llvm-project/llvm/runtime/libprofile/OptimalEdgeProfiling.c

46 lines
1.6 KiB
C

/*===-- 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(void) {
/* 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 guaranteed 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;
}