[Bug c++/100809] New: PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[Bug c++/100809] New: PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[jens.seifert at de dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

            Bug ID: 100809
           Summary: PPC: __int128 divide/modulo does not use P10
                    instructions vdivsq/vdivuq
           Product: gcc
           Version: 10.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jens.seifert at de dot ibm.com
  Target Milestone: ---

unsigned __int128 div(unsigned __int128 a, unsigned __int128 b)
{
   return a/b;
}

__int128 div(__int128 a, __int128 b)
{
   return a/b;
}

gcc -mcpu=power10 -save-temps -O2 int128.C

Output:
_Z3divoo:
.LFB0:
        .cfi_startproc
        .localentry     _Z3divoo,1
        mflr 0
        std 0,16(1)
        stdu 1,-32(1)
        .cfi_def_cfa_offset 32
        .cfi_offset 65, 16
        bl __udivti3@notoc
        addi 1,1,32
        .cfi_def_cfa_offset 0
        ld 0,16(1)
        mtlr 0
        .cfi_restore 65
        blr
        .long 0
        .byte 0,9,0,1,128,0,0,0
        .cfi_endproc
.LFE0:
        .size   _Z3divoo,.-_Z3divoo
        .globl __divti3
        .align 2
        .p2align 4,,15
        .globl _Z3divnn
        .type   _Z3divnn, @function
_Z3divnn:
.LFB1:
        .cfi_startproc
        .localentry     _Z3divnn,1
        mflr 0
        std 0,16(1)
        stdu 1,-32(1)
        .cfi_def_cfa_offset 32
        .cfi_offset 65, 16
        bl __divti3@notoc
        addi 1,1,32
        .cfi_def_cfa_offset 0
        ld 0,16(1)
        mtlr 0
        .cfi_restore 65
        blr
        .long 0
        .byte 0,9,0,1,128,0,0,0
        .cfi_endproc

Expected is the use of vdivsq/vdivuq.

GCC version:

/opt/rh/devtoolset-10/root/usr/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/rh/devtoolset-10/root/usr/bin/gcc
COLLECT_LTO_WRAPPER=/opt/rh/devtoolset-10/root/usr/libexec/gcc/ppc64le-redhat-linux/10/lto-wrapper
Target: ppc64le-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,fortran,lto --prefix=/opt/rh/devtoolset-10/root/usr
--mandir=/opt/rh/devtoolset-10/root/usr/share/man
--infodir=/opt/rh/devtoolset-10/root/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release
--enable-targets=powerpcle-linux --disable-multilib --with-system-zlib
--enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id --with-gcc-major-version-only
--with-linker-hash-style=gnu --with-default-libstdcxx-abi=gcc4-compatible
--enable-plugin --enable-initfini-array
--with-isl=/builddir/build/BUILD/gcc-10.2.1-20200804/obj-ppc64le-redhat-linux/isl-install
--disable-libmpx --enable-gnu-indirect-function --enable-secureplt
--with-long-double-128 --with-cpu-32=power8 --with-tune-32=power8
--with-cpu-64=power8 --with-tune-64=power8 --build=ppc64le-redhat-linux
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.2.1 20200804 (Red Hat 10.2.1-2) (GCC)

[Bug c++/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[jens.seifert at de dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

--- Comment #1 from Jens Seifert <jens.seifert at de dot ibm.com> ---
Same applies to modulo.

[Bug c++/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

--- Comment #2 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
I believe this work is pending, but the patches are still under review.

[Bug c++/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-06-01
             Status|UNCONFIRMED                 |NEW
                 CC|                            |carll at gcc dot gnu.org,
                   |                            |meissner at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #3 from Michael Meissner <meissner at gcc dot gnu.org> ---
Carl Love submitted a patch for this on April 26th.

[Bug c++/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

--- Comment #4 from Michael Meissner <meissner at gcc dot gnu.org> ---
Note, in looking at Carl's patch, it is only for adding the built-ins.  I don't
believe it adds direct support for {,u}divti3 and {,u}moddti3 to implement
these for normal __int128 variables.

[Bug c++/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |meissner at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

--- Comment #5 from Michael Meissner <meissner at gcc dot gnu.org> ---
Patch submitted:
https://gcc.gnu.org/pipermail/gcc-patches/2021-June/571942.html

[Bug target/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

--- Comment #6 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:852b11da11a181df517c0348df044354ff0656d6

commit r12-2135-g852b11da11a181df517c0348df044354ff0656d6
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Wed Jul 7 21:55:38 2021 -0400

    Generate 128-bit int divide/modulus on power10.

    This patch adds support for the VDIVSQ, VDIVUQ, VMODSQ, and VMODUQ
    instructions to do 128-bit arithmetic.

    2021-07-07  Michael Meissner  <meissner@linux.ibm.com>

    gcc/
            PR target/100809
            * config/rs6000/rs6000.md (udivti3): New insn.
            (divti3): New insn.
            (umodti3): New insn.
            (modti3): New insn.

    gcc/testsuite/
            PR target/100809
            * gcc.target/powerpc/p10-vdivq-vmodq.c: New test.

[Bug target/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Michael Meissner
<meissner@gcc.gnu.org>:

https://gcc.gnu.org/g:8ebcd3608584e544ae8e7c422b3f2400758c47f5

commit r11-8743-g8ebcd3608584e544ae8e7c422b3f2400758c47f5
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Wed Jul 14 13:23:51 2021 -0400

    Generate 128-bit int divide/modulus on power10.

    This patch adds support for the VDIVSQ, VDIVUQ, VMODSQ, and VMODUQ
    instructions to do 128-bit arithmetic.

    Backported from master: 2021-07-07  Michael Meissner 
<meissner@linux.ibm.com>

    2021-07-14  Michael Meissner  <meissner@linux.ibm.com>

    gcc/
            PR target/100809
            * config/rs6000/rs6000.md (udivti3): New insn.
            (divti3): New insn.
            (umodti3): New insn.
            (modti3): New insn.

    gcc/testsuite/
            PR target/100809
            * gcc.target/powerpc/p10-vdivq-vmodq.c: New test.

[Bug target/100809] PPC: __int128 divide/modulo does not use P10 instructions vdivsq/vdivuq

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100809

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

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

--- Comment #8 from Michael Meissner <meissner at gcc dot gnu.org> ---
Patch applied to mainline and GCC 11 branches.  PR closed.