Changeset 1887 in webkit for trunk/JavaScriptCore/kjs/ustring.cpp

Timestamp:

Aug 20, 2002, 10:23:31 PM (23 years ago)

Author:

darin

Message:

Three small changes to things that showed up in the sample.

5% speed increase on cvs-js-performance test.

• kjs/simple_number.h: Check if double is an integer with d == (double)(int)d instead of remainder(d, 1) == 0, saving a function call each time.

• kjs/ustring.cpp: (UString::find): Compare the first character before calling memcmp for the rest. (UString::rfind): Ditto. (KJS::operator==): Don't do a strlen before starting to compare the characters.

File:

• trunk/JavaScriptCore/kjs/ustring.cpp (modified) (4 diffs)

trunk/JavaScriptCore/kjs/ustring.cpp

@@ -488 +488 @@
 int UString::find(const UString &f, int pos) const
 {
-  if (size() < f.size())
+  int sz = size();
+  int fsz = f.size();
+  if (sz < fsz)
     return -1;
+  if (fsz == 0)
+    return 0;
   if (pos < 0)
     pos = 0;
-  const UChar *end = data() + size() - f.size();
-  long fsize = f.size() * sizeof(UChar);
-  const void *fdata = f.data();
+  const UChar *end = data() + sz - fsz;
+  long fsizeminusone = (fsz - 1) * sizeof(UChar);
+  const UChar *fdata = f.data();
   for (const UChar *c = data() + pos; c <= end; c++)
-    if (!memcmp(c, fdata, fsize))
+    if (*c == *fdata && !memcmp(c + 1, fdata + 1, fsizeminusone))
       return (c-data());
 
@@ -516 +520 @@
 int UString::rfind(const UString &f, int pos) const
 {
-  if (size() < f.size())
+  int sz = size();
+  int fsz = f.size();
+  if (sz < fsz)
     return -1;
-  if (pos + f.size() >= size())
-    pos = size() - f.size();
-  long fsize = f.size() * sizeof(UChar);
-  const void *fdata = f.data();
+  if (fsz == 0)
+    return 0;
+  if (pos < 0)
+    pos = 0;
+  long fsizeminusone = (fsz - 1) * sizeof(UChar);
+  const UChar *fdata = f.data();
   for (const UChar *c = data() + pos; c >= data(); c--) {
-    if (!memcmp(c, fdata, fsize))
+    if (*c == *fdata && !memcmp(c + 1, fdata + 1, fsizeminusone))
       return (c-data());
   }
@@ -603 +611 @@
   }
 
-  if (s1.size() != (int)strlen(s2))
-    return false;
-
   const UChar *u = s1.data();
-  while (*s2) {
+  const UChar *uend = u + s1.size();
+  while (u != uend && *s2) {
     if (u->uc != (unsigned char)*s2)
       return false;
@@ -614 +620 @@
   }
 
-  return true;
+  return u == uend && *s2 == 0;
 }