opr_convect_scalar.cu

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/*
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#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "convect_scalar_kernel.h"
#include "elem_block_tune.h"
#include <device/device_config.h>
#include <device/cuda/check.h>
 
extern "C" {
  #include <common/neko_log.h>
}
 
template < const int >
int tune_convect_scalar(void *du, void *u,
               void *cr, void *cs, void *ct,
               void *dx, void *dy, void *dz,
               int *nel, int *lx, int *eb_sel, int *ch_sel);
 
extern "C" {
 
  void cuda_convect_scalar(void *du, void *u,
                  void *cr, void *cs, void *ct,
                  void *dx, void *dy, void *dz,
                  int *nel, int *lx) {
 
    static int autotune[17] = { 0 };
    /* elements per block candidate chosen by the tuner */
    static int autotune_eb[17] = { 0 };
    /* chunk candidate chosen for the 1d variant */
    static int autotune_ch[17] = { 0 };
 
    const dim3 nthrds_1d(1024, 1, 1);
    const dim3 nthrds_kstep((*lx), (*lx), 1);
    const dim3 nblcks((*nel), 1, 1);
    const cudaStream_t stream = (cudaStream_t) glb_cmd_queue;
 
#define CASE_1D(LX, C)                                                          \
    convect_scalar_kernel_1d<real, LX, NEKO_CHUNKS(LX, C)>                      \
      <<<nblcks, NEKO_CHUNKS_NTHRDS(LX, C), 0, stream>>>                        \
      ((real *) du, (real *) u,                                                 \
       (real *) cr, (real *) cs, (real *) ct,                                   \
       (real *) dx, (real *) dy, (real *) dz);                                  \
    CUDA_CHECK(cudaGetLastError());
 
/* Runtime dispatch onto the tuned chunk candidate */
#define CASE_1D_SEL(LX, SEL)                                                    \
    switch (SEL) {                                                              \
    case 0:  CASE_1D(LX, 0); break;                                             \
    case 1:  CASE_1D(LX, 1); break;                                             \
    case 2:  CASE_1D(LX, 2); break;                                             \
    default: CASE_1D(LX, 3); break;                                             \
    }
 
#define CASE_KSTEP(LX, C)                                                       \
    convect_scalar_kernel_kstep<real, LX, NEKO_EB(LX, C)>                       \
      <<<NEKO_EB_NBLCKS(*nel, LX, C), NEKO_EB_NTHRDS(LX, C), 0, stream>>>       \
      ((real *) du, (real *) u,                                                 \
       (real *) cr, (real *) cs, (real *) ct,                                   \
       (real *) dx, (real *) dy, (real *) dz, *nel);                            \
    CUDA_CHECK(cudaGetLastError());
 
/* Runtime dispatch onto the tuned candidate */
#define CASE_KSTEP_SEL(LX, SEL)                                                 \
    switch (SEL) {                                                              \
    case 0:  CASE_KSTEP(LX, 0); break;                                          \
    case 1:  CASE_KSTEP(LX, 1); break;                                          \
    default: CASE_KSTEP(LX, 2); break;                                          \
    }
 
#define CASE(LX)                                                                \
    case LX:                                                                    \
      if(autotune[LX] == 0 ) {                                                  \
        autotune[LX]=tune_convect_scalar<LX>(du, u,                             \
                                    cr, cs, ct,                                 \
                                    dx, dy, dz,                                 \
                                    nel, lx, &autotune_eb[LX],                  \
                                    &autotune_ch[LX]);                          \
      } else if (autotune[LX] == 1 ) {                                          \
        CASE_1D_SEL(LX, autotune_ch[LX]);                                       \
      } else if (autotune[LX] == 2 ) {                                          \
        CASE_KSTEP_SEL(LX, autotune_eb[LX]);                                    \
      }                                                                         \
      break
 
#define CASE_LARGE(LX)                                                          \
    case LX:                                                                    \
      CASE_KSTEP(LX, 0);                                                        \
      break
 
 
    if ((*lx) < 11) {
      switch(*lx) {
        CASE(2);
        CASE(3);
        CASE(4);
        CASE(5);
        CASE(6);
        CASE(7);
        CASE(8);
        CASE(9);
        CASE(10);
      default:
        {
          fprintf(stderr, __FILE__ ": size not supported: %d\n", *lx);
          exit(1);
        }
      }
    }
    else {
      switch(*lx) {
        CASE_LARGE(11);
        CASE_LARGE(12);
        CASE_LARGE(13);
        CASE_LARGE(14);
        CASE_LARGE(15);
        CASE_LARGE(16);
      default:
        {
          fprintf(stderr, __FILE__ ": size not supported: %d\n", *lx);
          exit(1);
        }
      }
    }
  }
}
 
