Average Error: 0.0 → 0.0
Time: 5.6s
Precision: 64
\[5 \le a \le 10 \land 0 \le b \le 0.001\]
\[\left(a + b\right) \cdot \left(a + b\right)\]
↓
\[\mathsf{fma}\left(\left(\mathsf{fma}\left(2, a, b\right)\right), b, \left(a \cdot a\right)\right)\]
\left(a + b\right) \cdot \left(a + b\right)
↓
\mathsf{fma}\left(\left(\mathsf{fma}\left(2, a, b\right)\right), b, \left(a \cdot a\right)\right)
double f(double a, double b) {
        double r16283063 = a;
        double r16283064 = b;
        double r16283065 = r16283063 + r16283064;
        double r16283066 = r16283065 * r16283065;
        return r16283066;
}
↓
double f(double a, double b) {
        double r16283067 = 2.0;
        double r16283068 = a;
        double r16283069 = b;
        double r16283070 = fma(r16283067, r16283068, r16283069);
        double r16283071 = r16283068 * r16283068;
        double r16283072 = fma(r16283070, r16283069, r16283071);
        return r16283072;
}

Error

Bits error versus a

Bits error versus b

Target

Original0.0
Target0.0
Herbie0.0
\[\left(\left(b \cdot a + b \cdot b\right) + b \cdot a\right) + a \cdot a\]

Derivation

  1. Initial program 0.0

    \[\left(a + b\right) \cdot \left(a + b\right)\]

  2. Taylor expanded around -inf 0.0

    \[\leadsto \color{blue}{{a}^{2} + \left({b}^{2} + 2 \cdot \left(a \cdot b\right)\right)}\]

  3. Simplified0.0

    \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\mathsf{fma}\left(2, a, b\right)\right), b, \left(a \cdot a\right)\right)}\]

  4. Final simplification0.0

    \[\leadsto \mathsf{fma}\left(\left(\mathsf{fma}\left(2, a, b\right)\right), b, \left(a \cdot a\right)\right)\]

Reproduce

herbie shell --seed 2019120 +o rules:numerics
(FPCore (a b)
  :name "Expression 4, p15"
  :pre (and (<= 5 a 10) (<= 0 b 0.001))

  :herbie-target
  (+ (+ (+ (* b a) (* b b)) (* b a)) (* a a))

  (* (+ a b) (+ a b)))