[Tinycc-devel] RE : tcc doesn't set the inexact flag on inexact compile-time int-to-float conversion

[Christian JULLIEN]

Pardon me if wrong, but tcc uses gcc lib.
So you only reproduce gcc lib bug not tcc compilation error.

C.


> ----- Message d'origine -----
> De : "Vincent Lefevre" <address@hidden>
> Date lun. 22/04/2013 15:58 (GMT +02:00)
> À : "address@hidden" <address@hidden>
> Objet : [Tinycc-devel] tcc doesn't set the inexact flag on inexact compile-time int-to-float conversion
>
> tcc doesn't set the inexact flag on inexact compile-time int-to-float
> conversion:
>
> #include <stdio.h>
> #include <fenv.h>
>
> #pragma STDC FENV_ACCESS ON
>
> void test1 (void)
> {
>   volatile float c;
>
>   c = 0x7fffffbf;
>   printf ("c = %a, inexact = %d\n", c, fetestexcept (FE_INEXACT));
> }
>
> void test2 (void)
> {
>   volatile float c;
>   volatile int i = 0x7fffffbf;
>
>   c = i;
>   printf ("c = %a, inexact = %d\n", c, fetestexcept (FE_INEXACT));
> }
>
> int main (void)
> {
>   test1 ();
>   test2 ();
>   return 0;
> }
>
> With tin 0.9.25 under Linux/x86_64 (Debian):
>
> $ tcc -Wall -O2 conv-int-flt-inex.c -o conv-int-flt-inex -lm
> $ ./conv-int-flt-inex
> c = 0x1.fffffep+30, inexact = 0
> c = 0x1.fffffep+30, inexact = 32
>
> FYI, GCC has the same problem:
>
>   http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57029
>
> -- 
> Vincent Lefèvre <address@hidden> - Web: <http://www.vinc17.net/>
> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/>
> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
>
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