Re: [Tinycc-devel] libtcc bug when evaluating math expressions

[david wallin]

ah! thank you very much.

I thought I had covered that because I tried compiling a function like 
this:

"double evaluate_me(double v) { return fabs(v); }\0"

and evaluated it with -1.0 and got 1.0 back (this was with 0.9.19). So 
I thought it worked fine. I guess a 1.0 was left somewhere and returned.

cheers,

--david.

On Thursday, November 27, 2003, at 04:03 PM, Daniel Glöckner wrote:

> On Thu, Nov 27, 2003 at 01:28:45PM +0000, David Wallin wrote:
> >   char *eval_me =   "double evaluate_me(double x, double v) { return
> > (double) ((-1.0 * x) > v * fabs(v)); }\0" ;
>
> #include <math.h>
>
> fabs is not defined and so defaults to returning an integer in eax
> instead of a double in st0. On exit of fabs(), eax holds an undefined
> value which is then converted to a double and multiplied with v.
> GCC knows about fabs and generates the fabs instruction, even with -O0.
>
>   Daniel