\[0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}\]
0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} + re\right)}
double f(double re, double im) {
        double r28054 = 0.5;
        double r28055 = 2.0;
        double r28056 = re;
        double r28057 = r28056 * r28056;
        double r28058 = im;
        double r28059 = r28058 * r28058;
        double r28060 = r28057 + r28059;
        double r28061 = sqrt(r28060);
        double r28062 = r28061 + r28056;
        double r28063 = r28055 * r28062;
        double r28064 = sqrt(r28063);
        double r28065 = r28054 * r28064;
        return r28065;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019315 +o rules:numerics
(FPCore (re im)
  :name "math.sqrt on complex, real part"
  :precision binary64

  :herbie-target
  (if (< re 0.0) (* 0.5 (* (sqrt 2) (sqrt (/ (* im im) (- (sqrt (+ (* re re) (* im im))) re))))) (* 0.5 (sqrt (* 2 (+ (sqrt (+ (* re re) (* im im))) re)))))

  (* 0.5 (sqrt (* 2 (+ (sqrt (+ (* re re) (* im im))) re)))))

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
simplify/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/reduce.rkt160
hash-ref!/opt/racket-7.2/collects/racket/private/more-scheme.rkt3762
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/taylor.rkt29152
(unnamed)/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/taylor.rkt29126
hash-ref!/opt/racket-7.2/collects/racket/private/more-scheme.rkt3762
first-nonzero-exp/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/taylor.rkt2660
taylor-sqrt/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/taylor.rkt3520
map/opt/racket-7.2/collects/racket/private/map.rkt3513
taylor/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/taylor.rkt1700
for-loop/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/taylor.rkt3018
approximate9/data/pavpan/nightlies/herbie/fix-interface-bugs/src/core/taylor.rkt120
(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
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