Sooo… I changed this variable declaration from `let` to `var` and this function got 2x faster. WTF @v8js! https://github.com/parcel-bundler/parcel/blob/master/src/SourceMap.js#L214 …
“Unsupported phi use of const or let variable” was the bailout message.
-
-
Replying to @devongovett @v8js
You should probably ask
@bmeurer - he knows a lot about these inner details.1 reply 0 retweets 2 likes -
You should upgrade to a more recent version of
@NodeJS
1 reply 0 retweets 2 likes -
Replying to @bmeurer @sebastiansoft and
This is node 8 which is the current LTS version…
2 replies 0 retweets 0 likes -
Replying to @devongovett @sebastiansoft and
Definitely not, since that message is only produced by Crankshaft and Crankshaft is not included in Node 8.
1 reply 0 retweets 1 like -
Replying to @bmeurer @sebastiansoft and
v8.2.1 to be exact. I saw the message in the remote chrome profiler for the process, so maybe it’s showing the wrong one? either way, changing to var makes a HUGE difference to perf.
1 reply 0 retweets 1 like -
Replying to @devongovett @sebastiansoft and
8.2.1 has Crankshaft inside and is not the LTS version
1 reply 0 retweets 0 likes -
Replying to @bmeurer @sebastiansoft and
ah hmm, does not appear to happen in v8.11.1. I just assumed that they wouldn’t do a major bump of v8 in the middle of a single major node release…
2 replies 0 retweets 2 likes -
Replying to @devongovett @bmeurer and
It's backward compatible, so why not?
1 reply 0 retweets 1 like -
Replying to @probablyup @bmeurer and
I guess, but the performance characteristics of this code changed completely in a point release…
1 reply 0 retweets 0 likes
They changed in a good way though, right? It’s a win for everybody.
-
-
Replying to @mathias @probablyup and
I have another function that is much slower now though as well… haven’t nailed down the cause yet buthttps://github.com/babel/minify/blob/master/packages/babel-plugin-minify-mangle-names/src/index.js#L256-L336 …
2 replies 0 retweets 3 likes -
Replying to @devongovett @probablyup and
Please let us know when you narrow this down! We’re always on the lookout for performance cliffs to eliminate.
0 replies 1 retweet 3 likes
End of conversation
New conversation -
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.
JavaScript, HTML, CSS, HTTP, performance, security, Bash, Unicode, i18n, macOS.