PPC: [undetectable] Really get comparisons of document.all right now.

src/ppc/code-stubs-ppc.cc

Index: src/ppc/code-stubs-ppc.cc
diff --git a/src/ppc/code-stubs-ppc.cc b/src/ppc/code-stubs-ppc.cc
index 0ff2beaa10d0523b6f3d222484e987d9d6532816..2457d763bad46c643d2032575b2905cf7ad8683a 100644
--- a/src/ppc/code-stubs-ppc.cc
+++ b/src/ppc/code-stubs-ppc.cc
@@ -494,8 +494,9 @@ static void EmitCheckForTwoHeapNumbers(MacroAssembler* masm, Register lhs,
   __ b(both_loaded_as_doubles);
 }
 
-
-// Fast negative check for internalized-to-internalized equality.
+// Fast negative check for internalized-to-internalized equality or receiver
+// equality. Also handles the undetectable receiver to null/undefined
+// comparison.
 static void EmitCheckForInternalizedStringsOrObjects(MacroAssembler* masm,
                                                      Register lhs, Register rhs,
                                                      Label* possible_strings,
@@ -503,7 +504,7 @@ static void EmitCheckForInternalizedStringsOrObjects(MacroAssembler* masm,
   DCHECK((lhs.is(r3) && rhs.is(r4)) || (lhs.is(r4) && rhs.is(r3)));
 
   // r5 is object type of rhs.
-  Label object_test, return_unequal, undetectable;
+  Label object_test, return_equal, return_unequal, undetectable;
   STATIC_ASSERT(kInternalizedTag == 0 && kStringTag == 0);
   __ andi(r0, r5, Operand(kIsNotStringMask));
   __ bne(&object_test, cr0);
@@ -541,6 +542,16 @@ static void EmitCheckForInternalizedStringsOrObjects(MacroAssembler* masm,
   __ bind(&undetectable);
   __ andi(r0, r8, Operand(1 << Map::kIsUndetectable));
   __ beq(&return_unequal, cr0);
+
+  // If both sides are JSReceivers, then the result is false according to
+  // the HTML specification, which says that only comparisons with null or
+  // undefined are affected by special casing for document.all.
+  __ CompareInstanceType(r5, r5, ODDBALL_TYPE);
+  __ beq(&return_equal);
+  __ CompareInstanceType(r6, r6, ODDBALL_TYPE);
+  __ bne(&return_unequal);
+
+  __ bind(&return_equal);
   __ li(r3, Operand(EQUAL));
   __ Ret();
 }