Specification

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(y \cdot 4\right) \cdot y\\ \frac{x \cdot x - t\_0}{x \cdot x + t\_0} \end{array} \end{array} \]

(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* y 4.0) y))) (/ (- (* x x) t_0) (+ (* x x) t_0))))

double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}

real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    t_0 = (y * 4.0d0) * y
    code = ((x * x) - t_0) / ((x * x) + t_0)
end function

public static double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}

def code(x, y):
	t_0 = (y * 4.0) * y
	return ((x * x) - t_0) / ((x * x) + t_0)

function code(x, y)
	t_0 = Float64(Float64(y * 4.0) * y)
	return Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0))
end

function tmp = code(x, y)
	t_0 = (y * 4.0) * y;
	tmp = ((x * x) - t_0) / ((x * x) + t_0);
end

code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]

\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\frac{x \cdot x - t\_0}{x \cdot x + t\_0}
\end{array}
\end{array}

Reproduce

herbie shell --seed 2024035 
(FPCore (x y)
  :name "Diagrams.TwoD.Arc:arcBetween from diagrams-lib-1.3.0.3"
  :precision binary64

  :herbie-target
  (if (< (/ (- (* x x) (* (* y 4.0) y)) (+ (* x x) (* (* y 4.0) y))) 0.9743233849626781) (- (/ (* x x) (+ (* x x) (* (* y y) 4.0))) (/ (* (* y y) 4.0) (+ (* x x) (* (* y y) 4.0)))) (- (pow (/ x (sqrt (+ (* x x) (* (* y y) 4.0)))) 2.0) (/ (* (* y y) 4.0) (+ (* x x) (* (* y y) 4.0)))))

  (/ (- (* x x) (* (* y 4.0) y)) (+ (* x x) (* (* y 4.0) y))))

Please file a bug report with this information.

Backtrace

list-ref: index too large for list index: 256 in: '(#f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #f #t #t #t #t #t #t #t #t #t #t #t #t #t #t #t #t #t...		L	C
valid-splitindices?	/home/nightlies/herbie/zane-regimes-2/src/core/regimes.rkt	170	0
(unnamed)	.../private/arr-i.rkt	961	8
option-on-expr	/home/nightlies/herbie/zane-regimes-2/src/core/regimes.rkt	106	0
infer-splitpoints	/home/nightlies/herbie/zane-regimes-2/src/core/regimes.rkt	39	0
loop	/home/nightlies/herbie/zane-regimes-2/src/core/regimes.rkt	27	2
extract!	/home/nightlies/herbie/zane-regimes-2/src/mainloop.rkt	365	0
run-improve!	/home/nightlies/herbie/zane-regimes-2/src/mainloop.rkt	339	0
get-alternatives/report	/home/nightlies/herbie/zane-regimes-2/src/sandbox.rkt	169	0
(unnamed)	/home/nightlies/herbie/zane-regimes-2/src/sandbox.rkt	262	6
(unnamed)	/usr/local/racket/share/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/local/racket/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/usr/local/racket/collects/racket/engine.rkt	42	24