+#define OVERLAP_BASE 10000
+
+/* Compare the static estimated profile to the actual profile, and
+ return the "degree of overlap" measure between them.
+
+ Degree of overlap is a number between 0 and OVERLAP_BASE. It is
+ the sum of each basic block's minimum relative weights between
+ two profiles. And overlap of OVERLAP_BASE means two profiles are
+ identical. */
+
+static int
+compute_frequency_overlap (void)
+{
+ gcov_type count_total = 0, freq_total = 0;
+ int overlap = 0;
+ basic_block bb;
+
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ {
+ count_total += bb->count;
+ freq_total += bb->frequency;
+ }
+
+ if (count_total == 0 || freq_total == 0)
+ return 0;
+
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ overlap += MIN (bb->count * OVERLAP_BASE / count_total,
+ bb->frequency * OVERLAP_BASE / freq_total);
+
+ return overlap;
+}
+