Changeset 1825 in webkit for trunk/JavaScriptCore/kjs/value.cpp

Timestamp:

Aug 15, 2002, 5:02:07 AM (23 years ago)

Author:

mjs

Message:

Phase 2 of fixnum optimization. Store any integral number that
will fit in two bits less than a long inside the ValueImp *
itself, thus avoiding the need to deal with the garbage collector
at all for these types. Such numbers comprised .5 million of the
1.7 million ValueImps created during the cvs-js-performance test,
so traffic through the garbage collector should be

20% improvement on cvs-js-performance. This may also show up on
cvs-base, but I did not compare and I am too lazy to make clean in
WebCore yet again.

This also significantly reduces memory footprint on
JavaScript-heavy pages. Size after going through
cvs-js-performance suite is now down from 22 MB to 17.5 MB.

• JavaScriptCore.pbproj/project.pbxproj:
• kjs/simple_number.h: Added. Some inline static methods for handling simple numbers that are stored in the pointer.
• kjs/ustring.h:
• kjs/ustring.cpp: (UString::from): Added new overload for long.
• kjs/value.cpp: (ValueImp::marked): Add special case for simple numbers. (ValueImp::setGcAllowed): Likewise. (ValueImp::toInteger): Call dispatch version of toUInt32(unsigned&), not the real method. (ValueImp::toInt32): Likewise. (ValueImp::toUInt32): Likewise. (ValueImp::toUInt16): Likewise. (ValueImp::dispatchType): Add special case for simple numbers. (ValueImp::dispatchToPrimitive): Likewise. (ValueImp::dispatchToBoolean): Likewise. (ValueImp::dispatchToNumber): Likewise. (ValueImp::dispatchToString): Likewise. (ValueImp::dispatchToObject): Likewise. (ValueImp::dispatchToUInt32): Likewise. (ValueImp::dispatchGetBase): Likewise. (ValueImp::dispatchGetPropertyName): Likewise. (ValueImp::dispatchPutValue): Likewise. (ValueImp::dispatchDeleteValue): Likewise. (Number::Number): Create a simple number instead of a full-blown ValueImp when possible. (Number::value): Likewise.
• kjs/value.h:

File:

• trunk/JavaScriptCore/kjs/value.cpp (modified) (9 diffs)

trunk/JavaScriptCore/kjs/value.cpp

@@ -37 +37 @@
 #include "error_object.h"
 #include "nodes.h"
+#include "simple_number.h"
 
 using namespace KJS;
@@ -64 +65 @@
 bool ValueImp::marked() const
 {
-  // FIXNUM: need special case for fixnum, they should act as if
-  // always marked.
-  return (_flags & VI_MARKED);
+  // simple numbers are always considered marked
+  return SimpleNumber::isSimpleNumber(this) || (_flags & VI_MARKED);
 }
 
 void ValueImp::setGcAllowed()
 {
-  // FIXNUM: need special case for fixnum, should be a no-op
-  //fprintf(stderr,"ValueImp::setGcAllowed %p\n",(void*)this);
-  _flags |= VI_GCALLOWED;
+  // simple numbers are never seen by the collector so setting this
+  // flag is irrelevant
+  if (!SimpleNumber::isSimpleNumber(this)) {
+    //fprintf(stderr,"ValueImp::setGcAllowed %p\n",(void*)this);
+    _flags |= VI_GCALLOWED;
+  }
 }
 
@@ -95 +98 @@
 {
   unsigned i;
-  if (toUInt32(i))
+  if (dispatchToUInt32(i))
     return (int)i;
   return int(roundValue(exec, Value(const_cast<ValueImp*>(this))));
@@ -103 +106 @@
 {
   unsigned i;
-  if (toUInt32(i))
+  if (dispatchToUInt32(i))
     return (int)i;
 
@@ -118 +121 @@
 {
   unsigned i;
-  if (toUInt32(i))
+  if (dispatchToUInt32(i))
     return i;
 
@@ -130 +133 @@
 {
   unsigned i;
-  if (toUInt32(i))
+  if (dispatchToUInt32(i))
     return (unsigned short)i;
 
@@ -181 +184 @@
 Type ValueImp::dispatchType() const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->type();
+  if (SimpleNumber::isSimpleNumber(this)) {
+    return NumberType;
+  } else {
+    return this->type();
+  }
 }
 
 Value ValueImp::dispatchToPrimitive(ExecState *exec, Type preferredType) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->toPrimitive(exec, preferredType);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    return Number((NumberImp*)this);
+  } else {
+    return this->toPrimitive(exec, preferredType);
+  }
 }
 
 bool ValueImp::dispatchToBoolean(ExecState *exec) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->toBoolean(exec);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    return SimpleNumber::longValue(this);
+  } else {
+    return this->toBoolean(exec);
+  }
 }
 
 double ValueImp::dispatchToNumber(ExecState *exec) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->toNumber(exec);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    return SimpleNumber::longValue(this);
+  } else {
+    return this->toNumber(exec);
+  }
 }
 
