\[\frac{\pi}{\sin \left(\pi \cdot z\right)} \cdot \left(\left(\left(\sqrt{\pi \cdot 2} \cdot {\left(\left(\left(\left(1 - z\right) - 1\right) + 7\right) + 0.5\right)}^{\left(\left(\left(1 - z\right) - 1\right) + 0.5\right)}\right) \cdot e^{-\left(\left(\left(\left(1 - z\right) - 1\right) + 7\right) + 0.5\right)}\right) \cdot \left(\left(\left(\left(\left(\left(\left(\left(0.9999999999998099298181841732002794742584 + \frac{676.5203681218850988443591631948947906494}{\left(\left(1 - z\right) - 1\right) + 1}\right) + \frac{-1259.139216722402807135949842631816864014}{\left(\left(1 - z\right) - 1\right) + 2}\right) + \frac{771.3234287776531346025876700878143310547}{\left(\left(1 - z\right) - 1\right) + 3}\right) + \frac{-176.6150291621405870046146446838974952698}{\left(\left(1 - z\right) - 1\right) + 4}\right) + \frac{12.50734327868690520801919774385169148445}{\left(\left(1 - z\right) - 1\right) + 5}\right) + \frac{-0.1385710952657201178173096423051902092993}{\left(\left(1 - z\right) - 1\right) + 6}\right) + \frac{9.984369578019571583242346146658263705831 \cdot 10^{-6}}{\left(\left(1 - z\right) - 1\right) + 7}\right) + \frac{1.505632735149311617592788074479481785772 \cdot 10^{-7}}{\left(\left(1 - z\right) - 1\right) + 8}\right)\right)\]
\frac{\pi}{\sin \left(\pi \cdot z\right)} \cdot \left(\left(\left(\sqrt{\pi \cdot 2} \cdot {\left(\left(\left(\left(1 - z\right) - 1\right) + 7\right) + 0.5\right)}^{\left(\left(\left(1 - z\right) - 1\right) + 0.5\right)}\right) \cdot e^{-\left(\left(\left(\left(1 - z\right) - 1\right) + 7\right) + 0.5\right)}\right) \cdot \left(\left(\left(\left(\left(\left(\left(\left(0.9999999999998099298181841732002794742584 + \frac{676.5203681218850988443591631948947906494}{\left(\left(1 - z\right) - 1\right) + 1}\right) + \frac{-1259.139216722402807135949842631816864014}{\left(\left(1 - z\right) - 1\right) + 2}\right) + \frac{771.3234287776531346025876700878143310547}{\left(\left(1 - z\right) - 1\right) + 3}\right) + \frac{-176.6150291621405870046146446838974952698}{\left(\left(1 - z\right) - 1\right) + 4}\right) + \frac{12.50734327868690520801919774385169148445}{\left(\left(1 - z\right) - 1\right) + 5}\right) + \frac{-0.1385710952657201178173096423051902092993}{\left(\left(1 - z\right) - 1\right) + 6}\right) + \frac{9.984369578019571583242346146658263705831 \cdot 10^{-6}}{\left(\left(1 - z\right) - 1\right) + 7}\right) + \frac{1.505632735149311617592788074479481785772 \cdot 10^{-7}}{\left(\left(1 - z\right) - 1\right) + 8}\right)\right)
double f(double z) {
        double r98009 = atan2(1.0, 0.0);
        double r98010 = z;
        double r98011 = r98009 * r98010;
        double r98012 = sin(r98011);
        double r98013 = r98009 / r98012;
        double r98014 = 2.0;
        double r98015 = r98009 * r98014;
        double r98016 = sqrt(r98015);
        double r98017 = 1.0;
        double r98018 = r98017 - r98010;
        double r98019 = r98018 - r98017;
        double r98020 = 7.0;
        double r98021 = r98019 + r98020;
        double r98022 = 0.5;
        double r98023 = r98021 + r98022;
        double r98024 = r98019 + r98022;
        double r98025 = pow(r98023, r98024);
        double r98026 = r98016 * r98025;
        double r98027 = -r98023;
        double r98028 = exp(r98027);
        double r98029 = r98026 * r98028;
        double r98030 = 0.9999999999998099;
        double r98031 = 676.5203681218851;
