Upgrade Core to 28d02328c467616ecec2bffd37c07930974fedf2 (#907)

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

Author: jviotti

DEPENDENCIES

@@ -1,3 +1,3 @@
 vendorpull https://github.com/sourcemeta/vendorpull 1dcbac42809cf87cb5b045106b863e17ad84ba02
-core https://github.com/sourcemeta/core fe450b982907f99e542a0cfc78bc60d2b600ff7a
+core https://github.com/sourcemeta/core 28d02328c467616ecec2bffd37c07930974fedf2
 bootstrap https://github.com/twbs/bootstrap 1a6fdfae6be09b09eaced8f0e442ca6f7680a61e

src/runtime/decoder_number.cc

@@ -1,15 +1,24 @@
 #include <sourcemeta/jsonbinpack/runtime_decoder.h>
 
-#include <cmath>   // std::pow
 #include <cstdint> // std::int64_t, std::uint64_t
 
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC optimize("no-reciprocal-math")
+#endif
+
 namespace sourcemeta::jsonbinpack {
 
 auto Decoder::DOUBLE_VARINT_TUPLE(const struct DOUBLE_VARINT_TUPLE &)
     -> sourcemeta::core::JSON {
+#ifdef __clang__
+#pragma clang fp reciprocal(off)
+#endif
   const std::int64_t digits{this->get_varint_zigzag()};
   const std::uint64_t point{this->get_varint()};
-  const double divisor{std::pow(10, static_cast<double>(point))};
+  double divisor{1.0};
+  for (std::uint64_t i = 0; i < point; ++i) {
+    divisor *= 10.0;
+  }
   return sourcemeta::core::JSON{static_cast<double>(digits) / divisor};
 }