From 58c68c2fcb37984893f3ff62991a18f5d8e04628 Mon Sep 17 00:00:00 2001
From: Brian White <mscdex@mscdex.net>
Date: Mon, 2 Oct 2017 02:58:24 -0400
Subject: [PATCH] util: use faster -0 check
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

PR-URL: https://github.com/nodejs/node/pull/15726
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Benedikt Meurer <benedikt.meurer@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
---
 benchmark/util/inspect.js | 6 +++++-
 lib/util.js               | 6 ++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/benchmark/util/inspect.js b/benchmark/util/inspect.js
index 913850690ce655..35253ac96682eb 100644
--- a/benchmark/util/inspect.js
+++ b/benchmark/util/inspect.js
@@ -22,7 +22,8 @@ const bench = common.createBenchmark(main, {
     'Error',
     'Array',
     'TypedArray',
-    'TypedArray_extra'
+    'TypedArray_extra',
+    'Number'
   ],
   option: Object.keys(opts)
 });
@@ -92,6 +93,9 @@ function main({ method, n, option }) {
       obj[Symbol('baz')] = 5;
       benchmark(n, obj, options);
       break;
+    case 'Number':
+      benchmark(n, 0, options);
+      break;
     default:
       throw new Error(`Unsupported method "${method}"`);
   }
diff --git a/lib/util.js b/lib/util.js
index c12d80de34086b..6fdae22c706b6c 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -614,8 +614,10 @@ function formatValue(ctx, value, recurseTimes, ln) {
 }
 
 function formatNumber(fn, value) {
-  // Format -0 as '-0'. Strict equality won't distinguish 0 from -0.
-  if (Object.is(value, -0))
+  // Format -0 as '-0'. A `value === -0` check won't distinguish 0 from -0.
+  // Using a division check is currently faster than `Object.is(value, -0)`
+  // as of V8 6.1.
+  if (1 / value === -Infinity)
     return fn('-0', 'number');
   return fn(`${value}`, 'number');
 }