Changeset 42065 in webkit for trunk/JavaScriptCore/jit/JIT.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/jit/JIT.cpp (modified) (1 diff)

trunk/JavaScriptCore/jit/JIT.cpp

@@ -820 +820 @@
             NEXT_OPCODE(op_jneq_null);
         }
+        case op_jneq_ptr: {
+            unsigned src = currentInstruction[1].u.operand;
+            JSCell* ptr = currentInstruction[2].u.jsCell;
+            unsigned target = currentInstruction[3].u.operand;
+            
+            emitGetVirtualRegister(src, regT0);
+            addJump(branchPtr(NotEqual, regT0, ImmPtr(JSValuePtr::encode(JSValuePtr(ptr)))), target + 3);            
+
+            RECORD_JUMP_TARGET(target + 3);
+            NEXT_OPCODE(op_jneq_ptr);
+        }
         case op_post_inc: {
             compileFastArith_op_post_inc(currentInstruction[1].u.operand, currentInstruction[2].u.operand);