MIRROR: javascript for 馃悳's, a tiny runtime with big ambitions
1const now = () => (typeof performance !== 'undefined' && performance.now ? performance.now() : Date.now());
2
3function readScale() {
4 if (typeof process === 'undefined' || !process || !process.argv) return 1;
5 const raw = Number(process.argv[2]);
6 return Number.isFinite(raw) && raw > 0 ? raw : 1;
7}
8
9const SCALE = readScale();
10const REPEATS = 5;
11
12function opaque(v) {
13 return v;
14}
15
16function runCase(name, rounds, fn) {
17 // Warm up once with a smaller trip count.
18 fn(Math.max(1, (rounds / 8) | 0));
19
20 const samples = [];
21 let out = 0;
22 for (let i = 0; i < REPEATS; i++) {
23 const t0 = now();
24 out = fn(rounds);
25 samples.push(now() - t0);
26 }
27
28 let best = samples[0];
29 let sum = 0;
30 for (let i = 0; i < samples.length; i++) {
31 if (samples[i] < best) best = samples[i];
32 sum += samples[i];
33 }
34 const avg = sum / samples.length;
35 console.log(`${name}: best ${best.toFixed(2)} ms, avg ${avg.toFixed(2)} ms`);
36 return { best, avg, out };
37}
38
39function reportPair(title, rounds, typedFn, unknownFn) {
40 console.log(`\n== ${title} (${rounds} rounds) ==`);
41 const typed = runCase('typed-friendly', rounds, typedFn);
42 const unknown = runCase('type-unknown ', rounds, unknownFn);
43
44 if (typed.out !== unknown.out) {
45 throw new Error(`${title}: result mismatch (${typed.out} vs ${unknown.out})`);
46 }
47
48 const ratio = unknown.best / typed.best;
49 const delta = unknown.best - typed.best;
50 const winner = ratio >= 1 ? 'typed-friendly' : 'type-unknown';
51 console.log(`speedup: ${ratio.toFixed(2)}x (winner: ${winner}, delta ${delta.toFixed(2)} ms)`);
52 return typed.out;
53}
54
55function forOfArrayTyped(rounds) {
56 const arr = [
57 1, 3, 5, 7, 9, 11, 13, 15,
58 17, 19, 21, 23, 25, 27, 29, 31,
59 33, 35, 37, 39, 41, 43, 45, 47,
60 49, 51, 53, 55, 57, 59, 61, 63
61 ];
62 let sum = 0;
63 for (let r = 0; r < rounds; r++) {
64 for (const v of arr) sum += v;
65 }
66 return sum;
67}
68
69function forOfArrayUnknown(rounds) {
70 const arr = [
71 1, 3, 5, 7, 9, 11, 13, 15,
72 17, 19, 21, 23, 25, 27, 29, 31,
73 33, 35, 37, 39, 41, 43, 45, 47,
74 49, 51, 53, 55, 57, 59, 61, 63
75 ];
76 const iterSrc = opaque(arr);
77 let sum = 0;
78 for (let r = 0; r < rounds; r++) {
79 for (const v of iterSrc) sum += v;
80 }
81 return sum;
82}
83
84function forOfStringTyped(rounds) {
85 const str = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
86 let sum = 0;
87 for (let r = 0; r < rounds; r++) {
88 for (const ch of str) sum += ch.length;
89 }
90 return sum;
91}
92
93function forOfStringUnknown(rounds) {
94 const str = opaque('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789');
95 let sum = 0;
96 for (let r = 0; r < rounds; r++) {
97 for (const ch of str) sum += ch.length;
98 }
99 return sum;
100}
101
102function arithmeticTyped(rounds) {
103 const a = 1.25;
104 const b = 3.75;
105 const c = 0.5;
106 const d = 9.125;
107 let acc = 0;
108 for (let i = 0; i < rounds; i++) {
109 acc = acc + (a * b) - (c / d) + (a + c) - (b - d);
110 }
111 return acc;
112}
113
114function arithmeticUnknown(rounds) {
115 const a = opaque(1.25);
116 const b = opaque(3.75);
117 const c = opaque(0.5);
118 const d = opaque(9.125);
119 let acc = 0;
120 for (let i = 0; i < rounds; i++) {
121 acc = acc + (a * b) - (c / d) + (a + c) - (b - d);
122 }
123 return acc;
124}
125
126function typeofGuardTyped(rounds) {
127 const x = 123;
128 let sum = 0;
129 for (let i = 0; i < rounds; i++) {
130 if (typeof x === 'number') sum += x;
131 else sum -= 1;
132 }
133 return sum;
134}
135
136function typeofGuardUnknown(rounds) {
137 const x = opaque(123);
138 let sum = 0;
139 for (let i = 0; i < rounds; i++) {
140 if (typeof x === 'number') sum += x;
141 else sum -= 1;
142 }
143 return sum;
144}
145
146const roundsForOfArray = Math.max(20000, Math.floor(70000 * SCALE));
147const roundsForOfString = Math.max(15000, Math.floor(50000 * SCALE));
148const roundsArithmetic = Math.max(500000, Math.floor(2500000 * SCALE));
149const roundsTypeof = Math.max(500000, Math.floor(3000000 * SCALE));
150
151console.log('compile-time type tracking benchmark');
152console.log(`scale: ${SCALE}`);
153console.log(`repeats: ${REPEATS}`);
154console.log('usage: ./build/ant tests/bench_type_tracking.js [scale]');
155
156let checksum = 0;
157checksum += reportPair('for..of array iterator hint', roundsForOfArray, forOfArrayTyped, forOfArrayUnknown);
158checksum += reportPair('for..of string iterator hint', roundsForOfString, forOfStringTyped, forOfStringUnknown);
159checksum += reportPair('numeric arithmetic specialization', roundsArithmetic, arithmeticTyped, arithmeticUnknown);
160checksum += reportPair('typeof guard folding', roundsTypeof, typeofGuardTyped, typeofGuardUnknown);
161
162console.log(`\nchecksum: ${checksum}`);