By excluding the denormal-operand exception from FE_ALL_EXCEPT, it will not be possible anymore to UNmask this exception by means of the API defined by /usr/include/fenv.h Note: terminology has changed since IEEE Std 854-1987; denormalized numbers are called subnormal numbers nowadays. This modification has basically been motivated by the fact that it is also not possible on Linux to manipulate the denormal-operand exception by means of the interface as defined by /usr/include/fenv.h. This has been the state of affairs on Linux since 2001 (Andreas Jaeger). The exceptions required by the standard (IEEE Std 754), in case they can be supported by the implementation, are: FE_INEXACT, FE_UNDERFLOW, FE_OVERFLOW, FE_DIVBYZERO and FE_INVALID. Although it is allowed to define additional exceptions, there is no reason to support the "denormal-operand exception" in this case (fenv.h), because the subnormal numbers can be handled almost as fast the normalized numbers by the hardware of the x86/x86_64 architecture. Said differently, a reason to trap on the input of subnormal numbers does not exist. At least that is what William Kahan and others at Intel asserted around 2000. (that is William Kahan of the K-C-S draft, the precursor to the standard) This commit modifies winsup/cygwin/include/fenv.h as follows: - redefines FE_ALL_EXCEPT from 0x3f to 0x3d - removes the definition for FE_DENORMAL - introduces __FE_DENORM (0x2) (enum in Linux also uses __FE_DENORM) - introduces FE_ALL_EXCEPT_X86 (0x3f), i.e. ALL x86/x86_64 FP exceptions |
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config | ||
etc | ||
include | ||
libgloss | ||
newlib | ||
texinfo | ||
winsup | ||
.drone.yml | ||
.gitattributes | ||
.gitignore | ||
COPYING | ||
COPYING.LIB | ||
COPYING.LIBGLOSS | ||
COPYING.NEWLIB | ||
COPYING3 | ||
COPYING3.LIB | ||
ChangeLog | ||
MAINTAINERS | ||
Makefile.def | ||
Makefile.in | ||
Makefile.tpl | ||
README | ||
README-maintainer-mode | ||
compile | ||
config-ml.in | ||
config.guess | ||
config.rpath | ||
config.sub | ||
configure | ||
configure.ac | ||
depcomp | ||
djunpack.bat | ||
install-sh | ||
libtool.m4 | ||
ltgcc.m4 | ||
ltmain.sh | ||
ltoptions.m4 | ||
ltsugar.m4 | ||
ltversion.m4 | ||
lt~obsolete.m4 | ||
makefile.vms | ||
missing | ||
mkdep | ||
mkinstalldirs | ||
move-if-change | ||
setup.com | ||
src-release | ||
symlink-tree | ||
ylwrap |
README
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.