fortran, libgfortran, v2: Avoid using libquadmath for glibc 2.26+

  On Thu, Jun 23, 2022 at 11:17:50PM +0200, Jakub Jelinek via Gcc-patches wrote:
> We currently use
> %rename lib liborig
> *lib: %{static-libgfortran:--as-needed} -lquadmath %{static-libgfortran:--no-as-needed} -lm %(libgcc) %(liborig)
> in libgfortran.spec (on targets where we do configure in libquadmath).
> So, I believe the patch as is is an ABI change for *.o files if they use
> real(kind=16) math functions (one needs to recompile them), but not
> for linked shared libraries or executables, because the above aranges
> for them to be linked with -lquadmath or for -static-libgfortran with
> --as-needed -lquadmath --no-as-needed.  The former adds libquadmath.so.0
> automatically to anything gfortran links, the latter to anything that
> actually needs it (i.e. has undefined math/complex *q symbols).
> 
> Note, libgfortran.so.5 itself is ABI compatible, just no longer has
> DT_NEEDED libquadmath.so.0 and uses the *f128 APIs + str{to,from}f128
> instead of *q APIs + strtoflt128 and quadmath_snprintf.
> 
> Now, what we could do if we'd want to also preserve *.o file compatibility,
> would be for gcc configured on glibc 2.26+ change libgfortran.spec to
> *lib: --as-needed -lquadmath --no-as-needed -lm %(libgcc) %(liborig)
> so that we even without -static-libgfortran link in libquadmath.so.0
> only if it is needed.  So, if there will be any gcc <= 12 compiled
> *.o files or *.o files compiled by gcc 13 if it was configured against
> glibc 2.25 or older, we'd link -lquadmath in, but if there are just
> *.o files referencing *f128 symbols, we wouldn't.
> 
> > Am I right in assuming that this also effectively fixes PR46539?
> > (Add -static-libquadmath).
> 
> That was one of the intents of the patch.
> But sure, it doesn't introduce -static-libquadmath, nor arranges for
> -static-libgfortran to link libquadmath statically, just in some cases
> (gcc configured on glibc 2.26 or later) and when everything that calls
> real(kind=16) math functions has been recompiled arranges for libquadmath
> not to be used at all.

Here is an updated patch that does that.

> > > --- gcc/fortran/trans-intrinsic.cc.jj	2022-05-16 11:14:57.587427707 +0200
> > > +++ gcc/fortran/trans-intrinsic.cc	2022-06-23 11:42:03.355899271 +0200
> > > @@ -155,7 +155,7 @@ builtin_decl_for_precision (enum built_i
> > >     else if (precision == TYPE_PRECISION (double_type_node))
> > >       i = m->double_built_in;
> > >     else if (precision == TYPE_PRECISION (long_double_type_node)
> > > -	   && (!gfc_real16_is_float128
> > > +	   && ((!gfc_real16_is_float128 & !gfc_real16_is__Float128)
> > 
> > Shouldn't this be && instead of & ?
> 
> You're right, will fix.

And this too.

So I believe it should now be fully ABI compatible.

