Re: arcbios_calls.S data hazards
Steve Rumble <[email protected]> Mon, 8 Dec 2025 22:34:12 -0800
| Newsgroups | gmane.os.netbsd.ports.mips.devel |
|---|---|
| Message-ID | <CAL4_dAR=b39Q33FGswguR4Uw71hd7FN5P_8F66A6T_PQPA_H6g@mail.gmail.com> |
On Mon, Dec 8, 2025 at 11:23=E2=80=AFAM Maciej W. Rozycki <[email protected]= k> wrote: > I guess you need to figure out what's wrong with your build system that > prevents the assembler from doing its job. I'm only familiar with the > compiler tool chain and not the NetBSD compilation setup. Thanks a lot for the detailed response! This ended up just me being daft. Given the data dependencies, the assembler can't move anything into the BDS I was looking at without creating a new data hazard. Also, since we're invoking via gcc (-x assembler-with-cpp) and aren't specifying an optimisation level, it looks like gcc passes its -O0 default into as, overriding as' -O2 default. If I pass -O2 to either gcc or into as specifically (via -Wa), as does appear to fill other delay slots where it can. I imagine we're producing suboptimal output where reordering is currently being used. Thanks again, Steve