Average Error: 0.0 → 0
Time: 5.4s
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 r9134770 = x;
        double r9134771 = y;
        double r9134772 = r9134770 * r9134771;
        double r9134773 = r9134772 - r9134770;
        return r9134773;
}
↓
double f(double x, double y) {
        double r9134774 = x;
        double r9134775 = y;
        double r9134776 = -r9134774;
        double r9134777 = fma(r9134774, r9134775, r9134776);
        return r9134777;
}

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 2019165 +o rules:numerics
(FPCore (x y)
  :name "Data.Histogram.Bin.LogBinD:$cbinSizeN from histogram-fill-0.8.4.1"
  (- (* x y) x))