Average Error: 0.0 → 0
Time: 3.6s
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 r7841837 = x;
        double r7841838 = y;
        double r7841839 = r7841837 * r7841838;
        double r7841840 = r7841839 - r7841837;
        return r7841840;
}
↓
double f(double x, double y) {
        double r7841841 = x;
        double r7841842 = y;
        double r7841843 = -r7841841;
        double r7841844 = fma(r7841841, r7841842, r7841843);
        return r7841844;
}

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 2019172 +o rules:numerics
(FPCore (x y)
  :name "Data.Histogram.Bin.LogBinD:$cbinSizeN from histogram-fill-0.8.4.1"
  (- (* x y) x))