| Message ID | 20220921135108.3324737-7-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | Fix -Os build | expand |
On Wed, Sep 21, 2022 at 10:51:08AM -0300, Adhemerval Zanella via Libc-alpha wrote: > The compiler might transform __stpcpy calls (which are routed to > __builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy > multiarch implementation does not build any working symbol due > ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld). Ohhhhhh... that is interesting. This changes the strcpy used in rtld for all x86_64 build options, and I'm going to ACK this, but we may need to revisit this if it shows up in a profile. CC'ing HJ here in case he wants to comment as a machine maintainer. LGTM. No regressions on x86_64. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com> > Checked on x86_64-linux-gnu. > --- > sysdeps/x86_64/multiarch/rtld-strcpy.S | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > create mode 100644 sysdeps/x86_64/multiarch/rtld-strcpy.S > > diff --git a/sysdeps/x86_64/multiarch/rtld-strcpy.S b/sysdeps/x86_64/multiarch/rtld-strcpy.S > new file mode 100644 > index 0000000000..19439c553d > --- /dev/null > +++ b/sysdeps/x86_64/multiarch/rtld-strcpy.S > @@ -0,0 +1,18 @@ > +/* Copyright (C) 2022 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <https://www.gnu.org/licenses/>. */ > + > +#include "../strcpy.S" OK. Uses Makeconfig:sysd-rules-patterns to capture rtld-*. > -- > 2.34.1 >
On Wed, Oct 5, 2022 at 7:10 AM Carlos O'Donell <carlos@redhat.com> wrote: > > On Wed, Sep 21, 2022 at 10:51:08AM -0300, Adhemerval Zanella via Libc-alpha wrote: > > The compiler might transform __stpcpy calls (which are routed to > > __builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy > > multiarch implementation does not build any working symbol due > > ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld). > > Ohhhhhh... that is interesting. This changes the strcpy used in rtld for > all x86_64 build options, and I'm going to ACK this, but we may need to > revisit this if it shows up in a profile. Will this lead to both strcpy and stpcpy in ld.so? Currently there is only stpcpy in ld.so. > CC'ing HJ here in case he wants to comment as a machine maintainer. > > LGTM. > > No regressions on x86_64. > > Reviewed-by: Carlos O'Donell <carlos@redhat.com> > Tested-by: Carlos O'Donell <carlos@redhat.com> > > > Checked on x86_64-linux-gnu. > > --- > > sysdeps/x86_64/multiarch/rtld-strcpy.S | 18 ++++++++++++++++++ > > 1 file changed, 18 insertions(+) > > create mode 100644 sysdeps/x86_64/multiarch/rtld-strcpy.S > > > > diff --git a/sysdeps/x86_64/multiarch/rtld-strcpy.S b/sysdeps/x86_64/multiarch/rtld-strcpy.S > > new file mode 100644 > > index 0000000000..19439c553d > > --- /dev/null > > +++ b/sysdeps/x86_64/multiarch/rtld-strcpy.S > > @@ -0,0 +1,18 @@ > > +/* Copyright (C) 2022 Free Software Foundation, Inc. > > + This file is part of the GNU C Library. > > + > > + The GNU C Library is free software; you can redistribute it and/or > > + modify it under the terms of the GNU Lesser General Public > > + License as published by the Free Software Foundation; either > > + version 2.1 of the License, or (at your option) any later version. > > + > > + The GNU C Library is distributed in the hope that it will be useful, > > + but WITHOUT ANY WARRANTY; without even the implied warranty of > > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > > + Lesser General Public License for more details. > > + > > + You should have received a copy of the GNU Lesser General Public > > + License along with the GNU C Library; if not, see > > + <https://www.gnu.org/licenses/>. */ > > + > > +#include "../strcpy.S" > > OK. Uses Makeconfig:sysd-rules-patterns to capture rtld-*. > > > -- > > 2.34.1 > > >
