412088 - TT: rewrite Array.dense_setAt in forth

Status: VERIFIED FIXED

(Tamarin Graveyard :: Virtual Machine, defect)

Description

[Edwin Smith]

callnative_x_glue has undue overhead, so even if the forth code uses a native helper, this is a win.  the signature requires that we pass the value as a reference as arg 2 however, so must do 411661 first if we want to avoid rotating the args just to fit IINVOKEXII's signature.

Comment 1

[Steven Johnson]

Actually, we don't have the dependency; we can make w_dense_setAt a superword, and the rotation will be "free" in interp mode.

Comment 2

[Edwin Smith]

True, although makes TT slightly more fragile, if certian words are required to be superwords.  I'm still yearning for the day when the choice of superwords is 100% machine driven.

i'm not that concerned either way, its not bad to use superwords, and 411661 is not a difficult change.  

Comment 3

[Steven Johnson]

Attachment: Patch

redo Array.dense_setAt in Forth (in the manner of dense_getAt) to avoid the overhead of callnative_x_glue. also remove unnecessary ibox from OP_getlocal and OP_setlocal.

Comment 4

[Edwin Smith]

Comment on attachment 297080 [details] [diff] [review]
Patch

Any preliminary results pro/con this change?

Comment 5

[Steven Johnson]

Unfortunately, I think the slowdown caused by early-binding and/or MAXTRACE are drowning out potential gains. 

Comment 6

[Steven Johnson]

pushed as changeset:   280:3af949d3cc11

Comment 7

[Chris Peyer]

Closing out all TT: transfer bugs that are resolved fixed.