Fixing performance regression in issue 1787.

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index d7d1d9c3cc0c244ae4d35c770414ed5e3c0ad42f..37b519aadcda16434145e0af3896e92ad221a6df 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -6673,6 +6673,11 @@ void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
                                                         Register name,
                                                         Register r0,
                                                         Register r1) {
+  ASSERT(!elements.is(r0));
+  ASSERT(!elements.is(r1));
+  ASSERT(!name.is(r0));
+  ASSERT(!name.is(r1));
+
   // Assert that name contains a string.
   if (FLAG_debug_code) __ AbortIfNotString(name);