lcc printf floating point

Question

I have following program:

#include <stdio.h>

int main(int args, char *argv[]) {
    printf("%f\n", 0.99999);
    printf("%e\n", 0.99999);
}

The result is:

0.009990
9.999900e-001

Why is the first number wrong? I use Windows XP, compiler "Logiciels Informatique lcc-win32 version 3.8. Compilation date: Nov 30 2012 19:38:03".

Answer 1

That program is correct, and its output should be:

0.999990
9.999900e-01

or something very similar to that.

(You don't use args or argv, and the usual name for the first parameter of main is argc rather than args, but neither of those is a problem that should affect your program's behavior.)

It looks like you've found a bug in your implementation, probably in the runtime library rather than in the compiler itself. My brief Google searches haven't turned up a reference to this particular bug (in fact, the top hit was this question).

I suggest contacting the maintainer of lcc-win; contact information is on the web site. A short description and a link to this question should provide enough information, at least to start.