[Bug tree-optimization/106375] New: [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[Bug tree-optimization/106375] New: [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

            Bug ID: 106375
           Summary: [13 regreesion] Lowering complex type mov regressed
                    loop distribution for memset/memcpy/memmov.
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: crazylht at gmail dot com
  Target Milestone: ---

void
foo (_Complex double* p, _Complex double* __restrict q)
{
  for (int i = 0; i != 1000; i++)
    p[i] = q[i];
}

before lowering complex type move


  <bb 2> [local count: 10737416]:
  __builtin_memcpy (p_10(D), q_9(D), 16000);
  return;


After r13-1762-gf9d4c3b45c5ed5f45c8089c990dbd4e181929c3d, it's 

18  <bb 3> [local count: 1063004409]:
19  # i_15 = PHI <i_12(5), 0(2)>
20  # ivtmp_13 = PHI <ivtmp_5(5), 1000(2)>
21  _1 = (long unsigned int) i_15;
22  _2 = _1 * 16;
23  _3 = q_9(D) + _2;
24  _4 = p_10(D) + _2;
25  _7 = REALPART_EXPR <*_3>;
26  _6 = IMAGPART_EXPR <*_3>;
27  REALPART_EXPR <*_4> = _7;
28  IMAGPART_EXPR <*_4> = _6;
29  i_12 = i_15 + 1;
30  ivtmp_5 = ivtmp_13 - 1;
31  if (ivtmp_5 != 0)
32    goto <bb 5>; [99.00%]
33  else

[Bug tree-optimization/106375] [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.0
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
           Keywords|                            |missed-optimization
   Last reconfirmed|                            |2022-07-21

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  Note it was a latent issue, if there was any _Complex lowered op in
the fn the copy would already have been lowered.

The memcpy pattern detection needs to be extended to "unrolled" copying to
cover this again (there might be a duplicate bug about this).

[Bug tree-optimization/106375] [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
Related failed testcase

FAIL: gcc.dg/pr56837.c scan-tree-dump-times optimized "memset ..c, 68, 16384.;"
1

[Bug tree-optimization/106375] [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

--- Comment #3 from Hongtao.liu <crazylht at gmail dot com> ---
Similar case for scalar types.

void
foo1 (double* p, double* __restrict q)
{
  for (int i = 0; i != 1000; i+=2)
    {
      p[i] = q[i];
      p[i+1] = q[i+1];
    }
}

[Bug tree-optimization/106375] [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

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

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

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
*** Bug 106451 has been marked as a duplicate of this bug. ***

[Bug tree-optimization/106375] [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|13.0                        |13.2

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 13.1 is being released, retargeting bugs to GCC 13.2.

[Bug tree-optimization/106375] [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|13.2                        |13.3

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 13.2 is being released, retargeting bugs to GCC 13.3.

[Bug tree-optimization/106375] [13 regreesion] Lowering complex type mov regressed loop distribution for memset/memcpy/memmov.

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106375

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|13.3                        |13.4

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 13.3 is being released, retargeting bugs to GCC 13.4.