v8/test/js-perf-test/BigInt/bigint-util.js
Nico Hartmann ba62172b82 [js-perf-test] Performance benchmarks for BigInt left and right shift
Bug: v8:11515
Change-Id: I9379187542499439debd293dd7c7d6d02e98accd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3308709
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78213}
2021-12-02 14:16:15 +00:00

71 lines
1.9 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";
// Test configuration.
const TEST_ITERATIONS = 1000;
const SLOW_TEST_ITERATIONS = 50;
const BITS_CASES = [32, 64, 128, 256, 512, 1024, 2048, 4096, 8192];
const RANDOM_BIGINTS_MAX_BITS = 64 * 100;
const BIGINT_MAX_BITS = %BigIntMaxLengthBits();
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;
}
// Make sure it does not start with four 0-bits.
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";
s += "F".repeat(bits / 4);
return BigInt(s);
}
// Generates a random BigInt between 2^(bits-4) and 2^bits-1 (for bits > 0).
function RandomBigIntWithBits(bits) {
console.assert(bits % 4 === 0);
if (bits <= 0) {
return 0n;
}
// Make sure it does not start with four 0-bits.
let s = "0x" + RandomHexDigit(false);
bits -= 4;
// Randomly generate remaining bits.
for (; bits > 0; bits -= 4) {
s += RandomHexDigit(true);
}
return BigInt(s);
}