[PATCH 4/5] perf diff: Fix output ordering to honor next column

[Namhyung Kim <namhyung@kernel.org>]

When perf diff prints output, it sorts the entries using baseline field
by default, but entries which don't have baseline are not sorted
properly.  This patch makes it sorted by values of next column.

Before:

  # Baseline/0  Delta/1  Delta/2  Shared Object      Symbol
  # ..........  .......  .......  .................  ..........................................
  #
        32.75%   +0.28%   -0.83%  libc-2.20.so       [.] malloc
        31.50%   -0.74%   -0.23%  libc-2.20.so       [.] _int_free
        22.98%   +0.51%   +0.52%  libc-2.20.so       [.] _int_malloc
         5.70%   +0.28%   +0.30%  libc-2.20.so       [.] free
         4.38%   -0.21%   +0.25%  a.out              [.] main
         1.32%   -0.15%   +0.05%  a.out              [.] free@plt
         1.31%   +0.03%   -0.06%  a.out              [.] malloc@plt
         0.01%   -0.01%   -0.01%  [kernel.kallsyms]  [k] native_write_msr_safe
         0.01%                    [kernel.kallsyms]  [k] scheduler_tick
         0.01%            -0.00%  [kernel.kallsyms]  [k] native_read_msr_safe
                          +0.01%  [kernel.kallsyms]  [k] _raw_spin_lock_irqsave
                 +0.01%   +0.01%  [kernel.kallsyms]  [k] apic_timer_interrupt
                          +0.01%  [kernel.kallsyms]  [k] intel_pstate_timer_func
                 +0.01%           [kernel.kallsyms]  [k] perf_adjust_freq_unthr_context.part.82
                 +0.01%           [kernel.kallsyms]  [k] read_tsc
                          +0.01%  [kernel.kallsyms]  [k] timekeeping_update.constprop.8

After:

  # Baseline/0  Delta/1  Delta/2  Shared Object      Symbol
  # ..........  .......  .......  .................  ..........................................
  #
        32.75%   +0.28%   -0.83%  libc-2.20.so       [.] malloc
        31.50%   -0.74%   -0.23%  libc-2.20.so       [.] _int_free
        22.98%   +0.51%   +0.52%  libc-2.20.so       [.] _int_malloc
         5.70%   +0.28%   +0.30%  libc-2.20.so       [.] free
         4.38%   -0.21%   +0.25%  a.out              [.] main
         1.32%   -0.15%   +0.05%  a.out              [.] free@plt
         1.31%   +0.03%   -0.06%  a.out              [.] malloc@plt
         0.01%   -0.01%   -0.01%  [kernel.kallsyms]  [k] native_write_msr_safe
         0.01%                    [kernel.kallsyms]  [k] scheduler_tick
         0.01%            -0.00%  [kernel.kallsyms]  [k] native_read_msr_safe
                 +0.01%   +0.01%  [kernel.kallsyms]  [k] apic_timer_interrupt
                 +0.01%           [kernel.kallsyms]  [k] read_tsc
                 +0.01%           [kernel.kallsyms]  [k] perf_adjust_freq_unthr_context.part.82
                          +0.01%  [kernel.kallsyms]  [k] intel_pstate_timer_func
                          +0.01%  [kernel.kallsyms]  [k] _raw_spin_lock_irqsave
                          +0.01%  [kernel.kallsyms]  [k] timekeeping_update.constprop.8

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-diff.c | 60 +++++++++++++++++++++++++++--------------------
 1 file changed, 34 insertions(+), 26 deletions(-)

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 3f86737da2c4..f490e24e9477 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -65,6 +65,7 @@ static bool show_period;
 static bool show_formula;
 static bool show_baseline_only;
 static unsigned int sort_compute;
+static unsigned int data_idx;
 
 static s64 compute_wdiff_w1;
 static s64 compute_wdiff_w2;
@@ -448,26 +449,30 @@ static void hists__precompute(struct hists *hists)
 	next = rb_first(root);
 	while (next != NULL) {
 		struct hist_entry *he, *pair;
+		struct data__file *d;
+		int i;
 
 		he   = rb_entry(next, struct hist_entry, rb_node_in);
 		next = rb_next(&he->rb_node_in);
 
