Average Error: 0.0 → 0.0
Time: 2.0s
Precision: binary64
\[e^{-\left(1 - x \cdot x\right)}\]
↓
\[{\left(e^{x + 1}\right)}^{x} \cdot e^{-1 - x}\]
e^{-\left(1 - x \cdot x\right)}
↓
{\left(e^{x + 1}\right)}^{x} \cdot e^{-1 - x}
(FPCore (x) :precision binary64 (exp (- (- 1.0 (* x x)))))
↓
(FPCore (x) :precision binary64 (* (pow (exp (+ x 1.0)) x) (exp (- -1.0 x))))
double code(double x) {
	return exp(-(1.0 - (x * x)));
}
↓
double code(double x) {
	return pow(exp(x + 1.0), x) * exp(-1.0 - x);
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 0.0

    \[e^{-\left(1 - x \cdot x\right)}\]

  2. Simplified0.0

    \[\leadsto \color{blue}{e^{x \cdot x - 1}}\]
  3. Using strategy rm

  4. Applied difference-of-sqr-1_binary64_480.0

    \[\leadsto e^{\color{blue}{\left(x + 1\right) \cdot \left(x - 1\right)}}\]

  5. Applied exp-prod_binary64_1300.0

    \[\leadsto \color{blue}{{\left(e^{x + 1}\right)}^{\left(x - 1\right)}}\]
  6. Using strategy rm

  7. Applied sub-neg_binary64_710.0

    \[\leadsto {\left(e^{x + 1}\right)}^{\color{blue}{\left(x + \left(-1\right)\right)}}\]

  8. Applied unpow-prod-up_binary64_1560.0

    \[\leadsto \color{blue}{{\left(e^{x + 1}\right)}^{x} \cdot {\left(e^{x + 1}\right)}^{\left(-1\right)}}\]

  9. Simplified0.0

    \[\leadsto {\left(e^{x + 1}\right)}^{x} \cdot \color{blue}{e^{-1 - x}}\]

  10. Final simplification0.0

    \[\leadsto {\left(e^{x + 1}\right)}^{x} \cdot e^{-1 - x}\]

Reproduce

herbie shell --seed 2021032 
(FPCore (x)
  :name "exp neg sub"
  :precision binary64
  (exp (- (- 1.0 (* x x)))))