message: Attempt to clarify perf suite FOM report
diff: @@ -507,15 +507,15 @@ void Executor::writeFOMReport(const string& filename)
  vector<double> col_max(ncols, -numeric_limits<double>::max());
  vector<double> col_avg(ncols, 0.0);
  vector<double> col_stddev(ncols, 0.0);
  - vector< vector<double> > rel_diff(kernels.size());
  + vector< vector<double> > pct_diff(kernels.size());
  for (size_t ik = 0; ik < kernels.size(); ++ik) {
  - rel_diff[ik] = vector<double>(ncols, 0.0);
  + pct_diff[ik] = vector<double>(ncols, 0.0);
  }
  //
  // Print title line.
  //
  - file << "FOM Report (RAJA variant speedup for each programming model: T_RAJA / T_baseline)";
  + file << "FOM Report (+/- % runtime diff for each prog model: 100 * (T_RAJA - T_baseline) / T_baseline )";
  for (size_t iv = 0; iv < ncols; ++iv) {
  file << sepchr;
  }
  @@ -563,24 +563,19 @@ void Executor::writeFOMReport(const string& filename)
  if ( kern->wasVariantRun(comp_vid) ) {
  col_exec_count[col]++;
  -#if 0 // RDH RETHINK
  - rel_diff[ik][col] =
  + pct_diff[ik][col] = 100.0 *
  (kern->getTotTime(comp_vid) - kern->getTotTime(base_vid)) /
  kern->getTotTime(base_vid);
  -#else
  - rel_diff[ik][col] =
  - kern->getTotTime(comp_vid) / kern->getTotTime(base_vid);
  -#endif
  file << sepchr <<left<< setw(fom_col_width) << setprecision(prec)
  - << rel_diff[ik][col];
  + << pct_diff[ik][col];
  //
  // Gather data for column summaries (unsigned).
  //
  - col_min[col] = min( col_min[col], rel_diff[ik][col] );
  - col_max[col] = max( col_max[col], rel_diff[ik][col] );
  - col_avg[col] += rel_diff[ik][col];
  + col_min[col] = min( col_min[col], pct_diff[ik][col] );
  + col_max[col] = max( col_max[col], pct_diff[ik][col] );
  + col_avg[col] += pct_diff[ik][col];
  } else { // variant was not run, print a big fat goose egg...
  @@ -625,8 +620,8 @@ void Executor::writeFOMReport(const string& filename)
  VariantID comp_vid = group.variants[gv];
  if ( kern->wasVariantRun(comp_vid) ) {
  - col_stddev[col] += ( rel_diff[ik][col] - col_avg[col] ) *
  - ( rel_diff[ik][col] - col_avg[col] );
  + col_stddev[col] += ( pct_diff[ik][col] - col_avg[col] ) *
  + ( pct_diff[ik][col] - col_avg[col] );
  }
  col++;
  