803753 - emscripten'd fannkuch gets 2x slower in IM (if we bump MAX_SCRIPT_SIZE)

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, defect)

Description

[Luke Wagner [:luke]]

Attachment: run in shell with arg "10"

Currently, fannkuch (attached) doesn't run in IM because _main() hits the MAX_SCRIPT_SIZE limit.  I bumped this to see what happened and we run 2x slower.  Callgrind shows that all our time is under ion::SideCannon (not compiling) and 30% of this time is under js::AddValues.

Comment 1

[Luke Wagner [:luke]]

Attachment: run in shell with args "10000 1000"

There is another instance of the same problem in the 'skinning' benchmark, except this time only ~6%, according to callgrind.

That this shows up twice makes me think this is a general problem with Emscripten code and it could really help us to figure it out and fix it.

Comment 2

[Lars T Hansen [:lth]]

asm.js issue, and this code has all changed. Also, emscripten-compiled wasm fannkuch is performant.