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WP 34S and 31S bugs and fixes
11-23-2014, 06:48 PM (This post was last modified: 11-23-2014 07:17 PM by Bit.)
Post: #4
RE: WP 34S and 31S bugs and fixes
Thank you, Marcus.

Another issue: The documentation says that the algorithm that PRIME? uses is believed to work up to 9e18, which is roughly 263, the limit above which the isPrime() function fails with a domain error.

However, because of integer overflows, this is what actually happens (in double precision mode and only considering the integer part of a number):
- Negative numbers are reported as not primes. But odd negative numbers whose absolute value has bit 63 set also produce a domain error. Compare -264+1 and -264-1.
- Between 0 and 263: The algorithm in isPrime() is applied, errors are not produced.
- Even numbers above 263 with bit 63 set: Reported as not primes, see e.g. 263+2.
- Odd numbers above 263 with bit 63 set: A domain error is produced and PRIME? returns true, try 263+1.
- Above 263 if bit 63 is not set: PRIME? returns the result of the input modulo 264, so for example the even number 264+2 is reported as a prime.

I've committed a patch that results in the following more consistent behavior:
- All negative numbers are reported as not primes and errors are never produced.
- The original algorithm in isPrime() is applied to numbers between 0 and 263-1 and errors are never produced.
- Numbers greater than or equal to 263 always produce an error and PRIME? returns true.
(The handling of the two infinities and NaNs didn't change: They're always reported as not primes and no error is produced.)

I think it makes sense to treat the same way all numbers for which the algorithm isn't supposed to work, i.e. produce an error rather than have a special case only for numbers divisible by 2 but not for those divisible by 3, 5 and so on. I'm not sure if PRIME? should return true or false after an error, so I left that unchanged (it returns true).

