Changeset 27095 in webkit for trunk/JavaScriptCore/kjs/string_object.cpp

Timestamp:

Oct 26, 2007, 12:51:25 AM (18 years ago)

Author:

darin

Message:

JavaScriptCore:

Reviewed by Maciej.

• ​http://bugs.webkit.org/show_bug.cgi?id=15703 fix numeric functions -- improve correctness and speed

Gives about 1% gain on SunSpider.

• kjs/value.h: Added toIntegerPreserveNan, removed toUInt16. (KJS::JSValue::toInt32): Changed to call getTruncatedInt32 in a way that works with both immediate and number values. (KJS::JSValue::toUInt32): Ditto.
• kjs/value.cpp: (KJS::JSValue::toInteger): Moved the logic from roundValue here, with a couple differences. One is that it now correctly returns 0 for NaN, and another is that there's no special case for 0 or infinity, since the general case already handles those correctly. (KJS::JSValue::toIntegerPreserveNaN): Added. Like toInteger, but without the check for NaN. (KJS::JSValue::toInt32SlowCase): Call toNumber instead of roundValue. The truncation done by the typecast already does the necessary truncation that roundValue was doing. (KJS::JSValue::toUInt32SlowCase): Ditto. (KJS::JSValue::toUInt16): Removed.

• kjs/internal.h: Removed roundValue.
• kjs/internal.cpp: Ditto.

• kjs/array_object.cpp: (KJS::ArrayProtoFunc::callAsFunction): Remove unneeded code to handle NaN in Array.slice; toInteger now never returns NaN as specified.

• kjs/date_object.cpp: (KJS::fillStructuresUsingTimeArgs): Replaced call to roundValue with a call to toNumber as specified. (KJS::DateProtoFunc::callAsFunction): In SetTime case, replaced call to roundValue with a call to toNumber and timeClip as specified. (KJS::DateObjectImp::construct): Removed unnecessary checks of numArgs in cases where the default behavior of toInt32 (returning 0) was already correct. Replaced call to roundValue with a call to toNumber as specified. (KJS::DateObjectFuncImp::callAsFunction): Ditto.

• kjs/math_object.cpp: (MathFuncImp::callAsFunction): Removed unnecessary special cases for the pow function that the library already handles correctly.

• kjs/number_object.cpp: (NumberProtoFunc::callAsFunction): Changed ToString to call toIntegerPreserveNaN, so we can continue to handle the NaN case differently. The real toInteger now returns 0 for NaN. Took out unneeded special case in ToFixed for undefined; was only needed because our toInteger was wrong. Same thing in ToExponential. Changed ToPrecision to call toIntegerPreserveNaN.

• kjs/string_object.cpp: (KJS::StringProtoFunc::callAsFunction): Took out CharAt and CharCodeAt special cases for undefined that were only needed because toInteger was wrong. Same in IndexOf, and was able to remove some special cases. In LastIndexOf, used toIntegerPreserveNaN, but was able to remove some special cases there too. Changed Substr implementation to preserve correct behavior with the change to toInteger and match the specification. Also made sure we weren't converting an out of range double to an int. (KJS::StringObjectFuncImp::callAsFunction): Changed constructor to just use toUInt32, because truncating toUInt32 to 16 bits is the same thing and there's no reason to have toUInt16 as a second, less-optimized function that's only called at this one call site.

• wtf/MathExtras.h: Added trunc function for Windows.

LayoutTests:

Reviewed by Maciej.

• test changes for ​http://bugs.webkit.org/show_bug.cgi?id=15703 fix numeric functions -- improve correctness and speed

• fast/js/resources/char-at.js: Updated test to expect that we get the first character if we pass NaN to charAt and charCodeAt; it's what the specification asks for and matches other browsers too.
• fast/js/char-at-expected.txt: Updated.

File:

• trunk/JavaScriptCore/kjs/string_object.cpp (modified) (6 diffs)

trunk/JavaScriptCore/kjs/string_object.cpp

@@ -458 +458 @@
     break;
   case CharAt:
-    // Other browsers treat an omitted parameter as 0 rather than NaN.
-    // That doesn't match the ECMA standard, but is needed for site compatibility.
-    dpos = a0->isUndefined() ? 0 : a0->toInteger(exec);
-    if (dpos >= 0 && dpos < len) // false for NaN
+    dpos = a0->toInteger(exec);
+    if (dpos >= 0 && dpos < len)
       u = s.substr(static_cast<int>(dpos), 1);
     else
@@ -468 +466 @@
     break;
   case CharCodeAt:
-    // Other browsers treat an omitted parameter as 0 rather than NaN.
-    // That doesn't match the ECMA standard, but is needed for site compatibility.
-    dpos = a0->isUndefined() ? 0 : a0->toInteger(exec);
-    if (dpos >= 0 && dpos < len) // false for NaN
+    dpos = a0->toInteger(exec);
+    if (dpos >= 0 && dpos < len)
       result = jsNumber(s[static_cast<int>(dpos)].unicode());
     else
@@ -486 +482 @@
   case IndexOf:
     u2 = a0->toString(exec);
-    if (a1->isUndefined())
+    dpos = a1->toInteger(exec);
+    if (dpos < 0)
       dpos = 0;
-    else {
-      dpos = a1->toInteger(exec);
-      if (dpos >= 0) { // false for NaN
-        if (dpos > len)
-          dpos = len;
-      } else
-        dpos = 0;
-    }
+    else if (dpos > len)
+      dpos = len;
     result = jsNumber(s.find(u2, static_cast<int>(dpos)));
     break;
@@ -501 +492 @@
     u2 = a0->toString(exec);
     d = a1->toNumber(exec);
-    if (a1->isUndefined() || KJS::isNaN(d))
+    dpos = a1->toIntegerPreserveNaN(exec);
+    if (dpos < 0)
+      dpos = 0;
+    else if (!(dpos <= len)) // true for NaN
       dpos = len;
-    else {
-      dpos = a1->toInteger(exec);
-      if (dpos >= 0) { // false for NaN
-        if (dpos > len)
-          dpos = len;
-      } else
-        dpos = 0;
-    }
     result = jsNumber(s.rfind(u2, static_cast<int>(dpos)));
     break;
@@ -659 +645 @@
     break;
   case Substr: {
-    double d = a0->toInteger(exec);
-    double d2 = a1->toInteger(exec);
-    if (!(d >= 0)) { // true for NaN
-      d += len;
-      if (!(d >= 0)) // true for NaN
-        d = 0;
-    }
-    if (isNaN(d2))
-      d2 = len - d;
-    else {
-      if (d2 < 0)
-        d2 = 0;
-      if (d2 > len - d)
-        d2 = len - d;
-    }
-    result = jsString(s.substr(static_cast<int>(d), static_cast<int>(d2)));
+    double start = a0->toInteger(exec);
+    double length = a1->isUndefined() ? len : a1->toInteger(exec);
+    if (start >= len)
+      return jsString("");
+    if (length < 0)
+      return jsString("");
+    if (start < 0) {
+      start += len;
+      if (start < 0)
+        start = 0;
+    }
+    if (length > len - d)
+      length = len - d;
+    result = jsString(s.substr(static_cast<int>(start), static_cast<int>(length)));
     break;
   }
@@ -853 +837 @@
     ListIterator it = args.begin();
     while (it != args.end()) {
-      unsigned short u = it->toUInt16(exec);
+      unsigned short u = it->toUInt32(exec);
       *p++ = UChar(u);
       it++;