TS 18661-1 adds an iscanonical classification macro to <math.h>.
The motivation for this is decimal floating-point, where some values
have both canonical and noncanonical encodings. For IEEE binary
interchange formats, all encodings are canonical. For x86/m68k
ldbl-96, and for ldbl-128ibm, there are encodings that do not
represent any valid value of the type; although formally iscanonical
does not need to handle trap representations (and so could just always
return 1), it seems useful, and in line with the description in the TS
of "representations that are extraneous to the floating-point model"
as being non-canonical (as well as "redundant representations of some
or all of its values"), for it to detect those representations and
return 0 for them.
This patch adds iscanonical to glibc. It goes in a header
<bits/iscanonical.h>, included under appropriate conditions in
<math.h>. The default header version just evaluates the argument
(converted to its semantic type, though current GCC will probably
discard that conversion and any exceptions resulting from it) and
returns 1. ldbl-96 and ldbl-128ibm then have versions of the header
that call a function __iscanonicall for long double (the sizeof-based
tests will of course need updating for float128 support, like other
such type-generic macro implementations). The ldbl-96 version of
__iscanonicall has appropriate conditionals to reflect the differences
in the m68k version of that format (where the high mantissa bit may be
either 0 or 1 when the exponent is 0 or 0x7fff). Corresponding tests
for those formats are added as well. Other architectures do not have
any new functions added because just returning 1 is correct for all
their floating-point formats.
Tested for x86_64, x86, mips64 (to test the default macro version) and
powerpc.
* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Include
<bits/iscanonical.h>.
* bits/iscanonical.h: New file.
* math/s_iscanonicall.c: Likewise.
* math/Versions (__iscanonicall): New libm symbol at version
GLIBC_2.25.
* math/libm-test.inc (iscanonical_test_data): New array.
(iscanonical_test): New function.
(main): Call iscanonical_test.
* math/Makefile (headers): Add bits/iscanonical.h.
(type-ldouble-routines): Add s_iscanonicall.
* manual/arith.texi (Floating Point Classes): Document
iscanonical.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
* sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h: New file.
* sysdeps/ieee754/ldbl-128ibm/s_iscanonicall.c: Likewise.
* sysdeps/ieee754/ldbl-128ibm/test-iscanonical-ldbl-128ibm.c:
Likewise.
* sysdeps/ieee754/ldbl-128ibm/Makefile (tests): Add
test-iscanonical-ldbl-128ibm.
* sysdeps/ieee754/ldbl-96/bits/iscanonical.h: New file.
* sysdeps/ieee754/ldbl-96/s_iscanonicall.c: Likewise.
* sysdeps/ieee754/ldbl-96/test-iscanonical-ldbl-96.c: Likewise.
* sysdeps/ieee754/ldbl-96/Makefile: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Update.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/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/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
Floating-point classification macros are supposed to remove any excess
range or precision from their arguments. This patch fixes the
non-sNaN version of iszero to do so, by casting the argument to its
own type. (This will of course work only for standard-conforming
excess precision, not for what GCC does on 32-bit x86 by default where
the back end hides excess precision from the front end; the same
applies to most of the classification macros in that case, as showed
up when we made them use GCC built-in functions.)
(iseqsig will have the reverse issue, needing to ensure that when an
underlying function is used it's for a type wide enough not to remove
any excess precision, since comparison macros must not remove excess
precision.)
Tested for x86_64 and x86.
* math/math.h
[__GLIBC_USE (IEC_60559_BFP_EXT) && !__SUPPORT_SNAN__] (iszero):
Cast argument to its own type.
* math/test-iszero-excess-precision.c: New file.
* math/Makefile (tests): Add test-iszero-excess-precision.
(CFLAGS-test-iszero-excess-precision.c): New variable.
TS 18661-1 adds an iszero classification macro to <math.h>. This
patch implements it for glibc. There are no new underlying functions
in libm because the implementation uses fpclassify when sNaN support
is required and a direct comparison otherwise; any optimizations for
this macro should be done through adding __builtin_iszero in GCC and
using it in the header for suitable GCC versions, not through adding
other optimized inline or out-of-line versions to glibc.
Tested for x86_64 and x86.
* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (iszero): New
macro.
* math/libm-test.inc (iszero_test_data): New array.
(iszero_test): New function.
(main): Call iszero_test.
* manual/arith.texi (Floating Point Classes): Document iszero.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
TS 18661-1 adds an issubnormal classification macro to <math.h>. This
patch implements it for glibc. There are no new underlying functions
in libm because the implementation uses fpclassify; any optimizations
for this macro should be done through adding __builtin_subnormal in
GCC and using it in the header for suitable GCC versions, not through
adding other optimized inline or out-of-line versions to glibc.
The intended structure of the NEWS entry for <math.h> features from TS
18661-1 is like:
* New <math.h> features are added from TS 18661-1:2014:
- Nearest integer functions: roundeven, roundevenf, roundevenl.
