[Bug bootstrap/100327] New: [12 regression] bootstrap failure after r12-228

[Bug bootstrap/100327] New: [12 regression] bootstrap failure after r12-228

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

            Bug ID: 100327
           Summary: [12 regression] bootstrap failure after r12-228
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: seurer at gcc dot gnu.org
  Target Milestone: ---

g:54f0224d55a1b56dde092460ddf76913670e6efc, r12-228

commit 54f0224d55a1b56dde092460ddf76913670e6efc (HEAD)
Author: Patrick McGehearty <patrick.mcgehearty@oracle.com>
Date:   Wed Apr 28 19:14:48 2021 +0000

    Practical improvement to libgcc complex divide


With this commit I am seeing the follow errors or similar on multiple powerpc64
test machines, possibly all of them.  Is this using things from a later version
of glibc or something that is now required?  If so this is going to be a
problem.

/home/seurer/gcc/git/build/gcc-trunk/./gcc/xgcc
-B/home/seurer/gcc/git/build/gcc-trunk/./gcc/
-B/home/seurer/gcc/git/install/gcc-trunk/powerpc64le-unknown-linux-gnu/bin/
-B/home/seurer/gcc/git/install/gcc-trunk/powerpc64le-unknown-linux-gnu/lib/
-isystem
/home/seurer/gcc/git/install/gcc-trunk/powerpc64le-unknown-linux-gnu/include
-isystem
/home/seurer/gcc/git/install/gcc-trunk/powerpc64le-unknown-linux-gnu/sys-include
   -g -O2 -O2  -g -O2 -DIN_GCC    -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition 
-isystem ./include   -fPIC -mlong-double-128 -mno-minimal-toc -g -DIN_LIBGCC2
-fbuilding-libgcc -fno-stack-protector   -fPIC -mlong-double-128
-mno-minimal-toc -I. -I. -I../.././gcc -I/home/seurer/gcc/git/gcc-trunk/libgcc
-I/home/seurer/gcc/git/gcc-trunk/libgcc/.
-I/home/seurer/gcc/git/gcc-trunk/libgcc/../gcc
-I/home/seurer/gcc/git/gcc-trunk/libgcc/../include
-I/home/seurer/gcc/git/gcc-trunk/libgcc/../libdecnumber/dpd
-I/home/seurer/gcc/git/gcc-trunk/libgcc/../libdecnumber -DHAVE_CC_TLS 
-Wno-type-limits -mvsx -mfloat128 -mno-float128-hardware -mno-gnu-attribute
-I/home/seurer/gcc/git/gcc-trunk/libgcc/soft-fp
-I/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000 -DFLOAT128_HW_INSNS -o
_divkc3.o -MT _divkc3.o -MD -MP -MF _divkc3.dep  -c
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c
-fvisibility=hidden -DHIDE_EXPORTS
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c: In function
'__divkc3_sw':
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:41:17: error:
'__LIBGCC_KF_MAX__' undeclared (first use in this function)
   41 | #define RBIG   (__LIBGCC_KF_MAX__ / 2)
      |                 ^~~~~~~~~~~~~~~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:68:23: note: in
expansion of macro 'RBIG'
   68 |       if (FABS (d) >= RBIG)
      |                       ^~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:41:17: note: each
undeclared identifier is reported only once for each function it appears in
   41 | #define RBIG   (__LIBGCC_KF_MAX__ / 2)
      |                 ^~~~~~~~~~~~~~~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:68:23: note: in
expansion of macro 'RBIG'
   68 |       if (FABS (d) >= RBIG)
      |                       ^~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:43:17: error:
'__LIBGCC_KF_EPSILON__' undeclared (first use in this function)
   43 | #define RMIN2  (__LIBGCC_KF_EPSILON__)
      |                 ^~~~~~~~~~~~~~~~~~~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:78:22: note: in
expansion of macro 'RMIN2'
   78 |       if (FABS (d) < RMIN2)
      |                      ^~~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:42:17: error:
'__LIBGCC_KF_MIN__' undeclared (first use in this function)
   42 | #define RMIN   (__LIBGCC_KF_MIN__)
      |                 ^~~~~~~~~~~~~~~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/config/rs6000/_divkc3.c:87:28: note: in
expansion of macro 'RMIN'
   87 |           if (((FABS (a) < RMIN) && (FABS (b) < RMAX2) && (FABS (d) <
RMAX2))
      |                            ^~~~
/home/seurer/gcc/git/gcc-trunk/libgcc/shared-object.mk:14: recipe for target
'_divkc3.o' failed
make[2]: *** [_divkc3.o] Error 1

