[strong] Disallow implicit conversions for comparison

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 6133281a6354f9c85da42917b7eab9c169ad4295..4bd2687e90f4ad705ea495c1a10636b621f96113 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -93,9 +93,8 @@ void InternalArrayNArgumentsConstructorStub::InitializeDescriptor(
 #define __ ACCESS_MASM(masm)
 
 
-static void EmitIdenticalObjectComparison(MacroAssembler* masm,
-                                          Label* slow,
-                                          Condition cond);
+static void EmitIdenticalObjectComparison(MacroAssembler* masm, Label* slow,
+                                          Condition cond, bool strong);
 static void EmitSmiNonsmiComparison(MacroAssembler* masm,
                                     Register lhs,
                                     Register rhs,
@@ -238,9 +237,8 @@ void DoubleToIStub::Generate(MacroAssembler* masm) {
 // Handle the case where the lhs and rhs are the same object.
 // Equality is almost reflexive (everything but NaN), so this is a test
 // for "identity and not NaN".
-static void EmitIdenticalObjectComparison(MacroAssembler* masm,
-                                          Label* slow,
-                                          Condition cond) {
+static void EmitIdenticalObjectComparison(MacroAssembler* masm, Label* slow,
+                                          Condition cond, bool strong) {
   Label not_identical;
   Label heap_number, return_equal;
   __ cmp(r0, r1);
@@ -251,10 +249,20 @@ static void EmitIdenticalObjectComparison(MacroAssembler* masm,
   // They are both equal and they are not both Smis so both of them are not
   // Smis.  If it's not a heap number, then return equal.
   if (cond == lt || cond == gt) {
+    // Call runtime on identical JSObjects.
     __ CompareObjectType(r0, r4, r4, FIRST_SPEC_OBJECT_TYPE);
     __ b(ge, slow);
+    // Call runtime on identical symbols since we need to throw a TypeError.
     __ cmp(r4, Operand(SYMBOL_TYPE));
     __ b(eq, slow);
+    if (strong) {
+      // Call the runtime on anything that is converted in the semantics, since
+      // we need to throw a TypeError. Smis have already been ruled out.
+      __ cmp(r4, Operand(HEAP_NUMBER_TYPE));
+      __ b(eq, &return_equal);
+      __ tst(r4, Operand(kIsNotStringMask));
+      __ b(ne, slow);
+    }
   } else {
     __ CompareObjectType(r0, r4, r4, HEAP_NUMBER_TYPE);
     __ b(eq, &heap_number);
@@ -262,8 +270,16 @@ static void EmitIdenticalObjectComparison(MacroAssembler* masm,
     if (cond != eq) {
       __ cmp(r4, Operand(FIRST_SPEC_OBJECT_TYPE));
       __ b(ge, slow);
+      // Call runtime on identical symbols since we need to throw a TypeError.
       __ cmp(r4, Operand(SYMBOL_TYPE));
       __ b(eq, slow);
+      if (strong) {
+        // Call the runtime on anything that is converted in the semantics,
+        // since we need to throw a TypeError. Smis and heap numbers have
+        // already been ruled out.
+        __ tst(r4, Operand(kIsNotStringMask));
+        __ b(ne, slow);
+      }
       // Normally here we fall through to return_equal, but undefined is
       // special: (undefined == undefined) == true, but
       // (undefined <= undefined) == false!  See ECMAScript 11.8.5.
@@ -561,7 +577,7 @@ void CompareICStub::GenerateGeneric(MacroAssembler* masm) {
 
   // Handle the case where the objects are identical.  Either returns the answer
   // or goes to slow.  Only falls through if the objects were not identical.
-  EmitIdenticalObjectComparison(masm, &slow, cc);
+  EmitIdenticalObjectComparison(masm, &slow, cc, strong());
 
   // If either is a Smi (we know that not both are), then they can only
   // be strictly equal if the other is a HeapNumber.
@@ -663,7 +679,7 @@ void CompareICStub::GenerateGeneric(MacroAssembler* masm) {
   if (cc == eq) {
     native = strict() ? Builtins::STRICT_EQUALS : Builtins::EQUALS;
   } else {
-    native = Builtins::COMPARE;
+    native = strong() ? Builtins::COMPARE_STRONG : Builtins::COMPARE;
     int ncr;  // NaN compare result
     if (cc == lt || cc == le) {
       ncr = GREATER;
@@ -3567,7 +3583,7 @@ void CompareICStub::GenerateNumbers(MacroAssembler* masm) {
 
   __ bind(&unordered);
   __ bind(&generic_stub);
-  CompareICStub stub(isolate(), op(), CompareICState::GENERIC,
+  CompareICStub stub(isolate(), op(), strong(), CompareICState::GENERIC,
                      CompareICState::GENERIC, CompareICState::GENERIC);
   __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);