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      1 /*===-- OptimalEdgeProfiling.c - Support library for opt. edge profiling --===*\
      2 |*
      3 |*                     The LLVM Compiler Infrastructure
      4 |*
      5 |* This file is distributed under the University of Illinois Open Source
      6 |* License. See LICENSE.TXT for details.
      7 |*
      8 |*===----------------------------------------------------------------------===*|
      9 |*
     10 |* This file implements the call back routines for the edge profiling
     11 |* instrumentation pass.  This should be used with the
     12 |* -insert-opt-edge-profiling LLVM pass.
     13 |*
     14 \*===----------------------------------------------------------------------===*/
     15 
     16 #include "Profiling.h"
     17 #include <stdlib.h>
     18 
     19 static unsigned *ArrayStart;
     20 static unsigned NumElements;
     21 
     22 /* OptEdgeProfAtExitHandler - When the program exits, just write out the
     23  * profiling data.
     24  */
     25 static void OptEdgeProfAtExitHandler(void) {
     26   /* Note that, although the array has a counter for each edge, not all
     27    * counters are updated, the ones that are not used are initialised with -1.
     28    * When loading this information the counters with value -1 have to be
     29    * recalculated, it is guaranteed that this is possible.
     30    */
     31   write_profiling_data(OptEdgeInfo, ArrayStart, NumElements);
     32 }
     33 
     34 
     35 /* llvm_start_opt_edge_profiling - This is the main entry point of the edge
     36  * profiling library.  It is responsible for setting up the atexit handler.
     37  */
     38 int llvm_start_opt_edge_profiling(int argc, const char **argv,
     39                                   unsigned *arrayStart, unsigned numElements) {
     40   int Ret = save_arguments(argc, argv);
     41   ArrayStart = arrayStart;
     42   NumElements = numElements;
     43   atexit(OptEdgeProfAtExitHandler);
     44   return Ret;
     45 }
     46