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fa26245a1c
The :mod:`math` and :mod:`cmath` implementation now require a C99 compatible ``libm`` and no longer ship with workarounds for missing acosh, asinh, expm1, and log1p functions. The changeset also removes ``_math.c`` and moves the last remaining workaround into ``_math.h``. This simplifies static builds with ``Modules/Setup`` and resolves symbol conflicts. Co-authored-by: Mark Dickinson <mdickinson@enthought.com> Co-authored-by: Brett Cannon <brett@python.org> Signed-off-by: Christian Heimes <christian@python.org>
25 lines
719 B
C
25 lines
719 B
C
/* log1p(x) = log(1+x). The log1p function is designed to avoid the
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significant loss of precision that arises from direct evaluation when x is
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small. Use the substitute from _math.h on all platforms: it includes
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workarounds for buggy handling of zeros.
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*/
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static double
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_Py_log1p(double x)
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{
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/* Some platforms supply a log1p function but don't respect the sign of
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zero: log1p(-0.0) gives 0.0 instead of the correct result of -0.0.
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To save fiddling with configure tests and platform checks, we handle the
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special case of zero input directly on all platforms.
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*/
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if (x == 0.0) {
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return x;
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}
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else {
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return log1p(x);
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}
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}
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#define m_log1p _Py_log1p
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