On Thu, 2021-01-28 at 21:42 -0500, Michael Meissner via Gcc-patches wrote: > [PATCH] Add conversions between _Float128 and Decimal. >
Hi, Just a couple cosmetic nits in the description. The changelog seems to match that patch contents OK. > This patch implements conversions between _Float128 and the 3 Decimal > floating types. It does by extendending the dfp-bit conversions to add a nit: 'does so' or 'does this' > new binary floating point type (KF), and doing the conversions in the same > mannor as the other binary/decimal conversions. manner. > > In particular for conversions from _Float128 to Decimal, it uses a sprintf > variant to convert _Float128 to strings, and a type specific function that > converts the string output to the appropriate Decimal type > > For conversions from one of the Decimal types to _Float128, it uses a decimal > function to convert to string (i.e. __decimal<n>ToString), and then uses a > variant of strtold to convert to _Float128. Are the sprintf and strtold functions called actually variants? > > If the user is linked against GLIBC 2.32 or newer, then the sprintf and > strtold > variant functions can use the features directly in GLIBC 2.32 to do this > conversion. > > If you have an older GLIBC and want to convert _Float128 to one of the Decimal > types, it will convert the _Float128 to __ibm128 and then convert that to > Decimal. > > Similarly if you have one of the Decimal types, and want to convert to > _Float128, it will first convert the Decimal type to __ibm128, and then > convert > __ibm128 to _Float128. > > These functions will primarily be used if/when the default PowerPC long double > type is changed to IEEE 128-bit, but they could also be used if the user > explicitly converts _Float128 to/from a Decimal type. > > One test case relating to Decimal fails if I build a compiler where the > default > is IEEE 128-bit: > > * c-c++-common/dfp/convert-bfp-11.c > > I have patches for this test, and they have been submitted separately. ok > > I have tested this patch by doing builds, bootstraps, and make check with 3 > builds on a power9 little endian server: > > * Build one used the default long double being IBM 128-bit; > * Build two set the long double default to IEEE 128-bit; (and) > * Build three set the long double default to 64-bit. > > The compilers built fine providing I recompiled gmp, mpc, and mpfr with the > appropriate long double options. There were a few differences in the test > suite runs that will be addressed in later patches, but over all it works > well. This patch is required to be able to build a toolchain where the > default > long double is IEEE 128-bit. > Can I check this patch into the master branch > for > GCC 11? Separate the check-in question from the description paragraph. > > I have also built compilers with this patch on a big endian power8 system that > has both 32-bit and 64-bit support. There were no regressions in running > these > tests on the system. > > Can I check this patch into the master branch? > > libgcc/ > 2021-01-28 Michael Meissner <meiss...@linux.ibm.com> > > * config/rs6000/_dd_to_kf.c: New file. > * config/rs6000/_kf_to_dd.c: New file. > * config/rs6000/_kf_to_sd.c: New file. > * config/rs6000/_kf_to_td.c: New file. > * config/rs6000/_sd_to_kf.c: New file. > * config/rs6000/_sprintfkf.c: New file. > * config/rs6000/_sprintfkf.h: New file. > * config/rs6000/_strtokf.h: New file. > * config/rs6000/_strtokf.c: New file. > * config/rs6000/_td_to_kf.c: New file. > * config/rs6000/quad-float128.h: Add new declarations. > * config/rs6000/t-float128 (fp128_dec_funcs): New macro. > (fp128_decstr_funcs): New macro. > (ibm128_dec_funcs): New macro. > (fp128_ppc_funcs): Add the new conversions. > (fp128_dec_objs): Force Decimal <-> __float128 conversions to be > compiled with -mabi=ieeelongdouble. > (fp128_decstr_objs): Force __float128 <-> string conversions to be > compiled with -mabi=ibmlongdouble. > (ibm128_dec_objs): Force Decimal <-> __float128 conversions to be > compiled with -mabi=ieeelongdouble. > (FP128_CFLAGS_DECIMAL): New macro. > (IBM128_CFLAGS_DECIMAL): New macro. > * dfp-bit.c (DFP_TO_BFP): Add PowerPC _Float128 support. > (BFP_TO_DFP): Add PowerPC _Float128 support. > * dfp-bit.h (BFP_KIND): Add new binary floating point kind for > IEEE 128-bit floating point. > (DFP_TO_BFP): Add PowerPC _Float128 support. > (BFP_TO_DFP): Add PowerPC _Float128 support. > (BFP_SPRINTF): New macro. > --- > libgcc/config/rs6000/_dd_to_kf.c | 37 ++++++++++++++++++ > libgcc/config/rs6000/_kf_to_dd.c | 37 ++++++++++++++++++ > libgcc/config/rs6000/_kf_to_sd.c | 37 ++++++++++++++++++ > libgcc/config/rs6000/_kf_to_td.c | 37 ++++++++++++++++++ > libgcc/config/rs6000/_sd_to_kf.c | 37 ++++++++++++++++++ > libgcc/config/rs6000/_sprintfkf.c | 57 ++++++++++++++++++++++++++++ > libgcc/config/rs6000/_sprintfkf.h | 28 ++++++++++++++ > libgcc/config/rs6000/_strtokf.c | 56 +++++++++++++++++++++++++++ > libgcc/config/rs6000/_strtokf.h | 27 +++++++++++++ > libgcc/config/rs6000/_td_to_kf.c | 37 ++++++++++++++++++ > libgcc/config/rs6000/quad-float128.h | 8 ++++ > libgcc/config/rs6000/t-float128 | 37 +++++++++++++++++- > libgcc/dfp-bit.c | 12 +++++- > libgcc/dfp-bit.h | 26 +++++++++++++ > 14 files changed, 470 insertions(+), 3 deletions(-) > create mode 100644 libgcc/config/rs6000/_dd_to_kf.c > create mode 100644 libgcc/config/rs6000/_kf_to_dd.c > create mode 100644 libgcc/config/rs6000/_kf_to_sd.c > create mode 100644 libgcc/config/rs6000/_kf_to_td.c > create mode 100644 libgcc/config/rs6000/_sd_to_kf.c > create mode 100644 libgcc/config/rs6000/_sprintfkf.c > create mode 100644 libgcc/config/rs6000/_sprintfkf.h > create mode 100644 libgcc/config/rs6000/_strtokf.c > create mode 100644 libgcc/config/rs6000/_strtokf.h > create mode 100644 libgcc/config/rs6000/_td_to_kf.c > > diff --git a/libgcc/config/rs6000/_dd_to_kf.c > b/libgcc/config/rs6000/_dd_to_kf.c > new file mode 100644 > index 00000000000..3b4d8500a57 > --- /dev/null > +++ b/libgcc/config/rs6000/_dd_to_kf.c > @@ -0,0 +1,37 @@ > +/* Copyright (C) 1989-2021 Free Software Foundation, Inc. Other source files in libgcc/config appear to have the copyright range starting at a later date, presumably when the file was created. So.. I think this should be Copyright (C) 2021 FSF.... > + > +This file is part of GCC. > + I have read through the rest of the patch, no further issues or comments noted by me. Thanks -WIll
