| Message ID | 20221108195415.2701208-1-philipp.tomsich@vrull.eu |
|---|---|
| State | New |
| Headers | show |
| Series | RISC-V: costs: handle BSWAP | expand |
On 11/8/22 12:54, Philipp Tomsich wrote: > The BSWAP operation is not handled in rtx_costs. Add it. > > With Zbb, BSWAP for XLEN is a single instruction; for smaller modes, > it will expand into two. > > gcc/ChangeLog: > > * config/riscv/riscv.c (rtx_costs): Add BSWAP. OK. Jeff
On Tue, 08 Nov 2022 18:57:26 PST (-0800), jeffreyalaw@gmail.com wrote: > > On 11/8/22 12:54, Philipp Tomsich wrote: >> The BSWAP operation is not handled in rtx_costs. Add it. >> >> With Zbb, BSWAP for XLEN is a single instruction; for smaller modes, >> it will expand into two. >> >> gcc/ChangeLog: >> >> * config/riscv/riscv.c (rtx_costs): Add BSWAP. > > OK. It's riscv_rtx_costs. (I don't usually read ChangeLog entries that closely, just happened to stumble on it when poking around.) > > Jeff
On Tue, Nov 8, 2022 at 7:16 PM Palmer Dabbelt <palmer@rivosinc.com> wrote: > > On Tue, 08 Nov 2022 18:57:26 PST (-0800), jeffreyalaw@gmail.com wrote: > > > > On 11/8/22 12:54, Philipp Tomsich wrote: > >> The BSWAP operation is not handled in rtx_costs. Add it. > >> > >> With Zbb, BSWAP for XLEN is a single instruction; for smaller modes, > >> it will expand into two. > >> > >> gcc/ChangeLog: > >> > >> * config/riscv/riscv.c (rtx_costs): Add BSWAP. > > > > OK. > > It's riscv_rtx_costs. > > (I don't usually read ChangeLog entries that closely, just happened to > stumble on it when poking around.) Using contrib/git-commit-mklog.py can help here to make sure you always get the correct format for the changelog and it does a decent job of figuring out function names too. You can also use contrib/gcc-git-customization.sh to install it such that you can use it when doing git commits. After invoking that inside the GCC git; you can just do "git gcc-commit-mklog ...." Where .... would be what you normally put for "git commit" (but as if in the toplevel directory). Thanks, Andrew Pinski > > > > > > Jeff
On Tue, 08 Nov 2022 20:43:20 PST (-0800), pinskia@gmail.com wrote: > On Tue, Nov 8, 2022 at 7:16 PM Palmer Dabbelt <palmer@rivosinc.com> wrote: >> >> On Tue, 08 Nov 2022 18:57:26 PST (-0800), jeffreyalaw@gmail.com wrote: >> > >> > On 11/8/22 12:54, Philipp Tomsich wrote: >> >> The BSWAP operation is not handled in rtx_costs. Add it. >> >> >> >> With Zbb, BSWAP for XLEN is a single instruction; for smaller modes, >> >> it will expand into two. >> >> >> >> gcc/ChangeLog: >> >> >> >> * config/riscv/riscv.c (rtx_costs): Add BSWAP. >> > >> > OK. >> >> It's riscv_rtx_costs. >> >> (I don't usually read ChangeLog entries that closely, just happened to >> stumble on it when poking around.) > > Using contrib/git-commit-mklog.py can help here to make sure you > always get the correct format for the changelog and it does a decent > job of figuring out function names too. > You can also use contrib/gcc-git-customization.sh to install it such > that you can use it when doing git commits. > After invoking that inside the GCC git; you can just do "git > gcc-commit-mklog ...." Where .... would be what you normally put for > "git commit" (but as if in the toplevel directory). Thanks, that's awesome.
On Wed, 9 Nov 2022 at 05:43, Andrew Pinski <pinskia@gmail.com> wrote: > > On Tue, Nov 8, 2022 at 7:16 PM Palmer Dabbelt <palmer@rivosinc.com> wrote: > > > > On Tue, 08 Nov 2022 18:57:26 PST (-0800), jeffreyalaw@gmail.com wrote: > > > > > > On 11/8/22 12:54, Philipp Tomsich wrote: > > >> The BSWAP operation is not handled in rtx_costs. Add it. > > >> > > >> With Zbb, BSWAP for XLEN is a single instruction; for smaller modes, > > >> it will expand into two. > > >> > > >> gcc/ChangeLog: > > >> > > >> * config/riscv/riscv.c (rtx_costs): Add BSWAP. > > > > > > OK. > > > > It's riscv_rtx_costs. > > > > (I don't usually read ChangeLog entries that closely, just happened to > > stumble on it when poking around.) > > Using contrib/git-commit-mklog.py can help here to make sure you > always get the correct format for the changelog and it does a decent > job of figuring out function names too. > You can also use contrib/gcc-git-customization.sh to install it such > that you can use it when doing git commits. > After invoking that inside the GCC git; you can just do "git > gcc-commit-mklog ...." Where .... would be what you normally put for > "git commit" (but as if in the toplevel directory). We always pass them through contrib/mklog,py (or git-commit-mklog.py, which invokes it) anyway, but (as the ".c" in the filename indicates) this one hasn't been refreshed in over a year's time. Don't worry, this will need to get adjusted again once I merge it (as the commit hooks won't let it pass). Philipp.
Applied to master, with the commit-message regenerated as:
gcc/ChangeLog:
* config/riscv/riscv.cc (riscv_rtx_costs): Add BSWAP.
Thanks,
Philipp.
On Wed, 9 Nov 2022 at 04:15, Palmer Dabbelt <palmer@rivosinc.com> wrote:
>
> On Tue, 08 Nov 2022 18:57:26 PST (-0800), jeffreyalaw@gmail.com wrote:
> >
> > On 11/8/22 12:54, Philipp Tomsich wrote:
> >> The BSWAP operation is not handled in rtx_costs. Add it.
> >>
> >> With Zbb, BSWAP for XLEN is a single instruction; for smaller modes,
> >> it will expand into two.
> >>
> >> gcc/ChangeLog:
> >>
> >> * config/riscv/riscv.c (rtx_costs): Add BSWAP.
> >
> > OK.
>
> It's riscv_rtx_costs.
>
> (I don't usually read ChangeLog entries that closely, just happened to
> stumble on it when poking around.)
>
>
> >
> > Jeff
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc index 32f9ef9ade9..ab6c745c722 100644 --- a/gcc/config/riscv/riscv.cc +++ b/gcc/config/riscv/riscv.cc @@ -2562,6 +2562,16 @@ riscv_rtx_costs (rtx x, machine_mode mode, int outer_code, int opno ATTRIBUTE_UN *total = riscv_extend_cost (XEXP (x, 0), GET_CODE (x) == ZERO_EXTEND); return false; + case BSWAP: + if (TARGET_ZBB) + { + /* RISC-V only defines rev8 for XLEN, so we will need an extra + shift-right instruction for smaller modes. */ + *total = COSTS_N_INSNS (mode == word_mode ? 1 : 2); + return true; + } + return false; + case FLOAT: case UNSIGNED_FLOAT: case FIX:
The BSWAP operation is not handled in rtx_costs. Add it. With Zbb, BSWAP for XLEN is a single instruction; for smaller modes, it will expand into two. gcc/ChangeLog: * config/riscv/riscv.c (rtx_costs): Add BSWAP. --- gcc/config/riscv/riscv.cc | 10 ++++++++++ 1 file changed, 10 insertions(+)