perf diff: Change compute methods to work with pair directly

Changing compute methods to operate over hist entry and its pair
directly. This makes the code more obvious and readable, instead of all
time checking for pair being != NULL.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1354110769-2998-6-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/ui/hist.c b/tools/perf/ui/hist.c
index 6e639b5..108e5ed 100644
--- a/tools/perf/ui/hist.c
+++ b/tools/perf/ui/hist.c
@@ -268,14 +268,18 @@
 
 static int hpp__entry_delta(struct perf_hpp *hpp, struct hist_entry *he)
 {
+	struct hist_entry *pair = hist_entry__next_pair(he);
 	const char *fmt = symbol_conf.field_sep ? "%s" : "%7.7s";
 	char buf[32] = " ";
-	double diff;
+	double diff = 0.0;
 
-	if (he->diff.computed)
-		diff = he->diff.period_ratio_delta;
-	else
-		diff = perf_diff__compute_delta(he);
+	if (pair) {
+		if (he->diff.computed)
+			diff = he->diff.period_ratio_delta;
+		else
+			diff = perf_diff__compute_delta(he, pair);
+	} else
+		diff = perf_diff__period_percent(he, he->stat.period);
 
 	if (fabs(diff) >= 0.01)
 		scnprintf(buf, sizeof(buf), "%+4.2F%%", diff);
@@ -297,14 +301,17 @@
 
 static int hpp__entry_ratio(struct perf_hpp *hpp, struct hist_entry *he)
 {
+	struct hist_entry *pair = hist_entry__next_pair(he);
 	const char *fmt = symbol_conf.field_sep ? "%s" : "%14s";
 	char buf[32] = " ";
-	double ratio;
+	double ratio = 0.0;
 
-	if (he->diff.computed)
-		ratio = he->diff.period_ratio;
-	else
-		ratio = perf_diff__compute_ratio(he);
+	if (pair) {
+		if (he->diff.computed)
+			ratio = he->diff.period_ratio;
+		else
+			ratio = perf_diff__compute_ratio(he, pair);
+	}
 
 	if (ratio > 0.0)
 		scnprintf(buf, sizeof(buf), "%+14.6F", ratio);
@@ -326,14 +333,17 @@
 
 static int hpp__entry_wdiff(struct perf_hpp *hpp, struct hist_entry *he)
 {
+	struct hist_entry *pair = hist_entry__next_pair(he);
 	const char *fmt = symbol_conf.field_sep ? "%s" : "%14s";
 	char buf[32] = " ";
-	s64 wdiff;
+	s64 wdiff = 0;
 
-	if (he->diff.computed)
-		wdiff = he->diff.wdiff;
-	else
-		wdiff = perf_diff__compute_wdiff(he);
+	if (pair) {
+		if (he->diff.computed)
+			wdiff = he->diff.wdiff;
+		else
+			wdiff = perf_diff__compute_wdiff(he, pair);
+	}
 
 	if (wdiff != 0)
 		scnprintf(buf, sizeof(buf), "%14ld", wdiff);