[Bug tree-optimization/101028] New: [12 Regression] SLP compile-time hog since r12-1329-gce670e4faafb296d

[Bug tree-optimization/101028] New: [12 Regression] SLP compile-time hog since r12-1329-gce670e4faafb296d

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101028

            Bug ID: 101028
           Summary: [12 Regression] SLP compile-time hog since
                    r12-1329-gce670e4faafb296d
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: rguenth at gcc dot gnu.org
  Target Milestone: ---

The following is causing hog (reduced from imagick SPEC benchmark):

$ cat 1.i
void ConvertImageCommand();
void MagickCommandGenesis();
void MogrifyImages();
void TracePath();

typedef struct {
  double x, y;
} PointInfo;

typedef struct {
  PointInfo point;
} PrimitiveInfo;

int TraceBezier_alpha, TraceBezier_i;
double TraceBezier_weight;
PointInfo *TraceBezier_points;
PrimitiveInfo *TraceBezier_primitive_info;
void DrawImage() { TracePath(); }

void TracePath() {
  double *coefficients;
  PointInfo point;
  long j;
  for (; TraceBezier_i; TraceBezier_i++) {
    point.x = point.y = TraceBezier_alpha = 1.0;
    j = 0;
    for (; j < 4; j++) {
      point.x += TraceBezier_alpha * coefficients[j] *
                 TraceBezier_primitive_info->point.x;
      point.y += TraceBezier_alpha * TraceBezier_primitive_info->point.y;
      TraceBezier_alpha *= TraceBezier_weight;
      TraceBezier_primitive_info++;
    }
    TraceBezier_points[TraceBezier_i] = point;
    TraceBezier_weight += 1.0;
  }
}

void ConvertMain() { MagickCommandGenesis(ConvertImageCommand); }
void ConvertImageCommand() { MogrifyImages(); }
void MogrifyImages() { DrawImage(); }

int main() { return ConvertMain; }

$ gcc 1.i -flto=auto -Ofast  -shared -fPIC
...

likely never finishes :)

[Bug tree-optimization/101028] [12 Regression] SLP compile-time hog since r12-1329-gce670e4faafb296d

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101028

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-06-11
           Priority|P3                          |P1
             Blocks|                            |26163


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163
[Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95)

[Bug tree-optimization/101028] [12 Regression] SLP compile-time hog since r12-1329-gce670e4faafb296d

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101028

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:b9ec5ebb605936684e95b8dcc12e43ba7d8f2cb4

commit r12-1388-gb9ec5ebb605936684e95b8dcc12e43ba7d8f2cb4
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Jun 11 13:36:26 2021 +0200

    tree-optimization/101028 - fix endless SLP reassoc discovery

    This fixes a missing clearing of mismatched lanes from the
    fatal fail path in SLP reassoc discovery in the most conservative
    way.

    2021-06-11  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/101028
            * tree-vect-slp.c (vect_build_slp_tree_2): When SLP
            reassoc discovery fails fatally, mark appropriate lanes
            in matches[] so.

            * gcc.dg/pr101028.c: New testcase.

[Bug tree-optimization/101028] [12 Regression] SLP compile-time hog since r12-1329-gce670e4faafb296d

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101028

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

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

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.

[Bug tree-optimization/101028] [12 Regression] SLP compile-time hog since r12-1329-gce670e4faafb296d

[tnfchris at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101028

Tamar Christina <tnfchris at gcc dot gnu.org> changed:

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

--- Comment #3 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
This seems to have caused a compile time hog in SPECCPU 2006's 416.gamess as
well which is not fixed by the subsequent commit.

I'm attempting to reduce but it's taking a while since each test takes around 8
mins..

Compiling with

-mcpu=native -Ofast -fomit-frame-pointer -flto=auto --param
ipa-cp-eval-threshold=1 --param ipa-cp-unit-growth=80 -funconstrained-commons
-std=legacy -fno-inline-functions-called-once

and compile never finishes (have yet to reduce flags)