Changeset 41508 in webkit for trunk/JavaScriptCore/jit/JIT.cpp

Timestamp:

Mar 6, 2009, 8:58:36 PM (16 years ago)

Author:

[email protected]

Message:

2009-03-06 Gavin Barraclough <​[email protected]>

Reviewed by Oliver Hunt.

When preforming an op_mov, preserve any existing register mapping.

~0.5% progression on v8 tests x86-64.

• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass):

File:

• trunk/JavaScriptCore/jit/JIT.cpp (modified) (1 diff)

trunk/JavaScriptCore/jit/JIT.cpp

@@ -312 +312 @@
                 if (dst == m_lastResultBytecodeRegister)
                     killLastResultRegister();
-            } else {
+            } else if ((src == m_lastResultBytecodeRegister) || (dst == m_lastResultBytecodeRegister)) {
+                // If either the src or dst is the cached register go though
+                // get/put registers to make sure we track this correctly.
                 emitGetVirtualRegister(src, regT0);
                 emitPutVirtualRegister(dst);
+            } else {
+                // Perform the copy via regT1; do not disturb any mapping in regT0.
+                loadPtr(Address(callFrameRegister, src * sizeof(Register)), regT1);
+                storePtr(regT1, Address(callFrameRegister, dst * sizeof(Register)));
             }
             NEXT_OPCODE(op_mov);