Restore saved caller FP registers on stub failure

src/arguments.cc

 // Copyright 2013 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:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
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@@ skipping 98 matching lines @@
 FOR_EACH_CALLBACK_TABLE_MAPPING_0(WRITE_CALL_0)
 FOR_EACH_CALLBACK_TABLE_MAPPING_1(WRITE_CALL_1)
 FOR_EACH_CALLBACK_TABLE_MAPPING_2(WRITE_CALL_2)
 FOR_EACH_CALLBACK_TABLE_MAPPING_2_VOID_RETURN(WRITE_CALL_2_VOID)
 
 #undef WRITE_CALL_0
 #undef WRITE_CALL_1
 #undef WRITE_CALL_2
 #undef WRITE_CALL_2_VOID
 
+#ifdef DEBUG
+double ClobberDoubleRegisters(double x1, double x2, double x3, double x4) {

[danno, 2013/11/20 13:55:52]

This is pretty fragile. How about making this a platform-specific function that
is written in assembly? It also doesn't need to be #if DEBUG, either, the linker
will strip it if it's not used, and I prefer to compile all code if possible.

[ulan, 2013/11/20 16:20:05]

Removed DEBUG and add TODO for platform specific assembly implementation as
discussed.

On 2013/11/20 13:55:52, danno wrote:

+  return x1 * 1.01 + x2 * 2.02 + x3 * 3.03 + x4 * 4.04;
+}
+#endif
+
 
 } }  // namespace v8::internal