[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |https://gcc.gnu.org/piperma
                   |                            |il/gcc-patches/2020-Septemb
                   |                            |er/553661.html
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |bergner at gcc dot gnu.org
                 CC|                            |bergner at gcc dot gnu.org

--- Comment #3 from Peter Bergner <bergner at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #2)
> When you want the bits from bit MB to ME (inclusive) set, you can just do
> 
>   li t,-1
>   rldic d,T,MB,63-ME
> 
> (bit # 0 is the high bit; can also do wrap-around masks this way).

I submitted a patch that implements this idea.

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|bergner at gcc dot gnu.org         |amodra at gcc dot gnu.org

--- Comment #4 from Peter Bergner <bergner at gcc dot gnu.org> ---
(In reply to Peter Bergner from comment #3)
> I submitted a patch that implements this idea.

Actually, Alan is taking this over, so reassigning to him.

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

--- Comment #5 from Peter Bergner <bergner at gcc dot gnu.org> ---
Alan, didn't one of your recent patches fix this particular bug?  So can we
mark this as fixed?

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
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                URL|https://gcc.gnu.org/piperma |https://gcc.gnu.org/piperma
                   |il/gcc-patches/2020-Septemb |il/gcc-patches/2020-October
                   |er/553661.html              |/555760.html

--- Comment #6 from Alan Modra <amodra at gmail dot com> ---
No, the patch hasn't yet been reviewed.

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[jens.seifert at de dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

--- Comment #7 from Jens Seifert <jens.seifert at de dot ibm.com> ---
What happened ? Still waiting for improvement.

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |NEW
           Assignee|amodra at gcc dot gnu.org          |unassigned at gcc dot gnu.org

--- Comment #8 from Alan Modra <amodra at gmail dot com> ---
Nothing happened.  The patch wasn't reviewed.  I didn't ping the patch.  I'm
not working on gcc any more, so should remove myself as assignee for this bug.

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |guojiufu at gcc dot gnu.org,
                   |                            |linkw at gcc dot gnu.org

--- Comment #9 from Peter Bergner <bergner at gcc dot gnu.org> ---
Jeff, none of your constant generation patches covers this, correct?  If not,
maybe given your recent work on improving the code gen for contents, maybe you
could pick up the patch and shepherd it to approval?  I would like to see this
work finally committed.

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[jens.seifert at de dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

--- Comment #10 from Jens Seifert <jens.seifert at de dot ibm.com> ---
Looks like no patch in the area got delivered. I did a small test for 

unsigned long long c0000FFFF00000000()
{
    return 0x0000FFFF00000000ULL;
}

gcc 13.2.0:
        li 3,0
        ori 3,3,0xffff
        sldi 3,3,32

expected:
        li 3, -1
        rldic 3, 3, 32, 16

All consecutive ones can be created with li + rldic.

The rotate eliminates the bits on the right and the clear the bits on the left
as described below:

  li t,-1
  rldic d,T,MB,63-ME

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Sam James <sjames at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |sjames at gcc dot gnu.org

--- Comment #11 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Jens Seifert from comment #10)
> Looks like no patch in the area got delivered. I did a small test for 
> 

Peter's was at
https://inbox.sourceware.org/gcc-patches/838b2e97-dfa9-3ca0-c3c6-1767d60ddf05@linux.ibm.com/,
Alan's may be
https://gcc.gnu.org/pipermail/gcc-patches/2020-September/553927.html.

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[guojiufu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

--- Comment #12 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
Thanks a lot for asking!

The patch which handles this is submitted at:
https://gcc.gnu.org/pipermail/gcc-patches/2023-July/623519.html

I would ping this patch again.  If ok, I will commit to trunk.

(And the series patches could be committed for "li/lis; rldicl/rldicr/rldic"
https://gcc.gnu.org/pipermail/gcc-patches/2023-June/621000.html)

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[bergner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                URL|https://gcc.gnu.org/piperma |https://gcc.gnu.org/piperma
                   |il/gcc-patches/2020-October |il/gcc-patches/2023-July/62
                   |/555760.html                |3519.html
             Status|NEW                         |ASSIGNED

[Bug target/93176] PPC: inefficient 64-bit constant consecutive ones

[guojiufu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93176

Jiu Fu Guo <guojiufu at gcc dot gnu.org> changed:

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

--- Comment #13 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
Patches are committed for using "li/lis;rldicl/rldicr/rldic" to construct
constants.