- Comparison macros: iseqsig.
- Classification macros: iscanonical, issubnormal, iszero.
(that is, following the grouping of interfaces in TS 18661-1:2014,
with any group where any interfaces are new in glibc 2.25 being listed
like that).
Tested for x86_64 and x86.
* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (issubnormal): New
macro.
* math/libm-test.inc (issubnormal_test_data): New array.
(issubnormal_test): New function.
* manual/arith.texi (Floating Point Classes): Document
issubnormal.
* manual/libm-err-tab.pl: Update comment on interfaces without
ulps tabulated.
This requires adding a macro to synthesize the call
to __strto*_nan. Since this is likely to be the only
usage ever for strto* functions in generated libm
calls, a dedicated macro is defined for it.
Use the GCC builtin instead. With the exception of the
files built from a template, they are unused. This
is preparation for making the s_nanF objects generated.
This one is a little more tricky since it is built both for
libm and libc, and exports multiple aliases.
To simplify aliasing, a new macro is introduced which handles
aliasing to two symbols. By default, it just applies
declare_mgen_alias to both target symbols.
Likewise, the makefile is tweaked a little to generate
templates for shared files too, and a new rule is added
to build m_*.c objects from the objpfx directory.
Verified there are no symbol or code changes using a script
to diff the *_ldexp* object files on s390x, aarch64, arm,
x86_64, and ppc64.
TS 18661-1 defines a type femode_t to represent the set of dynamic
floating-point control modes (such as the rounding mode and trap
enablement modes), and functions fegetmode and fesetmode to manipulate
those modes (without affecting other state such as the raised
exception flags) and a corresponding macro FE_DFL_MODE.
This patch series implements those interfaces for glibc. This first
patch adds the architecture-independent pieces, the x86 and x86_64
implementations, and the <bits/fenv.h> and ABI baseline updates for
all architectures so glibc keeps building and passing the ABI tests on
all architectures. Subsequent patches add the fegetmode and fesetmode
implementations for other architectures.
femode_t is generally an integer type - the same type as fenv_t, or as
the single element of fenv_t where fenv_t is a structure containing a
single integer (or the single relevant element, where it has elements
for both status and control registers) - except where architecture
properties or consistency with the fenv_t implementation indicate
otherwise. FE_DFL_MODE follows FE_DFL_ENV in whether it's a magic
pointer value (-1 cast to const femode_t *), a value that can be
distinguished from valid pointers by its high bits but otherwise
contains a representation of the desired register contents, or a
pointer to a constant variable (the powerpc case; __fe_dfl_mode is
added as an exported constant object, an alias to __fe_dfl_env).
Note that where architectures (that share a register between control
and status bits) gain definitions of new floating-point control or
status bits in future, the implementations of fesetmode for those
architectures may need updating (depending on whether the new bits are
control or status bits and what the implementation does with
previously unknown bits), just like existing implementations of
<fenv.h> functions that take care not to touch reserved bits may need
updating when the set of reserved bits changes. (As any new bits are
outside the scope of ISO C, that's just a quality-of-implementation
issue for supporting them, not a conformance issue.)
As with fenv_t, femode_t should properly include any software DFP
rounding mode (and for both fenv_t and femode_t I'd consider that
fragment of DFP support appropriate for inclusion in glibc even in the
absence of the rest of libdfp; hardware DFP rounding modes should
already be included if the definitions of which bits are status /
control bits are correct).
Tested for x86_64, x86, mips64 (hard float, and soft float to test the
fallback version), arm (hard float) and powerpc (hard float, soft
float and e500). Other architecture versions are untested.
* math/fegetmode.c: New file.
* math/fesetmode.c: Likewise.
* sysdeps/i386/fpu/fegetmode.c: Likewise.
* sysdeps/i386/fpu/fesetmode.c: Likewise.
* sysdeps/x86_64/fpu/fegetmode.c: Likewise.
* sysdeps/x86_64/fpu/fesetmode.c: Likewise.
* math/fenv.h: Update comment on inclusion of <bits/fenv.h>.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (fegetmode): New function
declaration.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (fesetmode): Likewise.
* bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (femode_t): New
typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/aarch64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/alpha/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/arm/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/hppa/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/ia64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/m68k/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/microblaze/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/mips/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/nios2/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/powerpc/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (__fe_dfl_mode): New variable
declaration.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/s390/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/sh/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/sparc/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/tile/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* sysdeps/x86/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(femode_t): New typedef.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (FE_DFL_MODE): New macro.
* manual/arith.texi (FE_DFL_MODE): Document macro.
(fegetmode): Document function.
(fesetmode): Likewise.
* math/Versions (fegetmode): New libm symbol at version
GLIBC_2.25.
(fesetmode): Likewise.
* math/Makefile (libm-support): Add fegetmode and fesetmode.
(tests): Add test-femode and test-femode-traps.
