S390: [stubs] Split ToNumberStub into reusable subparts.

src/s390/code-stubs-s390.cc

Index: src/s390/code-stubs-s390.cc
diff --git a/src/s390/code-stubs-s390.cc b/src/s390/code-stubs-s390.cc
index 95eaec12443cb239c9da224c51561608cee8c4ee..177505fb16b83bbbaa7e5f94d978a998820c109a 100644
--- a/src/s390/code-stubs-s390.cc
+++ b/src/s390/code-stubs-s390.cc
@@ -2712,10 +2712,9 @@ void SubStringStub::Generate(MacroAssembler* masm) {
 
 void ToNumberStub::Generate(MacroAssembler* masm) {
   // The ToNumber stub takes one argument in r2.
-  Label not_smi;
-  __ JumpIfNotSmi(r2, &not_smi);
-  __ b(r14);
-  __ bind(&not_smi);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ TestIfSmi(r2);
+  __ Ret(eq);
 
   __ CompareObjectType(r2, r3, r3, HEAP_NUMBER_TYPE);
   // r2: receiver
@@ -2725,19 +2724,19 @@ void ToNumberStub::Generate(MacroAssembler* masm) {
   __ Ret();
   __ bind(&not_heap_number);
 
-  Label not_string, slow_string;
-  __ CmpLogicalP(r3, Operand(FIRST_NONSTRING_TYPE));
-  __ bge(&not_string, Label::kNear);
-  // Check if string has a cached array index.
-  __ LoadlW(r4, FieldMemOperand(r2, String::kHashFieldOffset));
-  __ AndP(r0, r4, Operand(String::kContainsCachedArrayIndexMask));
-  __ bne(&slow_string, Label::kNear);
-  __ IndexFromHash(r4, r2);
-  __ b(r14);
-  __ bind(&slow_string);
-  __ push(r2);  // Push argument.
-  __ TailCallRuntime(Runtime::kStringToNumber);
-  __ bind(&not_string);
+  NonNumberToNumberStub stub(masm->isolate());
+  __ TailCallStub(&stub);
+}
+
+void NonNumberToNumberStub::Generate(MacroAssembler* masm) {
+  // The NonNumberToNumber stub takes one argument in r2.
+  __ AssertNotNumber(r2);
+
+  __ CompareObjectType(r2, r3, r3, FIRST_NONSTRING_TYPE);
+  // r2: receiver
+  // r3: receiver instance type
+  StringToNumberStub stub(masm->isolate());
+  __ TailCallStub(&stub, lt);
 
   Label not_oddball;
   __ CmpP(r3, Operand(ODDBALL_TYPE));
@@ -2750,6 +2749,23 @@ void ToNumberStub::Generate(MacroAssembler* masm) {
   __ TailCallRuntime(Runtime::kToNumber);
 }
 
+void StringToNumberStub::Generate(MacroAssembler* masm) {
+  // The StringToNumber stub takes one argument in r2.
+  __ AssertString(r2);
+
+  // Check if string has a cached array index.
+  Label runtime;
+  __ LoadlW(r4, FieldMemOperand(r2, String::kHashFieldOffset));
+  __ And(r0, r4, Operand(String::kContainsCachedArrayIndexMask));
+  __ bne(&runtime);
+  __ IndexFromHash(r4, r2);
+  __ Ret();
+
+  __ bind(&runtime);
+  __ push(r2);  // Push argument.
+  __ TailCallRuntime(Runtime::kStringToNumber);
+}
+
 void ToLengthStub::Generate(MacroAssembler* masm) {
   // The ToLength stub takes one argument in r2.
   Label not_smi;