| // 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) |