* math/test-femode-traps.c: New file.
* math/test-femode.c: Likewise.
* sysdeps/powerpc/fpu/fenv_const.c (__fe_dfl_mode): Declare as
alias for __fe_dfl_env.
* sysdeps/powerpc/nofpu/fenv_const.c (__fe_dfl_mode): Likewise.
* sysdeps/powerpc/powerpc32/e500/nofpu/fenv_const.c
(__fe_dfl_mode): Likewise.
* sysdeps/powerpc/Versions (__fe_dfl_mode): New libm symbol at
version GLIBC_2.25.
* 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.
This is only used for the float and double variants.
Instead, just add it to the type specific list of files,
and remove all stubs, and remove the declaration from
math_private.h.
I verified x86_64, i486, ia64, m68k, and ppc64 build.
With the exception of those machines using the ldbl-opt in
an Implies file, this is a trivial transformation.
nextdownl is not subject to the non-trivial versioning rules
of the other generated functions, so to keep things simple,
it is handled as a one-off case in ldbl-opt to preserve the
existing behavior.
The only difference is the usage of math_narrow_eval when
building s_fdiml.c. This should be harmless for long double,
but I did observe some code generation changes on m68k, but
lack the resources to test it.
Likewise, to more easily support overriding symbol generation,
the aliasing macros are always conditionally defined on their
absence to reduce boilerplate.
I also ran builds for i486, ppc64, sparcv9, aarch64,
s390x and observed no changes to s_fdim* objects.
Convert cpow, clog, clog10, cexp, csqrt, and cproj functions
into generated templates. Note, ldbl-opt still retains
s_clog10l.c as the aliasing rules are non-trivial.
This patch has no function changes, except to
ensure the git history correctly tracks the
changes to convert the double version of these
functions into a templated version.
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.
This patch has no function changes, except to
ensure the git history correctly tracks the
changes to convert the double version of these
functions into a templated version.
This patch has no function changes, except to
ensure the git history correctly tracks the
changes to convert the double version of these
functions into a templated version.
A number of files share identical code for the
mul_split function.
This moves the duplicated function mul_split into its
own header, and refactors the fma usage into a single
selection macro. Likewise, mul_split when used by a
long double implementation is renamed mul_splitl for
clarity.
This patch has no function changes, except to
ensure the git history correctly tracks the
changes to convert the double version of these
functions into a templated version.
This defines a new classes of libm objects. The
<func>_template.c file which is used in conjunction
with the new makefile hooks to derive variants for
each type supported by the target machine.
The headers math-type-macros-TYPE.h are used to supply
macros to a common implementation of a function in
a file named FUNC_template.c and glued togethor via
a generated file matching existing naming in the
build directory.
This has the properties of preserving the existing
override mechanism and not requiring any arcane
build system twiddling. Likewise, it enables machines
to override these files without any additional work.
I have verified the built objects for ppc64, x86_64,
alpha, arm, and m68k do not change in any meaningful
way with these changes using the Fedora cross toolchains.
I have verified the x86_64 and ppc64 changes still run.
TS 18661-1 defines an fesetexcept function for setting floating-point
exception flags without the side-effect of causing enabled traps to be
taken.
This patch series implements this function for glibc. The present
patch adds the fallback stub implementation, x86 and x86_64
implementations, documentation, tests and ABI baseline updates. The
remaining patches, some of them untested, add implementations for
other architectures. The implementations generally follow those of
the fesetexceptflag function.
As for fesetexceptflag, the approach taken for architectures where
setting flags causes enabled traps to be taken is to set the flags
(and potentially cause traps) rather than refusing to set the flags
and returning an error. Since ISO C and TS 18661 provide no way to
enable traps, this is formally in accordance with the standards.
The NEWS entry should be considered a placeholder, since this patch
series is intended to be followed by further such series adding other
TS 18661-1 features, so that the NEWS entry would end up looking more
like
* New <fenv.h> features from TS 18661-1:2014 are added to libm: the
fesetexcept, fetestexceptflag, fegetmode and fesetmode functions,
the femode_t type and the FE_DFL_MODE macro.
with hopefully more such entries for other features, rather than
having an entry for a single function in the end.
I believe we have consensus for adding TS 18661-1 interfaces as per
<https://sourceware.org/ml/libc-alpha/2016-06/msg00421.html>.
Tested for x86_64, x86, mips64 (hard float, and soft float to test the
fallback version), arm (hard float) and powerpc (hard float, soft
float and e500).
* math/fesetexcept.c: New file.
* sysdeps/i386/fpu/fesetexcept.c: Likewise.
* sysdeps/x86_64/fpu/fesetexcept.c: Likewise.
* math/fenv.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (fesetexcept): New function
declaration.
* manual/arith.texi (fesetexcept): Document function.
* math/Versions (fesetexcept): New libm symbol at version
GLIBC_2.25.
