Following test:

--cut here--
#define _GNU_SOURCE
#include <fenv.h>
#include <signal.h>
#include <stdlib.h>

static void foo (int sig)
{
  exit (0);
}

float __attribute__((noinline)) test (float x) { return 2.0f / x; };
  
int main()
{
  signal (SIGFPE, foo);

  feclearexcept (FE_ALL_EXCEPT);
  feenableexcept (FE_INEXACT);

  test (3.0f);

  abort ();
}
--cut here--

aborts when compiled with optimizations, since the call to a procedure with a trapping insn is removed.

$ gcc -O2 -fnon-call-exceptions -ftrapping-math -lm sf.c
$ ./a.out
Aborted

$ gcc -lm sf.c
$ ./a.out
$ [...works OK...]

A wild guess is to blame tree optimizers, since in 123t.optimized we already have the call removed:

main ()
{
<bb 2>:
  signal (8, foo);
  feclearexcept (61);
  feenableexcept (32);
  abort ();

}