[Bug target/96236] New: __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[Bug target/96236] New: __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96236

            Bug ID: 96236
           Summary: __builtin_mma_disassemble_acc() doesn't store elements
                    correctly in LE mode
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bergner at gcc dot gnu.org
  Target Milestone: ---

The __builtin_mma_disassemble_acc built-in doesn't correctly account for little
endian byte ordering of the pointer type passed to it is not a __vector_quad
pointer as the following test case shows:

bergner@pike:~/$ cat disassemble.c 
void
buggy (void *dst)
{
  __vector_quad acc;
  __builtin_mma_xxsetaccz (&acc);
  __builtin_mma_disassemble_acc (dst, &acc);
}

void
foo (__vector_quad *dst)
{
  __vector_quad acc;
  __builtin_mma_xxsetaccz (&acc);
  __builtin_mma_disassemble_acc (dst, &acc);
}
bergner@pike:~/$ gcc -S -O2 -mcpu=power10 disassemble.c 
bergner@pike:~/$ cat disassemble.s 
buggy:
        xxsetaccz 0
        xxmfacc 0
        stxv 0,0(3)
        stxv 1,16(3)
        stxv 2,32(3)
        stxv 3,48(3)
        blr

foo:
        xxsetaccz 0
        xxmfacc 0
        stxvp 2,0(3)
        stxvp 0,32(3)
        blr

[Bug target/96236] __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96236

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2020-07-17
     Ever confirmed|0                           |1
             Target|                            |powerpc64le-linux
           Assignee|unassigned at gcc dot gnu.org      |bergner at gcc dot gnu.org

--- Comment #1 from Peter Bergner <bergner at gcc dot gnu.org> ---
Mine.  This is broken in the FSF GCC 10 branch as well.

[Bug target/96236] __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96236

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Peter Bergner <bergner@gcc.gnu.org>:

https://gcc.gnu.org/g:ae575662833d70cb7d74b9538096c7becc79af14

commit r11-2278-gae575662833d70cb7d74b9538096c7becc79af14
Author: Peter Bergner <bergner@linux.ibm.com>
Date:   Wed Jul 22 11:44:35 2020 -0500

    rs6000: __builtin_mma_disassemble_acc() doesn't store elements correctly in
LE mode

    PR96236 shows a problem where we don't correctly store our 512-bit
accumulators
    correctly in little-endian mode.  The patch below detects when we're doing
a
    little-endian memory access and stores to the correct memory locations.

    2020-07-22  Peter Bergner  <bergner@linux.ibm.com>

    gcc/
            PR target/96236
            * config/rs6000/rs6000-call.c (rs6000_gimple_fold_mma_builtin):
Handle
            little-endian memory ordering.

    gcc/testsuite/
            PR target/96236
            * gcc.target/powerpc/mma-double-test.c: Update storing results for
            correct little-endian ordering.
            * gcc.target/powerpc/mma-single-test.c: Likewise.

[Bug target/96236] __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96236

--- Comment #3 from Peter Bergner <bergner at gcc dot gnu.org> ---
Fixed on trunk.  I will backport to the GCC 10 release branch once it reopens.

I would have set the target milestone to 10.3, but that version isn't an option
right now.

[Bug target/96236] __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96236

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |10.3

[Bug target/96236] __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96236

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Peter Bergner
<bergner@gcc.gnu.org>:

https://gcc.gnu.org/g:5497677b497b95a261089d19f5295cc80f99a2b6

commit r10-8522-g5497677b497b95a261089d19f5295cc80f99a2b6
Author: Peter Bergner <bergner@linux.ibm.com>
Date:   Wed Jul 22 11:44:35 2020 -0500

    rs6000: __builtin_mma_disassemble_acc() doesn't store elements correctly in
LE mode

    PR96236 shows a problem where we don't correctly store our 512-bit
accumulators
    correctly in little-endian mode.  The patch below detects when we're doing
a
    little-endian memory access and stores to the correct memory locations.

    2020-07-22  Peter Bergner  <bergner@linux.ibm.com>

    gcc/
            PR target/96236
            * config/rs6000/rs6000-call.c (rs6000_gimple_fold_mma_builtin):
Handle
            little-endian memory ordering.

    gcc/testsuite/
            PR target/96236
            * gcc.target/powerpc/mma-double-test.c: Update storing results for
            correct little-endian ordering.
            * gcc.target/powerpc/mma-single-test.c: Likewise.

    (cherry picked from commit ae575662833d70cb7d74b9538096c7becc79af14)

[Bug target/96236] __builtin_mma_disassemble_acc() doesn't store elements correctly in LE mode

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96236

Peter Bergner <bergner at gcc dot gnu.org> changed:

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

--- Comment #5 from Peter Bergner <bergner at gcc dot gnu.org> ---
Fixed everywhere.