Re: [PATCH] fortran, libgfortran, v3: Avoid using libquadmath for glibc 2.26+

[Tobias Burnus <tobias@codesourcery.com>]

On 27.06.22 15:30, Jakub Jelinek via Gcc-patches wrote:

> Ok, here is an updated patch that uses _Float128/_Complex _Float128 for all
> of GFC_REAL_{16,17}_IS_FLOAT128, but still uses q/Q suffixes on literal
> constants etc. when using libquadmath and f128/F128 otherwise.
> This patch also includes the incremental powerpc64le fixes.
>
> Ok if it passes testing?

LGTM – I am not completely happy of having a TARGET_GLIBC_M{AJ,IN}OR check
in the FE (vs. a symbol-is-available check in libgfortran), but that
should be fine as it is unlikely to cause any issue in practice.

Thanks for the patch.

Tobias

> 2022-06-27  Jakub Jelinek  <jakub@redhat.com>
>
> gcc/fortran/
>       * gfortran.h (gfc_real_info): Add use_iec_60559 bitfield.
>       * trans-types.h (gfc_real16_use_iec_60559): Declare.
>       * trans-types.cc (gfc_real16_use_iec_60559): Define.
>       (gfc_init_kinds): When building powerpc64le-linux libgfortran
>       on glibc 2.26 to 2.31, set gfc_real16_use_iec_60559 and
>       use_iec_60559.
>       (gfc_build_real_type): Set gfc_real16_use_iec_60559 and use_iec_60559
>       on glibc 2.26 or later.
>       * trans-intrinsic.cc (gfc_build_intrinsic_lib_fndecls): Adjust
>       comment.  Handle gfc_real16_use_iec_60559.
>       (gfc_get_intrinsic_lib_fndecl): Handle use_iec_60559.
> libgfortran/
>       * configure.ac: Check for strtof128 and strfromf128.
>       Check for math and complex *f128 functions.  Set
>       have_iec_60559_libc_support to yes if *f128 support is around, for
>       --enable-libquadmath-support default to "default" rather than yes if
>       have_iec_60559_libc_support is yes.
>       * acinclude.m4 (LIBGFOR_CHECK_FLOAT128): Test
>       _Float128/_Complex _Float128 rather than __float128 and
>       _Complex float __attribute__((mode(TC))).  If libquadmath support
>       is defaulted and have_iec_60559_libc_support is yes, define and subst
>       USE_IEC_60559.  Remove unused LIBGFOR_BUILD_QUAD conditional.
>       * Makefile.am (kinds.h): Pass @USE_IEC_60559@ as an extra
>       mk-kinds-h.sh argument.
>       * mk-kinds-h.sh: Accept 4th use_iec_60559 argument.  Use
>       _Float128/_Complex _Float128 types instead of __float128 and
>          _Complex float __attribute__((mode(TC))), and if use_iec_60559 is yes,
>       use f128 suffix instead of q and define GFC_REAL_16_USE_IEC_60559.
>       * kinds-override.h: Use _Float128/_Complex _Float128 types instead of
>       __float128 and _Complex float __attribute__((mode(TC))), if
>       USE_IEC_60559 is defined, use f128 suffixes instead of q and
>       define GFC_REAL_17_USE_IEC_60559.
>       * libgfortran.h: Don't include quadmath_weak.h if USE_IEC_60559 is
>       defined.
>       (GFC_REAL_16_INFINITY, GFC_REAL_16_QUIET_NAN): Define
>       for GFC_REAL_16_USE_IEC_60559 differently.
>       * caf/single.c (convert_type): Use _Float128/_Complex _Float128
>       instead of __float128 and _Complex float __attribute__((mode(TC))).
>       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 (ieee854_float128_shape_type): Use
>       _Float128 instead of __float128.
>       (__issignalingf128): Change argument type to _Float128.
>       (issignaling): Use _Float128 instead of __float128 in _Generic.
>       * intrinsics/cshift0.c (cshift0): Use _Float128 instead of __float128
>       in a comment.  Fix a comment typo, logn double -> long double.
>       * intrinsics/erfc_scaled.c (_THRESH, _M_2_SQRTPI, _INF, _ERFC, _EXP):
>       Use different definitions if GFC_REAL_16_USE_IEC_60559.
>       (_THRESH, _M_2_SQRTPI): Use GFC_REAL_17_LITERAL macro.
>       (_ERFC, _EXP): Use different definitions if GFC_REAL_17_USE_IEC_60559.
>       * intrinsics/spread_generic.c (spread, spread_scalar): Use _Float128
>       instead of __float128 in a comment.  Fix a comment typo,
>       logn double -> long double.
>       * intrinsics/trigd.c (ENABLE_SIND, ENABLE_COSD, ENABLE_TAND): Handle
>       GFC_REAL_16_USE_IEC_60559.
>       * intrinsics/pack_generic.c (pack): Use _Float128 instead of
>       __float128 in a comment.  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_USE_IEC_60559 and GFC_REAL_17_USE_IEC_60559.
>       * io/transfer128.c (tmp1, tmp2): Don't define if libquadmath
>       isn't needed.
>       * io/write_float.def (gfor_strfromf128): New function.
>       (DTOA2Q, FDTOA2Q): Define differently if
>       GFC_REAL_16_USE_IEC_60559 or GFC_REAL_17_USE_IEC_60559.
>       * m4/mtype.m4: Use different suffix if GFC_REAL_16_USE_IEC_60559
>       or GFC_REAL_17_USE_IEC_60559.
>       * config.h.in: Regenerated.
>       * configure: Regenerated.
>       * Makefile.in: Regenerated.
>       * generated/bessel_r16.c: Regenerated.
>       * generated/bessel_r17.c: Regenerated.
>       * generated/norm2_r16.c: Regenerated.
>       * generated/norm2_r17.c: Regenerated.
> [...]
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