First prototype for new `JsString` using UTF-16

[jedel1043]

I think it's time to address the elephant in the room.

This Pull Request will (hopefully!) solve part of #736.

This is a complete rewrite of JsString, but instead of storing u8 bytes it stores u16 words. The encode! macro (renamed to utf16! for simplicity) from the const-utf16 crate allows us to create UTF-16 encoded arrays at compilation time. JsString implements Deref<Target=[u16]> to unlock the slice methods and possibly make some manipulations easier. However, we would need to create our own library of utilities for JsString.

[jedel1043]

In addition, the utf16_literal crate should be useful to convert runtime strings from String to JsString, but we could probably implement a parser ourselves.

[github-actions[bot]]

Test262 conformance changes

VM implementation

Test result	main count	PR count	difference
Total	92,565	92,565	0
Passed	68,926	68,948	+22
Ignored	17,394	17,394	0
Failed	6,245	6,223	-22
Panics	0	0	0
Conformance	74.46%	74.49%	+0.02%

Fixed tests (30):

test/built-ins/encodeURIComponent/S15.1.3.4_A1.3_T1.js [strict mode] (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.3_T1.js (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.1_T2.js [strict mode] (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.1_T2.js (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.1_T1.js [strict mode] (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.1_T1.js (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.2_T1.js [strict mode] (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.2_T1.js (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.2_T2.js [strict mode] (previously Failed)
test/built-ins/encodeURIComponent/S15.1.3.4_A1.2_T2.js (previously Failed)
test/built-ins/JSON/stringify/value-string-escape-ascii.js [strict mode] (previously Failed)
test/built-ins/JSON/stringify/value-string-escape-ascii.js (previously Failed)
test/built-ins/JSON/stringify/value-string-escape-unicode.js [strict mode] (previously Failed)
test/built-ins/JSON/stringify/value-string-escape-unicode.js (previously Failed)
test/built-ins/String/prototype/codePointAt/return-first-code-unit.js [strict mode] (previously Failed)
test/built-ins/String/prototype/codePointAt/return-first-code-unit.js (previously Failed)
test/built-ins/String/prototype/codePointAt/return-single-code-unit.js [strict mode] (previously Failed)
test/built-ins/String/prototype/codePointAt/return-single-code-unit.js (previously Failed)
test/built-ins/StringIteratorPrototype/next/next-iteration-surrogate-pairs.js [strict mode] (previously Failed)
test/built-ins/StringIteratorPrototype/next/next-iteration-surrogate-pairs.js (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.2_T1.js [strict mode] (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.2_T1.js (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.1_T1.js [strict mode] (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.1_T1.js (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.2_T2.js [strict mode] (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.2_T2.js (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.1_T2.js [strict mode] (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.1_T2.js (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.3_T1.js [strict mode] (previously Failed)
test/built-ins/encodeURI/S15.1.3.3_A1.3_T1.js (previously Failed)

Broken tests (8):

test/built-ins/RegExp/dotall/with-dotall-unicode.js [strict mode] (previously Passed)
test/built-ins/RegExp/dotall/with-dotall-unicode.js (previously Passed)
test/built-ins/RegExp/dotall/without-dotall-unicode.js [strict mode] (previously Passed)
test/built-ins/RegExp/dotall/without-dotall-unicode.js (previously Passed)
test/language/literals/regexp/S7.8.5_A1.1_T2.js [strict mode] (previously Passed)
test/language/literals/regexp/S7.8.5_A1.1_T2.js (previously Passed)
test/language/literals/regexp/S7.8.5_A2.1_T2.js [strict mode] (previously Passed)
test/language/literals/regexp/S7.8.5_A2.1_T2.js (previously Passed)

[codecov[bot]]

Codecov Report

Merging #1659 (82b78f7) into main (07389cb) will decrease coverage by 0.10%. The diff coverage is 50.00%.

@@            Coverage Diff             @@
##             main    #1659      +/-   ##
==========================================
- Coverage   40.93%   40.82%   -0.11%     
==========================================
  Files         238      240       +2     
  Lines       22509    22743     +234     
==========================================
+ Hits         9214     9285      +71     
- Misses      13295    13458     +163     

Impacted Files	Coverage Δ
boa_engine/src/builtins/eval/mod.rs	12.90% <0.00%> (+0.40%)	:arrow_up:
boa_engine/src/builtins/function/mod.rs	23.73% <0.00%> (-0.37%)	:arrow_down:
boa_engine/src/builtins/intl/date_time_format.rs	55.10% <0.00%> (-1.15%)	:arrow_down:
boa_engine/src/builtins/typed_array/mod.rs	3.75% <0.00%> (-0.01%)	:arrow_down:
boa_engine/src/builtins/uri/mod.rs	9.09% <0.00%> (ø)
boa_engine/src/class.rs	0.00% <ø> (ø)
boa_engine/src/context/mod.rs	30.73% <ø> (ø)
boa_engine/src/lib.rs	82.14% <ø> (ø)
boa_engine/src/syntax/ast/node/template/mod.rs	46.66% <0.00%> (-5.06%)	:arrow_down:
boa_tester/src/exec/js262.rs	0.00% <ø> (ø)
... and 88 more

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[github-actions[bot]]

