Commit graph

45 commits

Author SHA1 Message Date
nicoo
3a90e31307 factor::numeric::inv_mod_u64: Provide a more-helpful error message 2020-06-19 13:39:42 +02:00
nicoo
ef12991ee7 factors: Avoid repeatedly locking and flushing stdout
By default, stdout's LineWriter results one syscall per line, i.e. a billion
syscalls when factoring a billion numbers...

Buffering the output yields a ~28% speedup.
2020-06-18 16:45:40 -07:00
nicoo
2869248318 factor::Factors: Use a tree-based map internally
This eliminate the need for sorting the prime factors for display.
25% performance improvement after the changes from factor/montgomery.
2020-06-18 16:44:08 -07:00
nicoo
4b4d11b61a
factor: Add/update copyright notices as necessary (#1546) 2020-06-18 21:38:28 +02:00
Alex Lyon
6105cce69a
Merge pull request #1529 from nbraud/factor/montgomery
factor: Faster modular arithmetic with the Montgomery transform
2020-06-18 09:19:12 -07:00
nicoo
fb08d9ff9e factor::numeric::Montgomery::add: Deal with rare overflow case 2020-06-18 14:32:58 +02:00
nicoo
d1470dadf8 factor::numeric::gcd: Silence the (erroneous) dead code lint 2020-06-16 15:45:10 +02:00
nicoo
334e02786d factor: Run cargo fmt 2020-06-16 15:43:25 +02:00
Alex Lyon
110d6844ad
Use an iterator over OsString for uumain()
Additionally, restructure `uname` so that we don't need to find the
iterator's length.
2020-06-16 03:28:02 -05:00
nicoo
f1788d9e70 fixup! factor::numeric::Montgomery: Fix overflow bug 2020-06-16 01:17:16 +02:00
nicoo
4851619d62 factor::miller_rabin: Avoid repeatedly transforming 1 and -1
Approx. 25% speedup
2020-06-15 23:05:31 +02:00
nicoo
cb6051c580 factor::numeric::Montgomery: Fix overflow bug 2020-06-15 22:40:57 +02:00
nicoo
2238065c9d factor::numeric: Simplify Montgomery (remove superfluous Wrapping) 2020-06-15 19:18:34 +02:00
nicoo
19a0645a0a factor::numeric: Simplify inv_mod_u64
Just call `u64::wrapping_{mul,sub}` instead of (de)constructing Wrapping<u64>
values.
2020-06-15 19:18:34 +02:00
nicoo
918035e01e factor: Fix for old Rust 2020-06-15 19:18:34 +02:00
nicoo
f84d0f9398 factor::Factors::add: Make the precondition check a debug_assert 2020-06-15 19:18:34 +02:00
nicoo
33e18b4cd3 factor::numeric::Montgomery: Add debug assertions
In debug mode, checks that all arithmetic operations coincide with the
plain-u64 versions, as long as the latter does not overflow.
2020-06-15 19:18:34 +02:00
nicoo
8a4d0d30ad factor::numeric: Implement Montgomery's transform
This is a facter way to perform arithmetic mod n, when n is odd and a 64b
number.
2020-06-15 19:18:29 +02:00
nicoo
e91155519a factor::factor: Add integration tests 2020-06-15 19:10:16 +02:00
nicoo
bada7530fb factor::miller_rabin: Add tests 2020-06-15 19:10:16 +02:00
Roy Ivy III
fbbd881ca9 docs ~ reduce sub-crate meta-information keywords to the maximum of five 2020-05-31 15:48:54 -05:00
Roy Ivy III
f82de13847 docs ~ spell-check repairs and addition of exceptions 2020-05-30 01:36:02 -05:00
Roy Ivy III
ea3235c7e2 change ~ new_coreopts!() => app!() (from uucore v0.0.4) 2020-05-29 22:59:48 -05:00
Roy Ivy III
6f465eeb9f deps ~ update utils to uucore/uucore_procs v0.0.4 2020-05-29 22:59:48 -05:00
Roy Ivy III
d4aa3a2231 fix 'edition="2018"' module import errors
- ref: <https://users.rust-lang.org/t/imports-can-only-refer-to-extern-crate-names/24388> @@ <https://archive.is/iCaXp>
2020-05-29 22:59:47 -05:00
Roy Ivy III
d70db1f7d2 docs ~ improve/update sub-crate meta information 2020-05-29 22:59:47 -05:00
Roy Ivy III
db2e950918 change ~ make all sub-crates independent 2020-05-29 22:59:40 -05:00
Nicolas Braud-Santoni
4c3682aec7
factor::Factors::add: Split up to work without NLL
Co-authored-by: Roy Ivy III <rivy.dev@gmail.com>
2020-05-24 19:14:37 +02:00
nicoo
36a2948959 factor::miller_rabin: Avoid unecessary exponentiation
Instead of computing a^r and a^(n-1) = a^(r 2ⁱ) separately,
compute the latter by repeatedly squaring the former.

