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/* THIS IS OPEN SOURCE CODE */                                                                                                     

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/**                                                                                                                                

  * @file:    PAPI_Matlab.c

  * CVS:     $Id$    

  * @author Joseph Thomas <jthomas@cs.utk.edu>

  *

  *	@brief PAPI Matlab integration.

  *	See PAPI_Matlab.readme for more information.

  */

#include "mex.h"

#include "matrix.h"

#include "papi.h"

static long long accum_error = 0;

static long long start_time = 0;

void mexFunction(int nlhs, mxArray *plhs[],

                 int nrhs, const mxArray *prhs[]) {

  float real_time, proc_time, rate;

  int i;

  int number_of_counters;

  unsigned int mrows, nchars;

  unsigned int *events;

  unsigned int flop_events[2];

  long long ins = 0, *values, flop_values[2];

  long long elapsed_time;

  int result;

  char *input, *temp;

  char one_output[]	= "This function produces one output per running counter.";

  char no_input[]	= "This function expects no input.";

  char error_reading[]	= "Error reading the running counters.";

  /* Check for proper number of arguments. */

  if(nrhs < 1) {

    mexErrMsgTxt("This function expects input.");

  }

  nchars = mxGetNumberOfElements(prhs[0]);

  input = (char *)mxCalloc(nchars, sizeof(char) + 1);

  input = mxArrayToString(prhs[0]);

  if(!strncmp(input, "num", 3)) {

    if(nrhs != 1) {

      mexErrMsgTxt(no_input);

    }

    else if(nlhs != 1) {

      mexErrMsgTxt("This function produces one and only one output: counters.");

    }

    result = PAPI_num_counters();

    if(result < PAPI_OK) {

      mexPrintf("Error code: %d\n", result);

      mexErrMsgTxt("Error reading counters.");

    }

    plhs[0] = mxCreateDoubleScalar((double)result);

  }

  else if((!strncmp(input, "flip", 4)) || (!strncmp(input, "flop", 4))) {

    if(nrhs != 1) {

      mexErrMsgTxt(no_input);

    } else if(nlhs > 2) {

      if (input[2] == 'i')

	mexErrMsgTxt("This function produces 1 or 2 outputs: [ops, mflips].");

      else

	mexErrMsgTxt("This function produces 1 or 2 outputs: [ops, mflops].");

    }

    if (input[2] == 'i') {

      if(result = PAPI_flips( &real_time, &proc_time, &ins, &rate)

        mexPrintf("Error code: %d\n", result);

	     mexErrMsgTxt("Error getting flips.");

      }

    } else {

       if(result = PAPI_event_name_to_code("EMON_SSE_SSE2_COMP_INST_RETIRED_PACKED_DOUBLE", &(flop_events[0])) < PAPI_OK) {

          if(result = PAPI_flops( &real_time, &proc_time, &ins, &rate)

             mexPrintf("Error code: %d\n", result);

	          mexErrMsgTxt("Error getting flops.");

          }

       } else {

         if(start_time == 0) {

            flop_events[1] = PAPI_FP_OPS;

            start_time = PAPI_get_real_usec();

            if((result = PAPI_start_counters(flop_events, 2)) < PAPI_OK) {

               mexPrintf("Error code: %d\n", result);

               mexErrMsgTxt("Error getting flops.");

            } else {

               ins = 0;

               rate = 0;

            }

         } else {

            if((result = PAPI_read_counters(flop_values, 2)) < PAPI_OK) {

               mexPrintf("%d\n", result);

               mexErrMsgTxt(error_reading);

            } else {

               elapsed_time = PAPI_get_real_usec() - start_time;

               ins = (2*flop_values[0])+flop_values[1];

               rate = ((float)ins)/((float)elapsed_time);

            }

         }

       }

    }

    if(nlhs > 0) {

     plhs[0] = mxCreateDoubleScalar((double)(ins - accum_error));

      /* this call adds 7 fp instructions to the total */

      /* but apparently not on Pentium M with Matlab 7.0.4 */

/*      accum_error += 7; */

      if(nlhs == 2) {

        plhs[1] = mxCreateDoubleScalar((double)rate);

        /* the second call adds 4 fp instructions to the total */

      /* but apparently not on Pentium M with Matlab 7.0.4 */

/*        accum_error += 4; */

      }

    }

  }

  else if(!strncmp(input, "start", 5)) {

    if(nlhs != 0) {

      mexErrMsgTxt("This function produces no output.");

    }

    if(nrhs > (PAPI_num_counters() + 1)) {

      mexErrMsgTxt(one_output);

