\[\left(x \cdot 2 + x \cdot x\right) + y \cdot y\]
\left(x \cdot 2 + x \cdot x\right) + y \cdot y
double f(double x, double y) {
        double r187873 = x;
        double r187874 = 2.0;
        double r187875 = r187873 * r187874;
        double r187876 = r187873 * r187873;
        double r187877 = r187875 + r187876;
        double r187878 = y;
        double r187879 = r187878 * r187878;
        double r187880 = r187877 + r187879;
        return r187880;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020045 
(FPCore (x y)
  :name "Numeric.Log:$clog1p from log-domain-0.10.2.1, A"
  :precision binary64

  :herbie-target
  (+ (* y y) (+ (* 2 x) (* x x)))

  (+ (+ (* x 2) (* x x)) (* y y)))

Backtrace

hash-ref: no value found for key key: '(* #<enode 99(99)> #<enode 27(154)>)LC
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2706
update-leader!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2650
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt772
prune-phase/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt740
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt804
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt762
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt560
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt380
simplify!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt2240
run-iter!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3270
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3654
run-improve47/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3460
.../more-scheme.rkt:261:28unknown
run/opt/racket-7.5/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.5/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.5/collects/racket/private/more-scheme.rkt26128