/prog/ - Tfw CPU still suck

Name: Anonymous 2016-09-17 20:19

http://libdivide.com/
Its 2016 and CPUs are still slower to execute hardware division than an optimized function.

Name: Anonymous 2016-09-17 21:06

neat

Name: Anonymous 2016-09-17 21:14

I'd rather have CPUs that are 10^-8 of one nanosecond slower at division but don't fuck up when calculating how far to move the landing gears.

Name: Anonymous 2016-09-17 22:05

This why ARM doesn't even bother including hardware division.

Name: Barba 2016-09-19 8:51

non philosophum facit

http://www.reddit.com/r/justneckbeardthings

Name: Anonymous 2016-09-19 11:00

>>5
Why are you shilling for plebbit?

Name: Anonymous 2016-09-19 11:26

>>3
x86 gives you slow and incorrect division since 1985

Name: Tractatus 2016-09-19 11:36

Logico-philosophicus

http://medium.com/p/742c954733ea

Name: Anonymous 2016-09-21 17:26

NINE WAYS NOT TO ACCEPT SOMETHING AS COMPLETELY TRUE GET

Name: Anonymous 2016-09-21 19:13

>>1
this has always been the case, just make the operands big enough and fancy algorithms will beat whatever algorithm you can implement in hardware

Name: XML is Turing complete 2016-09-21 20:13

>>10
Can't you get around that by implementing a recursive division algorithm in hardware?

Name: Anonymous 2016-09-21 22:01

der softlock

Name: ANDRU 2016-09-22 10:46

http://medium.com/p/7390d7cca4

Name: Anonymous 2016-09-22 19:56

>>11
perhaps, but i've never seen it

Name: Anonymous 2016-09-22 21:21

>>11
It's only worth it if you're gonna repeatedly divide by the same denominator.
The algorithm uses the div instruction to calculate its magic constants to effectively to a multiplication by a reciprocal. At the end of the day somewhere you do need a general purpose (slow) long division if you're gonna calculate 1/n, and nothing can magically speed that up.

Name: Anonymous 2016-09-25 3:15

Isn't there a nice way of mapping n -> 1/n in binary

1 / 1001 ~= 0.000111 (1 / 9 = [0.00625 + ..)
1000 / 1001
10000 - 1001?

Name: delete meta 2016-09-25 3:26

>>16
No

Name: Anonymous 2016-09-25 13:15

Check em

Tfw CPU still suck

1 Name: Anonymous 2016-09-17 20:19

2 Name: Anonymous 2016-09-17 21:06

3 Name: Anonymous 2016-09-17 21:14

4 Name: Anonymous 2016-09-17 22:05

5 Name: Barba 2016-09-19 8:51

6 Name: Anonymous 2016-09-19 11:00

7 Name: Anonymous 2016-09-19 11:26

8 Name: Tractatus 2016-09-19 11:36

9 Name: Anonymous 2016-09-21 17:26

10 Name: Anonymous 2016-09-21 19:13

11 Name: XML is Turing complete 2016-09-21 20:13

12 Name: Anonymous 2016-09-21 22:01

13 Name: ANDRU 2016-09-22 10:46

14 Name: Anonymous 2016-09-22 19:56

15 Name: Anonymous 2016-09-22 21:21

16 Name: Anonymous 2016-09-25 3:15

17 Name: delete meta 2016-09-25 3:26

18 Name: Anonymous 2016-09-25 13:15