    }

    mrows = mxGetM(prhs[1]);

    events = (unsigned int *)mxCalloc(nrhs - 1, sizeof(int) + 1);

    for(i = 1; i < nrhs; i++) {

      if(mxIsComplex(prhs[i]) || !(mrows == 1) ) {

        mexErrMsgTxt("Input must be a list of strings.");

      }

      if(mxIsChar(prhs[i])) {

        nchars = mxGetNumberOfElements(prhs[i]);

        temp = (char *)mxCalloc(nchars, sizeof(char) + 1);

        temp = mxArrayToString(prhs[i]);

        if(result = PAPI_event_name_to_code(temp, &(events[i - 1])) < PAPI_OK) {

          mxFree(temp);

	  mexPrintf("Error code: %d\n", result);

          mexErrMsgTxt("Incorrect PAPI code given.");

       }

        mxFree(temp);

      }

      else {

        events[i - 1] = (unsigned int)mxGetScalar(prhs[i]);

      }

    }

    if((result = PAPI_start_counters(events, nrhs - 1)) < PAPI_OK) {

      mxFree(events);

      mexPrintf("Error code: %d\n", result);

      mexErrMsgTxt("Error initializing counters.");

    }

    mxFree(events);

  }

  else if(!strncmp(input, "stop", 4)) {

    if(nrhs != 1) {

      mexErrMsgTxt(no_input);

    }

	number_of_counters = PAPI_num_counters();

    if(nlhs > number_of_counters ) {

      mexErrMsgTxt(one_output);

    }

	if (nlhs == 0) 

	  values = (long long*)mxCalloc(number_of_counters, sizeof(long long));

	else 

	  values = (long long *)mxCalloc(nlhs, sizeof(long long) + 1);

	if (start_time == 0) {

	  if (nlhs == 0)

		result = PAPI_stop_counters(values, number_of_counters);

	  else

		result = PAPI_stop_counters(values, nlhs);

	} else {

	  start_time = 0;

	  result = PAPI_stop_counters(flop_values, 2);

	}

	if(result < PAPI_OK) {

	  if(result != PAPI_ENOTRUN) {

		mexPrintf("Error code: %d\n", result);

		mexErrMsgTxt("Error stopping the running counters.");

	  }

	}

	accum_error = 0;

	for(i = 0; i < nlhs; i++) {

	  plhs[i] = mxCreateDoubleScalar((double)values[i]);

	}

	mxFree(values);

  }

  else if(!strncmp(input, "read", 4)) {

    if(nrhs != 1) {

      mexErrMsgTxt(no_input);

    }

    if(nlhs > PAPI_num_counters()) {

      mexErrMsgTxt(one_output);

    }

    values = (long long *)mxCalloc(nlhs, sizeof(long long) + 1);

    if((result = PAPI_read_counters(values, nlhs)) < PAPI_OK) {

      mexPrintf("%d\n", result);

      mexErrMsgTxt(error_reading);

    }

    for(i = 0; i < nlhs; i++) {

      plhs[i] = mxCreateDoubleScalar((double)values[i]);

    }

    mxFree(values);

  }

  else if(!strncmp(input, "accum", 5)) {

    if(nrhs > PAPI_num_counters() + 1) {

      mexErrMsgTxt(no_input);

    }

    if(nlhs > PAPI_num_counters()) {

      mexErrMsgTxt(one_output);

    }

    values = (long long *)mxCalloc(nlhs, sizeof(long long) + 1);

    for(i = 0; i < nrhs - 1; i++) {

      values[i] = (long long)(*(mxGetPr(prhs[i + 1])));

    }

    if(result = PAPI_accum_counters(values, nlhs) < PAPI_OK) {

      mexPrintf("Error code: %d\n", result);

      mexErrMsgTxt(error_reading);

    }

    for(i = 0; i < nlhs; i++) {

      plhs[i] = mxCreateDoubleScalar((double)values[i]);

    }

    mxFree(values);

  }

  else if(!strncmp(input, "ipc", 3)) {

    if(nrhs != 1) {

      mexErrMsgTxt(no_input);

    } else if(nlhs > 2) {

      mexErrMsgTxt("This function produces 1 or 2 outputs: [ops, ipc].");

    }

    if(PAPI_ipc(&real_time, &proc_time, &ins, &rate)

      mexErrMsgTxt("Error getting instruction rate.");

    }

    if(nlhs > 0) {

      plhs[0] = mxCreateDoubleScalar((double)ins);

      if(nlhs == 2) {

        plhs[1] = mxCreateDoubleScalar((double)rate);

      }

    }

  }

  else {

    mexPrintf("Cannot find the command you specified.\n");

    mexErrMsgTxt("See the included readme file.");

  }

}