Average Error: 3.7 → 2.8
Time: 3.0s
Precision: 64
\[-14 \le a \le -13 \land -3 \le b \le -2 \land 3 \le c \le 3.5 \land 12.5 \le d \le 13.5\]
\[\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2\]
↓
\[\left(a + \left(\left(b + c\right) + d\right)\right) \cdot 2\]
\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2
↓
\left(a + \left(\left(b + c\right) + d\right)\right) \cdot 2
double f(double a, double b, double c, double d) {
        double r84810 = a;
        double r84811 = b;
        double r84812 = c;
        double r84813 = d;
        double r84814 = r84812 + r84813;
        double r84815 = r84811 + r84814;
        double r84816 = r84810 + r84815;
        double r84817 = 2.0;
        double r84818 = r84816 * r84817;
        return r84818;
}
↓
double f(double a, double b, double c, double d) {
        double r84819 = a;
        double r84820 = b;
        double r84821 = c;
        double r84822 = r84820 + r84821;
        double r84823 = d;
        double r84824 = r84822 + r84823;
        double r84825 = r84819 + r84824;
        double r84826 = 2.0;
        double r84827 = r84825 * r84826;
        return r84827;
}

Error

Bits error versus a

Bits error versus b

Bits error versus c

Bits error versus d

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original3.7
Target3.8
Herbie2.8
\[\left(a + b\right) \cdot 2 + \left(c + d\right) \cdot 2\]

Derivation

  1. Initial program 3.7

    \[\left(a + \left(b + \left(c + d\right)\right)\right) \cdot 2\]
  2. Using strategy rm

  3. Applied associate-+r+2.8

    \[\leadsto \left(a + \color{blue}{\left(\left(b + c\right) + d\right)}\right) \cdot 2\]
  4. Using strategy rm

  5. Applied log1p-expm1-u2.8

    \[\leadsto \color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(a + \left(\left(b + c\right) + d\right)\right)\right)} \cdot 2\]
  6. Using strategy rm

  7. Applied log1p-expm12.8

    \[\leadsto \color{blue}{\left(a + \left(\left(b + c\right) + d\right)\right)} \cdot 2\]

  8. Final simplification2.8

    \[\leadsto \left(a + \left(\left(b + c\right) + d\right)\right) \cdot 2\]

Reproduce

herbie shell --seed 2020001 +o rules:numerics
(FPCore (a b c d)
  :name "Expression, p6"
  :precision binary64
  :pre (and (<= -14 a -13) (<= -3 b -2) (<= 3 c 3.5) (<= 12.5 d 13.5))

  :herbie-target
  (+ (* (+ a b) 2) (* (+ c d) 2))

  (* (+ a (+ b (+ c d))) 2))