Benchmark for 4aee7ce

Click to view benchmark

Test	Base	PR	%
Arithmetic operations (Compiler)	564.1±27.87ns	582.7±75.83ns	+3.30%
Arithmetic operations (Execution)	2.6±0.13µs	2.7±0.27µs	+3.85%
Arithmetic operations (Parser)	7.6±0.38µs	7.5±0.32µs	-1.32%
Array access (Compiler)	1166.4±76.44ns	1199.9±61.94ns	+2.87%
Array access (Execution)	14.3±2.93µs	14.3±0.98µs	0.00%
Array access (Parser)	16.0±1.00µs	16.1±0.86µs	+0.63%
Array creation (Compiler)	1644.8±96.50ns	1655.6±123.97ns	+0.66%
Array creation (Execution)	4.3±0.32ms	4.0±0.27ms	-6.98%
Array creation (Parser)	17.8±1.36µs	17.7±0.73µs	-0.56%
Array pop (Compiler)	3.9±0.18µs	3.9±0.20µs	0.00%
Array pop (Execution)	1847.6±210.60µs	1726.3±116.35µs	-6.57%
Array pop (Parser)	197.6±12.44µs	209.2±12.54µs	+5.87%
Boolean Object Access (Compiler)	1003.5±77.50ns	984.8±68.53ns	-1.86%
Boolean Object Access (Execution)	9.5±0.60µs	9.2±0.53µs	-3.16%
Boolean Object Access (Parser)	18.7±1.21µs	18.8±1.00µs	+0.53%
Clean js (Compiler)	3.1±0.16µs	3.2±0.41µs	+3.23%
Clean js (Execution)	1959.8±205.91µs	1913.9±129.45µs	-2.34%
Clean js (Parser)	38.1±2.39µs	39.8±4.79µs	+4.46%
Create Realm	434.5±27.62ns	439.4±35.38ns	+1.13%
Dynamic Object Property Access (Compiler)	1614.8±114.98ns	1624.2±133.34ns	+0.58%
Dynamic Object Property Access (Execution)	9.3±0.60µs	9.7±0.67µs	+4.30%
Dynamic Object Property Access (Parser)	14.7±1.66µs	14.5±1.00µs	-1.36%
Fibonacci (Compiler)	2.2±0.19µs	2.2±0.10µs	0.00%
Fibonacci (Execution)	4.1±0.28ms	4.0±0.20ms	-2.44%
Fibonacci (Parser)	21.5±1.32µs	22.2±1.37µs	+3.26%
For loop (Compiler)	1792.0±80.59ns	1793.7±93.63ns	+0.09%
For loop (Execution)	58.8±4.67µs	60.2±4.26µs	+2.38%
For loop (Parser)	19.1±2.43µs	19.4±1.73µs	+1.57%
Mini js (Compiler)	3.2±0.72µs	3.1±0.15µs	-3.13%
Mini js (Execution)	1775.1±76.73µs	1765.1±78.25µs	-0.56%
Mini js (Parser)	33.4±5.70µs	33.8±2.14µs	+1.20%
Number Object Access (Compiler)	938.6±40.43ns	914.2±59.85ns	-2.60%
Number Object Access (Execution)	7.3±0.53µs	7.6±0.49µs	+4.11%
Number Object Access (Parser)	14.7±0.92µs	14.9±0.65µs	+1.36%
Object Creation (Compiler)	1384.0±98.98ns	1399.7±113.76ns	+1.13%
Object Creation (Execution)	8.5±0.52µs	8.8±0.55µs	+3.53%
Object Creation (Parser)	12.3±0.84µs	12.7±1.16µs	+3.25%
RegExp (Compiler)	1578.7±113.50ns	1590.9±80.37ns	+0.77%
RegExp (Execution)	17.2±1.15µs	17.5±1.29µs	+1.74%
RegExp (Parser)	13.7±1.87µs	14.0±1.31µs	+2.19%
RegExp Creation (Compiler)	1473.8±81.16ns	1466.4±75.59ns	-0.50%
RegExp Creation (Execution)	12.8±0.64µs	12.9±0.56µs	+0.78%
RegExp Creation (Parser)	11.3±0.93µs	11.6±0.68µs	+2.65%
RegExp Literal (Compiler)	1680.1±208.63ns	1620.1±88.26ns	-3.57%
RegExp Literal (Execution)	17.2±1.22µs	17.8±2.09µs	+3.49%
RegExp Literal (Parser)	10.8±0.74µs	11.3±1.63µs	+4.63%
RegExp Literal Creation (Compiler)	1496.1±92.33ns	1439.5±96.80ns	-3.78%
RegExp Literal Creation (Execution)	13.0±1.73µs	13.0±0.76µs	0.00%
RegExp Literal Creation (Parser)	8.4±0.62µs	8.7±0.89µs	+3.57%
Static Object Property Access (Compiler)	1407.0±100.29ns	1405.4±70.54ns	-0.11%
Static Object Property Access (Execution)	9.1±0.70µs	9.1±0.68µs	0.00%
Static Object Property Access (Parser)	13.0±0.86µs	13.8±1.07µs	+6.15%
String Object Access (Compiler)	1442.5±87.51ns	1416.3±94.23ns	-1.82%
String Object Access (Execution)	11.7±0.77µs	12.1±1.15µs	+3.42%
String Object Access (Parser)	17.9±0.78µs	18.9±1.27µs	+5.59%
String comparison (Compiler)	1850.1±90.20ns	1856.2±116.02ns	+0.33%
String comparison (Execution)	9.9±0.56µs	10.1±0.81µs	+2.02%
String comparison (Parser)	14.6±1.04µs	15.0±0.85µs	+2.74%
String concatenation (Compiler)	1554.1±114.18ns	1504.8±143.27ns	-3.17%
String concatenation (Execution)	8.7±0.62µs	8.8±0.76µs	+1.15%
String concatenation (Parser)	10.0±0.71µs	10.4±0.66µs	+4.00%
String copy (Compiler)	1239.7±66.39ns	1267.8±165.26ns	+2.27%
String copy (Execution)	7.5±0.71µs	7.3±0.36µs	-2.67%
String copy (Parser)	7.4±0.44µs	7.6±0.64µs	+2.70%
Symbols (Compiler)	944.0±47.55ns	951.7±58.75ns	+0.82%
Symbols (Execution)	7.0±0.53µs	7.1±1.35µs	+1.43%
Symbols (Parser)	5.8±0.32µs	5.9±0.34µs	+1.72%

[Razican]

Hi @jedel1043! Do you think you would be able to get back to this? This would be very nice to have :)

[jedel1043]

I'm still working on it locally :) I'll push incremental commits until I integrate the new type into all the builtins

[github-actions[bot]]

