Article: Increasing the D Compiler Speed by Over 75%

[deadalnix]

On Wednesday, 31 July 2013 at 23:26:32 UTC, Walter Bright wrote:
> On 7/31/2013 3:58 PM, John Colvin wrote:
>> It's a quite impressively unbalanced education that provides 
>> understanding of
>> memory allocation strategies, hashing and the performance 
>> pitfalls of integer
>> division, but not something as basic as a speed.
>
> Have you ever seen those cards that some "electrical engineers" 
> carry around, with the following equations on them:
>
>     V = I * R
>     R = V / I
>     I = V / R
>
> ?
>
> I found it: 
> https://docs.google.com/drawings/d/1StlhTYjiUEljnfVtFjP1BXLbixO30DIkbw-DpaYJoA0/edit?hl=en&pli=1
>
> Unbelievable. The author of it writes:
>
> "I'm going to explain to you how to use this cheat sheet in 
> case you've never seen this before."
>
> http://blog.ricardoarturocabral.com/2010/07/electronic-electrical-cheat-sheets.html
>
> Makes you want to cry.

Something I discovered during my studies when helping other is 
that most people to not even try to understand this kind of 
stuff. They simply brute-force the equation to their memory and 
regurgitate it as needed without understanding anything. Not 
because their aren't capable of understanding, simply because 
they never figured out that equation actually are saying 
something (and the teaching style often do not help here). They 
do not relate the equation to actual phenomenon they observe.

A nice example is the very basic mass times acceleration equals 
force.

Granted that acceleration is the variation of speed, this 
equation means the following :
  - If you push something it will start to move.
  - If you continue pushing it will move faster and faster.
  - If you do not push, it won't move (or continue moving the way 
it was).
  - The heavier it is, the harder it is to move that something.

Any child knows all the above, it is experienced it in everyday 
life. And the equation is simply the mathematical notation of 
this very basic experience.

If you don't relate such equation to anything real, you'll have 
all kind of trouble remembering it, knowing when to use it or how 
to use it.