Fast double-to-ascii conversion.

src/cached_powers.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 47 matching lines @@
 #include "powers_ten.h"  // NOLINT
 
 static const double kD_1_LOG2_10 = 0.30102999566398114;  //  1 / lg(10)
 
 // We can't use a function since we reference variables depending on the 'i'.
 // This way the compiler is able to see at compile time that only one
 // cache-array variable is used and thus can remove all the others.
 #define COMPUTE_FOR_CACHE(i) \
   if (!found && (gamma - alpha + 1 >= GRISU_CACHE_MAX_DISTANCE(i))) {   \
     int kQ = DiyFp::kSignificandSize;                                   \
-    int k = ceiling((alpha - e + kQ - 1) * kD_1_LOG2_10);               \
-    int index = (GRISU_CACHE_OFFSET + k - 1) / i + 1;                   \
+    double k = ceiling((alpha - e + kQ - 1) * kD_1_LOG2_10);            \
+    int index = (GRISU_CACHE_OFFSET + static_cast<int>(k) - 1) / i + 1; \
     cached_power = GRISU_CACHE_NAME(i)[index];                          \
     found = true;                                                       \
   }                                                                     \
 
 static void GetCachedPower(int e, int alpha, int gamma, int* mk, DiyFp* c_mk) {
   // The following if statement should be optimized by the compiler so that only
   // one array is referenced and the others are not included in the object file.
   bool found = false;
   CachedPower cached_power;
   COMPUTE_FOR_CACHE(20);
@@ skipping 30 matching lines @@
 #undef GRISU_REDUCTION
 #undef GRISU_CACHE_STRUCT
 #undef GRISU_CACHE_NAME
 #undef GRISU_CACHE_MAX_DISTANCE
 #undef GRISU_CACHE_OFFSET
 #undef GRISU_UINT64_C
 
 } }  // namespace v8::internal
 
 #endif  // V8_CACHED_POWERS_H_