mirror of
https://github.com/vercel-labs/scriptc.git
synced 2026-10-21 05:50:55 +08:00
Chris Tate
0328efe2e3
- Carry exact integer facts through branches, arithmetic, and computed indexes. - Lower ascending, descending, and strided loops with guarded integer induction. - Remove proven typed-array bounds checks while preserving number semantics and target-width safety.
66 lines
2.4 KiB
TypeScript
66 lines
2.4 KiB
TypeScript
function neighbors(values: Uint32Array): number {
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const last = values.length - 1;
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let sum = 0;
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for (let i = 0; i < last; i++) sum += values[i] ^ values[i + 1];
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return sum;
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}
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function backwards(values: Uint32Array): number {
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let sum = 0;
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for (let i = values.length; i > 0; i--) sum += values[i - 1];
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return sum;
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}
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function strided(values: Uint32Array): number {
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let sum = 0;
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for (let i = 1; i < values.length; i += 2) sum += values[i] + values[i - 1];
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return sum;
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}
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for (const length of [0, 1, 2, 7, 16]) {
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const values = new Uint32Array(length);
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for (let i = 0; i < values.length; i++) values[i] = Math.imul(i, 17);
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console.log("bounds", length, neighbors(values), backwards(values), strided(values));
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}
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function changedReceiver(): string {
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let values = new Uint32Array(8);
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const length = values.length;
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values = new Uint32Array([1, 2]);
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for (let i = 0; i < length; i++) values[i] = i + 10;
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return Array.from(values).join(",");
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}
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function replacedInBody(): string {
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let values = new Uint32Array([1, 2, 3]);
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const saved = values;
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const replacement = new Uint32Array(1);
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for (let i = 0; i < values.length; i++) values[i] = (values = replacement, i + 5);
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return `${Array.from(saved).join(",")}/${Array.from(replacement).join(",")}`;
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}
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console.log("replacement", changedReceiver(), replacedInBody());
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function shortOutput(values: Uint32Array): string {
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const out = new Uint32Array(2);
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for (let i = 0; i < values.length; i++) out[i] = values[i] + 7;
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return Array.from(out).join(",");
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}
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console.log("output", shortOutput(new Uint32Array([1, 2, 3, 4])));
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const backing = new Uint32Array([1, 2, 3, 4, 5, 6]);
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const input = backing.subarray(0, 4);
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const output = backing.subarray(1, 5);
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for (let i = 0; i < input.length; i++) output[i] = input[i] + 10;
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console.log("overlap", Array.from(backing).join(","));
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function wideIndex(input: number): string {
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const values = new Uint32Array([1, 2]);
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let index = input >>> 0;
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values[index + 4294967296] = 77;
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values[-(index + 4294967296)] = 66;
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if ((index & 1) === 0) index += 4294967296;
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else index = -index;
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values[index] = 99;
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values[index + 1] = 88;
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return Array.from(values).join(",");
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}
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console.log("wide", wideIndex(0), wideIndex(1));
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function roundedOffset(): string {
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const values = new Uint32Array(4);
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for (let i = 0; i < values.length; i++) values[(i + 9007199254740991) - 9007199254740991] = i + 10;
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return Array.from(values).join(",");
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}
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console.log("rounded-offset", roundedOffset());
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