Changeset 27748 in webkit for trunk/JavaScriptCore

Timestamp:

Nov 13, 2007, 12:05:03 AM (18 years ago)

Author:

[email protected]

Message:

Reviewed by Sam Weinig.

Fixed ​http://bugs.webkit.org/show_bug.cgi?id=15958
base64 spends 1.1% of total time checking for special Infinity case

Use a fast character test instead of calling strncmp.

1.1% speedup on string-base64. SunSpider reports a .4% speedup overall;
Sharks reports only .1%. Who are you going to believe? Huh?

• kjs/ustring.cpp: (KJS::UString::toDouble):

Location:

trunk/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• kjs/ustring.cpp (modified) (1 diff)

trunk/JavaScriptCore/ChangeLog

@@ +1 @@
+2007-11-12  Geoffrey Garen  <[email protected]>
+
+        Reviewed by Sam Weinig.
+        
+        Fixed http://bugs.webkit.org/show_bug.cgi?id=15958
+        base64 spends 1.1% of total time checking for special Infinity case
+        
+        Use a fast character test instead of calling strncmp.
+        
+        1.1% speedup on string-base64. SunSpider reports a .4% speedup overall;
+        Sharks reports only .1%. Who are you going to believe? Huh?
+
+        * kjs/ustring.cpp:
+        (KJS::UString::toDouble):
+
 2007-11-12  Eric Seidel  <[email protected]>
 

trunk/JavaScriptCore/kjs/ustring.cpp

@@ -1002 +1002 @@
       // whereas the ECMA spec requires that it be converted to NaN.
 
-      if (strncmp(c, "Infinity", 8) == 0) {
+      if (c[0] == 'I' && c[1] == 'n' && c[2] == 'f' && c[3] == 'i' && c[4] == 'n' && c[5] == 'i' && c[6] == 't' && c[7] == 'y') {
         d = sign * Inf;
         c += 8;