The return value is now -NaN.
This fixes a bug in the mingw-w64 code that was imported into Cygwin.
The fix is consistent with Posix and Linux. It is also consistent
with the current mingw-w64 code, with one exception: The mingw-w64
code sets errno to EDOM if the input is -NaN, but this appears to
differ from Posix and Linux.
Addresses: https://cygwin.com/pipermail/cygwin/2020-October/246606.html
On 32 bit x86, clang seems to miss loading input parameters based
on asm constraints for inline assembly that uses the x87 floating
registers, unless the snippet has got the volatile keyword.
Signed-off-by: Martin Storsjö <martin@martin.st>
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>
Ken Brown
Martin Storsjö
Corinna Vinschen
Jozef Lawrynowicz
Ray Donnelly