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// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "platform/globals.h"
#if defined(DART_HOST_OS_WINDOWS)
#include "platform/floating_point_win.h"
#include <limits> // NOLINT
// Taken from third_party/v8/src/platform-win32.cc
double fmod_ieee(double x, double y) {
// x is dividend, y is divisor.
// Work around MS fmod bugs. ISO Standard says:
// If dividend is finite and divisor is an infinity or
// dividend is a zero and divisor is nonzero finite,
// then dividend is returned.
if (!(_finite(x) && (!_finite(y) && !isnan(y))) &&
!(x == 0 && (y != 0 && _finite(y)))) {
x = fmod(x, y);
}
return x;
}
// Bring MSVC atan2 behavior in line with ISO standard.
// MSVC atan2 returns NaN when x and y are either +infinity or -infinity.
// Per ISO standard:
// - If y is +/-infinity and x is -infinity, +/-3*pi/4 is returned.
// - If y is +/-infinity and x is +infinity, +/-pi/4 is returned.
double atan2_ieee(double x, double y) {
int cls_x = _fpclass(x);
int cls_y = _fpclass(y);
if (((cls_x & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0) &&
((cls_y & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0)) {
// atan2 values at infinities listed above are the same as values at (+/-1,
// +/-1). index_x is 0, when x is +infinity, 1 when x is -infinity. Same is
// with index_y.
int index_x = (cls_x & _FPCLASS_PINF) != 0 ? 0 : 1;
int index_y = (cls_y & _FPCLASS_PINF) != 0 ? 0 : 1;
static double atans_at_infinities[2][2] = {
{atan2(1., 1.), atan2(1., -1.)}, {atan2(-1., 1.), atan2(-1., -1.)}};
return atans_at_infinities[index_x][index_y];
} else {
return atan2(x, y);
}
}
#endif // defined(DART_HOST_OS_WINDOWS)