From ec8b7d3e62e8f4d07997ab171d745ec81f57926d Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Tue, 9 Jun 2015 18:13:13 +0200
Subject: [PATCH] lib: fix expensive isNaN call in readable streams

Replace a call to `isNaN(n)` with `n !== n`.  Removes most of the
overhead from the following hotspot:

    13.59%  iojs             perf-603.map         [.] LazyCompile:*isNaN
    native v8natives.js:67
---
 lib/_stream_readable.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index bebbc80e2bf8dc..804b46e1f47d8d 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -211,7 +211,7 @@ function howMuchToRead(n, state) {
   if (state.objectMode)
     return n === 0 ? 0 : 1;
 
-  if (n === null || isNaN(n)) {
+  if (n === null || n !== n) {
     // only flow one buffer at a time
     if (state.flowing && state.buffer.length)
       return state.buffer[0].length;