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.
The switch between FMT_E and FMT_F is based on the absolute value.
Set r=0 for rounding toward zero and r = 1 otherwise.
If (exp_d - m) == 1 there is no rounding needed.
libgfortran/ChangeLog:
PR fortran/93567
* io/write_float.def (determine_en_precision): Fix switch between
FMT_E and FMT_F.
gcc/testsuite/ChangeLog:
PR fortran/93567
* gfortran.dg/round_3.f08: Add test cases.
The fix is obvious (I have added a comment). The tests are probably
an overkill, but it does not hurt.
libgfortran/ChangeLog:
PR fortran/93592
* io/write_float.def (build_float_string): Do not reset
nbefore for FMT_F and FMT_EN.
gcc/testsuite/ChangeLog:
PR fortran/93592
* gfortran.dg/fmt_en.f90: Adjust test.
* gfortran.dg/fmt_en_rd.f90: New test.
* gfortran.dg/fmt_en_rn.f90: New test.
* gfortran.dg/fmt_en_ru.f90: New test.
* gfortran.dg/fmt_en_rz.f90: New test.
PR libfortran/90374
* io/format.c (parse_format_list): Zero width not allowed with
FMT_D.
* io/write_float.def (build_float_string): Include range of
higher exponent values that require wider width.
PR libfortran/90274
* io/format.c (parse_format_list): Implement the E0 exponent
width to provide smallest possible width for exponent fields.
Refactor code for correct parsing and better readability of the
code.
* io/io.h (write_real_w0): Change interface to pass in pointer
to fnode.
* io/transfer.c: Update all calls to write_real_w0 to use the
new interface.
* io/write.c ((write_real_w0): Use the new interface with fnode
to access both the decimal precision and exponent widths used in
build_float_string.
* io/write_float.def (build_float_string): Use the passed in
exponent width to calculate the used width in the case of E0.
From-SVN: r279828
gcc/fortran ChangeLog:
2019-05-22 Jeff Law <law@redhat.com>
Mark Eggleston <mark.eggleston@codethink.com>
PR fortran/89100
* gfortran.texi: Add Default widths for F, G and I format
descriptors to Extensions section.
* invoke.texi: Add -fdec-format-defaults
* io.c (check_format): Use default widths for i, f and g when
flag_dec_format_defaults is enabled.
* lang.opt: Add new option.
* options.c (set_dec_flags): Add SET_BITFLAG for
flag_dec_format_defaults.
gcc/testsuite ChangeLog:
2019-05-22 Mark Eggleston <mark.eggleston@codethink.com>
PR fortran/89100
* gfortran.dg/fmt_f_default_field_width_1.f90: New test.
* gfortran.dg/fmt_f_default_field_width_2.f90: New test.
* gfortran.dg/fmt_f_default_field_width_3.f90: New test.
* gfortran.dg/fmt_g_default_field_width_1.f90: New test.
* gfortran.dg/fmt_g_default_field_width_2.f90: New test.
* gfortran.dg/fmt_g_default_field_width_3.f90: New test.
* gfortran.dg/fmt_i_default_field_width_1.f90: New test.
* gfortran.dg/fmt_i_default_field_width_2.f90: New test.
* gfortran.dg/fmt_i_default_field_width_3.f90: New test.
libgfortran ChangeLog:
2019-05-22 Jeff Law <law@redhat.com>
PR fortran/89100
* io/format.c (parse_format_list): set default width when the
IOPARM_DT_DEC_EXT flag is set for i, f and g.
* io/io.h: add default_width_for_integer, default_width_for_float
and default_precision_for_float.
* io/write.c (write_boz): extra parameter giving length of data
corresponding to the type's kind.
(write_b): pass data length as extra parameter in calls to
write_boz.
(write_o): pass data length as extra parameter in calls to
write_boz.
(write_z): pass data length as extra parameter in calls to
write_boz.
(size_from_kind): also set size is default width is set.
* io/write_float.def (build_float_string): new paramter inserted
before result parameter. If default width use values passed
instead of the values in fnode.
(FORMAT_FLOAT): macro modified to check for default width and
calls to build_float_string to pass in default width.
(get_float_string): set width and precision to defaults when
needed.
From-SVN: r271511
2016-09-06 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/77393
* io/write_float.def (build_float_string): Recognize when the
result will not fit in the user provided, star fill, and exit
early.
* gfortran.dg/fmt_f0_2.f90: Update test.
* gfortran.dg/fmt_f0_3.f90: New test.
From-SVN: r240018
2016-06-23 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/48852
* io/write.c: Cleaned up whitespace.
(write_d, write_e, write_f, write_es, write_en): Use new helper function
write_float_0. (write_float_0): New helper function.
(get_precision, select_buffer, select_string, write_float_string): New
helper functions used in remaining float writing functions. Helper function
write_float_string now contains code for writing to kind=4 character
internal units.
(write_real): Modified to establish working buffers at this level and to
use new helper functions.
(write_real_g0): Likewise modified.
