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100 lines
2.5 KiB
100 lines
2.5 KiB
"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.convertToNumber = convertToNumber;
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exports.roundToFloat16Bits = roundToFloat16Bits;
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var _primordials = require("./primordials.cjs");
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const buffer = new _primordials.NativeArrayBuffer(4);
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const floatView = new _primordials.NativeFloat32Array(buffer);
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const uint32View = new _primordials.NativeUint32Array(buffer);
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const baseTable = new _primordials.NativeUint32Array(512);
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const shiftTable = new _primordials.NativeUint32Array(512);
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for (let i = 0; i < 256; ++i) {
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const e = i - 127;
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if (e < -27) {
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baseTable[i] = 0x0000;
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baseTable[i | 0x100] = 0x8000;
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shiftTable[i] = 24;
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shiftTable[i | 0x100] = 24;
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} else if (e < -14) {
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baseTable[i] = 0x0400 >> -e - 14;
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baseTable[i | 0x100] = 0x0400 >> -e - 14 | 0x8000;
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shiftTable[i] = -e - 1;
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shiftTable[i | 0x100] = -e - 1;
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} else if (e <= 15) {
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baseTable[i] = e + 15 << 10;
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baseTable[i | 0x100] = e + 15 << 10 | 0x8000;
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shiftTable[i] = 13;
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shiftTable[i | 0x100] = 13;
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} else if (e < 128) {
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baseTable[i] = 0x7c00;
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baseTable[i | 0x100] = 0xfc00;
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shiftTable[i] = 24;
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shiftTable[i | 0x100] = 24;
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} else {
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baseTable[i] = 0x7c00;
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baseTable[i | 0x100] = 0xfc00;
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shiftTable[i] = 13;
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shiftTable[i | 0x100] = 13;
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}
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}
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function roundToFloat16Bits(num) {
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floatView[0] = num;
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const f = uint32View[0];
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const e = f >> 23 & 0x1ff;
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return baseTable[e] + ((f & 0x007fffff) >> shiftTable[e]);
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}
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const mantissaTable = new _primordials.NativeUint32Array(2048);
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const exponentTable = new _primordials.NativeUint32Array(64);
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const offsetTable = new _primordials.NativeUint32Array(64);
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for (let i = 1; i < 1024; ++i) {
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let m = i << 13;
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let e = 0;
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while ((m & 0x00800000) === 0) {
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m <<= 1;
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e -= 0x00800000;
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}
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m &= ~0x00800000;
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e += 0x38800000;
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mantissaTable[i] = m | e;
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}
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for (let i = 1024; i < 2048; ++i) {
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mantissaTable[i] = 0x38000000 + (i - 1024 << 13);
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}
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for (let i = 1; i < 31; ++i) {
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exponentTable[i] = i << 23;
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}
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exponentTable[31] = 0x47800000;
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exponentTable[32] = 0x80000000;
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for (let i = 33; i < 63; ++i) {
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exponentTable[i] = 0x80000000 + (i - 32 << 23);
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}
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exponentTable[63] = 0xc7800000;
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for (let i = 1; i < 64; ++i) {
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if (i !== 32) {
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offsetTable[i] = 1024;
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}
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}
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function convertToNumber(float16bits) {
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const m = float16bits >> 10;
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uint32View[0] = mantissaTable[offsetTable[m] + (float16bits & 0x3ff)] + exponentTable[m];
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return floatView[0];
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} |