[Bug target/113950] New: PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[Bug target/113950] New: PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[carll at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

            Bug ID: 113950
           Summary: PowerPC, ICE with -O1 or higher compiling
                    __builtin_vsx_splat_2di test case
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: carll at gcc dot gnu.org
  Target Milestone: ---

Power 10 LE
Fedora 38

Test of the __builtin_vsx_splat_2di ICEs on GCC 12 and later.

The following test case generates an ICE for -O1 and above.  It does work for
 -O0.

void abort (void);

int main ()
{
  int i;
  vector signed long long vsll_result, vsll_expected_result;
  signed long long sll_arg1;

  sll_arg1 = 300;
  vsll_expected_result = (vector signed long long) {300, 300};
  vsll_result = __builtin_vsx_splat_2di (sll_arg1);  //ISSUE                    

  for (i = 0; i < 2; i++)
    if (vsll_result[i] != vsll_expected_result[i])
      abort();

  return 0;
}

The test case compiles fine with -O0.

Here is the output when I try to compile  with -O1:

 gcc -g  -O1 compiler-bug.c -o compiler-bug
compiler-bug.c: In function ‘main’:
compiler-bug.c:19:1: error: unrecognizable insn:
   19 | }
      | ^
(insn 14 13 15 2 (set (reg:V2DI 117 [ _1 ])
        (vec_duplicate:V2DI (const_int 300 [0x12c]))) "compiler-bug.c":12:17 -1
     (nil))
during RTL pass: vregs
compiler-bug.c:19:1: internal compiler error: in extract_insn, at recog.cc:2791
Please submit a full bug report, with preprocessed source.
See <http://bugzilla.redhat.com/bugzilla> for instructions.
Preprocessed source stored into /tmp/ccnoI5lr.out file, please attach this to
your bugreport.

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2024-02-16
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Peter Bergner <bergner at gcc dot gnu.org> ---
Confirmed.

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jeevitha at gcc dot gnu.org
                 CC|                            |dje at gcc dot gnu.org,
                   |                            |linkw at gcc dot gnu.org,
                   |                            |meissner at gcc dot gnu.org,
                   |                            |segher at gcc dot gnu.org

--- Comment #2 from Peter Bergner <bergner at gcc dot gnu.org> ---
Jeevitha is looking into this for us.

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by jeevitha <jeevitha@gcc.gnu.org>:

https://gcc.gnu.org/g:fa0468877869f52b05742de6deef582e4dd296fc

commit r14-9362-gfa0468877869f52b05742de6deef582e4dd296fc
Author: Jeevitha <jeevitha@linux.ibm.com>
Date:   Thu Mar 7 07:41:38 2024 -0600

    rs6000: Don't ICE when compiling the __builtin_vsx_splat_2di [PR113950]

    When we expand the __builtin_vsx_splat_2di built-in, we were allowing
immediate
    value for second operand which causes an unrecognizable insn ICE. Even
though
    the immediate value was forced into a register, it wasn't correctly
assigned
    to the second operand. So corrected the assignment of op1 to operands[1].

    2024-03-07  Jeevitha Palanisamy  <jeevitha@linux.ibm.com>

    gcc/
            PR target/113950
            * config/rs6000/vsx.md (vsx_splat_<mode>): Correct assignment to
operand1
            and simplify else if with else.

    gcc/testsuite/
            PR target/113950
            * gcc.target/powerpc/pr113950.c: New testcase.

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

--- Comment #4 from Peter Bergner <bergner at gcc dot gnu.org> ---
The bogus vsx_splat_<mode> code goes all the way back to GCC 8, so we need
backports to the open release branches (GCC 13, 12, 11).

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by jeevitha <jeevitha@gcc.gnu.org>:

https://gcc.gnu.org/g:27eb6e81e6e578da9f9947d3f96c0fa58971fe7f

commit r13-8474-g27eb6e81e6e578da9f9947d3f96c0fa58971fe7f
Author: Jeevitha <jeevitha@linux.ibm.com>
Date:   Wed Mar 20 23:34:46 2024 -0500

    rs6000: Don't ICE when compiling the __builtin_vsx_splat_2di [PR113950]

    When we expand the __builtin_vsx_splat_2di built-in, we were allowing
immediate
    value for second operand which causes an unrecognizable insn ICE. Even
though
    the immediate value was forced into a register, it wasn't correctly
assigned
    to the second operand. So corrected the assignment of op1 to operands[1].

