Article: Increasing the D Compiler Speed by Over 75%

[JS]

On Tuesday, 30 July 2013 at 10:08:22 UTC, Leandro Lucarella wrote:
> JS, el 29 de July a las 22:32 me escribiste:
>> On Monday, 29 July 2013 at 19:38:51 UTC, Walter Bright wrote:
>> >On 7/29/2013 12:08 PM, JS wrote:
>> >>Trying to use distance and speed as a measure of performance 
>> >>of
>> >>a program is
>> >>just ridiculous.
>> >
>> >If you google "program execution speed" you'll find it's a
>> >commonly used term. "Lines per second" is a common measure of
>> >compiler execution speed - google "compiler lines per second" 
>> >and
>> >see.
>> >
>> >
>> >>(again, if we started with 12 second and went to 21 seconds, 
>> >>it
>> >>would be a near
>> >>75% increase. But a 75% increase is not a 75% 
>> >>decrease!!!!!!!!)
>> >
>> >Speed is the reciprocal of time, meaning a decrease in time 
>> >is an
>> >increase in speed.
>> 
>> You are right, sorry. There is no difference.
>> 
>> I think the issue is interpretation. When I read "X% increase 
>> in
>> speed" I think "X% faster [in time]".
>
> I just want to point out that being so much people getting this 
> wrong
> (and even fighting to convince other people that the wrong
> interpretation is right) might be an indication that the 
> message you
> wanted to give in that blog is not extremely clear :)
>
> That was my whole point. If you used some easier measure to 
> understand
> (like using time instead of speed) you could have avoided all 
> this
> confusion :)

It depends on the audience, but to write an article that is 
informal then use a very formal definition of speed is just 
begging for problems.

It's hard for me to really imagine that lines is a measurement of 
distance and speed is lines per second... but even if I allow 
this I don't understand why it is a better metric than just time 
alone(even though it is equivalent mathematically it is a 
convoluted approach).

If a compiler can compile n lines per second, is that really all 
that useful as a direct measurement? Are you saying I have to go 
count the lines of code in my program? Do I count empty lines? 
commented lines? etc...  Why don't you just give me the most 
direct answer?

Time is really all that matters, everything else is just 
obfuscation.