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* [Bug target/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1
[not found] <bug-82259-4@http.gcc.gnu.org/bugzilla/>
@ 2021-08-02 23:55 ` pinskia at gcc dot gnu.org
2021-08-02 23:56 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-02 23:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82259
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Uroš Bizjak from comment #2)
> A couple of *scc_bt patterns are missing. These are similar to already
> existing *jcc_bt patterns. Combine wants:
>
> Failed to match this instruction:
> (set (reg:QI 97)
> (eq:QI (zero_extract:SI (reg/v:SI 91 [ x ])
> (const_int 1 [0x1])
> (zero_extend:SI (subreg:QI (reg/v:SI 92 [ bit ]) 0)))
> (const_int 0 [0])))
I have a patch which changes that as I was running into something similar a few
days ago.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1
[not found] <bug-82259-4@http.gcc.gnu.org/bugzilla/>
2021-08-02 23:55 ` [Bug target/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1 pinskia at gcc dot gnu.org
@ 2021-08-02 23:56 ` pinskia at gcc dot gnu.org
2021-08-02 23:56 ` [Bug rtl-optimization/82259] " pinskia at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-02 23:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82259
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 51248
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51248&action=edit
patch for the eq issue
This is the patch for the eq issue
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug rtl-optimization/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1
[not found] <bug-82259-4@http.gcc.gnu.org/bugzilla/>
2021-08-02 23:55 ` [Bug target/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1 pinskia at gcc dot gnu.org
2021-08-02 23:56 ` pinskia at gcc dot gnu.org
@ 2021-08-02 23:56 ` pinskia at gcc dot gnu.org
2021-08-03 0:01 ` pinskia at gcc dot gnu.org
2023-06-23 3:47 ` [Bug middle-end/82259] " pinskia at gcc dot gnu.org
4 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-02 23:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82259
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|target |rtl-optimization
Ever confirmed|0 |1
Last reconfirmed| |2021-08-02
Severity|normal |enhancement
Status|UNCONFIRMED |NEW
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug rtl-optimization/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1
[not found] <bug-82259-4@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2021-08-02 23:56 ` [Bug rtl-optimization/82259] " pinskia at gcc dot gnu.org
@ 2021-08-03 0:01 ` pinskia at gcc dot gnu.org
2023-06-23 3:47 ` [Bug middle-end/82259] " pinskia at gcc dot gnu.org
4 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-03 0:01 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82259
--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #7)
> Created attachment 51248 [details]
> patch for the eq issue
>
> This is the patch for the eq issue
Of course after that we get:
(set (reg:QI 92)
(xor:QI (subreg:QI (zero_extract:SI (reg:SI 93)
(const_int 1 [0x1])
(and:SI (reg:SI 94)
(const_int 255 [0xff]))) 0)
(const_int 1 [0x1])))
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug middle-end/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1
[not found] <bug-82259-4@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2021-08-03 0:01 ` pinskia at gcc dot gnu.org
@ 2023-06-23 3:47 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-06-23 3:47 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82259
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2021-08-02 00:00:00 |2023-6-22
Component|rtl-optimization |middle-end
--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is an expansion issue not taking into cost of expanding using shifts
rather than test/set.
I am still working in this area and might improve this for GCC 14 but still
deciding on how to get some good infrastructure for the cost modeling ...
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-06-23 3:47 UTC | newest]
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[not found] <bug-82259-4@http.gcc.gnu.org/bugzilla/>
2021-08-02 23:55 ` [Bug target/82259] missed optimization: use LEA to add 1 to flip the low bit when copying before AND with 1 pinskia at gcc dot gnu.org
2021-08-02 23:56 ` pinskia at gcc dot gnu.org
2021-08-02 23:56 ` [Bug rtl-optimization/82259] " pinskia at gcc dot gnu.org
2021-08-03 0:01 ` pinskia at gcc dot gnu.org
2023-06-23 3:47 ` [Bug middle-end/82259] " pinskia at gcc dot gnu.org
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