The R language has some hacks specifically for mingw-w64 that
were caused by our handling of NaNs in sqrt(x). R uses a
special valued NaN to mean 'Not Available' and expects it to
be retained through various calculations. Our sqrt(x) doesn't
do this, instead it normalises such a NaN (retaining sign).
From:
http://wwwf.imperial.ac.uk/~drmii/M3SC_2016/IEEE_2008_4610935.pdf
"6.2.3 NaN propagation
An operation that propagates a NaN operand to its result and
has a single NaN as an input should produce a NaN with the
payload of the input NaN if representable in the destination
format."
There might even be a slight speed-up from this too.
Thanks to Duncan Murdoch for finding the reference.
This patch adds the long double functions missing in newlib to Cygwin.
Apart from some self-written additions (exp10l, finite{f,l}, isinf{f,l},
isnan{f,l}, pow10l) the files are taken from the Mingw-w64 math lib.
Minor changes were required, e.g. substitue _WIN64 with __x86_64__ and
fixing __FLT_RPT_DOMAIN/__FLT_RPT_ERANGE for Cygwin.
Cygwin:
* math: New subdir with math functions.
* Makefile.in (VPATH): Add math subdir.
(MATH_OFILES): List of object files collected from building files in
math subdir.
(DLL_OFILES): Add $(MATH_OFILES).
${CURDIR}/libm.a: Add $(MATH_OFILES) to build.
* common.din: Add new functions from math subdir.
* i686.din: Align to new math subdir. Remove functions now commonly
available.
* x86_64.din: Ditto.
* math.h: math.h wrapper to define mingw structs used in some files in
math subdir.
* include/cygwin/version.h: Bump API minor version.
newlib:
* libc/include/complex.h: Add prototypes for complex long double
functions. Only define for Cygwin.
* libc/include/math.h: Additionally enable prototypes of long double
functions for Cygwin. Add Cygwin-only prototypes for dreml, sincosl,
exp10l and pow10l. Explain why we don't add them to newlib.
* libc/include/tgmath.h: Enable long double handling on Cygwin.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>