* math/Makefile (libm-support): Add fesetexcept.
(tests): Add test-fesetexcept and test-fesetexcept-traps.
* math/test-fesetexcept.c: New file.
* math/test-fesetexcept-traps.c: Likewise.
* 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.
ISO C allows feraiseexcept to raise "inexact", in addition to the
requested exceptions, when requested to raise "overflow" or
"underflow". Testing on ARM and PowerPC e500 (where glibc's
feraiseexcept has this property) showed that the new test-fexcept test
failed to allow for this; this patch fixes it, by wrapping
feraiseexcept to clear FE_INEXACT if implicitly raised and not raised
before the call. (It would also be possible to do this with
fesetexcept, which always affects exactly the requested flags, but
this patch avoids making this fix depend on the fesetexcept changes.)
Tested for x86_64, x86, arm and e500.
* math/test-fexcept.c (feraiseexcept_exact): New function.
(test_set): Call feraiseexcept_exact instead of feraiseexcept.
(test_except): Likewise.
I noticed that there was no meaningful test coverage for
fegetexceptflag and fesetexceptflag (one test ensures that calls to
them compile and link, but nothing to verify they work correctly).
This patch adds tests for these functions.
fesetexceptflag is meant to set the relevant exception flag bits to
the saved state without causing enabled traps to be taken. On some
architectures, it is not possible to set exception flag bits without
causing enabled traps to occur. Such architectures need to define
EXCEPTION_SET_FORCES_TRAP to 1 in their math-tests.h, as is done in
this patch for powerpc. x86 avoids needing to define this because the
traps resulting from setting exception bits don't occur until the next
floating-point operation or fwait instruction.
Tested for x86_64, x86 and powerpc. Note that test-fexcept fails for
powerpc because of a pre-existing bug in fesetexceptflag for powerpc,
which I'll fix separately.
* math/test-fexcept-traps.c: New file.
* math/test-fexcept.c: Likewise.
* math/Makefile (tests): Add test-fexcept and test-fexcept-traps.
* sysdeps/generic/math-tests.h (EXCEPTION_SET_FORCES_TRAP): New
macro.
* sysdeps/powerpc/math-tests.h [!__NO_FPRS__]
(EXCEPTION_SET_FORCES_TRAP): Likewise.
sparc32 passes floating point values in the integer registers. VIS3
instructions gives access to the movwtos instruction to directly
transfer a value from an integer register to a floating point register.
Therefore it makes sense to provide a VIS3 version consisting in the
generic version compiled with -mvis3.
Changelog:
* math/s_fdim.c: Avoid alias renamed.
* math/s_fdimf.c: Likewise.
* sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/Makefile
[$(subdir) = math && $(have-as-vis3) = yes] (libm-sysdep_routines):
Add s_fdimf-vis3, s_fdim-vis3.
(CFLAGS-s_fdimf-vis3.c): New. Set to -Wa,-Av9d -mvis3.
(CFLAGS-s_fdim-vis3.c): Likewise.
sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_fdim-vis3.c: New file.
sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_fdim.c: Likewise.
When bootstrapping float128, this exposed a number of areas where
the L suffix is incorrectly applied to simple expressions when it
should be applied to each constant in the expression.
In order to stave off more macros in libm-test.inc, apply_lit is
made slightly more intelligent. It will now split expressions
based on space characters, and attempt to apply LIT() to each
token.
Having done this, there are numerous spacing issues within
libm-test.inc which have been fixed.
The above is problematic when the L real suffix is not the most
expressive modifier, and the compiler complains (i.e ppc64) or
silently truncates a value (i.e ppc64).
math.h has a comment about definitions from <bits/mathdef.h>. This
comment is in the wrong place in math.h, far below the inclusion of
<bits/mathdef.h>. It was originally above the inclusion, but the
inclusion was moved by
1998-11-05 Ulrich Drepper <drepper@cygnus.com>
* math/math.h: Unconditionally include bits/mathdef.h. Declare
long double functions only if __NO_LONG_DOUBLE_MATH is not
defined.
[...]
without moving the comment. Furthermore, the comment refers
incorrectly to FLT_EVAL_METHOD and DECIMAL_DIG, which are actually
<float.h> macros, and INFINITY, which is in <bits/inf.h>.
This patch moves the comment back above the include it refers to and
removes the description of macros not defined by the header.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* math/math.h: Move comment about <bits/mathdef.h> definitions
above inclusion of <bits/mathdef.h>. Do not mention
FLT_EVAL_METHOD, INFINITY or DECIMAL_DIG in that comment.
When libm functions return a NaN: if it is for NaN input, it should be
computed from that input (e.g. adding it to itself), so that payloads
are propagated and signaling NaNs quieted, while if it is for non-NaN
input, it should be produced by a computation such as
(x - x) / (x - x), which raises "invalid" at the same time as
producing an appropriate NaN, so avoiding any need for a call to
feraiseexcept.
