Added float16.h

src/CMakeLists.txt

@@ -50,6 +50,7 @@ list( APPEND cdi_src_files
   exse.h
   extra.h
   extralib.c
+  float16.h
   file.c
   file.h
   gaussian_latitudes.c

src/Makefile.am

@@ -127,6 +127,7 @@ libcdi_la_SOURCES = \
   exse.h \
   extra.h \
   extralib.c \
+  float16.h \
   file.c \
   file.h \
   gaussian_latitudes.c \

src/binary.c

@@ -170,9 +170,19 @@ binWriteFlt64(int fileID, int byteswap, size_t size, double *ptr)
 {
   if (byteswap) swap8byte(ptr, size);
   fileWrite(fileID, (void *) ptr, 8 * size);
+  return 0;
+}
 
+#ifdef HAVE_FLOAT16
+int
+binWriteFlt16(int fileID, int byteswap, size_t size, _Float16 *ptr)
+{
+  if (byteswap) swap4byte(ptr, size);
+  fileWrite(fileID, (void *) ptr, 2 * size);
   return 0;
 }
+#endif
+
 /*
  * Local Variables:
  * c-file-style: "Java"

src/binary.h

@@ -3,6 +3,7 @@
 
 #include <stdio.h>
 #include <inttypes.h>
+#include "float16.h"
 
 #ifndef HOST_ENDIANNESS
 #ifdef __cplusplus
@@ -30,6 +31,10 @@ int binWriteInt64(int fileID, int byteswap, size_t size, int64_t *ptr);
 int binWriteFlt32(int fileID, int byteswap, size_t size, float *ptr);
 int binWriteFlt64(int fileID, int byteswap, size_t size, double *ptr);
 
+#ifdef HAVE_FLOAT16
+int binWriteFlt16(int fileID, int byteswap, size_t size, _Float16 *ptr);
+#endif
+
 #endif /* BINARY_H */
 /*
  * Local Variables:

src/float16.h

+#ifndef FLOAT16_H
+#define FLOAT16_H
+
+// CAUTION: __is_identifier behaves opposite how you would expect!
+// '__is_identifier' returns '0' if '__x' is a reserved identifier provided by
+// the compiler and '1' otherwise.
+// borrowed from LLVM __config header under Apache license 2. 
+// (https://www.mend.io/blog/top-10-apache-license-questions-answered/)
+#ifndef __is_identifier       // Optional of course.
+#define __is_identifier(x) 1  // Compatibility with non-clang compilers.
+#endif
+
+// More sensible macro for keyword detection
+#define __has_keyword(__x) !(__is_identifier(__x))
+
+// map a half float type, if available, to _OptionalHalfFloatType
+#if __has_keyword(_Float16)
+#define HAVE_FLOAT16
+#endif
+
+#endif