Re: [gcc r14-2455] riscv: Prepare backend for index registers

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Andreas Schwab]

Why didn't you test that?

../../gcc/config/riscv/riscv.cc: In function 'int riscv_regno_ok_for_index_p(int)':
../../gcc/config/riscv/riscv.cc:864:33: error: unused parameter 'regno' [-Werror=unused-parameter]
  864 | riscv_regno_ok_for_index_p (int regno)
      |                             ~~~~^~~~~
cc1plus: all warnings being treated as errors
make[3]: *** [Makefile:2499: riscv.o] Error 1

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Christoph Müllner]

On Fri, Jul 14, 2023 at 12:28 PM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> Why didn't you test that?

Thanks for reporting, and sorry for introducing this warning.

I test all patches before sending them.
In the case of RISC-V backend patches, I build a 2-stage
cross-toolchain and run all regression tests for RV32 and RV64 (using
QEMU).
Testing is done with and without patches applied to identify regressions.

The build process shows a lot of warnings. Therefore I did not
investigate finding a way to use -Werror.
This means that looking for compiler warnings is a manual step, and I
might miss one while scrolling through the logs.

Sorry for the inconvenience,
Christoph


>
> ../../gcc/config/riscv/riscv.cc: In function 'int riscv_regno_ok_for_index_p(int)':
> ../../gcc/config/riscv/riscv.cc:864:33: error: unused parameter 'regno' [-Werror=unused-parameter]
>   864 | riscv_regno_ok_for_index_p (int regno)
>       |                             ~~~~^~~~~
> cc1plus: all warnings being treated as errors
> make[3]: *** [Makefile:2499: riscv.o] Error 1
>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
> "And now for something completely different."

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Andreas Schwab]

On Jul 17 2023, Christoph Müllner wrote:

> The build process shows a lot of warnings.

Then you are using a bad compiler.  The build is 100% -Werror clean.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Christoph Müllner]

On Mon, Jul 17, 2023 at 9:24 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Jul 17 2023, Christoph Müllner wrote:
>
> > The build process shows a lot of warnings.
>
> Then you are using a bad compiler.  The build is 100% -Werror clean.

My host compiler is: gcc version 13.1.1 20230614 (Red Hat 13.1.1-4) (GCC)

Some examples:

> /home/cm/src/gcc/riscv-mainline/gcc/text-art/table.cc: In member function ‘int text_art::table_geometry::table_x_to_canvas_x(int) const’:
> /home/cm/src/gcc/riscv-mainline/gcc/text-art/table.cc:561:15: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
>   561 |   if (table_x == m_col_start_x.size ())
>       |       ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

> /home/cm/src/gcc/riscv-mainline/gcc/text-art/table.cc: In function ‘void selftest::test_spans_3()’:
> /home/cm/src/gcc/riscv-mainline/gcc/text-art/table.cc:947:62: warning: unquoted keyword ‘char’ in format [-Wformat-diag]
>  947 |                                                      "'buf' (char[%i])",
>       |                                                              ^~~~

> /home/cm/src/gcc/riscv-mainline/gcc/gengtype-lex.l: In function ‘int yylex(const char**)’:
> gengtype-lex.cc:356:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
>   356 |  */
>       |  ~~           ^

> In file included from /home/cm/src/gcc/riscv-mainline/libgcc/unwind-dw2.c:410:
> ./md-unwind-support.h: In function 'riscv_fallback_frame_state':
> ./md-unwind-support.h:67:6: warning: assignment to 'struct sigcontext *' from incompatible pointer type 'mcontext_t *' [-Wincompatible-pointer-types]
>   67 |   sc = &rt_->uc.uc_mcontext;
>      |      ^

> /home/cm/src/gcc/riscv-mainline/libgcc/config/riscv/atomic.c:36:8: warning: conflicting types for built-in function '__sync_fetch_and_add_1'; expected 'unsigned char(volatile void *, unsigned char)' [-Wbuiltin-declaration-mismatch]
>    36 |   type __sync_fetch_and_ ## opname ## _ ## size (type *p, type v)       \
>       |        ^~~~~~~~~~~~~~~~~

Please let me know if I am doing something wrong.

BR
Christoph


>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
> "And now for something completely different."

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Andreas Schwab]

On Jul 17 2023, Christoph Müllner wrote:

> My host compiler is: gcc version 13.1.1 20230614 (Red Hat 13.1.1-4) (GCC)

Too old.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Christoph Müllner]

On Mon, Jul 17, 2023 at 9:44 AM Andreas Schwab <schwab@linux-m68k.org> wrote:
>
> On Jul 17 2023, Christoph Müllner wrote:
>
> > My host compiler is: gcc version 13.1.1 20230614 (Red Hat 13.1.1-4) (GCC)
>
> Too old.

