perf annotate: Add and use ins__is_nop()

Likewise, add ins__is_nop() to check if the current instruction is NOP.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240329215812.537846-3-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/annotate.c

@@ -757,6 +757,11 @@ static struct ins_ops ret_ops = {
 	.scnprintf = ins__raw_scnprintf,
 };
 
+bool ins__is_nop(const struct ins *ins)
+{
+	return ins->ops == &nop_ops;
+}
+
 bool ins__is_ret(const struct ins *ins)
 {
 	return ins->ops == &ret_ops;
@@ -1785,7 +1790,7 @@ static void delete_last_nop(struct symbol *sym)
 		dl = list_entry(list->prev, struct disasm_line, al.node);
 
 		if (dl->ins.ops) {
-			if (dl->ins.ops != &nop_ops)
+			if (!ins__is_nop(&dl->ins))
 				return;
 		} else {
 			if (!strstr(dl->al.line, " nop ") &&

tools/perf/util/annotate.h

@@ -74,6 +74,7 @@ struct ins_ops {
 
 bool ins__is_jump(const struct ins *ins);
 bool ins__is_call(const struct ins *ins);
+bool ins__is_nop(const struct ins *ins);
 bool ins__is_ret(const struct ins *ins);
 bool ins__is_lock(const struct ins *ins);
 int ins__scnprintf(struct ins *ins, char *bf, size_t size, struct ins_operands *ops, int max_ins_name);