Add static variables as per code review comments.

c/enc/block_splitter_inc.h

@@ -118,6 +118,7 @@ static size_t FN(FindBlocks)(const DataType* data, const size_t length,
     size_t insert_cost_ix = symbol * num_histograms;
     double min_cost = 1e99;
     double block_switch_cost = block_switch_bitcost;
+    static const double threshold = 0.07 / 2000.0;
     size_t k;
     for (k = 0; k < num_histograms; ++k) {
       /* We are coding the symbol with entropy code k. */
@@ -129,7 +130,7 @@ static size_t FN(FindBlocks)(const DataType* data, const size_t length,
     }
     /* More blocks for the beginning. */
     if (byte_ix < 2000) {
-      block_switch_cost *= 0.77 + 0.000035 * (double)byte_ix;
+      block_switch_cost *= 0.77 + threshold * (double)byte_ix;
     }
     for (k = 0; k < num_histograms; ++k) {
       cost[k] -= min_cost;

c/enc/literal_cost.c

@@ -106,6 +106,7 @@ static void EstimateBitCostsForLiteralsUTF8(size_t pos, size_t len, size_t mask,
       size_t utf8_pos = UTF8Position(last_c, c, max_utf8);
       size_t masked_pos = (pos + i) & mask;
       size_t histo = histogram[256 * utf8_pos + data[masked_pos]];
+      static const double threshold = 0.35 / 2000.0;
       double lit_cost;
       if (histo == 0) {
         histo = 1;
@@ -121,7 +122,7 @@ static void EstimateBitCostsForLiteralsUTF8(size_t pos, size_t len, size_t mask,
          rapidly in the beginning of the file, perhaps because the beginning
          of the data is a statistical "anomaly". */
       if (i < 2000) {
-        lit_cost += 0.7 - ((double)(2000 - i) * 0.000175);
+        lit_cost += 0.7 - ((double)(2000 - i) * threshold);
       }
       cost[i] = (float)lit_cost;
     }