perf c2c: Refactor hist entry validation

This patch has no functionality changes but refactors hist entry
validation for cache line resorting.

It renames function "valid_hitm_or_store()" to "is_valid_hist_entry()",
changes return type from integer type to bool type.  In the function,
it uses switch-case instead of ternary operators, which is easier
to extend for more display types.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210114154646.209024-3-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-c2c.c

@@ -1888,16 +1888,32 @@ static bool he__display(struct hist_entry *he, struct c2c_stats *stats)
 	return he->filtered == 0;
 }
 
-static inline int valid_hitm_or_store(struct hist_entry *he)
+static inline bool is_valid_hist_entry(struct hist_entry *he)
 {
 	struct c2c_hist_entry *c2c_he;
-	bool has_hitm;
+	bool has_record = false;
 
 	c2c_he = container_of(he, struct c2c_hist_entry, he);
-	has_hitm = c2c.display == DISPLAY_TOT ? c2c_he->stats.tot_hitm :
-		   c2c.display == DISPLAY_LCL ? c2c_he->stats.lcl_hitm :
-						c2c_he->stats.rmt_hitm;
-	return has_hitm || c2c_he->stats.store;
+
+	/* It's a valid entry if contains stores */
+	if (c2c_he->stats.store)
+		return true;
+
+	switch (c2c.display) {
+	case DISPLAY_LCL:
+		has_record = !!c2c_he->stats.lcl_hitm;
+		break;
+	case DISPLAY_RMT:
+		has_record = !!c2c_he->stats.rmt_hitm;
+		break;
+	case DISPLAY_TOT:
+		has_record = !!c2c_he->stats.tot_hitm;
+		break;
+	default:
+		break;
+	}
+
+	return has_record;
 }
 
 static void set_node_width(struct c2c_hist_entry *c2c_he, int len)
@@ -1951,7 +1967,7 @@ static int filter_cb(struct hist_entry *he, void *arg __maybe_unused)
 
 	calc_width(c2c_he);
 
-	if (!valid_hitm_or_store(he))
+	if (!is_valid_hist_entry(he))
 		he->filtered = HIST_FILTER__C2C;
 
 	return 0;