odd using of macro MODLIMB_INVERSE_3

[Andy]

In file toom_interpolate_6pts.c is:
/* For odd divisors, mpn_divexact_1 works fine with two's complement. */
#ifndef mpn_divexact_by3
#if HAVE_NATIVE_mpn_pi1_bdiv_q_1 && MODLIMB_INVERSE_3
#define mpn_divexact_by3(dst,src,size)
mpn_pi1_bdiv_q_1(dst,src,size,3,MODLIMB_INVERSE_3,0)
#else
#define mpn_divexact_by3(dst,src,size) mpn_divexact_1(dst,src,size,3)
#endif
#endif
This can make some problems on some compilers.
if I have correctly guessed the intentions of this conditional, it doesn't
matter what the value is MODLIMB_INVERSE_3 but if is defined,
should be .
#if HAVE_NATIVE_mpn_pi1_bdiv_q_1 && defined MODLIMB_INVERSE_3
?