\[\frac{x}{y} + \frac{2 + \left(z \cdot 2\right) \cdot \left(1 - t\right)}{t \cdot z}\]

\frac{x}{y} + \frac{2 + \left(z \cdot 2\right) \cdot \left(1 - t\right)}{t \cdot z}

double code(double x, double y, double z, double t) {
	return ((double) (((double) (x / y)) + ((double) (((double) (2.0 + ((double) (((double) (z * 2.0)) * ((double) (1.0 - t)))))) / ((double) (t * z))))));
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020155 
(FPCore (x y z t)
  :name "Data.HashTable.ST.Basic:computeOverhead from hashtables-1.2.0.2"
  :precision binary64

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

  (+ (/ x y) (/ (+ 2.0 (* (* z 2.0) (- 1.0 t))) (* t z))))

Backtrace

hash-ref: no value found for key key: 'x		L	C
range-table->hyperrects	/data/pavpan/nightlies/herbie/ival-find-range/src/findroot.rkt	58	0
make-sampler	/data/pavpan/nightlies/herbie/ival-find-range/src/points.rkt	124	0
prepare-points-intervals	/data/pavpan/nightlies/herbie/ival-find-range/src/points.rkt	155	0
run-improve47	/data/pavpan/nightlies/herbie/ival-find-range/src/mainloop.rkt	365	0
.../more-scheme.rkt:261:28	unknown
run	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.5/collects/racket/private/more-scheme.rkt	261	28

Reproduce

herbie shell --seed 2020155 
(FPCore (x y z t)
  :name "Data.HashTable.ST.Basic:computeOverhead from hashtables-1.2.0.2"
  :precision binary64

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

  (+ (/ x y) (/ (+ 2.0 (* (* z 2.0) (- 1.0 t))) (* t z))))