Implicit function declaration when calling MathArray::exp with -specmode aud

This code:

module e; export {foo};

float[*] tof(int[*] x) { return { iv -> _tof_S_ (_sel_VxA_ (iv, x)) }; } 

void foo ()
{
  StdIO::print(MathArray::exp(tof([1,2,3])));
}

causes this warning:

In file included from /tmp/sac2c/build_d/include/sac.h:50,
                 from /tmp/SAC_aHNwH1/header.h:278,
                 from /tmp/SAC_aHNwH1/fun1.c:1:
/tmp/SAC_aHNwH1/fun1.c: In function ‘SACf_e__foo’:
/tmp/SAC_aHNwH1/fun1.c:459:20: warning: implicit declaration of function ‘SACwf_MathArray__exp__f_S’; did you mean ‘SACf_MathArray__exp__f_P’? [-Wimplicit-function-declaration]
  459 |     SAC_ND_FUNAP2( SACwf_MathArray__exp__f_S,  SAC_ND_ARG_out( SAC_SET_NT_USG( FAG, (SACp_flat_42, (AUD, (NHD, (NUQ, (FLO, (GLO, (NON, (NOT, (NDI, (FLO, ))))))))))), float), SAC_ND_ARG_in( SAC_SET_NT_USG( FAG, (SACp_flat_43, (AUD, (NHD, (NUQ, (FLO, (GLO, (NON, (NOT, (NDI, (FLO, ))))))))))), float))
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~
/tmp/sac2c/build_d/include/runtime/essentials_h/std.h:331:34: note: in definition of macro ‘SAC_ND_FUNAP2’
  331 | #define SAC_ND_FUNAP2(name, ...) name (__VA_ARGS__);
      |                                  ^~~~