Average Error: 45.8 → 0
Time: 14.4s
Precision: 64
\[\mathsf{fma}\left(x, y, z\right) - \left(1 + \left(x \cdot y + z\right)\right)\]
↓
\[-1\]
\mathsf{fma}\left(x, y, z\right) - \left(1 + \left(x \cdot y + z\right)\right)
↓
-1
double f(double x, double y, double z) {
        double r1118461 = x;
        double r1118462 = y;
        double r1118463 = z;
        double r1118464 = fma(r1118461, r1118462, r1118463);
        double r1118465 = 1.0;
        double r1118466 = r1118461 * r1118462;
        double r1118467 = r1118466 + r1118463;
        double r1118468 = r1118465 + r1118467;
        double r1118469 = r1118464 - r1118468;
        return r1118469;
}
↓
double f(double __attribute__((unused)) x, double __attribute__((unused)) y, double __attribute__((unused)) z) {
        double r1118470 = -1.0;
        return r1118470;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Target

Original45.8
Target0
Herbie0
\[-1\]

Derivation

  1. Initial program 45.8

    \[\mathsf{fma}\left(x, y, z\right) - \left(1 + \left(x \cdot y + z\right)\right)\]

  2. Simplified0

    \[\leadsto \color{blue}{-1}\]

  3. Final simplification0

    \[\leadsto -1\]

Reproduce

herbie shell --seed 2019141 +o rules:numerics
(FPCore (x y z)
  :name "simple fma test"

  :herbie-target
  -1

  (- (fma x y z) (+ 1 (+ (* x y) z))))