Skip to content
By using Twitter’s services you agree to our Cookies Use. We and our partners operate globally and use cookies, including for analytics, personalisation, and ads.
  • Home Home Home, current page.
  • About

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @
  • Language: English
    • Bahasa Indonesia
    • Bahasa Melayu
    • Català
    • Čeština
    • Dansk
    • Deutsch
    • English UK
    • Español
    • Filipino
    • Français
    • Hrvatski
    • Italiano
    • Magyar
    • Nederlands
    • Norsk
    • Polski
    • Português
    • Română
    • Slovenčina
    • Suomi
    • Svenska
    • Tiếng Việt
    • Türkçe
    • Ελληνικά
    • Български език
    • Русский
    • Српски
    • Українська мова
    • עִבְרִית
    • العربية
    • فارسی
    • मराठी
    • हिन्दी
    • বাংলা
    • ગુજરાતી
    • தமிழ்
    • ಕನ್ನಡ
    • ภาษาไทย
    • 한국어
    • 日本語
    • 简体中文
    • 繁體中文
  • Have an account? Log in
    Have an account?
    · Forgot password?

    New to Twitter?
    Sign up
cmuratori's profile
Casey Muratori
Casey Muratori
Casey Muratori
@cmuratori

Tweets

Casey Muratori

@cmuratori

I'm worried that the baby thinks people can't change.

Seattle
caseymuratori.com
Joined March 2009

Tweets

  • © 2021 Twitter
  • About
  • Help Center
  • Terms
  • Privacy policy
  • Cookies
  • Ads info
Dismiss
Previous
Next

Go to a person's profile

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @

Promote this Tweet

Block

  • Tweet with a location

    You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more

    Your lists

    Create a new list


    Under 100 characters, optional

    Privacy

    Copy link to Tweet

    Embed this Tweet

    Embed this Video

    Add this Tweet to your website by copying the code below. Learn more

    Add this video to your website by copying the code below. Learn more

    Hmm, there was a problem reaching the server.

    By embedding Twitter content in your website or app, you are agreeing to the Twitter Developer Agreement and Developer Policy.

    Preview

    Why you're seeing this ad

    Log in to Twitter

    · Forgot password?
    Don't have an account? Sign up »

    Sign up for Twitter

    Not on Twitter? Sign up, tune into the things you care about, and get updates as they happen.

    Sign up
    Have an account? Log in »

    Two-way (sending and receiving) short codes:

    Country Code For customers of
    United States 40404 (any)
    Canada 21212 (any)
    United Kingdom 86444 Vodafone, Orange, 3, O2
    Brazil 40404 Nextel, TIM
    Haiti 40404 Digicel, Voila
    Ireland 51210 Vodafone, O2
    India 53000 Bharti Airtel, Videocon, Reliance
    Indonesia 89887 AXIS, 3, Telkomsel, Indosat, XL Axiata
    Italy 4880804 Wind
    3424486444 Vodafone
    » See SMS short codes for other countries

    Confirmation

     

    Welcome home!

    This timeline is where you’ll spend most of your time, getting instant updates about what matters to you.

    Tweets not working for you?

    Hover over the profile pic and click the Following button to unfollow any account.

    Say a lot with a little

    When you see a Tweet you love, tap the heart — it lets the person who wrote it know you shared the love.

    Spread the word

    The fastest way to share someone else’s Tweet with your followers is with a Retweet. Tap the icon to send it instantly.

    Join the conversation

    Add your thoughts about any Tweet with a Reply. Find a topic you’re passionate about, and jump right in.

    Learn the latest

    Get instant insight into what people are talking about now.

    Get more of what you love

    Follow more accounts to get instant updates about topics you care about.

    Find what's happening

    See the latest conversations about any topic instantly.

    Never miss a Moment

    Catch up instantly on the best stories happening as they unfold.

    1. Casey Muratori‏ @cmuratori 4 Mar 2020
      Replying to @BatmanAoD @mttkay and

      It depends what you mean by "abstraction". If an "abstraction" removes a choice, then it is not zero cost, because the programmer can no longer create the code that would have resulted from the removed direction of the choice, and it's only a matter of time before it is needed.