On 05/10/22 14:21, H.J. Lu wrote: > On Wed, Oct 5, 2022 at 7:10 AM Carlos O'Donell <carlos@redhat.com> wrote: >> >> On Wed, Sep 21, 2022 at 10:51:08AM -0300, Adhemerval Zanella via Libc-alpha wrote: >>> The compiler might transform __stpcpy calls (which are routed to >>> __builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy >>> multiarch implementation does not build any working symbol due >>> ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld). >> >> Ohhhhhh... that is interesting. This changes the strcpy used in rtld for >> all x86_64 build options, and I'm going to ACK this, but we may need to >> revisit this if it shows up in a profile. > > Will this lead to both strcpy and stpcpy in ld.so? Currently there is only > stpcpy in ld.so. I think that is expected behavior if compiler creates a reference for a supported string function in the loader (rtld build pulls the implementation). > >> CC'ing HJ here in case he wants to comment as a machine maintainer. >> >> LGTM. >> >> No regressions on x86_64. >> >> Reviewed-by: Carlos O'Donell <carlos@redhat.com> >> Tested-by: Carlos O'Donell <carlos@redhat.com> >> >>> Checked on x86_64-linux-gnu. >>> --- >>> sysdeps/x86_64/multiarch/rtld-strcpy.S | 18 ++++++++++++++++++ >>> 1 file changed, 18 insertions(+) >>> create mode 100644 sysdeps/x86_64/multiarch/rtld-strcpy.S >>> >>> diff --git a/sysdeps/x86_64/multiarch/rtld-strcpy.S b/sysdeps/x86_64/multiarch/rtld-strcpy.S >>> new file mode 100644 >>> index 0000000000..19439c553d >>> --- /dev/null >>> +++ b/sysdeps/x86_64/multiarch/rtld-strcpy.S >>> @@ -0,0 +1,18 @@ >>> +/* Copyright (C) 2022 Free Software Foundation, Inc. >>> + This file is part of the GNU C Library. >>> + >>> + The GNU C Library is free software; you can redistribute it and/or >>> + modify it under the terms of the GNU Lesser General Public >>> + License as published by the Free Software Foundation; either >>> + version 2.1 of the License, or (at your option) any later version. >>> + >>> + The GNU C Library is distributed in the hope that it will be useful, >>> + but WITHOUT ANY WARRANTY; without even the implied warranty of >>> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >>> + Lesser General Public License for more details. >>> + >>> + You should have received a copy of the GNU Lesser General Public >>> + License along with the GNU C Library; if not, see >>> + <https://www.gnu.org/licenses/>. */ >>> + >>> +#include "../strcpy.S" >> >> OK. Uses Makeconfig:sysd-rules-patterns to capture rtld-*. >> >>> -- >>> 2.34.1 >>> >> > >
On Wed, Oct 5, 2022 at 10:38 AM Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> wrote: > > > > On 05/10/22 14:21, H.J. Lu wrote: > > On Wed, Oct 5, 2022 at 7:10 AM Carlos O'Donell <carlos@redhat.com> wrote: > >> > >> On Wed, Sep 21, 2022 at 10:51:08AM -0300, Adhemerval Zanella via Libc-alpha wrote: > >>> The compiler might transform __stpcpy calls (which are routed to > >>> __builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy > >>> multiarch implementation does not build any working symbol due > >>> ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld). > >> > >> Ohhhhhh... that is interesting. This changes the strcpy used in rtld for > >> all x86_64 build options, and I'm going to ACK this, but we may need to > >> revisit this if it shows up in a profile. > > > > Will this lead to both strcpy and stpcpy in ld.so? Currently there is only > > stpcpy in ld.so. > > I think that is expected behavior if compiler creates a reference for a > supported string function in the loader (rtld build pulls the > implementation). strcpy is only generated in dl-profile.os: text data bss dec hex filename 2716 0 72 2788 ae4 dl-profile.os (-O2) 2265 0 72 2337 921 dl-profile.os (-Os) 1840 0 0 1840 730 strcpy.os Should we compile dl-profile.c with -O2 with CFLAGS-dl-profile.c += $(if $(findstring -Os,$(+cflags)), -O2) It will create a smaller ld.so. > > > >> CC'ing HJ here in case he wants to comment as a machine maintainer. > >> > >> LGTM. > >> > >> No regressions on x86_64. > >> > >> Reviewed-by: Carlos O'Donell <carlos@redhat.com> > >> Tested-by: Carlos O'Donell <carlos@redhat.com> > >> > >>> Checked on x86_64-linux-gnu. > >>> --- > >>> sysdeps/x86_64/multiarch/rtld-strcpy.S | 18 ++++++++++++++++++ > >>> 1 file changed, 18 insertions(+) > >>> create mode 100644 sysdeps/x86_64/multiarch/rtld-strcpy.S > >>> > >>> diff --git a/sysdeps/x86_64/multiarch/rtld-strcpy.S b/sysdeps/x86_64/multiarch/rtld-strcpy.S > >>> new file mode 100644 > >>> index 0000000000..19439c553d > >>> --- /dev/null > >>> +++ b/sysdeps/x86_64/multiarch/rtld-strcpy.S > >>> @@ -0,0 +1,18 @@ > >>> +/* Copyright (C) 2022 Free Software Foundation, Inc. > >>> + This file is part of the GNU C Library. > >>> + > >>> + The GNU C Library is free software; you can redistribute it and/or > >>> + modify it under the terms of the GNU Lesser General Public > >>> + License as published by the Free Software Foundation; either > >>> + version 2.1 of the License, or (at your option) any later version. > >>> + > >>> + The GNU C Library is distributed in the hope that it will be useful, > >>> + but WITHOUT ANY WARRANTY; without even the implied warranty of > >>> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > >>> + Lesser General Public License for more details. > >>> + > >>> + You should have received a copy of the GNU Lesser General Public > >>> + License along with the GNU C Library; if not, see > >>> + <https://www.gnu.org/licenses/>. */ > >>> + > >>> +#include "../strcpy.S" > >> > >> OK. Uses Makeconfig:sysd-rules-patterns to capture rtld-*. > >> > >>> -- > >>> 2.34.1 > >>> > >> > > > >
