Cleanup: use xorps to zero out an xmm register on ia32 too.

src/ia32/disasm-ia32.cc

Index: src/ia32/disasm-ia32.cc
diff --git a/src/ia32/disasm-ia32.cc b/src/ia32/disasm-ia32.cc
index d1c869a2c2352295b30c1d60515b45a087b90e6c..7a59a4f62ac85cb88e16c5e4ca1c52d27f827f2b 100644
--- a/src/ia32/disasm-ia32.cc
+++ b/src/ia32/disasm-ia32.cc
@@ -1,4 +1,4 @@
-// Copyright 2007-2008 the V8 project authors. All rights reserved.
+// Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -981,6 +981,14 @@ int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
                            NameOfXMMRegister(regop),
                            NameOfXMMRegister(rm));
             data++;
+          } else if (f0byte == 0x57) {
+            data += 2;
+            int mod, regop, rm;
+            get_modrm(*data, &mod, &regop, &rm);
+            AppendToBuffer("xorps %s,%s",
+                           NameOfXMMRegister(regop),
+                           NameOfXMMRegister(rm));
+            data++;
           } else if ((f0byte & 0xF0) == 0x80) {
             data += JumpConditional(data, branch_hint);
           } else if (f0byte == 0xBE || f0byte == 0xBF || f0byte == 0xB6 ||