Average Error: 0.0 → 0
Time: 4.1s
Precision: 64
\[x \cdot y - x\]
↓
\[\mathsf{fma}\left(x, y, -x\right)\]
x \cdot y - x
↓
\mathsf{fma}\left(x, y, -x\right)
double f(double x, double y) {
        double r129576 = x;
        double r129577 = y;
        double r129578 = r129576 * r129577;
        double r129579 = r129578 - r129576;
        return r129579;
}
↓
double f(double x, double y) {
        double r129580 = x;
        double r129581 = y;
        double r129582 = -r129580;
        double r129583 = fma(r129580, r129581, r129582);
        return r129583;
}

Error

Bits error versus x

Bits error versus y

Derivation

  1. Initial program 0.0

    \[x \cdot y - x\]
  2. Using strategy rm

  3. Applied fma-neg0

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

  4. Final simplification0

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

Reproduce

herbie shell --seed 2019198 +o rules:numerics
(FPCore (x y)
  :name "Data.Histogram.Bin.LogBinD:$cbinSizeN from histogram-fill-0.8.4.1"
  (- (* x y) x))