On 09-Mar-2024, at 3:24 PM, Christophe Leroy [off-list ref] wrote:



Le 09/03/2024 à 08:25, Athira Rajeev a écrit :

quoted

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 <redacted>
---
 tools/perf/arch/powerpc/util/dwarf-regs.c | 29 +++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/tools/perf/arch/powerpc/util/dwarf-regs.c b/tools/perf/arch/powerpc/util/dwarf-regs.c
index 0c4f4caf53ac..d955e3e577ea 100644
--- a/tools/perf/arch/powerpc/util/dwarf-regs.c
+++ b/tools/perf/arch/powerpc/util/dwarf-regs.c

@@ -98,3 +98,32 @@ int regs_query_register_offset(const char *name)
  return roff->ptregs_offset;
  return -EINVAL;
 }
+
+struct dwarf_regs_idx {
+ const char *name;
+ int idx;
+};
+
+static const struct dwarf_regs_idx powerpc_regidx_table[] = {
+ { "r0", 0 }, { "r1", 1 }, { "r2", 2 }, { "r3", 3 }, { "r4", 4 },
+ { "r5", 5 }, { "r6", 6 }, { "r7", 7 }, { "r8", 8 }, { "r9", 9 },
+ { "r10", 10 }, { "r11", 11 }, { "r12", 12 }, { "r13", 13 }, { "r14", 14 },
+ { "r15", 15 }, { "r16", 16 }, { "r17", 17 }, { "r18", 18 }, { "r19", 19 },
+ { "r20", 20 }, { "r21", 21 }, { "r22", 22 }, { "r23", 23 }, { "r24", 24 },
+ { "r25", 25 }, { "r26", 26 }, { "r27", 27 }, { "r27", 27 }, { "r28", 28 },
+ { "r29", 29 }, { "r30", 30 }, { "r31", 31 },
+};
+
+int get_arch_regnum(const char *name)
+{
+ unsigned int i;
+
+ if (*name != 'r')
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(powerpc_regidx_table); i++)
+ if (!strcmp(powerpc_regidx_table[i].name, name))
+ return powerpc_regidx_table[i].idx;

Can you do more simple ?

Something like:

int n;

if (*name != 'r')
return -EINVAL;
n = atoi(name + 1);
return n >= 0 && n < 32 ? n : -ENOENT;

Hi Christophe,

Thanks for reviewing patch and for the suggestions.

Sure, I will check this approach and address in V2

Thanks
Athira

quoted

+
+ return -ENOENT;
+}