Benchmark for f902625

Click to view benchmark

Test	Base	PR	%
Arithmetic operations (Compiler)	398.7±0.55ns	396.0±0.77ns	-0.68%
Arithmetic operations (Execution)	1730.5±3.13ns	1963.3±64.78ns	+13.45%
Arithmetic operations (Parser)	5.5±0.01µs	5.6±0.01µs	+1.82%
Array access (Compiler)	827.2±2.40ns	828.0±2.04ns	+0.10%
Array access (Execution)	10.3±0.03µs	10.4±0.03µs	+0.97%
Array access (Parser)	10.4±0.02µs	12.0±0.02µs	+15.38%
Array creation (Compiler)	1154.2±2.80ns	1181.8±3.46ns	+2.39%
Array creation (Execution)	3.2±0.01ms	3.2±0.01ms	0.00%
Array creation (Parser)	13.2±0.02µs	13.4±0.02µs	+1.52%
Array pop (Compiler)	3.0±0.01µs	3.0±0.01µs	0.00%
Array pop (Execution)	1361.2±4.15µs	1370.2±4.79µs	+0.66%
Array pop (Parser)	135.9±0.08µs	137.2±0.13µs	+0.96%
Boolean Object Access (Compiler)	691.0±1.16ns	712.2±1.18ns	+3.07%
Boolean Object Access (Execution)	6.8±0.02µs	6.8±0.02µs	0.00%
Boolean Object Access (Parser)	13.9±0.01µs	14.1±0.02µs	+1.44%
Clean js (Compiler)	2.2±0.00µs	2.2±0.01µs	0.00%
Clean js (Execution)	1464.4±10.65µs	1496.7±11.26µs	+2.21%
Clean js (Parser)	28.3±0.03µs	28.6±0.04µs	+1.06%
Create Realm	329.1±0.21ns	335.9±0.32ns	+2.07%
Dynamic Object Property Access (Compiler)	1140.9±2.49ns	1163.1±3.74ns	+1.95%
Dynamic Object Property Access (Execution)	6.8±0.05µs	6.9±0.04µs	+1.47%
Dynamic Object Property Access (Parser)	10.6±0.02µs	10.7±0.03µs	+0.94%
Fibonacci (Compiler)	1468.2±3.29ns	1471.3±3.66ns	+0.21%
Fibonacci (Execution)	2.7±0.00ms	2.7±0.00ms	0.00%
Fibonacci (Parser)	15.8±0.02µs	16.0±0.05µs	+1.27%
For loop (Compiler)	1261.4±3.40ns	1282.8±3.58ns	+1.70%
For loop (Execution)	43.7±0.17µs	42.5±0.11µs	-2.75%
For loop (Parser)	13.5±0.03µs	13.7±0.03µs	+1.48%
Mini js (Compiler)	2.2±0.01µs	2.2±0.01µs	0.00%
Mini js (Execution)	1204.6±7.60µs	1362.3±7.69µs	+13.09%
Mini js (Parser)	24.8±0.02µs	24.9±0.03µs	+0.40%
Number Object Access (Compiler)	647.9±1.49ns	659.3±1.64ns	+1.76%
Number Object Access (Execution)	5.5±0.04µs	5.3±0.02µs	-3.64%
Number Object Access (Parser)	11.0±0.01µs	9.7±0.01µs	-11.82%
Object Creation (Compiler)	957.8±4.72ns	971.4±2.58ns	+1.42%
Object Creation (Execution)	6.1±0.03µs	6.3±0.04µs	+3.28%
Object Creation (Parser)	9.2±0.02µs	9.3±0.03µs	+1.09%
RegExp (Compiler)	1153.0±6.03ns	1135.3±1.40ns	-1.54%
RegExp (Execution)	13.1±0.06µs	13.2±0.03µs	+0.76%
RegExp (Parser)	8.8±0.02µs	10.2±0.06µs	+15.91%
RegExp Creation (Compiler)	1024.9±3.41ns	1042.2±3.11ns	+1.69%
RegExp Creation (Execution)	9.9±0.06µs	10.0±0.05µs	+1.01%
RegExp Creation (Parser)	8.3±0.02µs	8.6±0.03µs	+3.61%
RegExp Literal (Compiler)	1123.0±6.26ns	1160.4±4.06ns	+3.33%
RegExp Literal (Execution)	13.2±0.03µs	11.6±0.03µs	-12.12%
RegExp Literal (Parser)	8.0±0.01µs	7.3±0.01µs	-8.75%
RegExp Literal Creation (Compiler)	1021.9±3.17ns	1029.9±2.64ns	+0.78%
RegExp Literal Creation (Execution)	9.9±0.05µs	10.0±0.05µs	+1.01%
RegExp Literal Creation (Parser)	6.3±0.01µs	6.4±0.01µs	+1.59%
Static Object Property Access (Compiler)	969.3±2.62ns	982.6±2.46ns	+1.37%
Static Object Property Access (Execution)	6.4±0.03µs	6.5±0.03µs	+1.56%
Static Object Property Access (Parser)	9.9±0.02µs	10.0±0.03µs	+1.01%
String Object Access (Compiler)	1013.2±3.34ns	1046.0±6.56ns	+3.24%
String Object Access (Execution)	8.7±0.08µs	8.8±0.03µs	+1.15%
String Object Access (Parser)	13.7±0.03µs	13.8±0.04µs	+0.73%
String comparison (Compiler)	1274.0±4.16ns	1302.4±36.73ns	+2.23%
String comparison (Execution)	7.2±0.03µs	6.3±0.03µs	-12.50%
String comparison (Parser)	10.6±0.02µs	10.7±0.17µs	+0.94%
String concatenation (Compiler)	1043.7±1.68ns	1053.0±3.54ns	+0.89%
String concatenation (Execution)	6.1±0.02µs	6.1±0.02µs	0.00%
String concatenation (Parser)	7.4±0.02µs	7.4±0.04µs	0.00%
String copy (Compiler)	773.0±1.92ns	877.7±2.70ns	+13.54%
String copy (Execution)	5.2±0.02µs	5.3±0.02µs	+1.92%
String copy (Parser)	5.5±0.01µs	5.6±0.02µs	+1.82%
Symbols (Compiler)	639.3±1.20ns	642.2±1.28ns	+0.45%
Symbols (Execution)	4.9±0.02µs	5.0±0.03µs	+2.04%
Symbols (Parser)	3.7±0.01µs	4.3±0.02µs	+16.22%

[github-actions[bot]]

