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/*===-- BasicBlockTracing.c - Support library for basic block tracing -----===*\
|*
|* 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 basic block tracing
|* instrumentation pass. This should be used with the -trace-basic-blocks
|* LLVM pass.
|*
\*===----------------------------------------------------------------------===*/
#include "Profiling.h"
#include <stdlib.h>
#include <stdio.h>
static unsigned *ArrayStart, *ArrayEnd, *ArrayCursor;
/* WriteAndFlushBBTraceData - write out the currently accumulated trace data
* and reset the cursor to point to the beginning of the buffer.
*/
static void WriteAndFlushBBTraceData () {
write_profiling_data(BBTraceInfo, ArrayStart, (ArrayCursor - ArrayStart));
ArrayCursor = ArrayStart;
}
/* BBTraceAtExitHandler - When the program exits, just write out any remaining
* data and free the trace buffer.
*/
static void BBTraceAtExitHandler() {
WriteAndFlushBBTraceData ();
free (ArrayStart);
}
/* llvm_trace_basic_block - called upon hitting a new basic block. */
void llvm_trace_basic_block (unsigned BBNum) {
*ArrayCursor++ = BBNum;
if (ArrayCursor == ArrayEnd)
WriteAndFlushBBTraceData ();
}
/* llvm_start_basic_block_tracing - This is the main entry point of the basic
* block tracing library. It is responsible for setting up the atexit
* handler and allocating the trace buffer.
*/
int llvm_start_basic_block_tracing(int argc, const char **argv,
unsigned *arrayStart, unsigned numElements) {
int Ret;
const unsigned BufferSize = 128 * 1024;
unsigned ArraySize;
Ret = save_arguments(argc, argv);
/* Allocate a buffer to contain BB tracing data */
ArraySize = BufferSize / sizeof (unsigned);
ArrayStart = malloc (ArraySize * sizeof (unsigned));
ArrayEnd = ArrayStart + ArraySize;
ArrayCursor = ArrayStart;
/* Set up the atexit handler. */
atexit (BBTraceAtExitHandler);
return Ret;
}