Changeset 137988 in webkit for trunk/Source/JavaScriptCore/parser/ASTBuilder.h

Timestamp:

Dec 17, 2012, 10:54:52 PM (13 years ago)

Author:

[email protected]

Message:

Constant fold !{number} in the parser
​https://bugs.webkit.org/show_bug.cgi?id=105232

Reviewed by Filip Pizlo.

Typically, we wait for hot execution and constant fold in the DFG.
However, !0 and !1 are common enough in minifiers that it can be good
to get them out of the way early, for faster/smaller parsing and startup.

• parser/ASTBuilder.h:

(JSC::ASTBuilder::createLogicalNot): !{literal} is super simple, especially
since there's no literal form of NaN or Inf.

File:

• trunk/Source/JavaScriptCore/parser/ASTBuilder.h (modified) (1 diff)

trunk/Source/JavaScriptCore/parser/ASTBuilder.h

@@ -146 +146 @@
     ExpressionNode* makeURightShiftNode(const JSTokenLocation&, ExpressionNode* left, ExpressionNode* right, bool rightHasAssignments);
 
-    ExpressionNode* createLogicalNot(const JSTokenLocation& location, ExpressionNode* expr) { return new (m_globalData) LogicalNotNode(location, expr); }
+    ExpressionNode* createLogicalNot(const JSTokenLocation& location, ExpressionNode* expr)
+    {
+        if (expr->isNumber())
+            return createBoolean(location, !static_cast<NumberNode*>(expr)->value());
+
+        return new (m_globalData) LogicalNotNode(location, expr);
+    }
     ExpressionNode* createUnaryPlus(const JSTokenLocation& location, ExpressionNode* expr) { return new (m_globalData) UnaryPlusNode(location, expr); }
     ExpressionNode* createVoid(const JSTokenLocation& location, ExpressionNode* expr)