Add fetestexceptflag.

TS 18661-1 defines an fetestexceptflag function to test the exception
state saved in an fexcept_t object by fegetexceptflag.

This patch implements this function for glibc.  Almost all
architectures save exception state in such a way that it can be
directly ANDed with exception flag bits, so rather than having lots of
fetestexceptflag implementations that all do the same thing, the math/
implementation is made to use this generic logic (which is also OK in
the fallback case where FE_ALL_EXCEPT is zero).  The only architecture
that seems to need anything different is s390.

(fegetexceptflag and fesetexceptflag use abbreviated filenames
fgetexcptflg.c and fsetexcptflg.c.  Because we are no longer concerned
by 14-character filename limits, fetestexceptflag uses the obvious
filename fetestexceptflag.c.)

The NEWS entry is intended to be expanded along the lines given in
<https://sourceware.org/ml/libc-alpha/2016-08/msg00356.html> when
fegetmode and fesetmode are added.

Tested for x86_64, x86, mips64 and powerpc.

	* math/fetestexceptflag.c: New file.
	* sysdeps/s390/fpu/fetestexceptflag.c: Likewise.  Comment by
	Stefan Liebler.
	* math/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
	(fetestexceptflag): New function declaration.
	* manual/arith.texi (fetestexceptflag): Document function.
	* math/Versions (fetestexceptflag): New libm symbol at version
	GLIBC_2.25.
	* math/Makefile (libm-support): Add fetestexceptflag.
	(tests): Add test-fetestexceptflag.
	* math/test-fetestexceptflag.c: New file.
	* sysdeps/nacl/libm.abilist: Update.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.

4 files changed, 4 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist
index ad61a97f93..7eea14aded 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist
@@ -423,6 +423,7 @@ GLIBC_2.24 nextupf F
 GLIBC_2.24 nextupl F
 GLIBC_2.25 GLIBC_2.25 A
 GLIBC_2.25 fesetexcept F
+GLIBC_2.25 fetestexceptflag F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 __clog10l F
 GLIBC_2.4 __finitel F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist
index 85422382f6..5eb2e9bb40 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist
@@ -422,6 +422,7 @@ GLIBC_2.24 nextupf F
 GLIBC_2.24 nextupl F
 GLIBC_2.25 GLIBC_2.25 A
 GLIBC_2.25 fesetexcept F
+GLIBC_2.25 fetestexceptflag F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 __clog10l F
 GLIBC_2.4 __finitel F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist
index b2f06083db..36b8e77d47 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist
@@ -417,3 +417,4 @@ GLIBC_2.24 nextupf F
 GLIBC_2.24 nextupl F
 GLIBC_2.25 GLIBC_2.25 A
 GLIBC_2.25 fesetexcept F
+GLIBC_2.25 fetestexceptflag F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist
index e5d36a1707..2efd4ebb33 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist
@@ -98,6 +98,7 @@ GLIBC_2.24 nextupf F
 GLIBC_2.24 nextupl F
 GLIBC_2.25 GLIBC_2.25 A
 GLIBC_2.25 fesetexcept F
+GLIBC_2.25 fetestexceptflag F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 _LIB_VERSION D 0x4
 GLIBC_2.3 __clog10 F