Benchmark for c3d66b0

Click to view benchmark

Test	Base	PR	%
Arithmetic operations (Compiler)	353.7±0.89ns	343.9±0.65ns	-2.77%
Arithmetic operations (Execution)	1725.9±7.77ns	1915.1±2.08ns	+10.96%
Arithmetic operations (Parser)	4.9±0.01µs	4.9±0.01µs	0.00%
Array access (Compiler)	724.5±4.91ns	829.4±2.78ns	+14.48%
Array access (Execution)	9.1±0.05µs	9.1±0.03µs	0.00%
Array access (Parser)	10.6±0.02µs	11.9±0.02µs	+12.26%
Array creation (Compiler)	1014.6±4.81ns	1176.1±7.15ns	+15.92%
Array creation (Execution)	2.8±0.01ms	2.9±0.01ms	+3.57%
Array creation (Parser)	11.8±0.02µs	13.3±0.02µs	+12.71%
Array pop (Compiler)	2.6±0.01µs	3.0±0.01µs	+15.38%
Array pop (Execution)	1204.0±3.91µs	1373.0±4.87µs	+14.04%
Array pop (Parser)	137.4±0.53µs	137.2±0.33µs	-0.15%
Boolean Object Access (Compiler)	606.5±2.08ns	709.8±0.93ns	+17.03%
Boolean Object Access (Execution)	6.0±0.03µs	6.0±0.01µs	0.00%
Boolean Object Access (Parser)	14.2±0.03µs	14.0±0.01µs	-1.41%
Clean js (Compiler)	2.2±0.00µs	1952.3±6.92ns	-11.26%
Clean js (Execution)	1297.6±12.26µs	1498.4±11.14µs	+15.47%
Clean js (Parser)	25.4±0.03µs	28.6±0.19µs	+12.60%
Create Realm	328.2±0.13ns	294.8±0.88ns	-10.18%
Dynamic Object Property Access (Compiler)	1016.9±5.12ns	1167.5±12.46ns	+14.81%
Dynamic Object Property Access (Execution)	6.4±0.41µs	6.1±0.06µs	-4.69%
Dynamic Object Property Access (Parser)	9.5±0.02µs	10.6±0.01µs	+11.58%
Fibonacci (Compiler)	1465.1±4.14ns	1296.1±2.92ns	-11.54%
Fibonacci (Execution)	2.4±0.00ms	2.4±0.00ms	0.00%
Fibonacci (Parser)	14.2±0.04µs	14.1±0.03µs	-0.70%
For loop (Compiler)	1288.0±7.41ns	1157.6±3.97ns	-10.12%
For loop (Execution)	38.2±0.13µs	37.7±0.10µs	-1.31%
For loop (Parser)	12.1±0.03µs	13.7±0.12µs	+13.22%
Mini js (Compiler)	2.1±0.00µs	1948.4±5.81ns	-7.22%
Mini js (Execution)	1192.5±5.06µs	1382.4±11.06µs	+15.92%
Mini js (Parser)	25.1±0.04µs	25.0±0.03µs	-0.40%
Number Object Access (Compiler)	570.8±1.10ns	672.2±1.57ns	+17.76%
Number Object Access (Execution)	4.8±0.03µs	4.7±0.01µs	-2.08%
Number Object Access (Parser)	9.8±0.01µs	9.7±0.02µs	-1.02%
Object Creation (Compiler)	972.9±3.26ns	853.8±3.23ns	-12.24%
Object Creation (Execution)	5.4±0.02µs	5.5±0.01µs	+1.85%
Object Creation (Parser)	8.2±0.02µs	9.2±0.02µs	+12.20%
RegExp (Compiler)	1034.4±15.66ns	1147.9±2.80ns	+10.97%
RegExp (Execution)	11.6±0.04µs	11.5±0.03µs	-0.86%
RegExp (Parser)	9.0±0.01µs	10.1±0.02µs	+12.22%
RegExp Creation (Compiler)	904.8±14.12ns	1035.3±3.09ns	+14.42%
RegExp Creation (Execution)	8.8±0.06µs	8.8±0.03µs	0.00%
RegExp Creation (Parser)	8.5±0.02µs	8.5±0.02µs	0.00%
RegExp Literal (Compiler)	1020.4±19.18ns	1157.0±3.53ns	+13.39%
RegExp Literal (Execution)	13.2±0.09µs	11.5±0.04µs	-12.88%
RegExp Literal (Parser)	8.2±0.02µs	7.2±0.02µs	-12.20%
RegExp Literal Creation (Compiler)	910.1±6.98ns	1015.1±4.35ns	+11.54%
RegExp Literal Creation (Execution)	8.7±0.03µs	8.7±0.11µs	0.00%
RegExp Literal Creation (Parser)	5.7±0.02µs	5.6±0.02µs	-1.75%
Static Object Property Access (Compiler)	849.2±2.96ns	866.0±2.52ns	+1.98%
Static Object Property Access (Execution)	5.7±0.01µs	5.7±0.01µs	0.00%
Static Object Property Access (Parser)	8.8±0.02µs	9.8±0.04µs	+11.36%
String Object Access (Compiler)	915.6±1.99ns	1030.3±6.12ns	+12.53%
String Object Access (Execution)	8.8±0.09µs	7.8±0.03µs	-11.36%
String Object Access (Parser)	13.9±0.02µs	12.1±0.03µs	-12.95%
String comparison (Compiler)	1140.0±6.61ns	1137.1±1.78ns	-0.25%
String comparison (Execution)	6.3±0.03µs	6.3±0.02µs	0.00%
String comparison (Parser)	10.8±0.01µs	10.7±0.03µs	-0.93%
String concatenation (Compiler)	920.6±5.73ns	931.7±2.03ns	+1.21%
String concatenation (Execution)	5.4±0.02µs	5.3±0.01µs	-1.85%
String concatenation (Parser)	6.6±0.01µs	6.7±0.34µs	+1.52%
String copy (Compiler)	754.0±2.71ns	859.2±3.58ns	+13.95%
String copy (Execution)	4.6±0.03µs	5.2±0.01µs	+13.04%
String copy (Parser)	5.6±0.01µs	5.6±0.03µs	0.00%
Symbols (Compiler)	650.2±1.81ns	578.9±1.37ns	-10.97%
Symbols (Execution)	4.9±0.02µs	4.4±0.01µs	-10.20%
Symbols (Parser)	3.8±0.02µs	3.8±0.02µs	0.00%

[jedel1043]

Time to see how many tests break... 😅

[jedel1043]

Well, I expected to see more failed tests tbh, I'll probably fix those today or tomorrow. It could also be that we cannot parse string literals with UTF-16 codepoints; the interner automatically converts unpaired surrogates to \uFFFD.

On another note, the interner doesn't support UTF-16 strings, so we will need to contribute to string-interner the missing features.

[jedel1043]

These are the tests that are unfixable without an UTF-16 interner:

• https://github.com/tc39/test262/blob/main/test/built-ins/Array/prototype/concat/Array.prototype.concat_spreadable-string-wrapper.js
• https://github.com/tc39/test262/blob/main/test/built-ins/RegExp/prototype/exec/u-captured-value.js
• https://github.com/tc39/test262/blob/main/test/annexB/built-ins/String/prototype/substr/surrogate-pairs.js
• https://github.com/tc39/test262/blob/main/test/built-ins/String/prototype/padEnd/normal-operation.js
• https://github.com/tc39/test262/blob/main/test/built-ins/String/prototype/padStart/normal-operation.js

[Razican]

Well, I expected to see more failed tests tbh, I'll probably fix those today or tomorrow. It could also be that we cannot parse string literals with UTF-16 codepoints; the interner automatically converts unpaired surrogates to \uFFFD.

On another note, the interner doesn't support UTF-16 strings, so we will need to contribute to string-interner the missing features.

Yes, but they might not want to add this feature, so we might end up needing to write our own interner. Let's see if we can open them an issue.

[jedel1043]

I'm gonna mark this as blocked on https://github.com/Robbepop/string-interner/pull/42. In the best case scenario, it'll get merged soon. Also, the two failing tests have to do with our (lack of) support for UTF-16 regex, so I'm gonna work on https://github.com/ridiculousfish/regress/issues/43 in the meantime.

[jedel1043]

OK, this is officially unblocked by #2147. I'll work on rebasing this today :)

[jedel1043]

Checked all the broken tests and all of them are related to our lack of UTF-16 handling in Regexp. All tests previously passed because our string parser converted the unpaired surrogates to 0xFFFD, which passed the equality test.

This shouldn't be a blocker then, and with some final contributions to regress it should be solved on their next release.

[jedel1043]

Marking as ready for review since this is pretty much feature complete. It's still missing some docs adjustments but it would be good to have some reviews in the meantime.

[raskad]

Amost done with my review. We should probably do a benchmark on this right @jedel1043?

