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* [Bug c++/107190] New: [aarch64] regression with optimization -fexpensive-optimizations @ 2022-10-09 10:33 zhongyunde at huawei dot com 2022-10-10 16:54 ` [Bug rtl-optimization/107190] " pinskia at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: zhongyunde at huawei dot com @ 2022-10-09 10:33 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107190 Bug ID: 107190 Summary: [aarch64] regression with optimization -fexpensive-optimizations Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: zhongyunde at huawei dot com Target Milestone: --- This case is simplify from https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107090, and we can see that the codegen of function `test_m` has some regression with optimization -fexpensive-optimizations, https://gcc.godbolt.org/z/zbKrEox4j This is because the pass 208t.widening_mul is controlled by -fexpensive-optimizations (default on at -O3), it conversion ``` m_12 = m_9 + m1_10; if (m1_10 > m_12) ``` into ``` _17 = .ADD_OVERFLOW (m_9, m1_10); m_12 = REALPART_EXPR <_17>; _18 = IMAGPART_EXPR <_17>; if (_18 != 0)`` ``` ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug rtl-optimization/107190] [aarch64] regression with optimization -fexpensive-optimizations 2022-10-09 10:33 [Bug c++/107190] New: [aarch64] regression with optimization -fexpensive-optimizations zhongyunde at huawei dot com @ 2022-10-10 16:54 ` pinskia at gcc dot gnu.org 2022-10-10 17:31 ` [Bug middle-end/107190] " pinskia at gcc dot gnu.org 2023-05-19 1:22 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2022-10-10 16:54 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107190 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|c++ |rtl-optimization --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to vfdff from comment #0) > This case is simplify from > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107090, and we can see that the > codegen of function `test_m` has some regression with optimization > -fexpensive-optimizations, https://gcc.godbolt.org/z/zbKrEox4j > > This is because the pass 208t.widening_mul is controlled by > -fexpensive-optimizations (default on at -O3), it conversion > > ``` > m_12 = m_9 + m1_10; > if (m1_10 > m_12) > ``` > into > > ``` > _17 = .ADD_OVERFLOW (m_9, m1_10); > m_12 = REALPART_EXPR <_17>; > _18 = IMAGPART_EXPR <_17>; > if (_18 != 0)`` This should always be better. If ifcvt.cc does not handle this case, then it should be improved. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/107190] [aarch64] regression with optimization -fexpensive-optimizations 2022-10-09 10:33 [Bug c++/107190] New: [aarch64] regression with optimization -fexpensive-optimizations zhongyunde at huawei dot com 2022-10-10 16:54 ` [Bug rtl-optimization/107190] " pinskia at gcc dot gnu.org @ 2022-10-10 17:31 ` pinskia at gcc dot gnu.org 2023-05-19 1:22 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2022-10-10 17:31 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107190 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|rtl-optimization |middle-end --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- I think it is the expansion of the add with overflow causing things to be worse. (insn 16 15 17 (set (reg:DI 102 [ _17+8 ]) (const_int 0 [0])) -1 (nil)) (insn 17 16 18 (parallel [ (set (reg:CC_C 66 cc) (compare:CC_C (plus:DI (reg:DI 109 [ m ]) (reg:DI 111 [ m1 ])) (reg:DI 109 [ m ]))) (set (reg:DI 112) (plus:DI (reg:DI 109 [ m ]) (reg:DI 111 [ m1 ]))) ]) -1 (nil)) (jump_insn 18 17 19 (set (pc) (if_then_else (ltu (reg:CC_C 66 cc) (const_int 0 [0])) (label_ref 21) (pc))) -1 (int_list:REG_BR_PROB 536868 (nil))) (jump_insn 19 18 20 (set (pc) (label_ref 23)) -1 (nil)) (barrier 20 19 21) (code_label 21 20 22 3 (nil) [0 uses]) (insn 22 21 23 (set (reg:DI 102 [ _17+8 ]) (const_int 1 [0x1])) -1 (nil)) (code_label 23 22 24 2 (nil) [0 uses]) I don't see why we need to expand to a jump here rather than a cset? I think there is another bug about this already too. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/107190] [aarch64] regression with optimization -fexpensive-optimizations 2022-10-09 10:33 [Bug c++/107190] New: [aarch64] regression with optimization -fexpensive-optimizations zhongyunde at huawei dot com 2022-10-10 16:54 ` [Bug rtl-optimization/107190] " pinskia at gcc dot gnu.org 2022-10-10 17:31 ` [Bug middle-end/107190] " pinskia at gcc dot gnu.org @ 2023-05-19 1:22 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-05-19 1:22 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107190 --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Created attachment 55113 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55113&action=edit testcase ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-05-19 1:22 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-10-09 10:33 [Bug c++/107190] New: [aarch64] regression with optimization -fexpensive-optimizations zhongyunde at huawei dot com 2022-10-10 16:54 ` [Bug rtl-optimization/107190] " pinskia at gcc dot gnu.org 2022-10-10 17:31 ` [Bug middle-end/107190] " pinskia at gcc dot gnu.org 2023-05-19 1:22 ` pinskia at gcc dot gnu.org
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