(write_complex): Likewise modified. Gets both float strings before
output so that final lengths can be determined which allows right
justifying the complex number with no intervening spaces.
* io/write_float.def (build_float_string): Renamed from previosly
output_float, modified to use buffers passed in from higher functions,
builds a null terminated string of the floating point value. Character
kind=4 code eliminated.
(write_infnan): Likewise modified to use incoming buffers and eliminate
kind=4 related code.
(OUTPUT_FLOAT_FMT_G): Deleted, functionality moved into FORMAT_FLOAT.
(FORMAT_FLOAT): Renamed macro from WRITE_FLOAT. Use build_float_string.
(get_float_string): Renamed from write_float, uses FORMAT_FLOAT macro.
Buffer allocation removed, now at higher level.
PR libgfortran/48852
* gfortran.dg/char4_iunit_1.f03: Update test.
* gfortran.dg/f2003_io_5.f03: Update test.
* gfortran.dg/real_const_3.f90: Update test.
From-SVN: r237735
2016-03-30 Jerry DeLisle <jvdelisle@gcc.gnu.org>
Dominique d'Humieres <dominiq@lps.ens.fr>
PR libgfortran/70235
* io/write_float.def: Fix PF format for negative values of the scale
factor.
2016-03-30 Dominique d'Humieres <dominiq@lps.ens.fr>
Jerry DeLisle <jvdelisle@gcc.gnu.org>
* gfortran.dg/fmt_pf.f90: New test.
From-SVN: r234600
2015-11-22 Jerry DeLisle <jvdelisle@gcc.gnu.org>
* io/write_float.def (output_float): Move block determining
room for leading zero to before checkng g0 formatting.
From-SVN: r230728
PR libfortran/57496
* io/write_float.def: Use built-in type-generic functions defined
by libgfortran.h for isfinite, isnan, and signbit.
From-SVN: r227136
2015-02-10 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/57822
* io/write_float.def (output_float): Apply fix of previous patch
to correctly calculate the exponent number of digits and take
care of wide character output.
From-SVN: r220606
2015-02-09 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/57822
* io/write_float.def (output_float): If doing g0 editing and
exponent is zero, do not emit exponent.
From-SVN: r220564
2014-11-13 Janne Blomqvist <jb@gcc.gnu.org>
PR libfortran/60324
* configure: Regenerated.
* configure.ac (AM_CFLAGS): Add Werror=vla.
* libgfortran.h (gfc_alloca): Remove macro.
(fc_strdup_notrim): New prototype.
* intrinsics/access.c (access_func): Use fc_strdup rather than
stack allocation.
* intrinsics/chdir.c (chdir_i4_sub): Likewise.
(chdir_i8_sub): Likewise.
* intrinsics/chmod.c (chmod_internal): New function, move logic
here.
(chmod_func): Call chmod_internal.
* intrinsics/env.c (getenv): Use fc_strdup rather than stack
allocation.
(get_environment_variable_i4): Likewise.
* intrinsics/execute_command_line.c (execute_command_line):
Likewise.
* intrinsics/hostnm.c (hostnm_0): New function, use static buffer
rather than VLA.
(hostnm_i4_sub): Call hostnm_0.
(hostnm_i8_sub): Likewise.
(hostnm): Likewise.
* intrinsics/link.c (link_internal): New function, use fc_strdup
rather than stack allocation.
(link_i4_sub): Call link_internal.
(link_i8_sub): Likewise.
(link_i4): Likewise.
(link_i8): Likewise.
* intrinsics/perror.c (perror_sub): Use fc_strdup rather than
stack allocation.
* intrinsics/random.c (random_seed_i4): Use static buffer rather
than VLA, use _Static_assert to make sure it's big enough.
* intrinsics/rename.c (rename_internal): New function, use
fc_strdup rather than stack allocation.
(rename_i4_sub): Call rename_internal.
(rename_i8_sub): Likewise.
(rename_i4): Likewise.
(rename_i8): Likewise.
* intrinsics/stat.c (stat_i4_sub_0): Use fc_strdup rather than
stack allocation.
(stat_i8_sub_0): Likewise.
* intrinsics/symlink.c (symlnk_internal): New function, use
fc_strdup rather than stack allocation.
(symlnk_i4_sub): Call symlnk_internal.
(symlnk_i8_sub): Likewise.
(symlnk_i4): Likewise.
(symlnk_i8): Likewise.
* intrinsics/system.c (system_sub): Use fc_strdup rather than
stack allocation.
* intrinsics/unlink.c (unlink_i4_sub): Likewise.
* io/file_pos.c (READ_CHUNK): Make it a macro rather than variable.
* io/list_read.c (nml_get_obj_data): Use fixed stack buffer, fall
back to xmalloc/free for large sizes.
* io/read.c (read_f): Likewise.
* io/transfer.c (MAX_READ): Make it a macro rather than variable.
(WRITE_CHUNK): Likewise.
* io/write_float.def (write_float): Use fixed stack buffer, fall
back to xmalloc/free for large sizes.
