[Bug middle-end/33699] [4.3/4.4/4.5/4.6 regression] missing optimization on const addr area store

[Bug middle-end/33699] [4.3/4.4/4.5/4.6 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|mips*-* powerpc*-*-*        |mips*-* powerpc*-*-*
                   |                            |x86_64-*-*
   Last reconfirmed|2010-03-12 23:56:39         |2011-03-04 23:56:39
      Known to fail|                            |4.6.0

--- Comment #11 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-04 12:12:27 UTC ---
Even on x86 it's smaller to not replicate 0xDEAD and to use
offset addressing, like

0000000000000000 <f>:
   0: b8 d0 fe 00 00            mov    $0xfed0,%eax
   5: bb ad de 00 00            mov    $0xdead,%ebx
   a: 89 18                     mov    %ebx,(%rax)
   c: 89 58 08                  mov    %ebx,0x8(%rax)
   f: 89 58 10                  mov    %ebx,0x10(%rax)
  12: 89 58 18                  mov    %ebx,0x18(%rax)
  15: c3                        retq   

instead of the generated

   0: c7 04 25 d0 fe 00 00      movl   $0xdead,0xfed0
   7: ad de 00 00 
   b: c7 04 25 d8 fe 00 00      movl   $0xdead,0xfed8
  12: ad de 00 00 
  16: c7 04 25 e0 fe 00 00      movl   $0xdead,0xfee0
  1d: ad de 00 00 
  21: c7 04 25 e8 fe 00 00      movl   $0xdead,0xfee8
  28: ad de 00 00 
  2c: c3                        retq

[Bug middle-end/33699] [4.3/4.4/4.5/4.6 regression] missing optimization on const addr area store

[matz at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

Michael Matz <matz at gcc dot gnu.org> changed:

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

--- Comment #12 from Michael Matz <matz at gcc dot gnu.org> 2011-03-04 15:33:04 UTC ---
Smaller perhaps, but it uses two registers, where it originally used none.
For x86 that's the better tradeoff.

[Bug middle-end/33699] [4.3/4.4/4.5/4.6/4.7 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.3.6                       |4.4.7

--- Comment #13 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-06-27 12:14:26 UTC ---
4.3 branch is being closed, moving to 4.4.7 target.

[Bug middle-end/33699] [4.5/4.6/4.7/4.8 regression] missing optimization on const addr area store

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.7                       |4.5.4

--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-13 12:47:52 UTC ---
4.4 branch is being closed, moving to 4.5.4 target.

[Bug middle-end/33699] [4.5/4.6/4.7/4.8 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.5.4                       |4.6.4

--- Comment #15 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-07-02 11:48:47 UTC ---
The 4.5 branch is being closed, adjusting target milestone.

[Bug middle-end/33699] [4.6/4.7/4.8 regression] missing optimization on const addr area store

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

--- Comment #16 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-12-31 10:09:07 UTC ---
(In reply to comment #12)
> Smaller perhaps, but it uses two registers, where it originally used none.
> For x86 that's the better tradeoff.

Except for the obvious -Os.

[Bug middle-end/33699] [4.7/4.8/4.9 regression] missing optimization on const addr area store

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.4                       |4.7.4

--- Comment #17 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-12 15:17:00 UTC ---
GCC 4.6.4 has been released and the branch has been closed.

[Bug middle-end/33699] [4.7/4.8/4.9/4.10 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.7.4                       |4.8.4

--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> ---
The 4.7 branch is being closed, moving target milestone to 4.8.4.

[Bug middle-end/33699] [4.8/4.9/5 regression] missing optimization on const addr area store

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.4                       |4.8.5

--- Comment #19 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.

[Bug middle-end/33699] [4.8/4.9/5/6 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.5                       |4.9.3

--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> ---
The gcc-4_8-branch is being closed, re-targeting regressions to 4.9.3.

[Bug middle-end/33699] [4.9/5/6 regression] missing optimization on const addr area store

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

--- Comment #21 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.9.3 has been released.

[Bug middle-end/33699] [4.9/5/6 regression] missing optimization on const addr area store

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.9.3                       |4.9.4

[Bug middle-end/33699] [9/10/11/12 regression] missing optimization on const addr area store

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.5                         |9.4

--- Comment #30 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 8 branch is being closed.

[Bug middle-end/33699] [9/10/11/12 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.4                         |9.5

--- Comment #31 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug middle-end/33699] [9/10/11/12 regression] missing optimization on const addr area store

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

Michael Meissner <meissner at gcc dot gnu.org> changed:

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

--- Comment #32 from Michael Meissner <meissner at gcc dot gnu.org> ---
I looked at adding the following powerpc patch that was proposed in March,
2021:
https://gcc.gnu.org/pipermail/gcc-patches/2021-March/566744.html

There are two parts to the patch, that are sort of unrelated.

The first part is to add minimum and maximum section anchor offset values and
use -fsection anchors.  I ran a spec 2017 benchmark on a pre-production power10
system, comparing my normal run times to run times with -fsection-anchors and
setting the minimum/maximum section anchor offsets.

Two benchmarks improved and two benchmarks regressed:

    xalancbmk_r: 1.75% regression
    cactuBSSN_r: 4.24% improvement
    blender_r: 1.92% regression
    roms_r: 1.05% improvement

I then built spec 2017 with just the part of setting const_anchor, but not the
section anchor minimum/maximum offsets.  Eight benchmarks did not build due to
assertion failures in cse.c:

    gcc_r
    exchange2_r
    cactuBSSN_r
    wrf_r
    blender_r
    cam4_r
    fotonik3d_r
    roms_r

If I specify the section anchor minimum/maximum offsets, add -fsection-anchors,
and set the const_anchor, all 23 INT+FP benchmarks build, but WRF_R does not
run correctly.  So without more debugging, I don't recommend setting
const_anchor.  It is probably useful to set the minimum/maximum section anchor
offsets in case people use -fsection-anchors.

As an aside, if we wanted to accept using constant addresses in the PowerPC, we
would need to recognize a constant address as being legitimate.  This may be
useful in some embedded environments where you have devices at certain memory
locations.  But somebody would need to add the support.

[Bug middle-end/33699] [10/11/12/13 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #33 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug middle-end/33699] [10/11/12/13 regression] missing optimization on const addr area store

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #34 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug middle-end/33699] [11/12/13/14 regression] missing optimization on const addr area store

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=33699

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #35 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.