[csa] Add IsNumber and IsNumberNormalized predicates

IsNumber returns true for Smi/HeapNumber arguments.

IsNumberNormalized expects a number argument and returns true if
it is either a Smi, or a HeapNumber with a value outside the Smi
range.

BUG=

Review-Url: https://codereview.chromium.org/2813623003
Cr-Commit-Position: refs/heads/master@{#44556}

src/builtins/builtins-regexp-gen.cc

@@ -249,7 +249,7 @@ Node* RegExpBuiltinsAssembler::IrregexpExec(Node* const context,
   CSA_ASSERT(this, TaggedIsNotSmi(string));
   CSA_ASSERT(this, IsString(string));
 
-  CSA_ASSERT(this, IsHeapNumberMap(LoadReceiverMap(last_index)));
+  CSA_ASSERT(this, IsNumber(last_index));
   CSA_ASSERT(this, IsFixedArrayMap(LoadReceiverMap(match_info)));
 
   Node* const int_zero = IntPtrConstant(0);
@@ -1548,12 +1548,9 @@ Node* RegExpBuiltinsAssembler::AdvanceStringIndex(Node* const string,
                                                   Node* const is_unicode,
                                                   bool is_fastpath) {
   CSA_ASSERT(this, IsString(string));
-  CSA_ASSERT(this, IsHeapNumberMap(LoadReceiverMap(index)));
+  CSA_ASSERT(this, IsNumberNormalized(index));
   if (is_fastpath) CSA_ASSERT(this, TaggedIsPositiveSmi(index));
 
-  // Default to last_index + 1.
-  // Smi range.
-
   // Default to last_index + 1.
   Node* const index_plus_one = NumberInc(index);
   VARIABLE(var_result, MachineRepresentation::kTagged, index_plus_one);
@@ -2368,7 +2365,7 @@ TF_BUILTIN(RegExpSplit, RegExpBuiltinsAssembler) {
   {
     // The runtime call passes in limit to ensure the second ToUint32(limit)
     // call is not observable.
-    CSA_ASSERT(this, IsHeapNumberMap(LoadReceiverMap(limit)));
+    CSA_ASSERT(this, IsNumber(limit));
     Return(CallRuntime(Runtime::kRegExpSplit, context, regexp, string, limit));
   }
 }

src/code-stub-assembler.cc

@@ -3152,6 +3152,35 @@ Node* CodeStubAssembler::IsJSRegExp(Node* object) {
   return HasInstanceType(object, JS_REGEXP_TYPE);
 }
 
+Node* CodeStubAssembler::IsNumber(Node* object) {
+  return Select(TaggedIsSmi(object), [=] { return Int32Constant(1); },
+                [=] { return IsHeapNumber(object); },
+                MachineRepresentation::kWord32);
+}
+
+Node* CodeStubAssembler::IsNumberNormalized(Node* number) {
+  CSA_ASSERT(this, IsNumber(number));
+
+  VARIABLE(var_result, MachineRepresentation::kWord32, Int32Constant(1));
+  Label out(this);
+
+  GotoIf(TaggedIsSmi(number), &out);
+
+  Node* const value = LoadHeapNumberValue(number);
+  Node* const smi_min = Float64Constant(static_cast<double>(Smi::kMinValue));
+  Node* const smi_max = Float64Constant(static_cast<double>(Smi::kMaxValue));
+
+  GotoIf(Float64LessThan(value, smi_min), &out);
+  GotoIf(Float64GreaterThan(value, smi_max), &out);
+  GotoIfNot(Float64Equal(value, value), &out);  // NaN.
+
+  var_result.Bind(Int32Constant(0));
+  Goto(&out);
+
+  BIND(&out);
+  return var_result.value();
+}
+
 Node* CodeStubAssembler::StringCharCodeAt(Node* string, Node* index,
                                           ParameterMode parameter_mode) {
   if (parameter_mode == SMI_PARAMETERS) CSA_ASSERT(this, TaggedIsSmi(index));

src/code-stub-assembler.h

@@ -739,6 +739,13 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   Node* IsFixedTypedArray(Node* object);
   Node* IsJSRegExp(Node* object);
 
+  // True iff |object| is a Smi or a HeapNumber.
+  Node* IsNumber(Node* object);
+
+  // True iff |number| is either a Smi, or a HeapNumber whose value is not
+  // within Smi range.
+  Node* IsNumberNormalized(Node* number);
+
   // ElementsKind helpers:
   Node* IsFastElementsKind(Node* elements_kind);
   Node* IsHoleyFastElementsKind(Node* elements_kind);