running into an interesting situation where some b...

# android

[vince]

running into an interesting situation where some basic math to colorize a f16 depth image to rgb is running more than 2x slower in Kotlin than in Java...

is there an equivalent of the Kotlin Bytecode viewer but in Java I can use to compare?

[vince]

Here's a gist of the function:

[vince]

https://gist.github.com/vinc3m1/d56ff294a73ad506a5fa5ffb3e46185f

[vince]

java takes 20-25ms, kotlin takes 60+

[vince]

my guess is all the boxing

[vince]

all the operators are calling invoke-virtual for Int.plus and Int.times, etc

[vince]

Updated the gist with dex bytecode from java and kotlin files, you can see that the kotlin dex is full of invoke-virtual from basic math functions due to operator overloading... is this expected? should the compiler be able to inline or optimize that out?

[vince]

hmmm looking at a release build this seems to be fixed in the kotlin bytecode, but let me confirm...

[vince]

yep definitely fixed in release. I guess that's expected then? just somewhat surprising behavior. there's an easy way to enable that optimization in a debug build that'd be nice

[vince]

Ah dang, this is totally a jetpack compose thing