The documentation states that PRIME? uses the absolute value of numbers but the original code explicitly (it didn't look like a typo) tested the sign to exclude negative numbers. I didn't change that and I suggest we keep this behavior because it makes sense and just update the documentation. But it'd be easy to use absolute values if that's what's desired. Please comment.
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WP 34S and 31S bugs and fixes - Bit - 11-22-2014, 07:49 PM
RE: WP 34S and 31S bugs and fixes - Bit - 11-23-2014 06:48 PM
RE: WP 34S and 31S bugs and fixes - Bit - 11-24-2014, 02:21 AM
RE: WP 34S and 31S bugs and fixes - Bit - 11-25-2014, 05:11 AM
RE: WP 34S and 31S bugs and fixes - Bit - 11-26-2014, 05:24 AM
RE: WP 34S and 31S bugs and fixes - Bit - 11-26-2014, 01:35 PM
RE: WP 34S and 31S bugs and fixes - Bit - 11-26-2014, 01:38 PM
RE: WP 34S and 31S bugs and fixes - Bit - 11-26-2014, 07:56 PM
RE: WP 34S and 31S bugs and fixes - Bit - 11-27-2014, 02:13 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-31-2015, 01:32 AM
RE: WP 34S and 31S bugs and fixes - Bit - 11-29-2014, 08:31 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-06-2014, 03:23 AM
RE: WP 34S and 31S bugs and fixes - Bit - 12-06-2014, 03:02 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-07-2014, 09:38 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-12-2014, 03:20 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-06-2014, 08:44 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-07-2014, 10:01 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-08-2014, 03:38 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-08-2014, 05:19 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-08-2014, 05:49 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-08-2014, 06:34 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-16-2014, 02:57 AM
RE: WP 34S and 31S bugs and fixes - Bit - 12-24-2014, 01:09 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-24-2014, 02:36 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-24-2014, 04:30 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-17-2014, 12:55 AM
RE: WP 34S and 31S bugs and fixes - Bit - 12-23-2014, 04:03 AM
RE: WP 34S and 31S bugs and fixes - Bit - 12-23-2014, 01:23 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-23-2014, 04:48 AM
RE: WP 34S and 31S bugs and fixes - Bit - 12-23-2014, 01:38 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-01-2015, 10:42 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-24-2014, 01:11 PM
RE: WP 34S and 31S bugs and fixes - Bit - 12-24-2014, 04:36 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-08-2015, 03:04 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-08-2015, 04:34 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-08-2015, 05:28 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-09-2015, 12:32 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-09-2015, 12:38 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-10-2015, 06:28 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-17-2015, 04:50 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 03:42 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 05:32 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 06:47 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 08:54 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 09:12 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 09:37 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-11-2015, 05:07 AM
RE: WP 34S and 31S bugs and fixes - DMaier - 01-11-2015, 06:51 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-12-2015, 12:48 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-12-2015, 01:31 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-12-2015, 02:00 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-12-2015, 05:44 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-12-2015, 11:39 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-17-2015, 02:34 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-17-2015, 05:16 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-17-2015, 05:47 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-17-2015, 04:20 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-17-2015, 04:35 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 03:11 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-18-2015, 09:56 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-24-2015, 04:37 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-25-2015, 04:42 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-25-2015, 05:27 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-25-2015, 05:50 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-25-2015, 06:08 PM
RE: WP 34S and 31S bugs and fixes - Bit - 01-28-2015, 12:26 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-21-2015, 12:40 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-22-2015, 05:16 AM
RE: WP 34S and 31S bugs and fixes - Bit - 01-31-2015, 12:52 AM
RE: WP 34S and 31S bugs and fixes - Bit - 02-07-2015, 06:17 PM
RE: WP 34S and 31S bugs and fixes - Bit - 02-08-2015, 05:58 PM
RE: WP 34S and 31S bugs and fixes - Bit - 02-20-2015, 04:52 AM
RE: WP 34S and 31S bugs and fixes - Bit - 02-24-2015, 03:50 AM
RE: WP 34S and 31S bugs and fixes - Bit - 03-15-2015, 04:55 PM
RE: WP 34S and 31S bugs and fixes - Dieter - 03-15-2015, 10:41 PM
RE: WP 34S and 31S bugs and fixes - Bit - 03-15-2015, 10:50 PM
RE: WP 34S and 31S bugs and fixes - Pascal - 05-07-2015, 07:47 AM
RE: WP 34S and 31S bugs and fixes - fhub - 05-07-2015, 11:56 AM
RE: WP 34S and 31S bugs and fixes - fhub - 05-07-2015, 02:05 PM
RE: WP 34S and 31S bugs and fixes - fhub - 05-07-2015, 03:23 PM
RE: WP 34S and 31S bugs and fixes - fhub - 05-09-2015, 05:19 PM
RE: WP 34S and 31S bugs and fixes - Marcio - 06-10-2015, 07:06 AM
RE: WP 34S and 31S bugs and fixes - Marcio - 06-10-2015, 01:06 PM
RE: WP 34S and 31S bugs and fixes - 2far - 08-27-2015, 11:06 AM
RE: WP 34S and 31S bugs and fixes - 2far - 08-27-2015, 04:09 PM
RE: WP 34S and 31S bugs and fixes - 2far - 08-27-2015, 09:55 PM
RE: WP 34S and 31S bugs and fixes - fhub - 10-01-2015, 03:37 PM
RE: WP 34S and 31S bugs and fixes - d b - 10-02-2015, 03:21 AM
RE: WP 34S and 31S bugs and fixes - Pascal - 12-21-2015, 04:40 PM
RE: WP 34S and 31S bugs and fixes - Marcio - 12-21-2015, 08:41 PM
RE: WP 34S and 31S bugs and fixes - fhub - 12-22-2015, 10:39 AM
RE: WP 34S and 31S bugs and fixes - fhub - 12-22-2015, 01:20 PM
Moving off-screen window - striegel - 01-13-2016, 11:10 AM
RE: WP 34S and 31S bugs and fixes - fhub - 01-13-2016, 03:10 PM
RE: WP 34S and 31S bugs and fixes - Leonid - 02-04-2017, 06:48 AM
RE: WP 34S and 31S bugs and fixes - Nick - 02-07-2017, 02:47 PM
RE: WP 34S and 31S bugs and fixes - Leonid - 02-08-2017, 08:10 AM
RE: WP 34S and 31S bugs and fixes - Nick - 02-08-2017, 08:41 AM
RE: WP 34S and 31S bugs and fixes - vido - 02-07-2017, 08:00 AM
RE: WP 34S and 31S bugs and fixes - vido - 02-07-2017, 07:35 PM
RE: WP 34S and 31S bugs and fixes - Dieter - 05-23-2017, 12:19 PM
RE: WP 34S and 31S bugs and fixes - Dieter - 05-23-2017, 05:05 PM



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