Re: [PATCH 3/3] tools/perf/arch/powerc: Add get_arch_regnum for powerpc

From: Namhyung Kim <namhyung@kernel.org>
To: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: irogers@google.com, Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
	kjain@linux.ibm.com, adrian.hunter@intel.com, acme@kernel.org,
	linux-perf-users@vger.kernel.org, maddy@linux.ibm.com,
	jolsa@kernel.org, disgoel@linux.vnet.ibm.com,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 3/3] tools/perf/arch/powerc: Add get_arch_regnum for powerpc
Date: Mon, 1 Apr 2024 14:46:07 -0700	[thread overview]
Message-ID: <CAM9d7cg1eKQByUcDCbF25Bd8vM2ut5st1zPDzMQEi+nTC8cpsw@mail.gmail.com> (raw)
In-Reply-To: <4072f03b-a8a2-5611-901e-bc16e97c3fe6@loongson.cn>

Hello,

On Tue, Mar 26, 2024 at 2:35 AM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>
> Hi Athira and Namhyung,
>
> On 03/09/2024 03:25 PM, Athira Rajeev wrote:
> > The function get_dwarf_regnum() returns a DWARF register number
> > from a register name string. This calls arch specific function
> > get_arch_regnum to return register number for corresponding arch.
> > Add mappings for register name to register number in powerpc code:
> > arch/powerpc/util/dwarf-regs.c
> >
> > Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> > ---
> >  tools/perf/arch/powerpc/util/dwarf-regs.c | 29 +++++++++++++++++++++++
> >  1 file changed, 29 insertions(+)
>
> I found commit 3eee606757ad ("perf dwarf-regs: Add get_dwarf_regnum()")
> for x86, would you be able to share how to test these changes? What is
> the difference with and without the patches?

Hmm.. I guess it won't work well without the patch.  This is
needed to map register numbers (from objdump) to what
DWARF can understand (IOW they use different numbers).

Thanks,
Namhyung