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

seurer at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
              Build|                            |powerpc64*-linux-gnu
             Target|                            |powerpc64*-linux-gnu
               Host|                            |powerpc64*-linux-gnu

--- Comment #1 from seurer at gcc dot gnu.org ---
Note:  I could not find an email for patrick.mcgehearty@oracle.com that worked
to add him to the CC: list.

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
   Target Milestone|---                         |12.0

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think backends or the FE are supposed to pre-define __LIBGCC_KF_* if
-fbuilding-libgcc

See c-family/c-cppbuiltin.c where it checks for flag_building_libgcc.

Not sure why that doesn't pick up KFmode?

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Possibly

          if (!targetm.scalar_mode_supported_p (mode)
              || !targetm.libgcc_floating_mode_supported_p (mode))
            continue;

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

Michael Meissner <meissner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |meissner at gcc dot gnu.org

--- Comment #4 from Michael Meissner <meissner at gcc dot gnu.org> ---
Created attachment 50708
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50708&action=edit
patch to define floating point constants for KFmode and IFmode.

I am about to kick off a bootstrap with this patch.

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

--- Comment #5 from Michael Meissner <meissner at gcc dot gnu.org> ---
Unfortunately the patch does not work because there aren't suffixes for IFmode
and KFmode.

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

Michael Meissner <meissner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #50708|0                           |1
        is obsolete|                            |
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2021-04-29
           Assignee|unassigned at gcc dot gnu.org      |meissner at gcc dot gnu.org

--- Comment #6 from Michael Meissner <meissner at gcc dot gnu.org> ---
Created attachment 50709
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50709&action=edit
Use FLT128 constants for complex KFmode division.

This patch uses the FLT128 constants that are already defined for building
_divkf3.c instead of trying expect the constants to be defined as __LIBGCC_KF. 
The __LIBGCC_KF constants are not defined.

I am starting a build now with this patch.

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

Michael Meissner <meissner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #7 from Michael Meissner <meissner at gcc dot gnu.org> ---
Patch committed on April 29th, 2021.

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org

--- Comment #8 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Michael Meissner from comment #7)
> Patch committed on April 29th, 2021.

Actually, no patch was committed – albeit some patches were submitted. Still,
this PR was closed as FIXED ...

Current status: PR 100350.

[Bug bootstrap/100327] [12 regression] bootstrap failure after r12-228

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100327

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Michael Meissner <meissner@gcc.gnu.org>:

https://gcc.gnu.org/g:d9398dd2902a0142fa3b493cf61a340f1f5ab46f

commit r12-325-gd9398dd2902a0142fa3b493cf61a340f1f5ab46f
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Fri Apr 30 12:32:08 2021 -0400

    Define target hook to emit KFmode constants for libgcc.

    This patch defines a target hook so that the KFmode constants
    (__LIBGCC_KF_MAX__, __LIBGCC_KF_MIN__, and __LIBGCC_KF_EPSILON__) needed to
    build _divkc3.c in libgcc are defined.  The need for these constants were
added
    in the April 28th changes to libgcc that added complex division
optimizations.

    We only define the KFmode constants if IEEE 128-bit floating point is
    supported, but long double does not use the IEEE 128-bit format.  If long
    double uses the IEEE 128-bit format, it will use TFmode and not KFmode.

    gcc/
    2021-04-30  Michael Meissner  <meissner@linux.ibm.com>

            PR bootstrap/100327
            * config/rs6000/rs6000.c
            (TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P): Define.
            (rs6000_libgcc_floating_mode_supported_p): New target hook.