OptimalEdgeProfiling: Creation of profiles.

This adds the instrumentation and runtime part of OptimalEdgeProfiling.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80712 91177308-0d34-0410-b5e6-96231b3b80d8

runtime/libprofile/OptimalEdgeProfiling.c

@@ -0,0 +1,45 @@
+/*===-- OptimalEdgeProfiling.c - Support library for opt. edge profiling --===*\
+|*
+|*                     The LLVM Compiler Infrastructure
+|*
+|* This file is distributed under the University of Illinois Open Source      
+|* License. See LICENSE.TXT for details.                                      
+|* 
+|*===----------------------------------------------------------------------===*|
+|* 
+|* This file implements the call back routines for the edge profiling
+|* instrumentation pass.  This should be used with the
+|* -insert-opt-edge-profiling LLVM pass.
+|*
+\*===----------------------------------------------------------------------===*/
+
+#include "Profiling.h"
+#include <stdlib.h>
+
+static unsigned *ArrayStart;
+static unsigned NumElements;
+
+/* OptEdgeProfAtExitHandler - When the program exits, just write out the
+ * profiling data.
+ */
+static void OptEdgeProfAtExitHandler() {
+  /* Note that, although the array has a counter for each edge, not all
+   * counters are updated, the ones that are not used are initialised with -1.
+   * When loading this information the counters with value -1 have to be
+   * recalculated, it is guranteed that this is possible.
+   */
+  write_profiling_data(OptEdgeInfo, ArrayStart, NumElements);
+}
+
+
+/* llvm_start_opt_edge_profiling - This is the main entry point of the edge
+ * profiling library.  It is responsible for setting up the atexit handler.
+ */
+int llvm_start_opt_edge_profiling(int argc, const char **argv,
+                                  unsigned *arrayStart, unsigned numElements) {
+  int Ret = save_arguments(argc, argv);
+  ArrayStart = arrayStart;
+  NumElements = numElements;
+  atexit(OptEdgeProfAtExitHandler);
+  return Ret;
+}