2022-06-24  Jakub Jelinek  <jakub@redhat.com>

gcc/fortran/
	* gfortran.h (gfc_real_inf0: Add c__Float128 bitfield.
	* trans-types.h (gfc_real16_is_float128): Update comment.
	(gfc_real16_is__Float128): Declare.
	* trans-types.cc (gfc_real16_is__Float128): Define.
	(gfc_init_kinds): When building powerpc64le-linux libgfortran
	on glibc 2.26 to 2.31, set gfc_real16_is__Float128 and
	c__Float128 instead of gfc_real16_is_float128 and c_float128.
	(gfc_build_real_type): Don't set c_long_double if c__Float128.
	Set gfc_real16_is__Float128 and c__Float128 instead of
	gfc_real16_is_float128 and c_float128 on glibc 2.26 or later.
	(gfc_init_types): Handle c__Float128 like c_float128.
	* trans-intrinsic.cc (builtin_decl_for_precision): Handle
	gfc_real16_is__Float128 like gfc_real16_is_float128.
	(gfc_builtin_decl_for_float_kind): Handle c__Float128 like c_float128.
	(gfc_build_intrinsic_lib_fndecls): For gfc_real16_is__Float128
	use *f128 APIs rather than *q APIs used for gfc_real16_is_float128.
	(gfc_get_intrinsic_lib_fndecl): Likewise.
	* trans-expr.cc (gfc_conv_power_op): Handle gfc_real16_is__Float128
	like gfc_real16_is_float128.
libgfortran/
	* configure.ac: Check for strtof128 and strfromf128.
	Check for math and complex *f128 functions.  Set
	have__Float128_libc_support to yes if *f128 support is around, for
	--enable-libquadmath-support default to "default" rather than yes if
	have__Float128_libc_support is yes.
	* acinclude.m4 (LIBGFOR_CHECK_FLOAT128): If libquadmath support
	is defaulted and have__Float128_libc_support is yes, test
	_Float128/_Complex _Float128 support and define and subst
	HAVE__FLOAT128.  Remove unused LIBGFOR_BUILD_QUAD conditional.
	* Makefile.am (kinds.h): Pass @HAVE__FLOAT128@ as an extra
	mk-kinds-h.sh argument.
	* mk-kinds-h.sh: Accept 4th have__float128 argument, if it is yes,
	use _Float128/_Complex _Float128 types insted of __float128 and
	_Complex float __attribute__((mode(TC))), use f128 suffix instead
	of q and define GFC_REAL_16_IS__FLOAT128 instead of
	GFC_REAL_16_IS_FLOAT128.
	* kinds-override.h: Add consistency check for GFC_REAL_16_IS__FLOAT128.
	* libgfortran.h (GFC_REAL_16_INFINITY, GFC_REAL_16_QUIET_NAN): Define
	for GFC_REAL_16_IS__FLOAT128.
	* caf/single.c (convert_type): Use _Float128/_Complex _Float128 for
	GFC_REAL_16_IS__FLOAT128.  For HAVE_GFC_REAL_10 when HAVE_GFC_REAL_16
	isn't defined use _Complex long double instead of long double.
	* ieee/issignaling_fallback.h (__issignalingf128): Handle
	GFC_REAL_16_IS__FLOAT128.
	(issignaling): Likewise.
	* ieee/ieee_helper.c: Handle GFC_REAL_16_IS__FLOAT128 like
	GFC_REAL_16_IS_FLOAT128.
	* intrinsics/cshift0.c (cshift0): Likewise.  Fix a comment typo,
	logn double -> long double.
	* intrinsics/erfc_scaled.c (_THRESH, _M_2_SQRTPI, _INF, _ERFC, _EXP):
	Handle GFC_REAL_16_IS_FLOAT128.
	* intrinsics/spread_generic.c (spread, spread_scalar): Handle
	GFC_REAL_16_IS__FLOAT128 like GFC_REAL_16_IS_FLOAT128.  Fix a comment
	typo, logn double -> long double.
	* intrinsics/trigd.c (GFC_REAL_16_IS_LONG_DOUBLE): Handle
	GFC_REAL_16_IS_LONG_DOUBLE.
	* intrinsics/pack_generic.c (pack): Handle GFC_REAL_16_IS__FLOAT128
	like GFC_REAL_16_IS_FLOAT128.  Fix a comment typo, logn double ->
	long double.
	* intrinsics/unpack_generic.c (unpack1, unpack0): Likewise.
	* runtime/in_pack_generic.c (internal_pack): Likewise.
	* runtime/in_unpack_generic.c (internal_unpack): Likewise.
	* io/read.c (convert_real, convert_infnan): Handle
	GFC_REAL_16_IS__FLOAT128.
	* io/transfer128.c: Enable also for GFC_REAL_16_IS__FLOAT128,
	but don't define tmp1 and tmp2 vars in that case.
	* io/write_float.def (gfor_strfromf128): New function.
	(DTOA2F128, FDTOA2F128): Define.
	(determine_en_precision, get_float_string): Handle
	GFC_REAL_16_IS__FLOAT128.
	* m4/mtype.m4: Likewise.
	* config.h.in: Regenerated.
	* configure: Regenerated.
	* Makefile.in: Regenerated.
	* generated/norm2_r16.c: Regenerated.
	* generated/bessel_r16.c: Regenerated.

	Jakub

Message ID	YrWR/feBR28AlWlz@tucnak
State	New
Headers	DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org DDD0B384D18C Date: Fri, 24 Jun 2022 12:29:17 +0200 To: Harald Anlauf <anlauf@gmx.de>, gcc-patches@gcc.gnu.org, "Joseph S. Myers" <joseph@codesourcery.com>, fortran@gcc.gnu.org Subject: [PATCH] fortran, libgfortran, v2: Avoid using libquadmath for glibc 2.26+ Message-ID: <YrWR/feBR28AlWlz@tucnak> References: <YrRWw/7sfjW83px/@tucnak> <b5141887-84f8-ede1-c546-c6c86c32107e@gmx.de> <YrTYfo8/qRjh15Ci@tucnak> MIME-Version: 1.0 In-Reply-To: <YrTYfo8/qRjh15Ci@tucnak> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: list From: Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org> Reply-To: Jakub Jelinek <jakub@redhat.com> Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" <gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org>
Series	fortran, libgfortran, v2: Avoid using libquadmath for glibc 2.26+ \| fortran, libgfortran, v2: Avoid using libquadmath for glibc 2.26+

fortran, libgfortran, v2: Avoid using libquadmath for glibc 2.26+

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