text: /*
  * Histogram (HST-L) with multiple tasklets
  *
  */
  #include <stdint.h>
  #include <stdio.h>
  #include <defs.h>
  #include <mram.h>
  #include <alloc.h>
  #include <perfcounter.h>
  #include <barrier.h>
  #include <atomic_bit.h>
  #include <mutex.h>
  
  #include "../support/common.h"
  
  __host dpu_arguments_t DPU_INPUT_ARGUMENTS;
  
  // Array for communication between adjacent tasklets
  uint32_t* message[NR_TASKLETS];
  // DPU histogram
  uint32_t* histo_dpu;
  
  // Barrier
  BARRIER_INIT(my_barrier, NR_TASKLETS);
  ATOMIC_BIT_INIT(barriers_mutexes)[NR_HISTO];
  barrier_t barriers[NR_HISTO];
  
  // Mutex
  mutex_id_t my_mutex[NR_HISTO];
  
  // Histogram in each tasklet
  static void histogram(uint32_t* histo, uint32_t bins, T *input, uint32_t histo_id, unsigned int l_size){
      for(unsigned int j = 0; j < l_size; j++) {
          T d = (input[j] * bins) >> DEPTH;
          mutex_lock(my_mutex[histo_id]);
          histo[d] += 1;
          mutex_unlock(my_mutex[histo_id]);
      }
  }
  
  extern int main_kernel1(void);
  
  int (*kernels[nr_kernels])(void) = {main_kernel1};
  
  int main(void) { 
      // Kernel
      return kernels[DPU_INPUT_ARGUMENTS.kernel](); 
  }
  
  // main_kernel1
  int main_kernel1() {
      unsigned int tasklet_id = me();
  #if PRINT
      printf("tasklet_id = %u\n", tasklet_id);
  #endif
      unsigned int l_tasklet_id = tasklet_id / NR_HISTO;
      unsigned int nr_l_tasklet = NR_TASKLETS / NR_HISTO;
      unsigned int my_histo_id = tasklet_id & (NR_HISTO - 1);
  
      if (tasklet_id == 0){ // Initialize once the cycle counter
          mem_reset(); // Reset the heap
          // Initialize barriers
          for (unsigned int each_barrier = 0; each_barrier < NR_HISTO; each_barrier++) {
              barriers[each_barrier].wait_queue = 0xff;
              barriers[each_barrier].count = nr_l_tasklet;
              barriers[each_barrier].initial_count = nr_l_tasklet;
              barriers[each_barrier].lock = (uint8_t) &ATOMIC_BIT_GET(barriers_mutexes)[each_barrier];
          }
      }
      // Barrier
      barrier_wait(&my_barrier);
  
      uint32_t input_size_dpu_bytes = DPU_INPUT_ARGUMENTS.size;
      uint32_t input_size_dpu_bytes_transfer = DPU_INPUT_ARGUMENTS.transfer_size; // Transfer input size per DPU in bytes
      uint32_t bins = DPU_INPUT_ARGUMENTS.bins;
  
      // Address of the current processing block in MRAM
      uint32_t base_tasklet = tasklet_id << BLOCK_SIZE_LOG2;
      uint32_t mram_base_addr_A = (uint32_t)DPU_MRAM_HEAP_POINTER;
      uint32_t mram_base_addr_histo = (uint32_t)(DPU_MRAM_HEAP_POINTER + input_size_dpu_bytes_transfer);
  
      // Initialize a local cache to store the MRAM block
      T *cache_A = (T *) mem_alloc(BLOCK_SIZE);
  	
      // Local histogram
      if (tasklet_id < NR_HISTO){ // Allocate DPU histogram
          uint32_t *histo = (uint32_t *) mem_alloc(bins * sizeof(uint32_t));
          message[tasklet_id] = histo;
      }
      // Barrier
      barrier_wait(&barriers[my_histo_id]);
  
      uint32_t *my_histo = message[my_histo_id];
  
      // Initialize local histogram
      for(unsigned int i = l_tasklet_id; i < bins; i += nr_l_tasklet){
          my_histo[i] = 0;
      }
      // Barrier
      barrier_wait(&barriers[my_histo_id]);
  
      // Compute histogram
      for(unsigned int byte_index = base_tasklet; byte_index < input_size_dpu_bytes; byte_index += BLOCK_SIZE * NR_TASKLETS){
  
          // Bound checking
          uint32_t l_size_bytes = (byte_index + BLOCK_SIZE >= input_size_dpu_bytes) ? (input_size_dpu_bytes - byte_index) : BLOCK_SIZE;
  
          // Load cache with current MRAM block
          mram_read((const __mram_ptr void*)(mram_base_addr_A + byte_index), cache_A, l_size_bytes);
  
          // Histogram in each tasklet
          histogram(my_histo, bins, cache_A, my_histo_id, l_size_bytes >> DIV);
      }
  
      // Barrier
      barrier_wait(&my_barrier);
  
      uint32_t *histo_dpu = message[0];
      for (unsigned int i = tasklet_id; i < bins; i += NR_TASKLETS){
          uint32_t b = 0;
          for (unsigned int j = 0; j < NR_HISTO; j++){			
              b += *(message[j] + i);
          }
          histo_dpu[i] = b;
      }
  
      // Barrier
      barrier_wait(&my_barrier);
  
      // Write dpu histogram to current MRAM block
      if(tasklet_id == 0){
          if(bins * sizeof(uint32_t) <= 2048)
              mram_write(histo_dpu, (__mram_ptr void*)(mram_base_addr_histo), bins * sizeof(uint32_t));
          else 
              for(unsigned int offset = 0; offset < ((bins * sizeof(uint32_t)) >> 11); offset++){
      	        mram_write(histo_dpu + (offset << 9), (__mram_ptr void*)(mram_base_addr_histo + (offset << 11)), 2048);
              }
      }
  
      return 0;
  }
  