X64 implementation: Emit correct merge code for virtual frames at CFG merges.

src/x64/codegen-x64.cc

 // Copyright 2009 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
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 108 matching lines @@
           "// Put all code in anonymous function to avoid global scope.\n"
           "(function(){"
           "  function test_if_then_else(x, y, z){"
           "    if (x) {"
           "      x = y;"
           "    } else {"
           "      x = z;"
           "    }"
           "    return x;"
           "  }"
+          "\n"
+          "  function test_recursion_with_base(x, y, z, w) {"
+          "    if (x) {"
+          "     x = x;"
+          "    } else {"
+          "      x = test_recursion_with_base(y, z, w, 0);"
+          "    }"
+          "    return x;"
+          "  }"
+          "\n"
           "  function test_local_variables(x, y){"
           "    var w; y = x; x = w; w = y; y = x; return w;"
           "  };"
           "  test_local_variables(2,3);"
           "  function test_nesting_calls(x, y, zee){return zee;};"
           "  test_local_variables("
           "      test_nesting_calls(test_local_variables(1,3), 42, 47),"
           "      test_local_variables(-25.3, 2));"
-          "  return test_if_then_else(1, 47, 39);"
+          "  return test_if_then_else(0, 46, 47);"
+          "  // return test_recursion_with_base(0, 0, 0, 47);\n"
           "})()")),
       Factory::NewStringFromAscii(CStrVector("CodeGeneratorTestScript")),
       0,
       0,
       NULL,
       NULL);
 
   Code* code_object = test_function->code();  // Local for debugging ease.
   USE(code_object);
 
@@ skipping 2407 matching lines @@
   __ addq(rsp, Immediate(2 * kPointerSize));  // remove markers
 
   // Restore frame pointer and return.
   __ pop(rbp);
   __ ret(0);
 }
 
 #undef __
 
 } }  // namespace v8::internal