[jedel1043]

Yep, let me push to activate the bot

[jedel1043]

Hm, a segmentation fault that is only detected by benchmarks. That's really weird... I'll redesign the interner to see if that's the cause

[github-actions[bot]]

Benchmark for 94c5586

Click to view benchmark

Test	Base	PR	%
Arithmetic operations (Compiler)	510.0±1.07ns	504.0±1.31ns	-1.18%
Arithmetic operations (Execution)	507.7±0.31ns	509.8±0.66ns	+0.41%
Arithmetic operations (Parser)	6.3±0.01µs	6.3±0.02µs	0.00%
Array access (Compiler)	1517.0±3.54ns	1537.7±4.31ns	+1.36%
Array access (Execution)	8.5±0.02µs	11.3±0.03µs	+32.94%
Array access (Parser)	14.0±0.06µs	13.8±0.04µs	-1.43%
Array creation (Compiler)	2.3±0.00µs	2.4±0.00µs	+4.35%
Array creation (Execution)	2.4±0.01ms	2.7±0.00ms	+12.50%
Array creation (Parser)	16.1±0.09µs	15.8±0.04µs	-1.86%
Array pop (Compiler)	4.1±0.01µs	4.1±0.01µs	0.00%
Array pop (Execution)	1123.8±5.00µs	1350.6±11.60µs	+20.18%
Array pop (Parser)	152.8±0.11µs	154.2±0.24µs	+0.92%
Boolean Object Access (Compiler)	1167.3±8.89ns	1161.5±2.55ns	-0.50%
Boolean Object Access (Execution)	4.5±0.02µs	5.8±0.03µs	+28.89%
Boolean Object Access (Parser)	16.4±0.02µs	16.6±0.04µs	+1.22%
Clean js (Compiler)	5.0±0.01µs	5.0±0.01µs	0.00%
Clean js (Execution)	742.8±3.90µs	898.7±6.21µs	+20.99%
Clean js (Parser)	35.0±0.31µs	34.4±0.09µs	-1.71%
Create Realm	242.9±0.16ns	244.3±0.25ns	+0.58%
Dynamic Object Property Access (Compiler)	1816.6±3.90ns	1834.2±4.66ns	+0.97%
Dynamic Object Property Access (Execution)	5.5±0.01µs	6.4±0.03µs	+16.36%
Dynamic Object Property Access (Parser)	12.9±0.06µs	12.5±0.03µs	-3.10%
Fibonacci (Compiler)	2.8±0.01µs	2.8±0.01µs	0.00%
Fibonacci (Execution)	1389.8±7.65µs	1624.7±6.24µs	+16.90%
Fibonacci (Parser)	19.1±0.07µs	18.9±0.10µs	-1.05%
For loop (Compiler)	2.7±0.02µs	2.7±0.01µs	0.00%
For loop (Execution)	16.6±0.04µs	17.7±0.07µs	+6.63%
For loop (Parser)	16.4±0.04µs	16.3±0.11µs	-0.61%
Mini js (Compiler)	4.4±0.05µs	4.4±0.01µs	0.00%
Mini js (Execution)	684.6±9.01µs	846.3±18.40µs	+23.62%
Mini js (Parser)	30.6±0.09µs	30.0±0.07µs	-1.96%
Number Object Access (Compiler)	1090.8±3.23ns	1092.5±4.36ns	+0.16%
Number Object Access (Execution)	3.5±0.01µs	4.4±0.02µs	+25.71%
Number Object Access (Parser)	12.8±0.02µs	13.0±0.03µs	+1.56%
Object Creation (Compiler)	1605.3±5.37ns	1622.5±8.23ns	+1.07%
Object Creation (Execution)	5.1±0.09µs	6.1±0.02µs	+19.61%
Object Creation (Parser)	11.2±0.02µs	10.9±0.05µs	-2.68%
RegExp (Compiler)	1842.2±6.34ns	1819.6±7.33ns	-1.23%
RegExp (Execution)	12.4±0.07µs	15.9±0.20µs	+28.23%
RegExp (Parser)	12.1±0.07µs	11.7±0.02µs	-3.31%
RegExp Creation (Compiler)	1622.5±7.83ns	1656.4±4.25ns	+2.09%
RegExp Creation (Execution)	9.3±0.04µs	10.9±0.05µs	+17.20%
RegExp Creation (Parser)	10.0±0.02µs	9.8±0.04µs	-2.00%
RegExp Literal (Compiler)	1832.0±4.24ns	1838.8±4.25ns	+0.37%
RegExp Literal (Execution)	12.4±0.07µs	15.9±0.29µs	+28.23%
RegExp Literal (Parser)	10.1±0.02µs	9.5±0.02µs	-5.94%
RegExp Literal Creation (Compiler)	1633.9±8.56ns	1666.6±2.99ns	+2.00%
RegExp Literal Creation (Execution)	9.2±0.04µs	11.5±0.47µs	+25.00%
RegExp Literal Creation (Parser)	7.8±0.03µs	7.6±0.02µs	-2.56%
Static Object Property Access (Compiler)	1624.3±7.62ns	1649.2±7.20ns	+1.53%
Static Object Property Access (Execution)	5.3±0.04µs	6.3±0.02µs	+18.87%
Static Object Property Access (Parser)	11.9±0.06µs	11.6±0.04µs	-2.52%
String Object Access (Compiler)	1463.2±5.18ns	1513.5±9.09ns	+3.44%
String Object Access (Execution)	6.6±0.02µs	8.2±0.03µs	+24.24%
String Object Access (Parser)	16.0±0.02µs	16.2±0.10µs	+1.25%
String comparison (Compiler)	2.3±0.01µs	2.4±0.01µs	+4.35%
String comparison (Execution)	4.7±0.04µs	5.5±0.02µs	+17.02%
String comparison (Parser)	13.3±0.02µs	12.7±0.05µs	-4.51%
String concatenation (Compiler)	1791.3±4.28ns	1811.6±3.94ns	+1.13%
String concatenation (Execution)	4.5±0.01µs	5.4±0.02µs	+20.00%
String concatenation (Parser)	9.2±0.03µs	8.9±0.03µs	-3.26%
String copy (Compiler)	1470.8±0.85ns	1505.5±3.70ns	+2.36%
String copy (Execution)	4.3±0.02µs	5.0±0.01µs	+16.28%
String copy (Parser)	6.9±0.02µs	6.9±0.04µs	0.00%
Symbols (Compiler)	1126.2±2.91ns	1125.3±2.97ns	-0.08%
Symbols (Execution)	4.3±0.02µs	5.1±0.03µs	+18.60%
Symbols (Parser)	5.4±0.01µs	5.1±0.02µs	-5.56%

[github-actions[bot]]

