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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]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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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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