\[\frac{4 \cdot \left(\left(x - y\right) - z \cdot 0.5\right)}{z}\]

\frac{4 \cdot \left(\left(x - y\right) - z \cdot 0.5\right)}{z}

double f(double x, double y, double z) {
        double r9156 = 4.0;
        double r9157 = x;
        double r9158 = y;
        double r9159 = r9157 - r9158;
        double r9160 = z;
        double r9161 = 0.5;
        double r9162 = r9160 * r9161;
        double r9163 = r9159 - r9162;
        double r9164 = r9156 * r9163;
        double r9165 = r9164 / r9160;
        return r9165;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019191 
(FPCore (x y z)
  :name "Data.Array.Repa.Algorithms.ColorRamp:rampColorHotToCold from repa-algorithms-3.4.0.1, B"

  :herbie-target
  (- (* 4.0 (/ x z)) (+ 2.0 (* 4.0 (/ y z))))

  (/ (* 4.0 (- (- x y) (* z 0.5))) z))

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