Benchmark for 010e382

Click to view benchmark

Test	Base	PR	%
Arithmetic operations (Compiler)	466.6±1.46ns	561.1±1.63ns	+20.25%
Arithmetic operations (Execution)	739.0±4.29ns	623.6±0.37ns	-15.62%
Arithmetic operations (Parser)	5.8±0.01µs	5.7±0.01µs	-1.72%
Array access (Compiler)	1416.3±3.16ns	1427.6±8.55ns	+0.80%
Array access (Execution)	8.2±0.03µs	10.3±0.03µs	+25.61%
Array access (Parser)	12.9±0.09µs	12.8±0.02µs	-0.78%
Array creation (Compiler)	2.2±0.01µs	2.2±0.01µs	0.00%
Array creation (Execution)	2.5±0.01ms	2.7±0.00ms	+8.00%
Array creation (Parser)	13.2±0.02µs	14.7±0.02µs	+11.36%
Array pop (Compiler)	4.1±0.01µs	4.0±0.01µs	-2.44%
Array pop (Execution)	1131.8±5.59µs	1312.2±6.13µs	+15.94%
Array pop (Parser)	143.4±0.21µs	142.4±0.19µs	-0.70%
Boolean Object Access (Compiler)	1005.7±3.04ns	990.4±2.78ns	-1.52%
Boolean Object Access (Execution)	4.3±0.01µs	5.3±0.01µs	+23.26%
Boolean Object Access (Parser)	15.6±0.02µs	13.5±0.02µs	-13.46%
Clean js (Compiler)	4.1±0.01µs	4.6±0.01µs	+12.20%
Clean js (Execution)	725.0±3.29µs	747.7±3.33µs	+3.13%
Clean js (Parser)	32.4±0.14µs	28.1±0.03µs	-13.27%
Create Realm	235.3±0.18ns	241.0±0.57ns	+2.42%
Dynamic Object Property Access (Compiler)	1709.7±5.53ns	1514.8±3.32ns	-11.40%
Dynamic Object Property Access (Execution)	5.4±0.02µs	5.6±0.23µs	+3.70%
Dynamic Object Property Access (Parser)	11.6±0.02µs	10.2±0.02µs	-12.07%
Fibonacci (Compiler)	2.6±0.01µs	2.6±0.01µs	0.00%
Fibonacci (Execution)	1346.2±3.36µs	1531.6±3.79µs	+13.77%
Fibonacci (Parser)	17.5±0.02µs	17.1±0.02µs	-2.29%
For loop (Compiler)	2.5±0.01µs	2.5±0.01µs	0.00%
For loop (Execution)	17.2±0.05µs	17.6±0.08µs	+2.33%
For loop (Parser)	15.2±0.02µs	15.2±0.04µs	0.00%
Mini js (Compiler)	3.6±0.02µs	4.1±0.01µs	+13.89%
Mini js (Execution)	671.4±3.41µs	702.1±3.72µs	+4.57%
Mini js (Parser)	28.2±0.03µs	27.7±0.04µs	-1.77%
Number Object Access (Compiler)	959.3±1.54ns	1070.6±4.05ns	+11.60%
Number Object Access (Execution)	3.4±0.01µs	4.1±0.01µs	+20.59%
Number Object Access (Parser)	12.2±0.02µs	12.1±0.05µs	-0.82%
Object Creation (Compiler)	1497.1±4.87ns	1522.2±3.99ns	+1.68%
Object Creation (Execution)	5.1±0.01µs	5.8±0.02µs	+13.73%
Object Creation (Parser)	10.2±0.03µs	10.1±0.02µs	-0.98%
RegExp (Compiler)	1688.2±6.53ns	1516.8±12.78ns	-10.15%
RegExp (Execution)	12.4±0.04µs	13.2±0.03µs	+6.45%
RegExp (Parser)	11.2±0.02µs	9.7±0.02µs	-13.39%
RegExp Creation (Compiler)	1344.2±3.68ns	1378.6±10.70ns	+2.56%
RegExp Creation (Execution)	8.2±0.03µs	9.1±0.05µs	+10.98%
RegExp Creation (Parser)	8.4±0.02µs	9.2±0.01µs	+9.52%
RegExp Literal (Compiler)	1490.8±2.94ns	1511.0±8.81ns	+1.35%
RegExp Literal (Execution)	12.3±0.04µs	13.3±0.03µs	+8.13%
RegExp Literal (Parser)	8.0±0.01µs	8.8±0.02µs	+10.00%
RegExp Literal Creation (Compiler)	1330.3±5.78ns	1352.1±5.49ns	+1.64%
RegExp Literal Creation (Execution)	9.2±0.05µs	9.2±0.04µs	0.00%
RegExp Literal Creation (Parser)	7.1±0.01µs	6.9±0.07µs	-2.82%
Static Object Property Access (Compiler)	1512.2±4.11ns	1529.7±4.01ns	+1.16%
Static Object Property Access (Execution)	5.3±0.01µs	6.1±0.20µs	+15.09%
Static Object Property Access (Parser)	10.9±0.01µs	9.5±0.02µs	-12.84%
String Object Access (Compiler)	1247.0±1.30ns	1262.9±4.80ns	+1.28%
String Object Access (Execution)	6.1±0.03µs	6.8±0.07µs	+11.48%
String Object Access (Parser)	15.1±0.02µs	15.1±0.16µs	0.00%
String comparison (Compiler)	2.2±0.00µs	1935.0±7.03ns	-12.05%
String comparison (Execution)	4.7±0.05µs	5.2±0.03µs	+10.64%
String comparison (Parser)	11.7±0.01µs	11.8±0.02µs	+0.85%
String concatenation (Compiler)	5.1±0.07µs	1509.9±16.24ns	-70.39%
String concatenation (Execution)	4.4±0.05µs	5.0±0.02µs	+13.64%
String concatenation (Parser)	8.2±0.01µs	8.3±0.01µs	+1.22%
String copy (Compiler)	1386.3±3.17ns	1388.8±6.34ns	+0.18%
String copy (Execution)	4.1±0.02µs	4.7±0.02µs	+14.63%
String copy (Parser)	6.2±0.01µs	6.2±0.01µs	0.00%
Symbols (Compiler)	1068.1±2.68ns	1065.1±1.89ns	-0.28%
Symbols (Execution)	4.2±0.02µs	4.9±0.02µs	+16.67%
Symbols (Parser)	4.3±0.01µs	4.7±0.01µs	+9.30%

[Razican]

Hmmm benchmarks show a clear regression :(

[jedel1043]

Hmmm benchmarks show a clear regression :(

Understandable, since we now have to use double the memory to store strings. That's not cache friendly at all. On the other hand, we still need UTF-16 strings for correctness.

I was thinking about some possible optimizations, and I think we could optimize JsString by only storing UTF-16 if the string has characters outside of the ASCII range, and storing only ASCII otherwise, but that would require a bit more design effort.

[HalidOdat]

I was thinking about some possible optimizations, and I think we could optimize JsString by only storing UTF-16 if the string has characters outside of the ASCII range, and storing only ASCII otherwise, but that would require a bit more design effort.

