47 lines
1.2 KiB
JavaScript
47 lines
1.2 KiB
JavaScript
|
// Copyright 2019 the V8 project authors. All rights reserved.
|
||
|
|
// Use of this source code is governed by a BSD-style license that can be
|
||
|
|
// found in the LICENSE file.
|
||
|
|
|
||
|
|
"use strict";
|
||
|
|
|
||
|
|
|
||
|
|
function RandomHexDigit(allow_zero) {
|
||
|
|
const chars = allow_zero ? '0123456789ABCDEF' : '123456789ABCDEF';
|
||
|
|
return chars.charAt(Math.floor(Math.random() * chars.length));
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
// Some benchmarks shall compute sums but the result must not grow in terms
|
||
|
|
// of digits. These can use "small" BigInts, which are BigInts where the most
|
||
|
|
// significant bits of a digit are 0, so it does not overflow.
|
||
|
|
function SmallRandomBigIntWithBits(bits) {
|
||
|
|
console.assert(bits % 4 === 0);
|
||
|
|
if (bits <= 0) {
|
||
|
|
return 0n;
|
||
|
|
}
|
||
|
|
|
||
|
|
let s = "0x" + RandomHexDigit(false);
|
||
|
|
bits -= 4;
|
||
|
|
// Digits are at least 32 bits long, so we round down to the next smaller
|
||
|
|
// multiple of 32 to keep the most significant digit small.
|
||
|
|
bits = Math.floor(bits / 32) * 32;
|
||
|
|
for (; bits > 0; bits -= 4) {
|
||
|
|
s += RandomHexDigit(true);
|
||
|
|
}
|
||
|
|
return BigInt(s);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
function MaxBigIntWithBits(bits) {
|
||
|
|
console.assert(bits % 4 === 0);
|
||
|
|
if (bits <= 0) {
|
||
|
|
return 0n;
|
||
|
|
}
|
||
|
|
|
||
|
|
let s = "0x";
|
||
|
|
for (; bits > 0; bits -= 4) {
|
||
|
|
s += "F";
|
||
|
|
}
|
||
|
|
return BigInt(s);
|
||
|
|
}
|