[Tinycc-devel] unknown constraint 't'

[Mike S.]

I don't know if this would be called a bug, and I
apologize if it's already been posted (searching
turned up nothing), but I thought it might be worth
reporting this discrepancy between the compiler and
the included libraries.


OS: Windows XP Home SP2 and Pro SP2
tcc: 0.9.23 (taken straight off the web site
http://laurenssimonis.com/tcc/tcc-0.9.23.zip)

The following program fails to compile with the error
"unknown constraint 't'". 

----------------------------------------------------
/* asmt.c */

/*
Result when trying to compile:

    > tcc asmt.c -Iinclude
    asmt.c:288: unknown constraint 't'

*/

#include <math.h>

int main(int argc, char **argv) 
{
    double d = sqrt(-1.0);
    int i = isnan(d);
    return 0;
}
----------------------------------------------------

The problem lies in the inline __asm__ in math.h. A
handful of the functions use the 't' constraint, which
unfortunately isn't handled by tcc. 

__fpclassify()
__isnan()
__isnanf()
__signbit()
__signbitf()
__fp_unordered_compare()

The current tarball code at
http://landley.net/hg/tinycc doesn't appear to handle
the 't' constraint either (tinycc-3e7c64539eb2).