accept denormal floating point numbers in tokenizer class and utils::numeric()

src/tokenizer.cpp

@@ -19,6 +19,8 @@
 #include "fmt/format.h"
 #include "utils.h"
 
+#include <cmath>
+#include <cstdlib>
 #include <utility>
 
 using namespace LAMMPS_NS;
@@ -365,6 +367,11 @@ double ValueTokenizer::next_double()
     return val;
     // rethrow exceptions from std::stod()
   } catch (std::out_of_range const &) {
+    // could be a denormal number. try again with std::strtod().
+    char *end;
+    auto val = std::strtod(current.c_str(), &end);
+    // return value of denormal
+    if ((val != 0.0) && (val > -HUGE_VAL) && (val < HUGE_VAL)) return val;
     throw InvalidFloatException(current);
   } catch (std::invalid_argument const &) {
     throw InvalidFloatException(current);

src/utils.cpp

@@ -34,6 +34,8 @@
 
 #include <cctype>
 #include <cerrno>
+#include <cmath>
+#include <cstdlib>
 #include <cstring>
 #include <ctime>
 #include <stdexcept>
@@ -529,7 +531,7 @@ double utils::numeric(const char *file, int line, const std::string &str, bool d
       lmp->error->all(file, line, msg);
   }
 
-  double rv = 0;
+  double rv = 0.0;
   auto msg = fmt::format("Floating point number {} in input script or data file is invalid", buf);
   try {
     std::size_t endpos;
@@ -546,6 +548,12 @@ double utils::numeric(const char *file, int line, const std::string &str, bool d
     else
       lmp->error->all(file, line, msg);
   } catch (std::out_of_range const &) {
+    // could be a denormal number. try again with std::strtod().
+    char *end;
+    rv = std::strtod(buf.c_str(), &end);
+    // return value if denormal
+    if ((rv != 0.0) && (rv > -HUGE_VAL) && (rv < HUGE_VAL)) return rv;
+
     msg = fmt::format("Floating point number {} in input script or data file is out of range", buf);
     if (do_abort)
       lmp->error->one(file, line, msg);