Changeset 59355 in webkit for trunk/JavaScriptCore/runtime

Timestamp:

May 13, 2010, 2:36:54 AM (15 years ago)

Author:

[email protected]

Message:

2010-05-13 Maciej Stachowiak <​[email protected]>

Reviewed by Mark Rowe.

Various JavaScript string optimizations
​https://bugs.webkit.org/show_bug.cgi?id=39051

Approximately 1% SunSpider speedup.

• runtime/ArrayPrototype.cpp: (JSC::arrayProtoFuncJoin): Remove branches from the hot code path by moving the first pass outside the loop, and duplicating the hot loop to extract the loop-invariant branch.
• runtime/RegExp.cpp: (JSC::RegExp::match): resize ovector to 0 instead of clearing to avoid thrash in case of large matches.
• runtime/RegExpConstructor.h: (JSC::RegExpConstructor::performMatch): Mark ALWAYS_INLINE to make the compiler respect our authority.
• runtime/StringPrototype.cpp: (JSC::jsSpliceSubstringsWithSeparators): Inline. (JSC::stringProtoFuncSubstring): Rewrite boundary condition checks to reduce the number of floating point comparisons and branches.

Location:

trunk/JavaScriptCore/runtime

Files:

• ArrayPrototype.cpp (modified) (1 diff)
• RegExp.cpp (modified) (2 diffs)
• RegExpConstructor.h (modified) (1 diff)
• StringPrototype.cpp (modified) (2 diffs)

trunk/JavaScriptCore/runtime/ArrayPrototype.cpp

@@ -272 +272 @@
     if (isJSArray(&exec->globalData(), thisObj)) {
         JSArray* array = asArray(thisObj);
-        for (; k < length; k++) {
-            if (!array->canGetIndex(k))
-                break;
-            if (k >= 1) {
-                if (separator.isNull())
-                    strBuffer.append(',');
-                else
-                    strBuffer.append(separator);
-            }
+
+        if (length) {
+            if (!array->canGetIndex(k)) 
+                goto skipFirstLoop;
             JSValue element = array->getIndex(k);
             if (!element.isUndefinedOrNull())
                 strBuffer.append(element.toString(exec));
-        }
-    }
+            k++;
+        }
+
+        if (separator.isNull()) {
+            for (; k < length; k++) {
+                if (!array->canGetIndex(k))
+                    break;
+                strBuffer.append(',');
+                JSValue element = array->getIndex(k);
+                if (!element.isUndefinedOrNull())
+                    strBuffer.append(element.toString(exec));
+            }
+        } else {
+            for (; k < length; k++) {
+                if (!array->canGetIndex(k))
+                    break;
+                strBuffer.append(separator);
+                JSValue element = array->getIndex(k);
+                if (!element.isUndefinedOrNull())
+                    strBuffer.append(element.toString(exec));
+            }
+        }
+    }
+ skipFirstLoop:
     for (; k < length; k++) {
         if (k >= 1) {

trunk/JavaScriptCore/runtime/RegExp.cpp

@@ -108 +108 @@
         startOffset = 0;
     if (ovector)
-        ovector->clear();
+        ovector->resize(0);
 
     if (static_cast<unsigned>(startOffset) > s.size() || s.isNull())
@@ -132 +132 @@
         for (int j = 0; j < offsetVectorSize; ++j)
             offsetVector[j] = -1;
-
 
 #if ENABLE(YARR_JIT)

trunk/JavaScriptCore/runtime/RegExpConstructor.h

@@ -110 +110 @@
       e.g., RegExp.lastMatch and RegExp.leftParen.
     */
-    inline void RegExpConstructor::performMatch(RegExp* r, const UString& s, int startOffset, int& position, int& length, int** ovector)
+    ALWAYS_INLINE void RegExpConstructor::performMatch(RegExp* r, const UString& s, int startOffset, int& position, int& length, int** ovector)
     {
         position = r->match(s, startOffset, &d->tempOvector());

trunk/JavaScriptCore/runtime/StringPrototype.cpp

@@ -246 +246 @@
 };
 
-JSValue jsSpliceSubstringsWithSeparators(ExecState* exec, JSString* sourceVal, const UString& source, const StringRange* substringRanges, int rangeCount, const UString* separators, int separatorCount);
-JSValue jsSpliceSubstringsWithSeparators(ExecState* exec, JSString* sourceVal, const UString& source, const StringRange* substringRanges, int rangeCount, const UString* separators, int separatorCount)
+static ALWAYS_INLINE JSValue jsSpliceSubstringsWithSeparators(ExecState* exec, JSString* sourceVal, const UString& source, const StringRange* substringRanges, int rangeCount, const UString* separators, int separatorCount)
 {
     if (rangeCount == 1 && separatorCount == 0) {
@@ -755 +754 @@
 
     double start = a0.toNumber(exec);
-    double end = a1.toNumber(exec);
-    if (isnan(start))
+    double end;
+    if (!(start >= 0)) // check for negative values or NaN
         start = 0;
-    if (isnan(end))
-        end = 0;
-    if (start < 0)
-        start = 0;
-    if (end < 0)
-        end = 0;
-    if (start > len)
+    else if (start > len)
         start = len;
-    if (end > len)
-        end = len;
     if (a1.isUndefined())
         end = len;
+    else { 
+        end = a1.toNumber(exec);
+        if (!(end >= 0)) // check for negative values or NaN
+            end = 0;
+        else if (end > len)
+            end = len;
+    }
     if (start > end) {
         double temp = end;