Various libm functions, however, call __nan ("") (or __nanf or __nanl)
to determine the NaN to return, together with using feraiseexcept
(FE_INVALID) to raise the exception. sysdeps/generic/math_private.h
has an optimization for those functions with constant "" argument so
this doesn't actually involve a call to the __nan function, but it is
still not the preferred approach for producing NaNs. (The optimized
code also always uses the NAN macro, i.e. produces a default NaN for
float converted to whatever the target type is, and on some
architectures that may not be the same as the preferred default NaN
for double or long double.)
This patch fixes the scalb functions to use the conventional method of
generating NaNs and raising "invalid" with an appropriate
computation. (Most instances of this issue are in the complex
functions, where it can more readily be fixed once they have been made
type-generic and so only a third as many places need fixing. Some of
the complex functions use __nan ("") + __nan (""), where the addition
serves no purpose whatsoever.)
Tested for x86_64 and x86.
* math/e_scalb.c: Do not include <fenv.h>.
(invalid_fn): Do calculation resulting in NaN instead of raising
FE_INVALID and returning a NaN explicitly.
* math/e_scalbf.c: Do not include <fenv.h>.
(invalid_fn): Do calculation resulting in NaN instead of raising
FE_INVALID and returning a NaN explicitly.
* math/e_scalbl.c: Do not include <fenv.h>.
(invalid_fn): Do calculation resulting in NaN instead of raising
FE_INVALID and returning a NaN explicitly.
My __STDC_WANT_IEC_60559_BFP_EXT__ patch omitted to update the
conditions on the nextup and nextdown type-generic macros in
<tgmath.h>. This patch updates those conditions accordingly. (As
glibc doesn't currently have an exp10 type-generic macro, no such
changes are needed relating to __STDC_WANT_IEC_60559_FUNCS_EXT__;
adding such a type-generic macro would be a new feature.)
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch). Committed.
* math/tgmath.h (nextdown): Define if
[__GLIBC_USE (IEC_60559_BFP_EXT)], not if [__USE_GNU].
(nextup): Likewise.
This patch implements support for the
__STDC_WANT_IEC_60559_FUNCS_EXT__ feature test macro, following the
__GLIBC_USE approach used for other ISO C feature test macros.
Currently this only affects the exp10 functions (which glibc has had
for a long time).
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_FUNCS_EXT): New
macro.
* include/features.h (__STDC_WANT_IEC_60559_FUNCS_EXT__):
Document.
* manual/creature.texi (__STDC_WANT_IEC_60559_FUNCS_EXT__):
Document macro.
* manual/math.texi (exp10): Document as ISO from TS 18661-4:2015.
(exp10f): Likewise.
(exp10l): Likewise.
* math/bits/mathcalls.h (exp10): Declare if
[__GLIBC_USE (IEC_60559_FUNCS_EXT)], not [__USE_GNU].
This patch implements support for the __STDC_WANT_IEC_60559_BFP_EXT__
feature test macro from ISO/IEC 18661-1:2014, following the
__GLIBC_USE approach now used for __STDC_WANT_LIB_EXT2__. For this
macro, the relevant consideration is whether it is defined or
undefined when an affected header is included (not what its value is
if defined, and not whether it's defined or undefined when any other
unaffected system header is included).
Currently this macro only affects the issignaling macro and the nextup
and nextdown functions (so they can be enabled by defining this macro,
not just by defining _GNU_SOURCE as previously). Any further features
from this TS added in future would also be conditioned on this macro.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_BFP_EXT): New
macro.
* include/features.h (__STDC_WANT_IEC_60559_BFP_EXT__): Document.
* manual/arith.texi (issignaling): Document as ISO from TS
18661-1:2014.
(nextup): Likewise.
(nextupf): Likewise.
(nextupl): Likewise.
(nextdown): Likewise.
(nextdownf): Likewise.
(nextdownl): Likewise.
* manual/creature.texi (__STDC_WANT_IEC_60559_BFP_EXT__): Document
macro.
* math/math.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
(issignaling): Define if [__GLIBC_USE (IEC_60559_BFP_EXT)], not
[__USE_GNU].
* math/bits/mathcalls.h (nextdown): Declare if
[__GLIBC_USE (IEC_60559_BFP_EXT)], not [__USE_GNU].
(nextup): Likewise.
(__issignaling): Likewise.
While trying to convert the _Complex function wrappers
into a single generic implementation, a few minor
variations between identical versions emerged.
In order to support more types, the Makefile needs a few bits
shuffled.
F is explictly used as a placeholder to substitute for the
appropriate type suffix. This removes the need to demangle
_r suffixed objects.
The variable libm-compat-calls is added to house any objects which
are only built to provide compat symbols within libm. That is,
no newly added type should ever attempt building these. Note,
k_standard* files have been added there. By consensus they are
deprecated; in practice, we haven't gotten there yet.
