\[x + \frac{\left(y - x\right) \cdot \left(z - t\right)}{a - t}\]

x + \frac{\left(y - x\right) \cdot \left(z - t\right)}{a - t}

double f(double x, double y, double z, double t, double a) {
        double r380851 = x;
        double r380852 = y;
        double r380853 = r380852 - r380851;
        double r380854 = z;
        double r380855 = t;
        double r380856 = r380854 - r380855;
        double r380857 = r380853 * r380856;
        double r380858 = a;
        double r380859 = r380858 - r380855;
        double r380860 = r380857 / r380859;
        double r380861 = r380851 + r380860;
        return r380861;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019323 
(FPCore (x y z t a)
  :name "Graphics.Rendering.Chart.Axis.Types:linMap from Chart-1.5.3"
  :precision binary64

  :herbie-target
  (if (< a -1.6153062845442575e-142) (+ x (* (/ (- y x) 1) (/ (- z t) (- a t)))) (if (< a 3.774403170083174e-182) (- y (* (/ z t) (- y x))) (+ x (* (/ (- y x) 1) (/ (- z t) (- a t))))))

  (+ x (/ (* (- y x) (- z t)) (- a t))))

Backtrace

dict-ref: no value for key: 'branch380850 in: '((x . binary64) (y . binary64) (z . binary64) (t . binary64) (a . binary64))		L	C
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	106	4
make-sampler	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	99	0
prepare-points-intervals	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/points.rkt	121	0
for-loop	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	233	9
sindices->spoints	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/regimes.rkt	194	0
f33	/opt/racket-7.2/collects/racket/match/compiler.rkt	507	40
get-final-combination	/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt	369	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28