Did a quick benchmark with positions and found out there is an
deoptimization
pattern in some string functions:
if (%_ArgumentsLength() > 1) {
pos = %_Arguments(1); // position
pos = TO_INTEGER(pos);
}
should be
if (%_ArgumentsLength() > 1) {
var arg = %_Arguments(1); // position
if (!IS_UNDEFINED(arg)) {
pos = $toInteger(arg);
}
}
results into
String.startsWith
OLD NEW
search: warmup index:undefined
2105 1021
search: index:undefined
2136 1042
search: index:0
1122 1179
search: index:1
1117 1184
search: P index:undefined
2109 975
search: က index:undefined
2093 971
search: က index:100
1050 1119
A further optimization about 250 ms would be to directly specify the
argument to
remove ArgumentsLength() and _Arguments() but then
there need to be some way to fake the length property for the ecma spec.
Updated in StartsWith. I will make a new review for all other affected
functions.
https://codereview.chromium.org/1324353002/
--
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
---
You received this message because you are subscribed to the Google Groups "v8-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