New types would be added as noted in the comments preceding
type-TYPE-{suffix,routines,yes} variables. However, some manual
additions will still need to be done to add appropriate flags
when building the various variants of libm-test.c for a new type.
Likewise, test-ildoubl is renamed test-ildouble for consistency's
sake.
During the sincos consolidation I made two mistakes, one was a logical
error due to which cos(0x1.8475e5afd4481p+0) returned
sin(0x1.8475e5afd4481p+0) instead.
The second issue was an error in negating inputs for the correct
quadrants for sine. I could not find a suitable test case for this
despite running a program to search for such an input for a couple of
hours.
Following patch fixes both issues. Tested on x86_64. Thanks to Matt
Clay for identifying the issue.
[BZ #20357]
* sysdeps/ieee754/dbl-64/s_sin.c (sloww): Fix up condition
to call __mpsin/__mpcos and to negate values.
* math/auto-libm-test-in: Add test.
* math/auto-libm-test-out: Regenerate.
As discussed in
<https://sourceware.org/ml/libc-alpha/2016-05/msg00577.html>, TS
18661-1 disallows ceil, floor, round and trunc functions from raising
the "inexact" exception, in accordance with general IEEE 754 semantics
for when that exception is raised. Fixing this for x87 floating point
is more complicated than for the other versions of these functions,
because they use the frndint instruction that raises "inexact" and
this can only be avoided by saving and restoring the whole
floating-point environment.
As I noted in
<https://sourceware.org/ml/libc-alpha/2016-06/msg00128.html>, I have
now implemented a GCC option -fno-fp-int-builtin-inexact for GCC 7,
such that GCC will inline these functions on x86, without caring about
"inexact", when the default -ffp-int-builtin-inexact is in effect.
This allows users to get optimized code depending on the options they
pass to the compiler, while making the out-of-line functions follow TS
18661-1 semantics and avoid "inexact".
This patch duly fixes the out-of-line trunc function implementations
to avoid "inexact", in the same way as the nearbyint implementations.
I do not know how the performance of implementations such as these
based on saving the environment and changing the rounding mode
temporarily compares to that of the C versions or SSE 4.1 versions (of
course, for 32-bit x86 SSE implementations still need to get the
return value in an x87 register); it's entirely possible other
implementations could be faster in some cases.
Tested for x86_64 and x86.
[BZ #15479]
* sysdeps/i386/fpu/s_trunc.S (__trunc): Save and restore
floating-point environment rather than just control word.
* sysdeps/i386/fpu/s_truncf.S (__truncf): Likewise.
* sysdeps/i386/fpu/s_truncl.S (__truncl): Save and restore
floating-point environment, with "invalid" exceptions merged in,
rather than just control word.
* sysdeps/x86_64/fpu/s_truncl.S (__truncl): Likewise.
* math/libm-test.inc (trunc_test_data): Do not allow spurious
"inexact" exceptions.
As discussed in
<https://sourceware.org/ml/libc-alpha/2016-05/msg00577.html>, TS
18661-1 disallows ceil, floor, round and trunc functions from raising
the "inexact" exception, in accordance with general IEEE 754 semantics
for when that exception is raised. Fixing this for x87 floating point
is more complicated than for the other versions of these functions,
because they use the frndint instruction that raises "inexact" and
this can only be avoided by saving and restoring the whole
floating-point environment.
As I noted in
<https://sourceware.org/ml/libc-alpha/2016-06/msg00128.html>, I have
now implemented a GCC option -fno-fp-int-builtin-inexact for GCC 7,
such that GCC will inline these functions on x86, without caring about
"inexact", when the default -ffp-int-builtin-inexact is in effect.
This allows users to get optimized code depending on the options they
pass to the compiler, while making the out-of-line functions follow TS
18661-1 semantics and avoid "inexact".
This patch duly fixes the out-of-line floor function implementations
to avoid "inexact", in the same way as the nearbyint implementations.
I do not know how the performance of implementations such as these
based on saving the environment and changing the rounding mode
temporarily compares to that of the C versions or SSE 4.1 versions (of
course, for 32-bit x86 SSE implementations still need to get the
return value in an x87 register); it's entirely possible other
implementations could be faster in some cases.
Tested for x86_64 and x86.
[BZ #15479]
* sysdeps/i386/fpu/s_floor.S (__floor): Save and restore
floating-point environment rather than just control word.
* sysdeps/i386/fpu/s_floorf.S (__floorf): Likewise.
* sysdeps/i386/fpu/s_floorl.S (__floorl): Save and restore
floating-point environment, with "invalid" exceptions merged in,
rather than just control word.
* sysdeps/x86_64/fpu/s_floorl.S (__floorl): Likewise.
* math/libm-test.inc (floor_test_data): Do not allow spurious
"inexact" exceptions.