-		pair = get_pair_data(he, &data__files[sort_compute]);
-		if (!pair)
-			continue;
+		data__for_each_file_new(i, d) {
+			pair = get_pair_data(he, d);
+			if (!pair)
+				continue;
 
-		switch (compute) {
-		case COMPUTE_DELTA:
-			compute_delta(he, pair);
-			break;
-		case COMPUTE_RATIO:
-			compute_ratio(he, pair);
-			break;
-		case COMPUTE_WEIGHTED_DIFF:
-			compute_wdiff(he, pair);
-			break;
-		default:
-			BUG_ON(1);
+			switch (compute) {
+			case COMPUTE_DELTA:
+				compute_delta(he, pair);
+				break;
+			case COMPUTE_RATIO:
+				compute_ratio(he, pair);
+				break;
+			case COMPUTE_WEIGHTED_DIFF:
+				compute_wdiff(he, pair);
+				break;
+			default:
+				BUG_ON(1);
+			}
 		}
 	}
 }
@@ -517,7 +522,7 @@ __hist_entry__cmp_compute(struct hist_entry *left, struct hist_entry *right,
 
 static int64_t
 hist_entry__cmp_compute(struct hist_entry *left, struct hist_entry *right,
-			int c)
+			int c, int sort_idx)
 {
 	bool pairs_left  = hist_entry__has_pairs(left);
 	bool pairs_right = hist_entry__has_pairs(right);
@@ -529,8 +534,8 @@ hist_entry__cmp_compute(struct hist_entry *left, struct hist_entry *right,
 	if (!pairs_left || !pairs_right)
 		return pairs_left ? -1 : 1;
 
-	p_left  = get_pair_data(left,  &data__files[sort_compute]);
-	p_right = get_pair_data(right, &data__files[sort_compute]);
+	p_left  = get_pair_data(left,  &data__files[sort_idx]);
+	p_right = get_pair_data(right, &data__files[sort_idx]);
 
 	if (!p_left && !p_right)
 		return 0;
@@ -555,8 +560,13 @@ hist_entry__cmp_nop(struct hist_entry *left __maybe_unused,
 static int64_t
 hist_entry__cmp_baseline(struct hist_entry *left, struct hist_entry *right)
 {
-	if (sort_compute)
-		return 0;
+	/*
+	 * This function will be called first for each entry to resort
+	 * output.  Next compare-functions use this idx to find their
+	 * data and increase it for next data so we need to initialize
+	 * it everytime.
+	 */
+	data_idx = 0;
 
 	if (left->stat.period == right->stat.period)
 		return 0;
@@ -566,19 +576,19 @@ hist_entry__cmp_baseline(struct hist_entry *left, struct hist_entry *right)
 static int64_t
 hist_entry__cmp_delta(struct hist_entry *left, struct hist_entry *right)
 {
-	return hist_entry__cmp_compute(right, left, COMPUTE_DELTA);
+	return hist_entry__cmp_compute(right, left, COMPUTE_DELTA, ++data_idx);
 }
 
 static int64_t
 hist_entry__cmp_ratio(struct hist_entry *left, struct hist_entry *right)
 {
-	return hist_entry__cmp_compute(right, left, COMPUTE_RATIO);
+	return hist_entry__cmp_compute(right, left, COMPUTE_RATIO, ++data_idx);
 }
 
 static int64_t
 hist_entry__cmp_wdiff(struct hist_entry *left, struct hist_entry *right)
 {
-	return hist_entry__cmp_compute(right, left, COMPUTE_WEIGHTED_DIFF);
+	return hist_entry__cmp_compute(right, left, COMPUTE_WEIGHTED_DIFF, ++data_idx);
 }
 
 static void hists__process(struct hists *hists)
@@ -586,9 +596,7 @@ static void hists__process(struct hists *hists)
 	if (show_baseline_only)
 		hists__baseline_only(hists);
 
-	if (sort_compute)
-		hists__precompute(hists);
-
+	hists__precompute(hists);
 	hists__output_resort(hists, NULL);
 
 	hists__fprintf(hists, true, 0, 0, 0, stdout);
-- 
2.2.1