 UString ValueImp::dispatchToString(ExecState *exec) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->toString(exec);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    return UString::from(SimpleNumber::longValue(this));
+  } else {
+    return this->toString(exec);
+  }
 }
 
 Object ValueImp::dispatchToObject(ExecState *exec) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->toObject(exec);
+  if (SimpleNumber::isSimpleNumber(this)) {
+      List args;
+      args.append(Number(static_cast<NumberImp*>(const_cast<ValueImp *>(this))));
+      return Object::dynamicCast(exec->interpreter()->builtinNumber().construct(exec,args));
+  } else {
+    return this->toObject(exec);
+  }
 }
 
 bool ValueImp::dispatchToUInt32(unsigned& result) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->toUInt32(result);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    result = SimpleNumber::longValue(this);
+    return true;
+  } else {
+    return this->toUInt32(result);
+  }
 }
 
 Value ValueImp::dispatchGetBase(ExecState *exec) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->getBase(exec);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    Object err = Error::create(exec, ReferenceError, I18N_NOOP("Invalid reference base"));
+    exec->setException(err);
+    return err;
+  } else {
+    return this->getBase(exec);
+  }
 }
 
 UString ValueImp::dispatchGetPropertyName(ExecState *exec) const
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->getPropertyName(exec);
-}
-
-#if 0
-Value ValueImp::dispatchGetValue(ExecState *exec) const
-{
-  // FIXNUM: need special case for fixnums here 
-  return this->getValue(exec);
-}
-#endif
+  if (SimpleNumber::isSimpleNumber(this)) {
+    return UString();
+  } else {
+    return this->getPropertyName(exec);
+  }
+}
 
 void ValueImp::dispatchPutValue(ExecState *exec, const Value& w)
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->putValue(exec, w);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    Object err = Error::create(exec,ReferenceError);
+    exec->setException(err);
+  } else {
+    return this->putValue(exec, w);
+  }
 }
 
 bool ValueImp::dispatchDeleteValue(ExecState *exec)
 {
-  // FIXNUM: need special case for fixnums here 
-  return this->deleteValue(exec);
+  if (SimpleNumber::isSimpleNumber(this)) {
+    Object err = Error::create(exec,ReferenceError);
+    exec->setException(err);
+    return false;
+  } else {
+    return this->deleteValue(exec);
+  }
 }
 
@@ -372 +408 @@
 // ------------------------------ Number ---------------------------------------
 
-// FIXNUM: need fixnum special case in below constructor
 Number::Number(int i)
-  : Value(new NumberImp(static_cast<double>(i))) { }
-
-// FIXNUM: need fixnum special case in below constructor
+  : Value(SimpleNumber::fitsInSimpleNumber(i) ? SimpleNumber::makeSimpleNumber(i) : new NumberImp(static_cast<double>(i))) { }
+
 Number::Number(unsigned int u)
-  : Value(new NumberImp(static_cast<double>(u))) { }
-
-// FIXNUM: need fixnum special case in below constructor
+  : Value(SimpleNumber::fitsInSimpleNumber(u) ? SimpleNumber::makeSimpleNumber(u) : new NumberImp(static_cast<double>(u))) { }
+
 Number::Number(double d)
-  : Value(new NumberImp(d)) { }
-
-// FIXNUM: need fixnum special case in below constructor
+  : Value(SimpleNumber::fitsInSimpleNumber((long)d) ? SimpleNumber::makeSimpleNumber((long)d) : new NumberImp(d)) { }
+
 Number::Number(long int l)
-  : Value(new NumberImp(static_cast<double>(l))) { }
-
-// FIXNUM: need fixnum special case in below constructor
+  : Value(SimpleNumber::fitsInSimpleNumber(l) ? SimpleNumber::makeSimpleNumber(l) : new NumberImp(static_cast<double>(l))) { }
+
 Number::Number(long unsigned int l)
-  : Value(new NumberImp(static_cast<double>(l))) { }
+  : Value(SimpleNumber::fitsInSimpleNumber(l) ? SimpleNumber::makeSimpleNumber(l) : new NumberImp(static_cast<double>(l))) { }
 
 Number Number::dynamicCast(const Value &v)
@@ -402 +433 @@
 double Number::value() const
 {
-  assert(rep);
-  return ((NumberImp*)rep)->value();
+  if (SimpleNumber::isSimpleNumber(rep)) {
+    return (double)SimpleNumber::longValue(rep);
+  } else {
+    assert(rep);
+    return ((NumberImp*)rep)->value();
+  }
 }