As discussed in
<https://sourceware.org/ml/libc-alpha/2016-05/msg00577.html>, TS
18661-1 disallows ceil, floor, round and trunc functions from raising
the "inexact" exception, in accordance with general IEEE 754 semantics
for when that exception is raised. Fixing this for x87 floating point
is more complicated than for the other versions of these functions,
because they use the frndint instruction that raises "inexact" and
this can only be avoided by saving and restoring the whole
floating-point environment.
As I noted in
<https://sourceware.org/ml/libc-alpha/2016-06/msg00128.html>, I have
now implemented a GCC option -fno-fp-int-builtin-inexact for GCC 7,
such that GCC will inline these functions on x86, without caring about
"inexact", when the default -ffp-int-builtin-inexact is in effect.
This allows users to get optimized code depending on the options they
pass to the compiler, while making the out-of-line functions follow TS
18661-1 semantics and avoid "inexact".
This patch duly fixes the out-of-line ceil function implementations to
avoid "inexact", in the same way as the nearbyint implementations.
I do not know how the performance of implementations such as these
based on saving the environment and changing the rounding mode
temporarily compares to that of the C versions or SSE 4.1 versions (of
course, for 32-bit x86 SSE implementations still need to get the
return value in an x87 register); it's entirely possible other
implementations could be faster in some cases.
Tested for x86_64 and x86.
[BZ #15479]
* sysdeps/i386/fpu/s_ceil.S (__ceil): Save and restore
floating-point environment rather than just control word.
* sysdeps/i386/fpu/s_ceilf.S (__ceilf): Likewise.
* sysdeps/i386/fpu/s_ceill.S (__ceill): Save and restore
floating-point environment, with "invalid" exceptions merged in,
rather than just control word.
* sysdeps/x86_64/fpu/s_ceill.S (__ceill): Likewise.
* math/libm-test.inc (ceil_test_data): Do not allow spurious
"inexact" exceptions.
The x86_64 and i386 versions of scalbl return sNaN for some cases of
sNaN input and are missing "invalid" exceptions for other cases. This
results from overly complicated code that either returns a NaN input,
or discards both inputs when one is NaN and loads a NaN from memory.
This patch fixes this by simplifying the code to add the arguments
when either one is NaN.
Tested for x86_64 and x86.
[BZ #20296]
* sysdeps/i386/fpu/e_scalbl.S (__ieee754_scalbl): Add arguments
when either argument is a NaN.
* sysdeps/x86_64/fpu/e_scalbl.S (__ieee754_scalbl): Likewise.
* math/libm-test.inc (scalb_test_data): Add sNaN tests.
This patch adds tests of sNaN inputs to more functions to
libm-test.inc. This covers the remaining real functions except for
scalb, where there's a bug to fix, and hypot pow fmin fmax, where
there are cases where a qNaN input does not result in a qNaN output
and so sNaN support according to TS 18661-1 is more of a new feature.
Tested for x86_64 and x86.
* math/libm-test.inc (snan_value_ld): New macro.
(isgreater_test_data): Add sNaN tests.
(isgreaterequal_test_data): Likewise.
(isless_test_data): Likewise.
(islessequal_test_data): Likewise.
(islessgreater_test_data): Likewise.
(isunordered_test_data): Likewise.
(nextafter_test_data): Likewise.
(nexttoward_test_data): Likewise.
(remainder_test_data): Likewise.
(remquo_test_data): Likewise.
(significand_test_data): Likewise.
* math/gen-libm-test.pl (%beautify): Add snan_value_ld.
TS 18661 adds nextup and nextdown functions alongside nextafter to provide
support for float128 equivalent to it. This patch adds nextupl, nextup,
nextupf, nextdownl, nextdown and nextdownf to libm before float128 support.
The nextup functions return the next representable value in the direction of
positive infinity and the nextdown functions return the next representable
value in the direction of negative infinity. These are currently enabled
as GNU extensions.
fdim suffers from double rounding on i386 because subtracting two
double values can produce an inexact long double value exactly half
way between two double values. This patch fixes this by creating an
i386-specific version of fdim - C, based on the generic version,
unlike the previous .S version - which sets the x87 precision control
to double precision for the subtraction and then restores it
afterwards. As noted in the comment added, there are no issues of
double rounding for subnormals (a case that setting precision control
does not address) because subtraction cannot produce an inexact result
in the subnormal range.
Tested for x86_64 and x86.
[BZ #20255]
* sysdeps/i386/fpu/s_fdim.c: New file. Based on math/s_fdim.c.
* math/libm-test.inc (fdim_test_data): Add another test.
Some architectures have their own versions of fdim functions, which
are missing errno setting (bug 6796) and may also return sNaN instead
of qNaN for sNaN input, in the case of the x86 / x86_64 long double
versions (bug 20256).
