[Bug tree-optimization/106315] New: 7.8% increased codesize on specfp 507.cactuBSSN_r

[Bug tree-optimization/106315] New: 7.8% increased codesize on specfp 507.cactuBSSN_r

[admin at levyhsu dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

            Bug ID: 106315
           Summary: 7.8% increased codesize on specfp 507.cactuBSSN_r
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: admin at levyhsu dot com
  Target Milestone: ---

when compiled with march_native_ofast_lto (-march=native -Ofast -funroll-loops
-flto) on IceLake,CascadeLake, SkylakeW, Zen3 Server/Client,
r13-1268-g8c99e307b20c50 results 7.8%-7.9% codesize increment.

On aarch64 codesize looks ok.

[Bug tree-optimization/106315] [13 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|7.8% increased codesize on  |[13 Regression] 7.8%
                   |specfp 507.cactuBSSN_r      |increased codesize on
                   |                            |specfp 507.cactuBSSN_r
   Target Milestone|---                         |13.0
           Keywords|                            |missed-optimization

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
I'd check if a non-LTO build also shows a (maybe smaller) size difference so
isolation to most important TUs is easier.

[Bug tree-optimization/106315] [13 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Blocks|                            |26163
                 CC|                            |marxin at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2022-07-18


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/106315] [13 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[admin at levyhsu dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

--- Comment #2 from Levy Hsu <admin at levyhsu dot com> ---
Cheked non-LTO build (-march=native -Ofast -funroll-loops), codesize increasd
by 7.1%

[Bug tree-optimization/106315] [13 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hjl.tools at gmail dot com

--- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> ---
Can we find out which file/function gets big size increase?

[Bug tree-optimization/106315] [13 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[admin at levyhsu dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

--- Comment #4 from Levy Hsu <admin at levyhsu dot com> ---
So I cross-compared all sizes of those .o files in make.out:

list of all diff > 2% files:

Size1: 19464 Size2: 20760 File: PUGH/SetupPGV.o
Size1: 324675 Size2: 402929 File: LocalReduce/CountFunctions.o
Size1: 372967 Size2: 408964 File: LocalReduce/Norm4Functions.o
Size1: 378371 Size2: 434948 File: LocalReduce/Norm1Functions.o
Size1: 370431 Size2: 442340 File: LocalReduce/Norm2Functions.o
Size1: 373212 Size2: 460212 File: LocalReduce/SumFunctions.o
Size1: 373858 Size2: 452466 File: LocalReduce/AvgFunctions.o
Size1: 379238 Size2: 437511 File: LocalReduce/NormInfFunctions.o
Size1: 374379 Size2: 384654 File: LocalReduce/MaxFunctions.o
Size1: 377728 Size2: 387170 File: LocalReduce/MinFunctions.o
Size1: 379068 Size2: 395071 File: LocalReduce/Norm3Functions.o
Size1: 7136496 Size2: 7640664 File: cactusBSSN_r

Not sure if they were caused by the same head file

[Bug tree-optimization/106315] [13 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
Here is the testcase:
---
void
bar(int *indices, int max_iter, int *actual_indices,
    int *iters_per_dim, int N_dims)
{
  int iter = 0;
  int sum_indices = 0;
  int flag, k;
  while (iter < max_iter) {
    for (k = N_dims - 1; k > 0; k--) {
      sum_indices += actual_indices[k];
    }
    if (sum_indices >= max_iter) {
      return;
    }
    iter++;
    for (k = 0; k < N_dims; k++) {
      if (indices[k] < iters_per_dim[k] - 1) {
        indices[k]++;
        break;
      } 
    }
  }
}
---

The second loop is unrolled after the commit.

[Bug tree-optimization/106315] [13 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed as triggered by jump threading somehow.  Note the RTL unroller is
notoriously not tuned.

[Bug tree-optimization/106315] [13/14 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

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

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

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 13.1 is being released, retargeting bugs to GCC 13.2.

[Bug tree-optimization/106315] [13/14 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

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

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

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 13.2 is being released, retargeting bugs to GCC 13.3.

[Bug tree-optimization/106315] [13/14 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

Jeffrey A. Law <law at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at gcc dot gnu.org
           Priority|P3                          |P2

[Bug tree-optimization/106315] [13/14/15 Regression] 7.8% increased codesize on specfp 507.cactuBSSN_r

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106315

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

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

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 13.3 is being released, retargeting bugs to GCC 13.4.