\[\frac{\pi}{\sin \left(\pi \cdot z\right)} \cdot \left(\left(\left(\sqrt{\pi \cdot 2} \cdot {\left(\left(\left(\left(1 - z\right) - 1\right) + 7\right) + 0.5\right)}^{\left(\left(\left(1 - z\right) - 1\right) + 0.5\right)}\right) \cdot e^{-\left(\left(\left(\left(1 - z\right) - 1\right) + 7\right) + 0.5\right)}\right) \cdot \left(\left(\left(\left(\left(\left(\left(\left(0.9999999999998099298181841732002794742584 + \frac{676.5203681218850988443591631948947906494}{\left(\left(1 - z\right) - 1\right) + 1}\right) + \frac{-1259.139216722402807135949842631816864014}{\left(\left(1 - z\right) - 1\right) + 2}\right) + \frac{771.3234287776531346025876700878143310547}{\left(\left(1 - z\right) - 1\right) + 3}\right) + \frac{-176.6150291621405870046146446838974952698}{\left(\left(1 - z\right) - 1\right) + 4}\right) + \frac{12.50734327868690520801919774385169148445}{\left(\left(1 - z\right) - 1\right) + 5}\right) + \frac{-0.1385710952657201178173096423051902092993}{\left(\left(1 - z\right) - 1\right) + 6}\right) + \frac{9.984369578019571583242346146658263705831 \cdot 10^{-6}}{\left(\left(1 - z\right) - 1\right) + 7}\right) + \frac{1.505632735149311617592788074479481785772 \cdot 10^{-7}}{\left(\left(1 - z\right) - 1\right) + 8}\right)\right)\]
\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 r19442 = atan2(1.0, 0.0);
        double r19443 = z;
        double r19444 = r19442 * r19443;
        double r19445 = sin(r19444);
        double r19446 = r19442 / r19445;
        double r19447 = 2.0;
        double r19448 = r19442 * r19447;
        double r19449 = sqrt(r19448);
        double r19450 = 1.0;
        double r19451 = r19450 - r19443;
        double r19452 = r19451 - r19450;
        double r19453 = 7.0;
        double r19454 = r19452 + r19453;
        double r19455 = 0.5;
        double r19456 = r19454 + r19455;
        double r19457 = r19452 + r19455;
        double r19458 = pow(r19456, r19457);
        double r19459 = r19449 * r19458;
        double r19460 = -r19456;
        double r19461 = exp(r19460);
        double r19462 = r19459 * r19461;
        double r19463 = 0.9999999999998099;
        double r19464 = 676.5203681218851;
        double r19465 = r19452 + r19450;
        double r19466 = r19464 / r19465;
        double r19467 = r19463 + r19466;
        double r19468 = -1259.1392167224028;
        double r19469 = r19452 + r19447;
        double r19470 = r19468 / r19469;
        double r19471 = r19467 + r19470;
        double r19472 = 771.3234287776531;
        double r19473 = 3.0;
        double r19474 = r19452 + r19473;
        double r19475 = r19472 / r19474;
        double r19476 = r19471 + r19475;
        double r19477 = -176.6150291621406;
        double r19478 = 4.0;
        double r19479 = r19452 + r19478;
        double r19480 = r19477 / r19479;
        double r19481 = r19476 + r19480;
        double r19482 = 12.507343278686905;
        double r19483 = 5.0;
        double r19484 = r19452 + r19483;
        double r19485 = r19482 / r19484;
        double r19486 = r19481 + r19485;
        double r19487 = -0.13857109526572012;
        double r19488 = 6.0;
        double r19489 = r19452 + r19488;
        double r19490 = r19487 / r19489;
        double r19491 = r19486 + r19490;
        double r19492 = 9.984369578019572e-06;
        double r19493 = r19492 / r19454;
        double r19494 = r19491 + r19493;
        double r19495 = 1.5056327351493116e-07;
        double r19496 = 8.0;
        double r19497 = r19452 + r19496;
        double r19498 = r19495 / r19497;
        double r19499 = r19494 + r19498;
        double r19500 = r19462 * r19499;
        double r19501 = r19446 * r19500;
        return r19501;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019315 +o rules:numerics
(FPCore (z)
  :name "Jmat.Real.gamma, branch z less than 0.5"
  :precision binary64
  (* (/ PI (sin (* PI z))) (* (* (* (sqrt (* PI 2)) (pow (+ (+ (- (- 1 z) 1) 7) 0.5) (+ (- (- 1 z) 1) 0.5))) (exp (- (+ (+ (- (- 1 z) 1) 7) 0.5)))) (+ (+ (+ (+ (+ (+ (+ (+ 0.99999999999980993 (/ 676.520368121885099 (+ (- (- 1 z) 1) 1))) (/ -1259.13921672240281 (+ (- (- 1 z) 1) 2))) (/ 771.32342877765313 (+ (- (- 1 z) 1) 3))) (/ -176.615029162140587 (+ (- (- 1 z) 1) 4))) (/ 12.5073432786869052 (+ (- (- 1 z) 1) 5))) (/ -0.138571095265720118 (+ (- (- 1 z) 1) 6))) (/ 9.98436957801957158e-6 (+ (- (- 1 z) 1) 7))) (/ 1.50563273514931162e-7 (+ (- (- 1 z) 1) 8))))))

Backtrace

match: no matching clause for 'binary64LC
match:error/opt/racket-7.2/collects/racket/match/runtime.rkt240
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt2463
make-multiplication-subnode/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt2440
make-multiplication-node/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt2340
map/opt/racket-7.2/collects/racket/private/map.rkt3513
f45/opt/racket-7.2/collects/racket/match/compiler.rkt50740
simplify/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt160
(unnamed)/opt/racket-7.2/collects/racket/contract/private/arrow-higher-order.rkt36033
location-do/data/pavpan/nightlies/herbie/fix-interface-bugs/src/programs.rkt640
location-do/data/pavpan/nightlies/herbie/fix-interface-bugs/src/programs.rkt640
location-do/data/pavpan/nightlies/herbie/fix-interface-bugs/src/programs.rkt640
(unnamed)/opt/racket-7.2/collects/racket/contract/private/arrow-higher-order.rkt36033
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt1516
taylor-alt/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt1450
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt1667
gen-series!/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt1590
run-iter!/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt3260
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt3644
run-improve47/data/pavpan/nightlies/herbie/fix-interface-bugs/src/mainloop.rkt3450
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128
run/opt/racket-7.2/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.2/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.2/collects/racket/private/more-scheme.rkt26128