Exception for Main:bigenough3 from C

Math

\[\sqrt{x + 1} - \sqrt{x} \]

FPCore

(FPCore (x) :precision binary64 (- (sqrt (+ x 1.0)) (sqrt x)))

C

double code(double x) {
	return sqrt((x + 1.0)) - sqrt(x);
}

Fortran

real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt((x + 1.0d0)) - sqrt(x)
end function

Java

public static double code(double x) {
	return Math.sqrt((x + 1.0)) - Math.sqrt(x);
}

Python

def code(x):
	return math.sqrt((x + 1.0)) - math.sqrt(x)

Julia

function code(x)
	return Float64(sqrt(Float64(x + 1.0)) - sqrt(x))
end

MATLAB

function tmp = code(x)
	tmp = sqrt((x + 1.0)) - sqrt(x);
end

Wolfram

code[x_] := N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2023243 
(FPCore (x)
  :name "Main:bigenough3 from C"
  :precision binary64

  :herbie-target
  (/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x)))

  (- (sqrt (+ x 1.0)) (sqrt x)))

Backtrace

_arb-ptr: contract violation expected: _arb? given: '(ival-illegal)		L	C
_arb-ptr	unknown
arb->ival	/home/nightlies/herbie/arb-support/src/arb.rkt	160	0
search-step	/home/nightlies/herbie/arb-support/src/searchreals.rkt	37	0
find-intervals	/home/nightlies/herbie/arb-support/src/searchreals.rkt	87	0
make-sampler	/home/nightlies/herbie/arb-support/src/sampling.rkt	94	0
sample-points	/home/nightlies/herbie/arb-support/src/ground-truth.rkt	64	0
setup-context!	/home/nightlies/herbie/arb-support/src/mainloop.rkt	293	0
get-alternatives/report	/home/nightlies/herbie/arb-support/src/sandbox.rkt	148	0
(unnamed)	/home/nightlies/herbie/arb-support/src/sandbox.rkt	247	6
(unnamed)	/usr/share/racket/pkgs/profile-lib/main.rkt	40	10
profile-thunk	/usr/share/racket/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/usr/share/racket/collects/racket/engine.rkt	42	24