Ok understood.

Thanks,
Christoph

>
> --
> Andreas Schwab, schwab@linux-m68k.org
> GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
> "And now for something completely different."

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Andrew Pinski]

On Sun, Jul 16, 2023 at 11:49 PM Christoph Müllner
<christoph.muellner@vrull.eu> wrote:
>
> On Fri, Jul 14, 2023 at 12:28 PM Andreas Schwab <schwab@linux-m68k.org> wrote:
> >
> > Why didn't you test that?
>
> Thanks for reporting, and sorry for introducing this warning.
>
> I test all patches before sending them.
> In the case of RISC-V backend patches, I build a 2-stage
> cross-toolchain and run all regression tests for RV32 and RV64 (using
> QEMU).
> Testing is done with and without patches applied to identify regressions.
>
> The build process shows a lot of warnings. Therefore I did not
> investigate finding a way to use -Werror.
> This means that looking for compiler warnings is a manual step, and I
> might miss one while scrolling through the logs.

If you are building a cross compiler, and want to clean up warnings,
first build a native compiler and then build the cross using that.
Also maybe it is finding a way to do native bootstraps on riscv to do
testing of patches rather than doing just cross builds when testing
backend patches.
Especially when I have found the GCC testsuite but the bootstrap is
more likely to find backend issues and such.

Thanks,
Andrew

>
> Sorry for the inconvenience,
> Christoph
>
>
> >
> > ../../gcc/config/riscv/riscv.cc: In function 'int riscv_regno_ok_for_index_p(int)':
> > ../../gcc/config/riscv/riscv.cc:864:33: error: unused parameter 'regno' [-Werror=unused-parameter]
> >   864 | riscv_regno_ok_for_index_p (int regno)
> >       |                             ~~~~^~~~~
> > cc1plus: all warnings being treated as errors
> > make[3]: *** [Makefile:2499: riscv.o] Error 1
> >
> > --
> > Andreas Schwab, schwab@linux-m68k.org
> > GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
> > "And now for something completely different."

Re: [gcc r14-2455] riscv: Prepare backend for index registers

[Christoph Müllner]

On Mon, Jul 17, 2023 at 9:31 AM Andrew Pinski <pinskia@gmail.com> wrote:
>
> On Sun, Jul 16, 2023 at 11:49 PM Christoph Müllner
> <christoph.muellner@vrull.eu> wrote:
> >
> > On Fri, Jul 14, 2023 at 12:28 PM Andreas Schwab <schwab@linux-m68k.org> wrote:
> > >
> > > Why didn't you test that?
> >
> > Thanks for reporting, and sorry for introducing this warning.
> >
> > I test all patches before sending them.
> > In the case of RISC-V backend patches, I build a 2-stage
> > cross-toolchain and run all regression tests for RV32 and RV64 (using
> > QEMU).
> > Testing is done with and without patches applied to identify regressions.
> >
> > The build process shows a lot of warnings. Therefore I did not
> > investigate finding a way to use -Werror.
> > This means that looking for compiler warnings is a manual step, and I
> > might miss one while scrolling through the logs.
>
> If you are building a cross compiler, and want to clean up warnings,
> first build a native compiler and then build the cross using that.

Ok, will adjust my workflow accordingly.

> Also maybe it is finding a way to do native bootstraps on riscv to do
> testing of patches rather than doing just cross builds when testing
> backend patches.
> Especially when I have found the GCC testsuite but the bootstrap is
> more likely to find backend issues and such.

Yes, using the patch-under-testing to build a toolchain can identify
issues that the testsuite can't find. I did that a couple of times in a
QEMU environment, but I prefer the cross-toolchain approach because
it is faster. For patches that have a bigger impact, I test the toolchain
with SPEC CPU 2017.

Thanks,
Christoph

>
> Thanks,
> Andrew
>
> >
> > Sorry for the inconvenience,
> > Christoph
> >
> >
> > >
> > > ../../gcc/config/riscv/riscv.cc: In function 'int riscv_regno_ok_for_index_p(int)':
> > > ../../gcc/config/riscv/riscv.cc:864:33: error: unused parameter 'regno' [-Werror=unused-parameter]
> > >   864 | riscv_regno_ok_for_index_p (int regno)
> > >       |                             ~~~~^~~~~
> > > cc1plus: all warnings being treated as errors
> > > make[3]: *** [Makefile:2499: riscv.o] Error 1
> > >
> > > --
> > > Andreas Schwab, schwab@linux-m68k.org
> > > GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
> > > "And now for something completely different."