Average Error: 0.0 → 0.0
Time: 644.0ms
Precision: 64
\[\left(x \cdot y + x\right) + y\]
↓
\[\mathsf{fma}\left(x + 1, y, x\right)\]
\left(x \cdot y + x\right) + y
↓
\mathsf{fma}\left(x + 1, y, x\right)
double f(double x, double y) {
        double r77866 = x;
        double r77867 = y;
        double r77868 = r77866 * r77867;
        double r77869 = r77868 + r77866;
        double r77870 = r77869 + r77867;
        return r77870;
}
↓
double f(double x, double y) {
        double r77871 = x;
        double r77872 = 1.0;
        double r77873 = r77871 + r77872;
        double r77874 = y;
        double r77875 = fma(r77873, r77874, r77871);
        return r77875;
}

Error

Bits error versus x

Bits error versus y

Derivation

  1. Initial program 0.0

    \[\left(x \cdot y + x\right) + y\]

  2. Simplified0.0

    \[\leadsto \color{blue}{y + \mathsf{fma}\left(x, y, x\right)}\]
  3. Using strategy rm

  4. Applied *-un-lft-identity0.0

    \[\leadsto y + \color{blue}{1 \cdot \mathsf{fma}\left(x, y, x\right)}\]

  5. Applied *-un-lft-identity0.0

    \[\leadsto \color{blue}{1 \cdot y} + 1 \cdot \mathsf{fma}\left(x, y, x\right)\]

  6. Applied distribute-lft-out0.0

    \[\leadsto \color{blue}{1 \cdot \left(y + \mathsf{fma}\left(x, y, x\right)\right)}\]

  7. Simplified0.0

    \[\leadsto 1 \cdot \color{blue}{\mathsf{fma}\left(x + 1, y, x\right)}\]

  8. Final simplification0.0

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

Reproduce

herbie shell --seed 2020036 +o rules:numerics
(FPCore (x y)
  :name "Numeric.Log:$cexpm1 from log-domain-0.10.2.1, B"
  :precision binary64
  (+ (+ (* x y) x) y))