template < const int LX >
int tune_convect_scalar(void *du, void *u,
               void *cr, void *cs, void *ct,
               void *dx, void *dy, void *dz,
               int *nel, int *lx, int *eb_sel, int *ch_sel) {
  cudaEvent_t start,stop;
  float time1[NEKO_CHUNKS_CANDIDATES];
  int best1 = 0;
  float time2[NEKO_EB_CANDIDATES];
  const int rounds = neko_tune_rounds();
  const int iters = neko_tune_iters();
  const int sweep = neko_eb_sweep();
  int best = 0;
  int retval;
 
  for (int c = 0; c < NEKO_EB_CANDIDATES; c++) {
    time2[c] = NEKO_TUNE_INIT;
  }
  for (int c = 0; c < NEKO_CHUNKS_CANDIDATES; c++) {
    time1[c] = NEKO_TUNE_INIT;
  }
 
  const dim3 nthrds_1d(1024, 1, 1);
  const dim3 nthrds_kstep((*lx), (*lx), 1);
  const dim3 nblcks((*nel), 1, 1);
  const cudaStream_t stream = (cudaStream_t) glb_cmd_queue;
 
  char *env_value = NULL;
  char neko_log_buf[80];
 
  env_value=getenv("NEKO_AUTOTUNE");
 
  sprintf(neko_log_buf, "Autotune convect_scalar (lx: %d)", *lx);
  log_section(neko_log_buf);
 
  *eb_sel = 0;
  *ch_sel = 0;
 
  if(env_value) {
    if( !strcmp(env_value,"1D") ) {
      *ch_sel = neko_chunks_env();
      CASE_1D_SEL(LX, *ch_sel);
      sprintf(neko_log_buf,"Set by env   : 1 (1D, %d chunk)",
              NEKO_CHUNKS_SEL(LX, *ch_sel));
      log_message(neko_log_buf);
      log_end_section();
      return 1;
    } else if( !strcmp(env_value,"KSTEP") ) {
      *eb_sel = neko_eb_env();
      CASE_KSTEP_SEL(LX, *eb_sel);
      sprintf(neko_log_buf,"Set by env   : 2 (KSTEP, %d elem/block)",
              NEKO_EB_SEL(LX, *eb_sel));
      log_message(neko_log_buf);
      log_end_section();
      return 2;
    } else {
       sprintf(neko_log_buf, "Invalid value set for NEKO_AUTOTUNE");
       log_error(neko_log_buf);
    }
  }
 
  cudaEventCreate(&start);
  cudaEventCreate(&stop);
  /* Warm every variant before timing anything: each specialisation has to be
     resident and the clocks at steady state, or whichever is timed first is
     measured on a colder part */
  for (int i = 0; i < NEKO_TUNE_WARMUP; i++) {
    CASE_1D(LX, 0);
    CASE_1D(LX, 1);
    CASE_1D(LX, 2);
    CASE_1D(LX, 3);
    CASE_KSTEP(LX, 0);
    if (sweep) {
      CASE_KSTEP(LX, 1);
      CASE_KSTEP(LX, 2);
    }
  }
 
  /* Interleaved rounds, best time per variant */
  for (int r = 0; r < rounds; r++) {
    NEKO_TUNE_TIME(time1, CASE_1D, LX, 0, iters);
    NEKO_TUNE_TIME(time1, CASE_1D, LX, 1, iters);
    NEKO_TUNE_TIME(time1, CASE_1D, LX, 2, iters);
    NEKO_TUNE_TIME(time1, CASE_1D, LX, 3, iters);
    NEKO_TUNE_TIME(time2, CASE_KSTEP, LX, 0, iters);
    if (sweep) {
      NEKO_TUNE_TIME(time2, CASE_KSTEP, LX, 1, iters);
      NEKO_TUNE_TIME(time2, CASE_KSTEP, LX, 2, iters);
    }
  }
 
  NEKO_TUNE_LOG(LX, time1, time2);
  NEKO_TUNE_BEST(time1, best1, NEKO_CHUNKS_CANDIDATES);
  NEKO_TUNE_BEST(time2, best, NEKO_EB_CANDIDATES);
  *eb_sel = best;
  *ch_sel = best1;
 
  if (time1[best1] < time2[best]) {
    retval = 1;
  } else {
    retval = 2;
  }
 
  /* Leave the chosen kernel's output in place: the tuner stands in for a real
     evaluation and the variants do not sum in the same order */
  if (retval == 1) {
    CASE_1D_SEL(LX, best1);
  } else {
    CASE_KSTEP_SEL(LX, best);
  }
 
  if (retval == 1) {
    sprintf(neko_log_buf, "Chose        : 1 (1D, %d chunk)",
            NEKO_CHUNKS_SEL(LX, best1));
  } else {
    sprintf(neko_log_buf, "Chose        : 2 (KSTEP, %d elem/block)",
            NEKO_EB_SEL(LX, best));
  }
  log_message(neko_log_buf);
  log_end_section();
  return retval;
}