\[x.re \cdot y.im + x.im \cdot y.re\]
x.re \cdot y.im + x.im \cdot y.re
double f(double x_re, double x_im, double y_re, double y_im) {
        double r8425 = x_re;
        double r8426 = y_im;
        double r8427 = r8425 * r8426;
        double r8428 = x_im;
        double r8429 = y_re;
        double r8430 = r8428 * r8429;
        double r8431 = r8427 + r8430;
        return r8431;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019173 +o rules:numerics
(FPCore (x.re x.im y.re y.im)
  :name "_multiplyComplex, imaginary part"
  (+ (* x.re y.im) (* x.im y.re)))

Backtrace

atab-pick-alt: contract violation expected: alt? given: '(#<alt (λ (x.re x.im y.re y.im) (fma x.re y.im (* x.im y.re)))>) in: the range of the #:picking-func argument of (-> alt-table? #:only-fresh boolean? #:picking-func (-> (listof alt?) alt?) (values alt? alt-table?)) contract from: /data/pavpan/nightlies/herbie/no-costs-2/src/core/alt-table.rkt blaming: /data/pavpan/nightlies/herbie/no-costs-2/src/mainloop.rkt (assuming the contract is correct) at: /data/pavpan/nightlies/herbie/no-costs-2/src/core/alt-table.rkt:13.3LC
raise-blame-error16/opt/racket-7.0/collects/racket/contract/private/blame.rkt3470
(unnamed)/data/pavpan/nightlies/herbie/no-costs-2/src/core/alt-table.rkt590
(unnamed)/opt/racket-7.0/collects/racket/contract/private/arrow-val-first.rkt38818
choose-best-alt!/data/pavpan/nightlies/herbie/no-costs-2/src/mainloop.rkt1100
run-iter!/data/pavpan/nightlies/herbie/no-costs-2/src/mainloop.rkt3190
for-loop/data/pavpan/nightlies/herbie/no-costs-2/src/mainloop.rkt3534
run-improve43/data/pavpan/nightlies/herbie/no-costs-2/src/mainloop.rkt3380
(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