    2024-03-07  Jeevitha Palanisamy  <jeevitha@linux.ibm.com>

    gcc/
            PR target/113950
            * config/rs6000/vsx.md (vsx_splat_<mode>): Correct assignment to
operand1
            and simplify else if with else.

    gcc/testsuite/
            PR target/113950
            * gcc.target/powerpc/pr113950.c: New testcase.

    (cherry picked from commit fa0468877869f52b05742de6deef582e4dd296fc)

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by jeevitha <jeevitha@gcc.gnu.org>:

https://gcc.gnu.org/g:1b91818e47119863f827b19ae4c6c91af3962cd6

commit r12-10406-g1b91818e47119863f827b19ae4c6c91af3962cd6
Author: Jeevitha <jeevitha@linux.ibm.com>
Date:   Sun Apr 28 23:38:41 2024 -0500

    rs6000: Don't ICE when compiling the __builtin_vsx_splat_2di [PR113950]

    When we expand the __builtin_vsx_splat_2di built-in, we were allowing
immediate
    value for second operand which causes an unrecognizable insn ICE. Even
though
    the immediate value was forced into a register, it wasn't correctly
assigned
    to the second operand. So corrected the assignment of op1 to operands[1].

    2024-03-07  Jeevitha Palanisamy  <jeevitha@linux.ibm.com>

    gcc/
            PR target/113950
            * config/rs6000/vsx.md (vsx_splat_<mode>): Correct assignment to
operand1
            and simplify else if with else.

    gcc/testsuite/
            PR target/113950
            * gcc.target/powerpc/pr113950.c: New testcase.

    (cherry picked from commit fa0468877869f52b05742de6deef582e4dd296fc)

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[jeevitha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

--- Comment #7 from Jeevitha <jeevitha at gcc dot gnu.org> ---

In GCC 11, we encountered a different issue that didn't result in an ICE.

The following is the error message in GCC 11:

error: too few arguments to function '__builtin_vsx_splat_2di'
   11 |   vsll_result = __builtin_vsx_splat_2di (sll_arg1);  // ISSUE

The error indicated a shortage of arguments for the built-in function. It
expects two arguments because the function prototype is different in GCC 11
compared to GCC 12, 13, and 14.

I have found that the commit responsible for changing the function prototype
was made by Bill Schmidt (commit hash:
d08236359eb22918ba067489edcec02857109d09). In this commit, he introduced new
built-in functionality, where the function prototype is sourced from
rs6000-builtin-new.def, which includes the following declaration:

const vsll __builtin_vsx_splat_2di (signed long long);

Prior to this commit ie, in gcc11, the function prototype was sourced from
rs6000-builtin.def and included two arguments:

/* 2 argument VSX builtins.  */
BU_VSX_2 (SPLAT_2DI, "splat_2di", CONST, vsx_splat_v2di)

These changes are controlled by the setting new_builtins_are_live. Bill made
this change in his commit by adjusting this setting.

Due to the above prototype changes, we are not backporting to GCC 11.

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[jeevitha at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

Jeevitha <jeevitha at gcc dot gnu.org> changed:

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

--- Comment #8 from Jeevitha <jeevitha at gcc dot gnu.org> ---
Fixed, and all backports are done.

[Bug target/113950] PowerPC, ICE with -O1 or higher compiling __builtin_vsx_splat_2di test case

[shivam98.tkg at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950

--- Comment #9 from Shivam Gupta <shivam98.tkg at gmail dot com> ---
Good explanation 👍

On Thu, 16 May 2024 at 7:32 PM, jeevitha at gcc dot gnu.org via Gcc-bugs <
gcc-bugs@gcc.gnu.org> wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113950
>
> Jeevitha <jeevitha at gcc dot gnu.org> changed:
>
>            What    |Removed                     |Added
>
> ----------------------------------------------------------------------------
>          Resolution|---                         |FIXED
>              Status|ASSIGNED                    |RESOLVED
>
> --- Comment #8 from Jeevitha <jeevitha at gcc dot gnu.org> ---
> Fixed, and all backports are done.