* runtime/string.c (fc_strdup_notrim): New function.
From-SVN: r217480
2014-03-08 Dominique d'Humieres <dominiq@lps.ens.fr>
PR libgfortran/60128
* io/write_float.def (output_float): Remove unused variable
nzero_real. Replace a double space with a single one.
(determine_en_precision): Fix wrong handling of the EN format.
PR libfortran/60128
* gfortran.dg/fmt_en.f90: New test.
From-SVN: r208423
2013-03-19 Janne Blomqvist <jb@gcc.gnu.org>
* libgfortran.h: Include stdbool.h.
(enum try): Remove.
(notify_std): Change return type to bool.
* intrinsics/chmod.c: Don't include stdbool.h.
* intrinsics/execute_command_line.c: Likewise.
* io/format.c: Likewise.
* io/list_read.c (nml_parse_qualifier): Change return type to bool.
(nml_read_obj): Likewise.
(nml_get_obj_data): Likewise.
* io/transfer.c (read_block_form): Fix comment.
(write_buf): Change return type to bool.
* io/write.c: Don't include stdbool.h.
* io/write_float.def (output_float): Change return type to bool.
(output_float_FMT_G_ ## x): Change type of result variable.
* runtime/error.c (notify_std): Change return type to bool.
From-SVN: r196791
2012-03-17 Janne Blomqvist <jb@gcc.gnu.org>
PR libfortran/52608
* io/write_float.def (output_float): Move removal of initial zeros
until after the scale factor has been applied.
From-SVN: r185486
2012-03-15 Janne Blomqvist <jb@gcc.gnu.org>
PR libfortran/52434
PR libfortran/48878
PR libfortran/38199
* io/unit.c (get_internal_unit): Default to ROUND_UNSPECIFIED.
(init_units): Likewise.
* io/write_float.def (determine_precision): New function.
(output_float): Take into account buffer with %f format, no need
for our own rounding if unspecified or processor specified
rounding.
(DTOA): Simplify format string, add parameters.
(FDTOA): New macros similar to DTOA, but using %f format.
(OUTPUT_FLOAT_FMT_G): Stack allocate newf, determine correct
precision and fill buffer.
(EN_PREC): New macro.
(determine_en_precision): New function.
(WRITE_FLOAT): For G format, move buffer filling into
output_float_FMT_G, use FDTOA for F format.
(write_float): Increase buffer due to F format.
testsuite ChangeLog:
2012-03-15 Janne Blomqvist <jb@gcc.gnu.org>
PR libfortran/52434
PR libfortran/48878
PR libfortran/38199
* gfortran.dg/edit_real_1.f90: Don't assume roundTiesToAway.
* gfortran.dg/round_1.f03: Likewise.
From-SVN: r185433
2011-05-04 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/48787
* io/write_float.def (output_float): Adjust up and down rounding for
cases where 'd' = 0. Gather common code to one location.
From-SVN: r173408
2011-05-01 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/48787
* io/write_float.def (output_float): Gather up integer declarations and
add new 'p' for scale factor. Use 'p' in place of the 'dtp' reference
everywhere. For ROUND_UP scan the digit string and only perform
rounding if something other than '0' is found.
From-SVN: r173231
2011-04-29 Jerry DeLisle <jvdelisle@gcc.gnu.org>
Janne Blomqvist <jb@gcc.gnu.org>
PR libgfortran/48488
PR libgfortran/48602
PR libgfortran/48615
PR libgfortran/48684
PR libgfortran/48787
* io/write.c (write_d, write_e, write_f, write_en,
write_es): Add precision compemsation parameter to call.
(set_fnode_default): Adjust default widths to assure
round trip on write and read. (write_real): Adjust call to write_float.
(write_real_g0): Calculate compensation for extra precision and adjust
call to write_float.
* io/write_float.def (output_float_FMT_G_): Use volatile rather than
asm volatile to avoid optimization issue. Correctly calculate the
number of blanks (nb) to be appended and simplify calculation logic.
(write_float): Increase MIN_FIELD_WIDTH by one to accomodate the new
default widths. Eliminate the code that attempted to reduce the
the precision used in later sprintf functions. Add call parameter to
compensate for extra precision.
Co-Authored-By: Janne Blomqvist <jb@gcc.gnu.org>
From-SVN: r173166
2011-04-19 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/48602
* io/write_float.def (output_float_FMT_G): Fix reversal in conditional.
Use asm volatile to mark temp variable, avoiding optimization errors.
From-SVN: r172753
2011-04-17 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/48602
* io/write_float.def (output_float_FMT_G): Use current rounding mode
to set the rounding parameters. (output_float): Skip rounding
if value is zero.
From-SVN: r172634
2011-02-28 Jerry DeLisle <jvdelisle@gcc.gnu.org>
PR libgfortran/47567
* io/write_float.def (output_float): Move handling of w = 0 to after
output rounding. Check for zero and set zero_flag accordingly. Set
width according to zero_flag. Add better comments.
From-SVN: r170585
