[csa] Move NumberIsNaN to Torque

This CL implements NumberIsNaN in Torque and removes it from the
CodeStubAssembler. It is currently used in TypedArray.p.sort and
Array.p.sort.

R=jgruber@chromium.org

Change-Id: Iaaa81901f89c0df68997d4501607b302a0449012
Reviewed-on: https://chromium-review.googlesource.com/1092532
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53611}

src/builtins/base.tq

@@ -200,6 +200,7 @@ extern operator '<=' macro IntPtrLessThanOrEqual(intptr, intptr): bool;
 extern operator '>=' macro IntPtrGreaterThanOrEqual(intptr, intptr): bool;
 
 extern operator '==' macro Float64Equal(float64, float64): bool;
+extern operator '!=' macro Float64NotEqual(float64, float64): bool;
 
 extern operator
 '<' macro BranchIfNumberLessThan(Number, Number): never labels Taken, NotTaken;
@@ -449,5 +450,12 @@ extern macro IsCallable(HeapObject): bool;
 extern macro IsJSArray(HeapObject): bool;
 extern macro TaggedIsCallable(Object): bool;
 extern macro IsDetachedBuffer(JSArrayBuffer): bool;
+extern macro IsHeapNumber(HeapObject): bool;
 
-extern macro NumberIsNaN(Number): bool;
+// Return true iff number is NaN.
+macro NumberIsNaN(number: Number): bool {
+  if (TaggedIsSmi(number)) return false;
+
+  let value: float64 = convert<float64>(unsafe_cast<HeapNumber>(number));
+  return value != value;
+}

src/code-stub-assembler.cc

@@ -11937,26 +11937,5 @@ void CodeStubAssembler::InitializeFunctionContext(Node* native_context,
                                     native_context);
 }
 
-TNode<BoolT> CodeStubAssembler::NumberIsNaN(TNode<Number> value) {
-  Label is_heapnumber(this), done(this);
-  TVARIABLE(BoolT, result);
-
-  GotoIf(TaggedIsNotSmi(value), &is_heapnumber);
-  result = Int32FalseConstant();
-  Goto(&done);
-
-  BIND(&is_heapnumber);
-  {
-    CSA_ASSERT(this, IsHeapNumber(CAST(value)));
-
-    TNode<Float64T> value_f = LoadHeapNumberValue(CAST(value));
-    result = Float64NotEqual(value_f, value_f);
-    Goto(&done);
-  }
-
-  BIND(&done);
-  return result.value();
-}
-
 }  // namespace internal
 }  // namespace v8

src/code-stub-assembler.h

@@ -290,10 +290,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
     return CAST(result);
   }
 
-  // Returns true iff number is NaN.
-  // TOOD(szuend): Remove when UncheckedCasts are supported in Torque.
-  TNode<BoolT> NumberIsNaN(TNode<Number> number);
-
   Node* MatchesParameterMode(Node* value, ParameterMode mode);
 
 #define PARAMETER_BINOP(OpName, IntPtrOpName, SmiOpName) \