AFAIK V8 and spidermoney does this optimization, I think this could be done after we merge this first, since this PR is already huge

[raskad]

I was thinking about some possible optimizations, and I think we could optimize JsString by only storing UTF-16 if the string has characters outside of the ASCII range, and storing only ASCII otherwise, but that would require a bit more design effort.

AFAIK V8 and spidermoney does this optimization, I think this could be done after we merge this first, since this PR is already huge

@jedel1043, @HalidOdat, @Razican Since we are at the start of 0.17 now, do we want to rebase, review and merge this as is and set a goal to improve the performance until the 0.17 release?

[jedel1043]

+1 for @raskad 's suggestion, but I'm pretty much biased haha

[Razican]

I think we can merge it as-is, yes :) then improve performance before 0.17

[jedel1043]

Rebased!

[github-actions[bot]]

Benchmark for b2bc001

Click to view benchmark

Test	Base	PR	%
Arithmetic operations (Compiler)	668.1±35.79ns	653.5±47.45ns	-2.19%
Arithmetic operations (Execution)	770.6±39.00ns	747.0±38.71ns	-3.06%
Arithmetic operations (Parser)	7.8±0.50µs	7.5±0.46µs	-3.85%
Array access (Compiler)	1897.4±131.88ns	1939.2±80.56ns	+2.20%
Array access (Execution)	8.8±0.47µs	11.9±1.17µs	+35.23%
Array access (Parser)	16.4±0.73µs	16.7±0.81µs	+1.83%
Array creation (Compiler)	2.9±0.14µs	2.8±0.14µs	-3.45%
Array creation (Execution)	1277.7±66.54µs	1528.3±133.09µs	+19.61%
Array creation (Parser)	19.1±0.87µs	19.5±0.76µs	+2.09%
Array pop (Compiler)	5.4±0.20µs	5.1±0.24µs	-5.56%
Array pop (Execution)	685.6±46.05µs	920.6±51.96µs	+34.28%
Array pop (Parser)	190.6±9.82µs	193.7±6.82µs	+1.63%
Boolean Object Access (Compiler)	1464.0±113.84ns	1380.7±69.56ns	-5.69%
Boolean Object Access (Execution)	5.5±0.30µs	6.4±0.37µs	+16.36%
Boolean Object Access (Parser)	18.4±0.91µs	18.8±1.08µs	+2.17%
Clean js (Compiler)	6.1±0.31µs	6.5±0.37µs	+6.56%
Clean js (Execution)	749.6±49.34µs	931.9±38.19µs	+24.32%
Clean js (Parser)	40.1±2.97µs	39.8±3.53µs	-0.75%
Create Realm	286.9±16.85ns	294.0±15.28ns	+2.47%
Dynamic Object Property Access (Compiler)	2.3±0.13µs	2.2±0.13µs	-4.35%
Dynamic Object Property Access (Execution)	6.1±0.35µs	6.9±0.57µs	+13.11%
Dynamic Object Property Access (Parser)	14.8±0.79µs	14.4±0.79µs	-2.70%
Fibonacci (Compiler)	3.5±0.18µs	3.6±0.12µs	+2.86%
Fibonacci (Execution)	1351.0±51.47µs	1520.8±64.87µs	+12.57%
Fibonacci (Parser)	22.3±1.58µs	22.2±1.46µs	-0.45%
For loop (Compiler)	3.1±0.18µs	3.3±0.14µs	+6.45%
For loop (Execution)	21.1±1.06µs	22.2±1.24µs	+5.21%
For loop (Parser)	19.2±1.05µs	20.4±2.65µs	+6.25%
Mini js (Compiler)	5.2±0.33µs	5.3±0.31µs	+1.92%
Mini js (Execution)	654.9±40.30µs	829.9±31.68µs	+26.72%
Mini js (Parser)	34.8±1.72µs	32.9±1.72µs	-5.46%
Number Object Access (Compiler)	1335.7±128.16ns	1362.1±89.61ns	+1.98%
Number Object Access (Execution)	4.3±0.20µs	5.3±0.27µs	+23.26%
Number Object Access (Parser)	14.8±0.73µs	15.0±0.66µs	+1.35%
Object Creation (Compiler)	1996.8±135.10ns	1943.5±103.47ns	-2.67%
Object Creation (Execution)	5.6±0.28µs	6.7±0.44µs	+19.64%
Object Creation (Parser)	12.8±0.66µs	12.6±0.69µs	-1.56%
RegExp (Compiler)	2.2±0.12µs	2.2±0.13µs	0.00%
RegExp (Execution)	14.3±1.07µs	18.5±0.60µs	+29.37%
RegExp (Parser)	13.9±0.81µs	13.8±0.83µs	-0.72%
RegExp Creation (Compiler)	1967.8±107.67ns	2.1±0.09µs	+6.72%
RegExp Creation (Execution)	10.5±0.44µs	11.7±0.54µs	+11.43%
RegExp Creation (Parser)	11.5±0.62µs	11.8±0.61µs	+2.61%
RegExp Literal (Compiler)	2.2±0.11µs	2.3±0.18µs	+4.55%
RegExp Literal (Execution)	14.3±0.67µs	18.3±1.11µs	+27.97%
RegExp Literal (Parser)	11.1±0.82µs	11.1±0.37µs	0.00%
RegExp Literal Creation (Compiler)	1989.8±97.30ns	2.1±0.08µs	+5.54%
RegExp Literal Creation (Execution)	10.4±0.59µs	12.5±0.51µs	+20.19%
RegExp Literal Creation (Parser)	8.7±0.58µs	8.9±0.34µs	+2.30%
Static Object Property Access (Compiler)	2.1±0.21µs	2.0±0.09µs	-4.76%
Static Object Property Access (Execution)	6.0±0.31µs	6.9±0.43µs	+15.00%
Static Object Property Access (Parser)	14.2±0.87µs	13.8±0.85µs	-2.82%
String Object Access (Compiler)	1826.4±68.43ns	1842.3±102.70ns	+0.87%
String Object Access (Execution)	7.9±0.57µs	9.7±0.58µs	+22.78%
String Object Access (Parser)	18.0±1.03µs	18.2±0.94µs	+1.11%
String comparison (Compiler)	2.8±0.15µs	2.9±0.13µs	+3.57%
String comparison (Execution)	5.3±0.56µs	5.9±0.34µs	+11.32%
String comparison (Parser)	14.9±0.93µs	15.0±0.74µs	+0.67%
String concatenation (Compiler)	2.2±0.12µs	2.3±0.11µs	+4.55%
String concatenation (Execution)	4.9±0.31µs	5.4±0.33µs	+10.20%
String concatenation (Parser)	10.6±0.60µs	10.7±0.81µs	+0.94%
String copy (Compiler)	1768.1±111.20ns	1828.4±102.52ns	+3.41%
String copy (Execution)	4.5±0.23µs	5.2±0.26µs	+15.56%
String copy (Parser)	7.9±0.35µs	8.1±0.46µs	+2.53%
Symbols (Compiler)	1455.1±73.63ns	1392.7±67.88ns	-4.29%
Symbols (Execution)	4.6±0.28µs	5.4±0.31µs	+17.39%
Symbols (Parser)	6.1±0.36µs	6.0±0.54µs	-1.64%

