Changeset 36695 in webkit for trunk/JavaScriptCore/VM/CodeBlock.cpp

Timestamp:

Sep 19, 2008, 8:00:43 PM (17 years ago)

Author:

[email protected]

Message:

Improve peformance of local variable initialisation.

Reviewed by Maciej Stachowiak

Pull local and constant initialisation out of slideRegisterWindowForCall
and into its own opcode. This allows the JIT to generate the initialisation
code for a function directly into the instruction stream and so avoids a few
branches on function entry.

Results a 1% progression in SunSpider, particularly in a number of the bitop
tests where the called functions are very fast.

File:

• trunk/JavaScriptCore/VM/CodeBlock.cpp (modified) (1 diff)

trunk/JavaScriptCore/VM/CodeBlock.cpp

@@ -352 +352 @@
     int location = it - begin;
     switch (exec->machine()->getOpcodeID(it->u.opcode)) {
+        case op_initialise_locals: {
+            printf("[%4d] initialise_locals\n", location);
+            break;
+        }
         case op_unexpected_load: {
             int r0 = (++it)->u.operand;