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As mentioned by Joseph in PR105101, glibc 2.26 or later has on x86 (both -m32/-m64), powerpc64le, ia64 and mips support for *f128 math/complex APIs plus strtof128 and strfromf128, and these APIs allow us to avoid libquadmath for Fortran purposes on these architectures, replace *q math/complex APIs, strtof128 instead of strtoflt128 and, while strfromf128 unfortunately isn't a perfect replacement to quadmath_snprintf, it can be made to work. The advantage of this is that when configured against such glibcs (2.26 is now almost 5 years old), we can avoid linking against an extra shared library and the math support in glibc is maintained better than libquadmath. We need both a compiler change (so that for glibc 2.26+ it uses *f128 APIs instead of *q) and library change. The above mentioned problem with strfromf128 is that the strfrom* functions are severely restricted versions of snprintf. In libgfortran, we handle !isfinite differently and just use snprintf/quadmath_snprintf for %+-#.*{L,Q}{f,e} printing. strfrom* doesn't allow +, -, # modifiers and it only supports .34 or similar precision, not .* . The L/Q etc. letters are omitted. The + is there to force + sign at the start if it is positive. Workaround in the patch is to add the + at the start manually for !signbit (val). The - (left alignment instead of right) I don't understand why we need it, when minimum field width isn't specified (for strfrom* can't be specified), no padding is ever added anywhere I believe. The # is to force adding . - workaround is to search for first . or e or '\0' character, if it is '\0', just append ., if it is e, insert . before e and memmove the rest (which is just a few bytes, e, +/- and at most a few digits) one byte later. The .* case is handled by creating the format string for strfrom* by snprintf into a temporary buffer. As requested, this patch also switches from using __float128 type in libgfortran to _Float128 which is equivalent on all arches that support __float128. The change is done in a backwards compatible change, when GCC is configured against glibc 2.26 or newer, libgfortran.so.5 itself doesn't link against -lquadmath nor uses any libquadmath APIs, libgfortran.a doesn't use any libquadmath APIs either. User programs and libraries when being linked by gfortran driver are linked against -lgfortran and -lquadmath, but the latter only in the --as-needed linker mode, which means it needs to be around during linking and will be linked in if there are any calls to math/complex functions with real(kind=16) or complex(kind=16) in compilation units compiled by older versions of gcc, but if either user code doesn't call those math/complex functions for the largest supported kind, or the code is recompiled by gcc with this change in, libquadmath won't be linked in. 2022-06-28 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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.. | ||
abort.c | ||
access.c | ||
args.c | ||
associated.c | ||
c99_functions.c | ||
chdir.c | ||
chmod.c | ||
clock.c | ||
cpu_time.c | ||
cshift0.c | ||
ctime.c | ||
date_and_time.c | ||
dprod_r8.f90 | ||
dtime.c | ||
env.c | ||
eoshift0.c | ||
eoshift2.c | ||
erfc_scaled_inc.c | ||
erfc_scaled.c | ||
etime.c | ||
execute_command_line.c | ||
exit.c | ||
extends_type_of.c | ||
f2c_specifics.F90 | ||
fnum.c | ||
gerror.c | ||
getcwd.c | ||
getlog.c | ||
getXid.c | ||
hostnm.c | ||
ierrno.c | ||
is_contiguous.c | ||
ishftc.c | ||
kill.c | ||
link.c | ||
move_alloc.c | ||
mvbits.c | ||
pack_generic.c | ||
perror.c | ||
rand.c | ||
random_init.f90 | ||
random.c | ||
rename.c | ||
reshape_generic.c | ||
reshape_packed.c | ||
selected_char_kind.c | ||
selected_int_kind.f90 | ||
selected_real_kind.f90 | ||
signal.c | ||
size.c | ||
sleep.c | ||
spread_generic.c | ||
stat.c | ||
string_intrinsics_inc.c | ||
string_intrinsics.c | ||
symlnk.c | ||
system_clock.c | ||
system.c | ||
time_1.h | ||
time.c | ||
trigd_lib.inc | ||
trigd.c | ||
trigd.inc | ||
umask.c | ||
unlink.c | ||
unpack_generic.c |