Average Error: 58.7 → 0.0
Time: 2.8s
Precision: 64
\[-0.00017 \lt x\]
\[e^{x} - 1\]
↓
\[\mathsf{expm1}\left(x\right)\]
e^{x} - 1
↓
\mathsf{expm1}\left(x\right)
double f(double x) {
        double r1200927 = x;
        double r1200928 = exp(r1200927);
        double r1200929 = 1.0;
        double r1200930 = r1200928 - r1200929;
        return r1200930;
}
↓
double f(double x) {
        double r1200931 = x;
        double r1200932 = expm1(r1200931);
        return r1200932;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original58.7
Target0.5
Herbie0.0
\[x \cdot \left(\left(1 + \frac{x}{2}\right) + \frac{x \cdot x}{6}\right)\]

Derivation

  1. Initial program 58.7

    \[e^{x} - 1\]

  2. Simplified0.0

    \[\leadsto \color{blue}{\mathsf{expm1}\left(x\right)}\]

  3. Final simplification0.0

    \[\leadsto \mathsf{expm1}\left(x\right)\]

Reproduce

herbie shell --seed 2019153 +o rules:numerics
(FPCore (x)
  :name "expm1 (example 3.7)"
  :pre (< -0.00017 x)

  :herbie-target
  (* x (+ (+ 1 (/ x 2)) (/ (* x x) 6)))

  (- (exp x) 1))