      1 reply 1 retweet 5 likes
    2. Casey Muratori‏ @cmuratori 4 Mar 2020
      Replying to @cmuratori @BatmanAoD and

      It stems from the misunderstanding that programming is telling a computer _what_ to do. But telling a computer _how_ to do it is actually what programming is, and in order to be truly "zero cost", an abstraction must retain the ability for the programmer to specify "how".

      2 replies 2 retweets 20 likes
    3. Kyle J Strand‏ @BatmanAoD 4 Mar 2020
      Replying to @cmuratori @mttkay and

      "Zero cost" does not mean that there is no downside or drawback; it means that it is implemented in such a way that you do not lose performance compared to writing the same behavior without the abstraction. I agree that programming is often the art of telling a computer _how_...

      1 reply 0 retweets 0 likes
    4. Kyle J Strand‏ @BatmanAoD 4 Mar 2020
      Replying to @BatmanAoD @cmuratori and

      to do something, but that is not always the case. As an obvious example, optimizing compilers can generally do register allocation as well as humans could.

      1 reply 0 retweets 0 likes
    5. Casey Muratori‏ @cmuratori 4 Mar 2020
      Replying to @BatmanAoD @mttkay and

      No, they can't. To this day I still see compilers routinely screw up register allocation on code close or at the register limit. It is often not "zero cost", and that is why "zero cost" is a very bad term. It should be called "occasionally zero cost".

      1 reply 1 retweet 5 likes
    6. Casey Muratori‏ @cmuratori 4 Mar 2020
      Replying to @cmuratori @BatmanAoD and

      And similarly, the fact that people think that register allocation is "zero cost" is another good example of why that phrase is bad. People should understand that there are currently either no or almost no truly "zero cost" abstractions.

      1 reply 0 retweets 3 likes
    7. Casey Muratori‏ @cmuratori 4 Mar 2020
      Replying to @cmuratori @BatmanAoD and

      Many (all?) the things they think are free actually aren't free at all.

      1 reply 0 retweets 1 like
    8. Kyle J Strand‏ @BatmanAoD 4 Mar 2020
      Replying to @cmuratori @mttkay and

      I don't have experience actually writing assembly, but I can imagine there being cases where a human can hand-optimize register allocation better than some specific compiler, sure. So, to take a different example: what about generic monomorphization? Isn't that "free" at runtime?

      1 reply 0 retweets 0 likes
    9. Kyle J Strand‏ @BatmanAoD 4 Mar 2020
      Replying to @BatmanAoD @cmuratori and

      (...since it happens at compile time?) I.e., a monomorphized function call is equivalent to a non-polymorphic function call. So that seems truly zero-cost.

      0 replies 0 retweets 0 likes
    10. This Tweet is unavailable.
      Casey Muratori‏ @cmuratori 4 Mar 2020
      Replying to @Jonathan_Blow @BatmanAoD and

      But actually it's not even zero-cost if you remove all those things. It's hypothetical zero-cost is only if you assume that the compiler does a perfect job of trading off between "commonizing" and specializing the monomorphs, which no compiler does.

      12:20 PM - 4 Mar 2020
      • 4 Likes
      • Thatcher Ulrich Dautor Tom LePage Silvio M.
      1 reply 0 retweets 4 likes
        1. New conversation
        2. Casey Muratori‏ @cmuratori 4 Mar 2020
          Replying to @cmuratori @Jonathan_Blow and

          Because actually what happens is that the compiler usually overspecializes, producing specialized versions for every possible morph, rather than parameterizing some in ways that are free to do in asm (like with register instead of immediate offsets).

          1 reply 0 retweets 3 likes
        3. Casey Muratori‏ @cmuratori 4 Mar 2020
          Replying to @cmuratori @Jonathan_Blow and

          Really the core concept here that needs to be understood is anything that is not supervised by an expert is probably being done less efficiently than it should be. "Zero cost" is just not a good term. It's never zero cost. We could have a different term, surely.

          1 reply 0 retweets 4 likes
        4. Show replies

      Loading seems to be taking a while.

      Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.

        Promoted Tweet

        false

        • © 2021 Twitter
        • About
        • Help Center
        • Terms
        • Privacy policy
        • Cookies
        • Ads info