These versions are not actually doing anything that a compiler
couldn't generate, just straightforward comparisons / arithmetic (and,
in the x86 / x86_64 case, testing for NaNs with fxam, which isn't
actually needed once you use an unordered comparison and let the NaNs
pass through the same subtraction as non-NaN inputs). This patch
removes the x86 / x86_64 / powerpc versions, so that those
architectures use the generic C versions, which correctly handle
setting errno and deal properly with sNaN inputs. This seems better
than dealing with setting errno in lots of .S versions.
The i386 versions also return results with excess range and precision,
which is not appropriate for a function exactly defined by reference
to IEEE operations. For errno setting to work correctly on overflow,
it's necessary to remove excess range with math_narrow_eval, which
this patch duly does in the float and double versions so that the
tests can reliably pass on x86. For float, this avoids any double
rounding issues as the long double precision is more than twice that
of float. For double, double rounding issues will need to be
addressed separately, so this patch does not fully fix bug 20255.
Tested for x86_64, x86 and powerpc.
[BZ #6796]
[BZ #20255]
[BZ #20256]
* math/s_fdim.c: Include <math_private.h>.
(__fdim): Use math_narrow_eval on result.
* math/s_fdimf.c: Include <math_private.h>.
(__fdimf): Use math_narrow_eval on result.
* sysdeps/i386/fpu/s_fdim.S: Remove file.
* sysdeps/i386/fpu/s_fdimf.S: Likewise.
* sysdeps/i386/fpu/s_fdiml.S: Likewise.
* sysdeps/i386/i686/fpu/s_fdim.S: Likewise.
* sysdeps/i386/i686/fpu/s_fdimf.S: Likewise.
* sysdeps/i386/i686/fpu/s_fdiml.S: Likewise.
* sysdeps/powerpc/fpu/s_fdim.c: Likewise.
* sysdeps/powerpc/fpu/s_fdimf.c: Likewise.
* sysdeps/powerpc/powerpc32/fpu/s_fdim.c: Likewise.
* sysdeps/powerpc/powerpc64/fpu/s_fdim.c: Likewise.
* sysdeps/x86_64/fpu/s_fdiml.S: Likewise.
* math/libm-test.inc (fdim_test_data): Expect errno setting on
overflow. Add sNaN tests.
The generic fdim implementations have unnecessarily complicated code,
using fpclassify to determine whether the arguments are NaNs,
subtracting NaNs if so and otherwise subtracting the non-NaN arguments
if not (x <= y), then using fpclassify on the result to see if it is
infinite.
This patch simplifies the code. Instead of handling NaNs separately,
it suffices to use an unordered comparison with islessequal (x, y) to
determine whether to return zero, and otherwise NaNs can go through
the same subtraction as non-NaN arguments; no explicit tests for NaN
are needed at all. Then, isinf instead of fpclassify can be used to
determine whether to set errno (in the normal non-overflow case, only
one classification will need to occur, unlike the three in the
previous code, of which two occurred even if returning zero, because
the result will not be infinite in the normal case).
The resulting logic is essentially the same as that in the powerpc
version, except that the powerpc version is missing errno setting and
uses <= not islessequal, so relying on
<https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58684>, the GCC bug that
unordered comparison instructions are wrongly used on powerpc for
ordered comparisons.
The compiled code for fdim and fdimf on x86_64 is less than half the
size of the previous code.
Tested for x86_64.
* math/s_fdim.c (__fdim): Use islessequal and isinf instead of
fpclassify.
* math/s_fdimf.c (__fdimf): Likewise.
* math/s_fdiml.c (__fdiml): Likewise.
The dbl-64 implementation of atan2, passed arguments (sNaN, qNaN),
fails to raise the "invalid" exception. This patch fixes it to add
both arguments, rather than just adding the second argument to itself,
in the case where the second argument is a NaN (which is checked for
before checking for the first argument being a NaN). sNaN tests for
atan2 are added, along with some qNaN tests I noticed were missing but
should have been there by analogy with other tests present.
Tested for x86_64 and x86.
[BZ #20252]
* sysdeps/ieee754/dbl-64/e_atan2.c (__ieee754_atan2): Add both
arguments when second argument is a NaN.
* math/libm-test.inc (atan2_test_data): Add sNaN tests and more
qNaN tests.
Various implementations of frexp functions return sNaN for sNaN
input. This patch fixes them to add such arguments to themselves so
that qNaN is returned.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #20250]
* sysdeps/i386/fpu/s_frexpl.S (__frexpl): Add non-finite input to
itself.
* sysdeps/ieee754/dbl-64/s_frexp.c (__frexp): Add non-finite or
zero input to itself.
* sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c (__frexp):
Likewise.
* sysdeps/ieee754/flt-32/s_frexpf.c (__frexpf): Likewise.
* sysdeps/ieee754/ldbl-128/s_frexpl.c (__frexpl): Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Likewise.
* sysdeps/ieee754/ldbl-96/s_frexpl.c (__frexpl): Likewise.
* math/libm-test.inc (frexp_test_data): Add sNaN tests.
