Exception for Complex division, real part

Math

\[\frac{a \cdot c + b \cdot d}{c \cdot c + d \cdot d}\]

C

double f(double a, double b, double c, double d) {
        double r8512 = a;
        double r8513 = c;
        double r8514 = r8512 * r8513;
        double r8515 = b;
        double r8516 = d;
        double r8517 = r8515 * r8516;
        double r8518 = r8514 + r8517;
        double r8519 = r8513 * r8513;
        double r8520 = r8516 * r8516;
        double r8521 = r8519 + r8520;
        double r8522 = r8518 / r8521;
        return r8522;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 
(FPCore (a b c d)
  :name "Complex division, real part"

  :herbie-target
  (if (< (fabs d) (fabs c)) (/ (+ a (* b (/ d c))) (+ c (* d (/ d c)))) (/ (+ b (* a (/ c d))) (+ d (* c (/ c d)))))

  (/ (+ (* a c) (* b d)) (+ (* c c) (* d d))))

Backtrace

get-representation: Unknown representation #f		L	C
loop	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	122	4
prepare-points	/data/pavpan/nightlies/herbie/interface2/src/points.rkt	146	0
setup-prog!34	/data/pavpan/nightlies/herbie/interface2/src/mainloop.rkt	67	0
run-improve43	/data/pavpan/nightlies/herbie/interface2/src/mainloop.rkt	339	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28