0.7 / 1.0 ?= 0.52

[Hans Aberg]

On 14 Jun 2012, at 20:40, János Kukoda wrote:

> I have a 5.0.4 GMP downloaded, installed from MacPort. I use it with the newest Xcode, updated just now.
> 
> gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.9.00)
> 
> The division produce a funny bug. What do you think?
> 
>    mpf_t a;
>    mpf_init(a);
>    mpf_set_d(a, 0.7);
>    mpf_t b;
>    mpf_init(b);
>    mpf_set_d(b, 1.0);
>    mpf_t l;
>    mpf_init(l);
> 
>    gmp_printf ("%.*Ff \n", 5, a);		--- 0.70000
>    gmp_printf ("%.*Ff \n", 5, b);		--- 1.00000
> 
>    mpf_div(l, a, b);
>    gmp_printf ("%.*Ff", 5, l);			--- 0.52502

This example works on Mac OS X 10.7.4 with GMP 5.0.4 compiled directly from source, using the llvm-gcc 4.2.1 you indicate, and the example compiled using this compiler, clang 3.1 also from Xcode 4.3.2, and gcc 4.7.0 compiled from source using this llvm-gcc.

Hans