21 Sep 2026

Floating Point Decimal String to Binary Conversions

The fpio-test.x series of tests checks the ability of the 
compiler/interpreter to convert a decimal string for a 
recognized floating point number input into its IEEE 754 
double-precision binary64 representation, to within 1 ulp
(unit of least precision). For the text to succeed, the 
64-bit pattern to which the text of the decimal string 
is converted must match exactly that of the closest binary
representation.

In this folder, you will find C and Fortran source programs
for the tests. The tests are ported from their original
Forth version (kforth/fpio-test.4th). Build instructions
for several C and Fortran 90 compilers are found in the
comments at the top of the .c and .f90 source files.

The tests should give no errors for executables built with
the GNU C and Fortran compilers, unless they are very old
versions.