        double r98032 = r98019 + r98017;
        double r98033 = r98031 / r98032;
        double r98034 = r98030 + r98033;
        double r98035 = -1259.1392167224028;
        double r98036 = r98019 + r98014;
        double r98037 = r98035 / r98036;
        double r98038 = r98034 + r98037;
        double r98039 = 771.3234287776531;
        double r98040 = 3.0;
        double r98041 = r98019 + r98040;
        double r98042 = r98039 / r98041;
        double r98043 = r98038 + r98042;
        double r98044 = -176.6150291621406;
        double r98045 = 4.0;
        double r98046 = r98019 + r98045;
        double r98047 = r98044 / r98046;
        double r98048 = r98043 + r98047;
        double r98049 = 12.507343278686905;
        double r98050 = 5.0;
        double r98051 = r98019 + r98050;
        double r98052 = r98049 / r98051;
        double r98053 = r98048 + r98052;
        double r98054 = -0.13857109526572012;
        double r98055 = 6.0;
        double r98056 = r98019 + r98055;
        double r98057 = r98054 / r98056;
        double r98058 = r98053 + r98057;
        double r98059 = 9.984369578019572e-06;
        double r98060 = r98059 / r98021;
        double r98061 = r98058 + r98060;
        double r98062 = 1.5056327351493116e-07;
        double r98063 = 8.0;
        double r98064 = r98019 + r98063;
        double r98065 = r98062 / r98064;
        double r98066 = r98061 + r98065;
        double r98067 = r98029 * r98066;
        double r98068 = r98013 * r98067;
        return r98068;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019194 +o rules:numerics
(FPCore (z)
  :name "Jmat.Real.gamma, branch z less than 0.5"
  (* (/ PI (sin (* PI z))) (* (* (* (sqrt (* PI 2.0)) (pow (+ (+ (- (- 1.0 z) 1.0) 7.0) 0.5) (+ (- (- 1.0 z) 1.0) 0.5))) (exp (- (+ (+ (- (- 1.0 z) 1.0) 7.0) 0.5)))) (+ (+ (+ (+ (+ (+ (+ (+ 0.9999999999998099 (/ 676.5203681218851 (+ (- (- 1.0 z) 1.0) 1.0))) (/ -1259.1392167224028 (+ (- (- 1.0 z) 1.0) 2.0))) (/ 771.3234287776531 (+ (- (- 1.0 z) 1.0) 3.0))) (/ -176.6150291621406 (+ (- (- 1.0 z) 1.0) 4.0))) (/ 12.507343278686905 (+ (- (- 1.0 z) 1.0) 5.0))) (/ -0.13857109526572012 (+ (- (- 1.0 z) 1.0) 6.0))) (/ 9.984369578019572e-06 (+ (- (- 1.0 z) 1.0) 7.0))) (/ 1.5056327351493116e-07 (+ (- (- 1.0 z) 1.0) 8.0))))))

Backtrace

get-representation: Unknown representation #fLC
(unnamed)/data/pavpan/nightlies/herbie/js-tweaks/src/core/localize.rkt2313
hash-ref!/opt/racket-7.0/collects/racket/private/more-scheme.rkt3762
map/opt/racket-7.0/collects/racket/private/map.rkt3513
parse-loop30/opt/racket-7.0/collects/racket/match/compiler.rkt41815
hash-ref!/opt/racket-7.0/collects/racket/private/more-scheme.rkt3762
map/opt/racket-7.0/collects/racket/private/map.rkt3513
parse-loop30/opt/racket-7.0/collects/racket/match/compiler.rkt41815
hash-ref!/opt/racket-7.0/collects/racket/private/more-scheme.rkt3762
localize-error/data/pavpan/nightlies/herbie/js-tweaks/src/core/localize.rkt610
localize!/data/pavpan/nightlies/herbie/js-tweaks/src/mainloop.rkt1230
run-iter!/data/pavpan/nightlies/herbie/js-tweaks/src/mainloop.rkt3230
for-loop/data/pavpan/nightlies/herbie/js-tweaks/src/mainloop.rkt3594
run-improve47/data/pavpan/nightlies/herbie/js-tweaks/src/mainloop.rkt3420
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.0/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.0/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.0/collects/racket/private/more-scheme.rkt26128