Initial commit

node_modules/fast-check/lib/arbitrary/_internals/helpers/DoubleHelpers.js

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+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.decomposeDouble = decomposeDouble;
+exports.doubleToIndex = doubleToIndex;
+exports.indexToDouble = indexToDouble;
+const ArrayInt64_1 = require("./ArrayInt64");
+const safeNegativeInfinity = Number.NEGATIVE_INFINITY;
+const safePositiveInfinity = Number.POSITIVE_INFINITY;
+const safeEpsilon = Number.EPSILON;
+const INDEX_POSITIVE_INFINITY = { sign: 1, data: [2146435072, 0] };
+const INDEX_NEGATIVE_INFINITY = { sign: -1, data: [2146435072, 1] };
+const f64 = new Float64Array(1);
+const u32 = new Uint32Array(f64.buffer, f64.byteOffset);
+function bitCastDoubleToUInt64(f) {
+    f64[0] = f;
+    return [u32[1], u32[0]];
+}
+function decomposeDouble(d) {
+    const { 0: hi, 1: lo } = bitCastDoubleToUInt64(d);
+    const signBit = hi >>> 31;
+    const exponentBits = (hi >>> 20) & 0x7ff;
+    const significandBits = (hi & 0xfffff) * 0x100000000 + lo;
+    const exponent = exponentBits === 0 ? -1022 : exponentBits - 1023;
+    let significand = exponentBits === 0 ? 0 : 1;
+    significand += significandBits / 2 ** 52;
+    significand *= signBit === 0 ? 1 : -1;
+    return { exponent, significand };
+}
+function positiveNumberToInt64(n) {
+    return [~~(n / 0x100000000), n >>> 0];
+}
+function indexInDoubleFromDecomp(exponent, significand) {
+    if (exponent === -1022) {
+        const rescaledSignificand = significand * 2 ** 52;
+        return positiveNumberToInt64(rescaledSignificand);
+    }
+    const rescaledSignificand = (significand - 1) * 2 ** 52;
+    const exponentOnlyHigh = (exponent + 1023) * 2 ** 20;
+    const index = positiveNumberToInt64(rescaledSignificand);
+    index[0] += exponentOnlyHigh;
+    return index;
+}
+function doubleToIndex(d) {
+    if (d === safePositiveInfinity) {
+        return (0, ArrayInt64_1.clone64)(INDEX_POSITIVE_INFINITY);
+    }
+    if (d === safeNegativeInfinity) {
+        return (0, ArrayInt64_1.clone64)(INDEX_NEGATIVE_INFINITY);
+    }
+    const decomp = decomposeDouble(d);
+    const exponent = decomp.exponent;
+    const significand = decomp.significand;
+    if (d > 0 || (d === 0 && 1 / d === safePositiveInfinity)) {
+        return { sign: 1, data: indexInDoubleFromDecomp(exponent, significand) };
+    }
+    else {
+        const indexOpposite = indexInDoubleFromDecomp(exponent, -significand);
+        if (indexOpposite[1] === 0xffffffff) {
+            indexOpposite[0] += 1;
+            indexOpposite[1] = 0;
+        }
+        else {
+            indexOpposite[1] += 1;
+        }
+        return { sign: -1, data: indexOpposite };
+    }
+}
+function indexToDouble(index) {
+    if (index.sign === -1) {
+        const indexOpposite = { sign: 1, data: [index.data[0], index.data[1]] };
+        if (indexOpposite.data[1] === 0) {
+            indexOpposite.data[0] -= 1;
+            indexOpposite.data[1] = 0xffffffff;
+        }
+        else {
+            indexOpposite.data[1] -= 1;
+        }
+        return -indexToDouble(indexOpposite);
+    }
+    if ((0, ArrayInt64_1.isEqual64)(index, INDEX_POSITIVE_INFINITY)) {
+        return safePositiveInfinity;
+    }
+    if (index.data[0] < 0x200000) {
+        return (index.data[0] * 0x100000000 + index.data[1]) * 2 ** -1074;
+    }
+    const postIndexHigh = index.data[0] - 0x200000;
+    const exponent = -1021 + (postIndexHigh >> 20);
+    const significand = 1 + ((postIndexHigh & 0xfffff) * 2 ** 32 + index.data[1]) * safeEpsilon;
+    return significand * 2 ** exponent;
+}