CppCon 2014: Chandler Carruth "Efficiency with Algorithms, Performance with Data Structures"

So Hi there, everyone.

My name is Chandler Carruth.

I work for Google

I work on our C++ language platform

I work on our C++ compilers

specifically the CLANG and ?

And I'm here to talk to you a little about performance.

and efficiency, and making code fast,

and all the different things that go into that.

But before I do too much

I want to give actually give you guys a little bit of a

one might say are expectations.

Because I have been reading the twitter feed

from all these folks, that talk about all these crazy good questions

I just want you guys to essentially know this is my view

of what Performance 101 should be.

Okay? This is going to be kind of an intro talk.

You guys are hard core, really deep performance nuts.

You may be a little bit bored, and please be kind,

because I'm going to gloss over some things (:52)

And so it's important to

And to give you an idea of

I have to mention, he actually wrote

I did not actually realize thi

We're going to come back to

So, how many foks

Anyone?

It's a good book

Okay. I actually think that the idea that software is getting

And for a parti

There was a pretty similar event

how we look at computing devices

and this event was the iPhone

When Steve Jobs

But he was

Mobile was

It took the world

But that's what happened

We now have to care about

And we essentially

You have to choose one

We're going to choose small

The other problem

What do we do about the battery

How many folks here have charged their phone today

That's a problem.

That's not a feature, that's a bug.

How many

We've entered

Power became relevant

Power efficient instructions

Optimizing for power usage

Because this is mostly total junk science.

Here is the number one

Finish running the program

The faster your software runs, the lest

If I run

But it's not, okay?

Here's the thing.

We've only

We figured out how to turn them off.

if you have a

the way it conserves power is by turning itself off

The more

So we actually want to make code faster

There are some extreme exceptions to it

But 99.999999% of the time

But batteries aren't the only

You'll note that

The only thing it is doing is taking electricity and turning it into heat.

That is it's job

And unfortunately, electricity costs a lot of money

And so power becomes very, very important

And I find it interesting