33.6% performance improvement
2020-05-24 19:10:34 +02:00
nicoo
543c7b941a factor::rho: Small refactor 2020-05-24 19:10:29 +02:00
nicoo
30fd6a0309 factor::numeric: Replace lose functions with an Arithmetic trait 2020-05-24 18:16:21 +02:00
nicoo
29eb8fd77b format: Make clippy happy 2020-05-24 17:06:19 +02:00
nicoo
8241037690 factor::miller_rabin: Extract dividers from the primality test
Another 36% improvement.
2020-05-24 15:41:23 +02:00
nicoo
6b9585b1dc factor::miller_rabbin: Refactor before extracting dividers
Replace iterated division with u64::trailing_zeros, hoist the selection of `mul`
out of the loop, another cool 49.5% runtime improvement.
2020-05-24 15:41:23 +02:00
nicoo
e3ecc81d97 factor: Move the Miller-Rabin primality test to its own module. 2020-05-24 15:41:23 +02:00
nicoo
74054feb94 factor::factor: Remove extraneous call to the primality test
Another 6.97% runtime improvement
2020-05-24 15:41:23 +02:00
nicoo
e1a6dbe619 factor::table: Remove obsolete, commented code 2020-05-24 15:41:23 +02:00
nicoo
169740629b factor::table: Remove extraneous calls to the primality test
50% performance improvement on factoring all numbers between 2 and 10⁶.
2020-05-24 15:41:23 +02:00
nicoo
418fd61759 factor::factor: Short-circuit the fallback to Pollard's rho
When the remainder is smaller than the max. entry in the table,
it is guaranteed to be prime.
2020-05-24 15:41:23 +02:00
nicoo
bc11e57962 factor::factor: Use u64::trailing_zero instead of iterated division
No significant performance impact (most of the time is spent elsewhere),
but an easy and satisfying fix nevertheless.
2020-05-24 15:41:23 +02:00
nicoo
a1b2522750 factor: Move each factorisation method to its own module
Also decoupled the factorisation methods; now factor::factor contains
the logic that chains the different algorithms and aggregates results.

As a side-effect, rho::factor now performs extraneous allocations (as each
recursive step creates a new `Factors` value, which is then aggregated into
the previous one) but there is no significant performance impact.
2020-05-24 15:41:23 +02:00
nicoo
d9095a2539 factor: Refactor (eheh) around a Factors datatype
It is clearer to see what is going on, as opposed to passing around an
unmarked `Vec<u64>`, and there is a single place to add invariants checks.

This is also a more compact memory representation: each prime factor is
represented only once, with an additional byte for multiplicity.  The
performance impact is however not significant.
2020-05-24 15:41:23 +02:00
Roy Ivy III
5aa2b039a5 change ~ fixup paths (within workspace packages) to common code 2020-04-14 13:46:19 -05:00
Roy Ivy III
78c362c8b5 change ~ fixup paths (within workspace packages) 2020-04-14 13:46:18 -05:00
Roy Ivy III
f0b0e3b867 change ~ reorganize code files 2020-04-14 13:46:18 -05:00