PPC: [stubs] Introduce ToNameStub to implement %_ToName.

Port a0878333

Original commit message:
    We already had hand-written optimized code for %_ToName in fullcodegen,
    but the optimizing compilers always went to the runtime for %_ToName,
    which is pretty bad for many of our builtins. So this CL moves the
    existing native code to a ToNameStub (similar to the existing
    ToStringStub), and uses the ToNameStub consistently in all compilers to
    actually implement %_ToName.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1620313004

Cr-Commit-Position: refs/heads/master@{#33476}

src/full-codegen/ppc/full-codegen-ppc.cc

@@ -3528,26 +3528,6 @@ void FullCodeGenerator::EmitToInteger(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitToName(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK_EQ(1, args->length());
-
-  // Load the argument into r3 and convert it.
-  VisitForAccumulatorValue(args->at(0));
-
-  Label convert, done_convert;
-  __ JumpIfSmi(r3, &convert);
-  STATIC_ASSERT(FIRST_NAME_TYPE == FIRST_TYPE);
-  __ CompareObjectType(r3, r4, r4, LAST_NAME_TYPE);
-  __ ble(&done_convert);
-  __ bind(&convert);
-  __ Push(r3);
-  __ CallRuntime(Runtime::kToName);
-  __ bind(&done_convert);
-  context()->Plug(r3);
-}
-
-
 void FullCodeGenerator::EmitStringCharFromCode(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/ppc/code-stubs-ppc.cc

@@ -3232,6 +3232,37 @@ void ToStringStub::Generate(MacroAssembler* masm) {
 }
 
 
+void ToNameStub::Generate(MacroAssembler* masm) {
+  // The ToName stub takes one argument in r3.
+  Label is_number;
+  __ JumpIfSmi(r3, &is_number);
+
+  STATIC_ASSERT(FIRST_NAME_TYPE == FIRST_TYPE);
+  __ CompareObjectType(r3, r4, r4, LAST_NAME_TYPE);
+  // r3: receiver
+  // r4: receiver instance type
+  __ Ret(le);
+
+  Label not_heap_number;
+  __ cmpi(r4, Operand(HEAP_NUMBER_TYPE));
+  __ bne(&not_heap_number);
+  __ bind(&is_number);
+  NumberToStringStub stub(isolate());
+  __ TailCallStub(&stub);
+  __ bind(&not_heap_number);
+
+  Label not_oddball;
+  __ cmpi(r4, Operand(ODDBALL_TYPE));
+  __ bne(&not_oddball);
+  __ LoadP(r3, FieldMemOperand(r3, Oddball::kToStringOffset));
+  __ Ret();
+  __ bind(&not_oddball);
+
+  __ push(r3);  // Push argument.
+  __ TailCallRuntime(Runtime::kToName);
+}
+
+
 void StringHelper::GenerateFlatOneByteStringEquals(MacroAssembler* masm,
                                                    Register left,
                                                    Register right,

src/ppc/interface-descriptors-ppc.cc

@@ -112,6 +112,10 @@ const Register ToLengthDescriptor::ReceiverRegister() { return r3; }
 const Register ToStringDescriptor::ReceiverRegister() { return r3; }
 
 
+// static
+const Register ToNameDescriptor::ReceiverRegister() { return r3; }
+
+
 // static
 const Register ToObjectDescriptor::ReceiverRegister() { return r3; }