regression in tgamma?

[Paul Zimmermann]

       Hi,

while updating my comparison from Newlib 3.3.0 to Newlib 4.0.0, I found a
regression in tgamma on x86_64/Linux:

$ cat test3.c
#include <stdio.h>
#include <math.h>

#ifdef NEWLIB
int errno;
int* __errno () { return &errno; }
#endif

int main()
{
  double x = -0x1.53f198fe3b278p+7, y;
  y = tgamma (x);
  printf ("x=%a y=%a\n", x, y);
}

Newlib 3.3.0:
$ gcc -DNEWLIB -no-pie test3.c /localdisk/zimmerma/newlib-3.3.0/libm.a; ./a.out
x=-0x1.53f198fe3b278p+7 y=0x1.fd6d312572d9cp-1015

Newlib 4.0.0:
$ gcc -DNEWLIB -no-pie test3.c /localdisk/zimmerma/newlib-4.0.0/libm.a; ./a.out
x=-0x1.53f198fe3b278p+7 y=0x1p+0

Please can someone confirm?

Best regards,
Paul