On 05/10/22 15:06, H.J. Lu wrote: > On Wed, Oct 5, 2022 at 10:38 AM Adhemerval Zanella Netto > <adhemerval.zanella@linaro.org> wrote: >> >> >> >> On 05/10/22 14:21, H.J. Lu wrote: >>> On Wed, Oct 5, 2022 at 7:10 AM Carlos O'Donell <carlos@redhat.com> wrote: >>>> >>>> On Wed, Sep 21, 2022 at 10:51:08AM -0300, Adhemerval Zanella via Libc-alpha wrote: >>>>> The compiler might transform __stpcpy calls (which are routed to >>>>> __builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy >>>>> multiarch implementation does not build any working symbol due >>>>> ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld). >>>> >>>> Ohhhhhh... that is interesting. This changes the strcpy used in rtld for >>>> all x86_64 build options, and I'm going to ACK this, but we may need to >>>> revisit this if it shows up in a profile. >>> >>> Will this lead to both strcpy and stpcpy in ld.so? Currently there is only >>> stpcpy in ld.so. >> >> I think that is expected behavior if compiler creates a reference for a >> supported string function in the loader (rtld build pulls the >> implementation). > > strcpy is only generated in dl-profile.os: > > text data bss dec hex filename > 2716 0 72 2788 ae4 dl-profile.os (-O2) > 2265 0 72 2337 921 dl-profile.os (-Os) > 1840 0 0 1840 730 strcpy.os > > Should we compile dl-profile.c with -O2 with > > CFLAGS-dl-profile.c += $(if $(findstring -Os,$(+cflags)), -O2) > > It will create a smaller ld.so. It might be an option to a subsequent patch, but I would avoid trying to outsmart the compiler here since it might generate a smaller in other version and it would most likely be arch-specific (adding even more building complexity).
On Wed, Oct 5, 2022 at 1:43 PM Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> wrote: > > > > On 05/10/22 15:06, H.J. Lu wrote: > > On Wed, Oct 5, 2022 at 10:38 AM Adhemerval Zanella Netto > > <adhemerval.zanella@linaro.org> wrote: > >> > >> > >> > >> On 05/10/22 14:21, H.J. Lu wrote: > >>> On Wed, Oct 5, 2022 at 7:10 AM Carlos O'Donell <carlos@redhat.com> wrote: > >>>> > >>>> On Wed, Sep 21, 2022 at 10:51:08AM -0300, Adhemerval Zanella via Libc-alpha wrote: > >>>>> The compiler might transform __stpcpy calls (which are routed to > >>>>> __builtin_stpcpy as an optimization) to strcpy and x86_64 strcpy > >>>>> multiarch implementation does not build any working symbol due > >>>>> ISA_SHOULD_BUILD not being evaluated for IS_IN(rtld). > >>>> > >>>> Ohhhhhh... that is interesting. This changes the strcpy used in rtld for > >>>> all x86_64 build options, and I'm going to ACK this, but we may need to > >>>> revisit this if it shows up in a profile. > >>> > >>> Will this lead to both strcpy and stpcpy in ld.so? Currently there is only > >>> stpcpy in ld.so. > >> > >> I think that is expected behavior if compiler creates a reference for a > >> supported string function in the loader (rtld build pulls the > >> implementation). > > > > strcpy is only generated in dl-profile.os: > > > > text data bss dec hex filename > > 2716 0 72 2788 ae4 dl-profile.os (-O2) > > 2265 0 72 2337 921 dl-profile.os (-Os) > > 1840 0 0 1840 730 strcpy.os > > > > Should we compile dl-profile.c with -O2 with > > > > CFLAGS-dl-profile.c += $(if $(findstring -Os,$(+cflags)), -O2) > > > > It will create a smaller ld.so. > > It might be an option to a subsequent patch, but I would avoid trying to outsmart > the compiler here since it might generate a smaller in other version and it would > most likely be arch-specific (adding even more building complexity). > Fair enough. LGTM. Thanks.
diff --git a/sysdeps/x86_64/multiarch/rtld-strcpy.S b/sysdeps/x86_64/multiarch/rtld-strcpy.S new file mode 100644 index 0000000000..19439c553d --- /dev/null +++ b/sysdeps/x86_64/multiarch/rtld-strcpy.S @@ -0,0 +1,18 @@ +/* Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include "../strcpy.S"