static bool  force;
 static bool show_displacement;
 static bool show_baseline_only;
+static bool sort_compute;
 
 enum {
        COMPUTE_DELTA,
                return 0;
        }
 
+       if (*str == '+') {
+               sort_compute = true;
+               str++;
+               if (!*str)
+                       return 0;
+       }
+
        for (i = 0; i < COMPUTE_MAX; i++)
                if (!strcmp(str, compute_names[i])) {
                        *cp = i;
        return -EINVAL;
 }
 
+static double get_period_percent(struct hist_entry *he, u64 period)
+{
+       u64 total = he->hists->stats.total_period;
+       return (period * 100.0) / total;
+}
+
+double perf_diff__compute_delta(struct hist_entry *he)
+{
+       struct hist_entry *pair = he->pair;
+       double new_percent = get_period_percent(he, he->stat.period);
+       double old_percent = pair ? get_period_percent(pair, pair->stat.period) : 0.0;
+
+       he->diff.period_ratio_delta = new_percent - old_percent;
+       he->diff.computed = true;
+       return he->diff.period_ratio_delta;
+}
+
+double perf_diff__compute_ratio(struct hist_entry *he)
+{
+       struct hist_entry *pair = he->pair;
+       double new_period = he->stat.period;
+       double old_period = pair ? pair->stat.period : 0;
+
+       he->diff.computed = true;
+       he->diff.period_ratio = pair ? (new_period / old_period) : 0;
+       return he->diff.period_ratio;
+}
+
 static int hists__add_entry(struct hists *self,
                            struct addr_location *al, u64 period)
 {
        }
 }
 
+static void hists__precompute(struct hists *hists)
+{
+       struct rb_node *next = rb_first(&hists->entries);
+
+       while (next != NULL) {
+               struct hist_entry *he = rb_entry(next, struct hist_entry, rb_node);
+
+               next = rb_next(&he->rb_node);
+
+               switch (compute) {
+               case COMPUTE_DELTA:
+                       perf_diff__compute_delta(he);
+                       break;
+               case COMPUTE_RATIO:
+                       perf_diff__compute_ratio(he);
+                       break;
+               default:
+                       BUG_ON(1);
+               }
+       }
+}
+
+static int64_t cmp_doubles(double l, double r)
+{
+       if (l > r)
+               return -1;
+       else if (l < r)
+               return 1;
+       else
+               return 0;
+}
+
+static int64_t
+hist_entry__cmp_compute(struct hist_entry *left, struct hist_entry *right,
+                       int c)
+{
+       switch (c) {
+       case COMPUTE_DELTA:
+       {
+               double l = left->diff.period_ratio_delta;
+               double r = right->diff.period_ratio_delta;
+
+               return cmp_doubles(l, r);
+       }
+       case COMPUTE_RATIO:
+       {
+               double l = left->diff.period_ratio;
+               double r = right->diff.period_ratio;
+
+               return cmp_doubles(l, r);
+       }
+       default:
+               BUG_ON(1);
+       }
+
+       return 0;
+}
+
+static void insert_hist_entry_by_compute(struct rb_root *root,
+                                        struct hist_entry *he,
+                                        int c)
+{
+       struct rb_node **p = &root->rb_node;
+       struct rb_node *parent = NULL;
+       struct hist_entry *iter;
+
+       while (*p != NULL) {
+               parent = *p;
+               iter = rb_entry(parent, struct hist_entry, rb_node);
+               if (hist_entry__cmp_compute(he, iter, c) < 0)
+                       p = &(*p)->rb_left;
+               else
+                       p = &(*p)->rb_right;
+       }
+
+       rb_link_node(&he->rb_node, parent, p);
+       rb_insert_color(&he->rb_node, root);
+}
+
+static void hists__compute_resort(struct hists *hists)
+{
+       struct rb_root tmp = RB_ROOT;
+       struct rb_node *next = rb_first(&hists->entries);
+
+       while (next != NULL) {
+               struct hist_entry *he = rb_entry(next, struct hist_entry, rb_node);
+
+               next = rb_next(&he->rb_node);
+
+               rb_erase(&he->rb_node, &hists->entries);
+               insert_hist_entry_by_compute(&tmp, he, compute);
+       }
+
+       hists->entries = tmp;
+}
+
 static void hists__process(struct hists *old, struct hists *new)
 {
        hists__match(old, new);
        if (show_baseline_only)
                hists__baseline_only(new);
 
+       if (sort_compute) {
+               hists__precompute(new);
+               hists__compute_resort(new);
+       }
+
        hists__fprintf(new, true, 0, 0, stdout);
 }
 
 
 
 static int hpp__entry_delta(struct perf_hpp *hpp, struct hist_entry *he)
 {
-       struct hist_entry *pair = he->pair;
-       struct hists *pair_hists = pair ? pair->hists : NULL;
-       struct hists *hists = he->hists;
-       u64 old_total, new_total;
-       double old_percent = 0, new_percent = 0;
-       double diff;
        const char *fmt = symbol_conf.field_sep ? "%s" : "%7.7s";
        char buf[32] = " ";
+       double diff;
 
-       old_total = pair_hists ? pair_hists->stats.total_period : 0;
-       if (old_total > 0 && pair)
-               old_percent = 100.0 * pair->stat.period / old_total;
-
-       new_total = hists->stats.total_period;
-       if (new_total > 0)
-               new_percent = 100.0 * he->stat.period / new_total;
+       if (he->diff.computed)
+               diff = he->diff.period_ratio_delta;
+       else
+               diff = perf_diff__compute_delta(he);
 
-       diff = new_percent - old_percent;
        if (fabs(diff) >= 0.01)
                scnprintf(buf, sizeof(buf), "%+4.2F%%", diff);
 
 
 static int hpp__entry_ratio(struct perf_hpp *hpp, struct hist_entry *he)
 {
-       struct hist_entry *pair = he->pair;
-       double new_period = he->stat.period;
-       double old_period = pair ? pair->stat.period : 0;
-       double ratio = pair ? new_period / old_period : 0;
        const char *fmt = symbol_conf.field_sep ? "%s" : "%14s";
        char buf[32] = " ";
+       double ratio;
+
+       if (he->diff.computed)
+               ratio = he->diff.period_ratio;
+       else
+               ratio = perf_diff__compute_ratio(he);
 
        if (ratio > 0.0)
                scnprintf(buf, sizeof(buf), "%+14.6F", ratio);