Task #1 of the class Advanced Programming 2020.
Soft implementation of IEEE 754 with basic expression parser.
For some task submitting reason, it is a single-file program.
Just use gcc or clang to compile the file float64.c with option -O2. SSE2 must be supported.
It reads one line with an expression which can only include regular numbers, +, -, *, / and brackets from stdin. All spaces are filtered within the line.
Then the program evaluates the expression and prints the value with a precision of 1200 digits after the decimal point (the exact value of the float number).
NOTE: Buffer size is 100010 bytes long and the expression given to the program must be valid.