C: Invalid results when using few pow functions in the same expression

Asked Nov 23 '19 at 15:09

Active Nov 23 '19 at 15:09

Viewed 51 times

For some unknown to me reason this code produces different results.

#include <stdio.h>
#include <math.h>

main() {
    double y, y2;

    y = pow(2.0, 1.0) * pow(2.0, 1.0) * pow(2.0, 1.0);
    y2 = pow(2.0, 3.0);

    printf("%lf\n", y); // 2.000000
    printf("%lf\n", y2); // 8.000000

    return 0;
}

I am using tcc compiler and i guess this might matter since but i can't find any info about such problems.

asked Nov 23 '19 at 15:09

twojastara69

1

The program displays `8.000000` twice on my machine. Are you sure you're running exactly the code you posted? – zdimension Nov 23 '19 at 15:14
Yes. I'm sure. I just checked it. – twojastara69 Nov 23 '19 at 15:20
Could you post the full command you're using to compile/run it? – zdimension Nov 23 '19 at 15:24
1

tcc aaa.c where aaa.c is the name of the file – twojastara69 Nov 23 '19 at 15:27
to run i simply write aaa – twojastara69 Nov 23 '19 at 15:27
I was using `-run`, but I'm still getting 8 twice even by compiling and running separately. Could you compile the code with another compiler (such as gcc or clang) and report the output? – zdimension Nov 23 '19 at 15:29
I ran this code with Dev-C++ and the now both results equal 8. I don't know what's the problem with tcc though. – twojastara69 Nov 23 '19 at 16:08

C: Invalid results when using few pow functions in the same expression

0 Answers0