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9e6655f810
This change also requires prefacing the math calls with std::, i.e. isinf -> std::isinf. R=asiva@google.com, koda@google.com Review URL: https://codereview.chromium.org//353403004 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@37839 260f80e4-7a28-3924-810f-c04153c831b5
48 lines
1.8 KiB
C++
48 lines
1.8 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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#include "platform/globals.h"
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#if defined(TARGET_OS_WINDOWS)
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#include <limits> // NOLINT
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// Taken from third_party/v8/src/platform-win32.cc
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double fmod_ieee(double x, double y) {
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// x is dividend, y is divisor.
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// Work around MS fmod bugs. ISO Standard says:
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// If dividend is finite and divisor is an infinity or
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// dividend is a zero and divisor is nonzero finite,
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// then dividend is returned.
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if (!(_finite(x) && (!_finite(y) && !isnan(y))) &&
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!(x == 0 && (y != 0 && _finite(y)))) {
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x = fmod(x, y);
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}
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return x;
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}
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// Bring MSVC atan2 behavior in line with ISO standard.
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// MSVC atan2 returns NaN when x and y are either +infinity or -infinity.
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// Per ISO standard:
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// - If y is +/-infinity and x is -infinity, +/-3*pi/4 is returned.
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// - If y is +/-infinity and x is +infinity, +/-pi/4 is returned.
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double atan2_ieee(double x, double y) {
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int cls_x = _fpclass(x);
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int cls_y = _fpclass(y);
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if (((cls_x & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0) &&
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((cls_y & (_FPCLASS_PINF | _FPCLASS_NINF)) != 0)) {
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// atan2 values at infinities listed above are the same as values
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// at (+/-1, +/-1). index_x is 0, when x is +infinty, 1 when x is -infinty.
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// Same is with index_y.
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int index_x = (cls_x & _FPCLASS_PINF) != 0 ? 0 : 1;
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int index_y = (cls_y & _FPCLASS_PINF) != 0 ? 0 : 1;
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static double atans_at_infinities[2][2] =
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{ { atan2(1., 1.), atan2(1., -1.) },
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{ atan2(-1., 1.), atan2(-1., -1.) } };
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return atans_at_infinities[index_x][index_y];
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} else {
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return atan2(x, y);
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}
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}
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#endif // defined(TARGET_OS_WINDOWS)
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