably related to this: https://en.wikipedia.org/wiki/Computation_of_cyclic_redundancy_checks#CRC_variants ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: GNAT.CRC32.Get_Value 2017-07-15 20:06 ` GNAT.CRC32.Get_Value Simon Wright @ 2017-07-15 22:32 ` Aurele 2017-07-16 13:30 ` GNAT.CRC32.Get_Value gautier_niouzes 0 siblings, 1 reply; 4+ messages in thread From: Aurele @ 2017-07-15 22:32 UTC (permalink / raw) There is very little documentation on it but I think its typically used as value for a computed Checksum, or as a starting point for a reverse CRC32. I'm not sure. ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: GNAT.CRC32.Get_Value 2017-07-15 22:32 ` GNAT.CRC32.Get_Value Aurele @ 2017-07-16 13:30 ` gautier_niouzes 0 siblings, 0 replies; 4+ messages in thread From: gautier_niouzes @ 2017-07-16 13:30 UTC (permalink / raw) > There is very little documentation on it but I think its typically used as value for a computed Checksum, or as a starting point for a reverse CRC32. I'm not sure. Are you asking about Get_Value or CRC32 in general? Get_Value finalizes the computation of CRC32 (GNAT's System.CRC32 spec (s-crc32.ads) is pretty clear about the initialization and update parts). HTH Gautier _____________________________________________________________ A free online game in Ada: http://pasta.phyrama.com/game.html ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-07-16 13:30 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2017-07-15 19:56 GNAT.CRC32.Get_Value Aurele 2017-07-15 20:06 ` GNAT.CRC32.Get_Value Simon Wright 2017-07-15 22:32 ` GNAT.CRC32.Get_Value Aurele 2017-07-16 13:30 ` GNAT.CRC32.Get_Value gautier_niouzes
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