[builtins] Introduce proper Float64Atan and Float64Atan2 operators.

src/runtime/runtime-maths.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/assembler.h"
 #include "src/base/utils/random-number-generator.h"
 #include "src/bootstrapper.h"
@@ skipping 41 matching lines @@
   DCHECK(args.length() == 2);
   CONVERT_DOUBLE_ARG_CHECKED(x, 0);
   CONVERT_ARG_CHECKED(JSTypedArray, result, 1);
   CHECK(result->byte_length() == Smi::FromInt(2 * sizeof(double)));
   FixedFloat64Array* array = FixedFloat64Array::cast(result->elements());
   double* y = static_cast<double*>(array->DataPtr());
   return Smi::FromInt(fdlibm::rempio2(x, y));
 }
 
 
-static const double kPiDividedBy4 = 0.78539816339744830962;
-
-
-RUNTIME_FUNCTION(Runtime_MathAtan2) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 2);
-  isolate->counters()->math_atan2_runtime()->Increment();
-  CONVERT_DOUBLE_ARG_CHECKED(x, 0);
-  CONVERT_DOUBLE_ARG_CHECKED(y, 1);
-  double result;
-  if (std::isinf(x) && std::isinf(y)) {
-    // Make sure that the result in case of two infinite arguments
-    // is a multiple of Pi / 4. The sign of the result is determined
-    // by the first argument (x) and the sign of the second argument
-    // determines the multiplier: one or three.
-    int multiplier = (x < 0) ? -1 : 1;
-    if (y < 0) multiplier *= 3;
-    result = multiplier * kPiDividedBy4;
-  } else {
-    result = std::atan2(x, y);
-  }
-  return *isolate->factory()->NewNumber(result);
-}
-
-
 RUNTIME_FUNCTION(Runtime_MathExpRT) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   isolate->counters()->math_exp_runtime()->Increment();
 
   CONVERT_DOUBLE_ARG_CHECKED(x, 0);
   lazily_initialize_fast_exp(isolate);
   return *isolate->factory()->NewNumber(fast_exp(x, isolate));
 }
 
@@ skipping 90 matching lines @@
     base::RandomNumberGenerator::XorShift128(&state0, &state1);
     array[i] = base::RandomNumberGenerator::ToDouble(state0, state1);
   }
   // Persist current state.
   array[kState0Offset] = uint64_to_double(state0);
   array[kState1Offset] = uint64_to_double(state1);
   return *typed_array;
 }
 }  // namespace internal
 }  // namespace v8