Changeset 34480 in webkit for trunk/JavaScriptCore

Timestamp:

Jun 10, 2008, 7:54:39 AM (17 years ago)

Author:

[email protected]

Message:

Reviewed by Darin.

​https://bugs.webkit.org/show_bug.cgi?id=16503
match limit takes at least 13% of the time on the SunSpider regexp-dna test

Make the limit test slightly more efficient. It is not clear how much of a win it is,
as the improvement on regexp-dna varies from 2.3% to 0.6% depending on what revision I
apply the patch to. Today, the win on regexp-dna was minimal, but the total win was whopping
0.5%, due to random code generation changes.

• pcre/pcre_exec.cpp: (match): Avoid loading a constant on each iteration.

Location:

trunk/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• pcre/pcre_exec.cpp (modified) (2 diffs)

trunk/JavaScriptCore/ChangeLog

@@ +1 @@
+2008-06-10  Alexey Proskuryakov  <[email protected]>
+
+        Reviewed by Darin.
+
+        https://bugs.webkit.org/show_bug.cgi?id=16503
+        match limit takes at least 13% of the time on the SunSpider regexp-dna test
+
+        Make the limit test slightly more efficient. It is not clear how much of a win it is,
+        as the improvement on regexp-dna varies from 2.3% to 0.6% depending on what revision I
+        apply the patch to. Today, the win on regexp-dna was minimal, but the total win was whopping
+        0.5%, due to random code generation changes.
+
+        * pcre/pcre_exec.cpp: (match): Avoid loading a constant on each iteration.
+
 2008-06-09  Alp Toker  <[email protected]>
 

trunk/JavaScriptCore/pcre/pcre_exec.cpp

@@ -411 +411 @@
     int min;
     bool minimize = false; /* Initialization not really needed, but some compilers think so. */
-    unsigned matchCount = 0;
+    unsigned remainingMatchCount = matchLimit;
     
     MatchStack stack;
@@ -444 +444 @@
     
 RECURSE:
-    if (++matchCount > matchLimit)
+    if (!--remainingMatchCount)
         return matchError(JSRegExpErrorHitLimit, stack);