Add V8 benchmarks

Thanks @gengjiawen for the base runner script!

Author: saghul

README.md

@@ -46,3 +46,14 @@ Eg:
 ```bash
 ./build/run_octane
 ```
+
+### V8
+
+For the V8 benchmarks Node is used as the runner:
+
+```bash
+cd v8
+node benchmark.js "QuickJS (master)" ../../quickjs/build/qjs-master "QuickJS (this PR)" ../../quickjs/build/qjs "V8 (jitless)" "v8 --jitless"
+```
+
+The script takes pairs of "name" and "command" and generates a Markdown table at the end.

v8/benchmark.js

@@ -0,0 +1,149 @@
+const { exec } = require('child_process')
+const fs = require('fs')
+const process = require('process');
+
+
+function parseResults(output) {
+  const jsonString = output.match(/\[.*\]/)
+  return jsonString ? JSON.parse(jsonString[0]) : []
+}
+
+function createMarkdownTable(results, commandNames) {
+  const benchmarks = new Set()
+
+  commandNames.forEach((name) => {
+    results[name].forEach((entry) => {
+      benchmarks.add(entry.name)
+    })
+  })
+
+  const benchmarkArray = Array.from(benchmarks)
+  const columnWidths = [Math.max(...benchmarkArray.map((b) => b.length), 37)]
+
+  commandNames.forEach((name) => {
+    const maxLength = Math.max(
+      ...results[name].map((entry) => entry.result.toString().length),
+      name.length,
+      17
+    )
+    columnWidths.push(maxLength)
+  })
+
+  let table = '| Benchmark (Higher scores are better)  '
+  commandNames.forEach((name, index) => {
+    table += `| ${name.padEnd(columnWidths[index + 1])} `
+  })
+  table += '|\n'
+
+  table += '|-' + '-'.repeat(columnWidths[0]) + '-'
+  commandNames.forEach((_, index) => {
+    table += '|-' + '-'.repeat(columnWidths[index + 1]) + '-'
+  })
+  table += '|\n'
+
+  benchmarkArray.forEach((benchmark) => {
+    const row = [`| ${benchmark.padEnd(columnWidths[0])}`]
+    commandNames.forEach((name, index) => {
+      const result = results[name].find((entry) => entry.name === benchmark)
+      row.push(
+        `| ${
+          result
+            ? result.result.toString().padEnd(columnWidths[index + 1])
+            : 'N/A'.padEnd(columnWidths[index + 1])
+        }`
+      )
+    })
+    table += `${row.join(' ')} |\n`
+  })
+
+  return table
+}
+
+function createCSV(results, commandNames) {
+  let csv = 'Benchmark,'
+  csv += commandNames.join(',') + '\n'
+
+  const benchmarks = new Set()
+
+  commandNames.forEach((name) => {
+    results[name].forEach((entry) => {
+      benchmarks.add(entry.name)
+    })
+  })
+
+  benchmarks.forEach((benchmark) => {
+    const row = [benchmark]
+    commandNames.forEach((name) => {
+      const result = results[name].find((entry) => entry.name === benchmark)
+      row.push(result ? result.result.toString() : 'N/A')
+    })
+    csv += `${row.join(',')}\n`
+  })
+
+  return csv
+}
+
+const commands = [
+  //{ name: 'V8 --jitless', command: 'v8 --jitless },
+  //{ name: 'V8', command: 'v8' },
+  //{ name: 'JSC', command: 'jsc' },
+  // Add more engines here
+]
+
+const results = {}
+
+function main() {
+    commands.forEach(({ name, command }, index) => {
+        console.log(`Running ${name}: ${command}`)
+        exec(command, (error, stdout, stderr) => {
+          if (error) {
+            console.error(`Error executing ${name}: ${error.message}`)
+            return
+          }
+      
+          const r = parseResults(stdout)
+          console.log(name, r)
+          results[name] = r
+      
+          if (Object.keys(results).length === commands.length) {
+            const markdownTable = createMarkdownTable(
+              results,
+              commands.map((cmd) => cmd.name)
+            )
+            console.log('Markdown Table:')
+            console.log(markdownTable)
+
+            /*
+            const csvContent = createCSV(
+              results,
+              commands.map((cmd) => cmd.name)
+            )
+      
+            fs.writeFileSync('benchmark_results.csv', csvContent)
+            console.log('CSV file has been saved as benchmark_results.csv')
+            */
+          }
+        })
+      })
+}
+
+let args = process.argv.slice(2)
+
+for (;;) {
+    const [ name, cmd, ...rest ] = args
+
+    if (!name || !cmd)
+        break
+
+    commands.push({
+        name,
+        command: `${cmd} combined.js`
+    })
+
+    if (!rest.length)
+        break
+
+    args = rest
+}
+
+main()