Changeset 42065 in webkit for trunk/JavaScriptCore/interpreter/Interpreter.cpp

Timestamp:

Mar 27, 2009, 8:50:39 PM (16 years ago)

Author:

[email protected]

Message:

Improve performance of Function.prototype.call
<​https://bugs.webkit.org/show_bug.cgi?id=24907>

Reviewed by Gavin Barraclough

Optimistically assume that expression.call(..) is going to be a call to
Function.prototype.call, and handle it specially to attempt to reduce the
degree of VM reentrancy.

When everything goes right this removes the vm reentry improving .call()
by around a factor of 10.

File:

• trunk/JavaScriptCore/interpreter/Interpreter.cpp (modified) (1 diff)

trunk/JavaScriptCore/interpreter/Interpreter.cpp

@@ -2667 +2667 @@
         NEXT_INSTRUCTION();
     }
+    DEFINE_OPCODE(op_jneq_ptr) {
+        /* jneq_ptr src(r) ptr(jsCell) target(offset)
+         
+           Jumps to offset target from the current instruction, if the value r is equal
+           to ptr, using pointer equality.
+         */
+        int src = (++vPC)->u.operand;
+        JSValuePtr ptr = JSValuePtr((++vPC)->u.jsCell);
+        int target = (++vPC)->u.operand;
+        JSValuePtr srcValue = callFrame[src].jsValue(callFrame);
+        if (srcValue != ptr) {
+            vPC += target;
+            NEXT_INSTRUCTION();
+        }
+
+        ++vPC;
+        NEXT_INSTRUCTION();
+    }
     DEFINE_OPCODE(op_loop_if_less) {
         /* loop_if_less src1(r) src2(r) target(offset)