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Benchmark for 51affed

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Test	Base	PR	%
Arithmetic operations (Compiler)	508.3±1.36ns	488.9±0.75ns	-3.82%
Arithmetic operations (Execution)	523.8±0.46ns	530.7±0.50ns	+1.32%
Arithmetic operations (Parser)	6.7±0.05µs	6.9±0.07µs	+2.99%
Array access (Compiler)	1479.7±6.92ns	1458.9±6.92ns	-1.41%
Array access (Execution)	7.5±0.02µs	9.8±0.02µs	+30.67%
Array access (Parser)	14.6±0.04µs	14.9±0.08µs	+2.05%
Array creation (Compiler)	2.3±0.01µs	2.3±0.01µs	0.00%
Array creation (Execution)	1211.4±23.06µs	1385.3±6.46µs	+14.36%
Array creation (Parser)	17.0±0.05µs	17.2±0.06µs	+1.18%
Array pop (Compiler)	4.1±0.02µs	4.1±0.01µs	0.00%
Array pop (Execution)	631.6±2.75µs	838.8±3.13µs	+32.81%
Array pop (Parser)	159.5±0.15µs	156.9±0.19µs	-1.63%
Boolean Object Access (Compiler)	1177.4±4.11ns	1158.0±11.51ns	-1.65%
Boolean Object Access (Execution)	4.5±0.01µs	5.8±0.22µs	+28.89%
Boolean Object Access (Parser)	16.7±0.11µs	16.9±0.04µs	+1.20%
Clean js (Compiler)	5.0±0.01µs	5.1±0.01µs	+2.00%
Clean js (Execution)	644.1±3.89µs	794.3±3.05µs	+23.32%
Clean js (Parser)	35.2±0.10µs	35.2±0.07µs	0.00%
Create Realm	248.9±0.32ns	247.6±1.20ns	-0.52%
Dynamic Object Property Access (Compiler)	1789.2±8.97ns	1802.1±10.28ns	+0.72%
Dynamic Object Property Access (Execution)	4.9±0.02µs	5.6±0.01µs	+14.29%
Dynamic Object Property Access (Parser)	13.3±0.11µs	13.5±0.06µs	+1.50%
Fibonacci (Compiler)	2.8±0.01µs	2.8±0.01µs	0.00%
Fibonacci (Execution)	1117.1±10.31µs	1251.3±12.12µs	+12.01%
Fibonacci (Parser)	20.4±0.07µs	20.1±0.07µs	-1.47%
For loop (Compiler)	2.6±0.01µs	2.7±0.02µs	+3.85%
For loop (Execution)	16.5±0.04µs	17.3±0.03µs	+4.85%
For loop (Parser)	17.5±0.03µs	17.7±0.04µs	+1.14%
Mini js (Compiler)	4.4±0.01µs	4.4±0.04µs	0.00%
Mini js (Execution)	577.4±5.41µs	729.9±4.50µs	+26.41%
Mini js (Parser)	30.6±0.16µs	30.3±0.11µs	-0.98%
Number Object Access (Compiler)	1087.6±2.15ns	1083.8±23.64ns	-0.35%
Number Object Access (Execution)	3.4±0.01µs	4.5±0.01µs	+32.35%
Number Object Access (Parser)	13.1±0.11µs	13.4±0.03µs	+2.29%
Object Creation (Compiler)	1586.6±8.85ns	1551.6±5.48ns	-2.21%
Object Creation (Execution)	4.6±0.01µs	5.3±0.02µs	+15.22%
Object Creation (Parser)	11.7±0.05µs	11.8±0.08µs	+0.85%
RegExp (Compiler)	1815.6±11.55ns	1771.3±9.40ns	-2.44%
RegExp (Execution)	11.7±0.03µs	14.7±0.06µs	+25.64%
RegExp (Parser)	12.7±0.06µs	12.7±0.04µs	0.00%
RegExp Creation (Compiler)	1579.5±3.16ns	1598.5±7.67ns	+1.20%
RegExp Creation (Execution)	8.6±0.03µs	9.9±0.04µs	+15.12%
RegExp Creation (Parser)	10.6±0.06µs	10.7±0.05µs	+0.94%
RegExp Literal (Compiler)	1797.4±8.82ns	1777.7±7.66ns	-1.10%
RegExp Literal (Execution)	11.7±0.03µs	14.7±0.06µs	+25.64%
RegExp Literal (Parser)	10.2±0.03µs	10.2±0.03µs	0.00%
RegExp Literal Creation (Compiler)	1595.9±3.89ns	1588.5±5.74ns	-0.46%
RegExp Literal Creation (Execution)	8.6±0.03µs	9.9±0.03µs	+15.12%
RegExp Literal Creation (Parser)	8.0±0.02µs	8.1±0.02µs	+1.25%
Static Object Property Access (Compiler)	1612.5±8.76ns	1562.1±4.58ns	-3.13%
Static Object Property Access (Execution)	4.8±0.02µs	5.5±0.02µs	+14.58%
Static Object Property Access (Parser)	12.5±0.05µs	12.6±0.07µs	+0.80%
String Object Access (Compiler)	1464.1±5.35ns	1477.6±4.90ns	+0.92%
String Object Access (Execution)	6.3±0.03µs	8.4±0.12µs	+33.33%
String Object Access (Parser)	16.3±0.07µs	16.5±0.04µs	+1.23%
String comparison (Compiler)	2.3±0.01µs	2.4±0.01µs	+4.35%
String comparison (Execution)	4.2±0.02µs	4.7±0.01µs	+11.90%
String comparison (Parser)	13.5±0.01µs	13.9±0.05µs	+2.96%
String concatenation (Compiler)	1775.7±8.11ns	1775.3±8.22ns	-0.02%
String concatenation (Execution)	4.0±0.01µs	4.4±0.01µs	+10.00%
String concatenation (Parser)	9.5±0.03µs	9.7±0.05µs	+2.11%
String copy (Compiler)	1430.3±3.46ns	1468.6±6.57ns	+2.68%
String copy (Execution)	3.7±0.01µs	4.2±0.02µs	+13.51%
String copy (Parser)	7.2±0.03µs	7.4±0.04µs	+2.78%
Symbols (Compiler)	1067.6±10.94ns	1063.0±2.52ns	-0.43%
Symbols (Execution)	3.8±0.02µs	4.3±0.01µs	+13.16%
Symbols (Parser)	5.7±0.02µs	5.8±0.06µs	+1.75%