[Bug target/103498] New: Spec 2017 imagick_r is 2.62% slower on Power10 with pc-relative addressing compared to not using pc-relative addressing

[Bug target/103498] New: Spec 2017 imagick_r is 2.62% slower on Power10 with pc-relative addressing compared to not using pc-relative addressing

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103498

            Bug ID: 103498
           Summary: Spec 2017 imagick_r is 2.62% slower on Power10 with
                    pc-relative addressing compared to not using
                    pc-relative addressing
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: meissner at gcc dot gnu.org
  Target Milestone: ---

I was doing some Spec 2017 rate runs on a single power10 little endian 64-bit
CPU.  One of the runs disabled pc-relative addressing.  One benchmark
(imagick_r) was faster if PC-relative addressing was disabled.

For this run I used the options:
    -DSPEC \
    -DNDEBUG \
    -I. \
    -DSPEC_AUTO_SUPPRESS_OPENMP \
    -g \
    -save-temps=obj \
    -Ofast \
    -mcpu=power10 \
    -mrecip \
    -funroll-loops \
    -msave-toc-indirect \
    -mno-pcrel \
    -fgnu89-inline \
    -Wno-multichar \
    -DSPEC_LP64 \
    -frandom-seed=spec2017

[Bug target/103498] Spec 2017 imagick_r is 2.62% slower on Power10 with pc-relative addressing compared to not using pc-relative addressing

[guihaoc at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103498

HaoChen Gui <guihaoc at gcc dot gnu.org> changed:

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

--- Comment #1 from HaoChen Gui <guihaoc at gcc dot gnu.org> ---
Tested imagick_r on Power10 DD2. The performance is the same between Ofast with
pcrel and Ofast without pcrel. Not sure if DD2 fixed the regression.

[Bug target/103498] Spec 2017 imagick_r is 2.62% slower on Power10 with pc-relative addressing compared to not using pc-relative addressing

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103498

--- Comment #2 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Mike, do you still see this?

[Bug target/103498] Spec 2017 imagick_r is 2.62% slower on Power10 with pc-relative addressing compared to not using pc-relative addressing

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103498

--- Comment #3 from Peter Bergner <bergner at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #2)
> Mike, do you still see this?

Ping again.  Is this still an issue?

[Bug target/103498] Spec 2017 imagick_r is 2.62% slower on Power10 with pc-relative addressing compared to not using pc-relative addressing

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103498

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

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

--- Comment #4 from Michael Meissner <meissner at gcc dot gnu.org> ---
I just ran spec 2017 on a Power10 machine running RHEL 8, using the GCC 13.1
GCC and the Advance Toolchain 15.0 library.  In that run, I see no significant
(more than 1%) regressions if we use -mno-pcrel.  In fact, imagick_r was nearly
2% faster using PC-relative addressing.