On 2023-05-08 17:20 Kito Cheng <kito.ch...@gmail.com> wrote: > >-msave-restore is a different story; it's only enabled when the user >requests, but `-march` describes the capability of the target >architecture, not specify the preference of performance or size, which >should be determined by -O1~-O3/-Ofast or -Os/-Oz. >
I see and fully agree. I'll find a better way to resolve the conflict, My current idea is to diasble zcmp when shrink-wrap-separate is actually active. Thanks Kito and Andrew Pinski for your patience. BR, Fei >On Mon, May 8, 2023 at 4:54 PM Fei Gao <gao...@eswincomputing.com> wrote: >> >> On 2023-05-08 16:05 Kito Cheng <kito.ch...@gmail.com> wrote: >> > >> >> > diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc >> >> > index 45a63cab9c9..629e5e45cac 100644 >> >> > --- a/gcc/config/riscv/riscv.cc >> >> > +++ b/gcc/config/riscv/riscv.cc >> >> > @@ -5729,7 +5729,8 @@ riscv_get_separate_components (void) >> >> > >> >> > if (riscv_use_save_libcall (&cfun->machine->frame) >> >> > || cfun->machine->interrupt_handler_p >> >> > - || !cfun->machine->frame.gp_sp_offset.is_constant ()) >> >> > + || !cfun->machine->frame.gp_sp_offset.is_constant () >> >> > + || TARGET_ZCMP) >> >> > return components; >> >> >> >> I think this is a bad idea. I have a use case where we use the C >> >> extensions but still compile for -O2 because we want the code to be >> >> fast as possible but still having the savings of the C extensions. >> > >> >Yeah, agree, so I would prefer to drop this from the patch series. >> >> Zcmp is a little different here than C. >> C extension is done fully in AS. So we have the code to be >> fast as possible but still having the savings of the C extensions. >> >> Zcmp and shrink-wrap-separate are both done in prologue/epilogue pass >> and you can only have one switch active to direct sregs save and restore. >> In my understanding, zcmp push and pop insns seem to >> be mutually exclusive in functionality to shrink-wrap-separate. >> It's not expected to see zcmp insns at the begining/end of prologue/epilogue, >> and also repeated store/load sregs in separate blocks. >> >> Same for save and restore, and i guess that's why we have >> riscv_use_save_libcall (&cfun->machine->frame) check here. >> >> BR, >> Fei >> >> > >> >> Thanks, >> >> Andrew Pinski
