| Message ID | 20201022220510.GA11556@ibm-toto.the-meissners.org |
|---|---|
| State | New |
| Headers | show |
| Series | PowerPC: Add -mno-gnu-attributes to ibm-ldouble.o | expand |
On Thu, 2020-10-22 at 18:05 -0400, Michael Meissner via Gcc-patches wrote: > PowerPC: Add -mno-gnu-attributes to ibm-ldouble.o. > > I have split all of these patches into separate patches to hopefully get them > into the tree. > > This patch is split off from the patch adding __float128 <-> Decimal > conversions. This patch is needed to prevent the linker from issuing a > warning when the long double format is IEEE 128-bit. > > I have tested this patch with bootstrap builds on a little endian power9 system > running Linux. With the other patches, I have built two full bootstrap builds > using this patch and the patches after this patch. One build used the current > default for long double (IBM extended double) and the other build switched the > default to IEEE 128-bit. I used the Advance Toolchain AT 14.0 compiler as the > library used by this compiler. There are no regressions between the tests. > There are 3 fortran benchmarks (ieee/large_2.f90, default_format_2.f90, and > default_format_denormal_2.f90) that now pass. > > Can I install this into the trunk? > > We have gotten some requests to back port these changes to GCC 10.x. At the > moment, I am not planning to do the back port, but I may need to in the future. > > libgcc/ > 2020-10-22 Michael Meissner <meissner@linux.ibm.com> > > * config/rs6000/t-float128: Compile ibm-ldouble.o with > -mno-gnu-attributes. > --- > libgcc/config/rs6000/t-float128 | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/libgcc/config/rs6000/t-float128 b/libgcc/config/rs6000/t-float128 > index d5413445189..c2cb3e2b705 100644 > --- a/libgcc/config/rs6000/t-float128 > +++ b/libgcc/config/rs6000/t-float128 > @@ -69,6 +69,11 @@ $(fp128_ppc_obj) : INTERNAL_CFLAGS += $(FP128_CFLAGS_SW) > $(fp128_obj) : $(fp128_includes) > $(fp128_obj) : $(srcdir)/config/rs6000/quad-float128.h > > + > +# Turn off gnu attributes to allow using the IBM extended double support for > +# __ibm128 if long double uses the IEEE 128-bit representation. > +ibm-ldouble$(objext) : INTERNAL_CFLAGS += -mno-gnu-attribute > + I think from context you can drop the "if long double uses the IEEE 128-bit representation." portion of that comment. (Though this corrects a condition based on the configury, etc, there is no conditional logic here..) > $(fp128_softfp_src) : $(srcdir)/soft-fp/$(subst -sw,,$(subst kf,tf,$@)) $(fp128_dep) > @src="$(srcdir)/soft-fp/$(subst -sw,,$(subst kf,tf,$@))"; \ > echo "Create $@"; \ > -- > 2.22.0 > >
Please withdraw from consideration the patch that turned on -mno-gnu-attribute for just the ibm-ldouble.o module in favor of the patch for PR libgcc/97543 that I just posted: PR libgcc/97543 patch: https://gcc.gnu.org/pipermail/gcc-patches/2020-October/557413.html Withdrawn patch: https://gcc.gnu.org/pipermail/gcc-patches/2020-October/556863.html
diff --git a/libgcc/config/rs6000/t-float128 b/libgcc/config/rs6000/t-float128 index d5413445189..c2cb3e2b705 100644 --- a/libgcc/config/rs6000/t-float128 +++ b/libgcc/config/rs6000/t-float128 @@ -69,6 +69,11 @@ $(fp128_ppc_obj) : INTERNAL_CFLAGS += $(FP128_CFLAGS_SW) $(fp128_obj) : $(fp128_includes) $(fp128_obj) : $(srcdir)/config/rs6000/quad-float128.h + +# Turn off gnu attributes to allow using the IBM extended double support for +# __ibm128 if long double uses the IEEE 128-bit representation. +ibm-ldouble$(objext) : INTERNAL_CFLAGS += -mno-gnu-attribute + $(fp128_softfp_src) : $(srcdir)/soft-fp/$(subst -sw,,$(subst kf,tf,$@)) $(fp128_dep) @src="$(srcdir)/soft-fp/$(subst -sw,,$(subst kf,tf,$@))"; \ echo "Create $@"; \