perf tools: Add code to support PERF_SAMPLE_BRANCH_STACK

This patch adds:

 - ability to parse samples with PERF_SAMPLE_BRANCH_STACK
 - sort on branches (dso_from, symbol_from, dso_to, symbol_to, mispredict)
 - build histograms on branches

Signed-off-by: Roberto Agostino Vitillo <ravitillo@lbl.gov>
Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: acme@redhat.com
Cc: robert.richter@amd.com
Cc: ming.m.lin@intel.com
Cc: andi@firstfloor.org
Cc: asharma@fb.com
Cc: vweaver1@eecs.utk.edu
Cc: khandual@linux.vnet.ibm.com
Cc: dsahern@gmail.com
Link: http://lkml.kernel.org/r/1328826068-11713-12-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 302d49a..a1fd1cd 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -576,6 +576,16 @@
 		data->raw_data = (void *) pdata;
 	}
 
+	if (type & PERF_SAMPLE_BRANCH_STACK) {
+		u64 sz;
+
+		data->branch_stack = (struct branch_stack *)array;
+		array++; /* nr */
+
+		sz = data->branch_stack->nr * sizeof(struct branch_entry);
+		sz /= sizeof(u64);
+		array += sz;
+	}
 	return 0;
 }