Expression 1, p15

Average Error: 0.4 → 0.0

Time: 45.4s

Precision: 64

\[1 \le a \le 2 \le b \le 4 \le c \le 8 \le d \le 16 \le e \le 32\]

Math

\[\left(\left(\left(e + d\right) + c\right) + b\right) + a\]

↓

\[\log \left(\left(e^{e} \cdot e^{d}\right) \cdot \left(e^{b} \cdot \left(e^{c} \cdot e^{a}\right)\right)\right)\]

C

double f(double a, double b, double c, double d, double e) {
        double r45443575 = e;
        double r45443576 = d;
        double r45443577 = r45443575 + r45443576;
        double r45443578 = c;
        double r45443579 = r45443577 + r45443578;
        double r45443580 = b;
        double r45443581 = r45443579 + r45443580;
        double r45443582 = a;
        double r45443583 = r45443581 + r45443582;
        return r45443583;
}

↓

double f(double a, double b, double c, double d, double e) {
        double r45443584 = e;
        double r45443585 = exp(r45443584);
        double r45443586 = d;
        double r45443587 = exp(r45443586);
        double r45443588 = r45443585 * r45443587;
        double r45443589 = b;
        double r45443590 = exp(r45443589);
        double r45443591 = c;
        double r45443592 = exp(r45443591);
        double r45443593 = a;
        double r45443594 = exp(r45443593);
        double r45443595 = r45443592 * r45443594;
        double r45443596 = r45443590 * r45443595;
        double r45443597 = r45443588 * r45443596;
        double r45443598 = log(r45443597);
        return r45443598;
}

Error

Bits error versus a

Bits error versus b

Bits error versus c

Bits error versus d

Bits error versus e

Target

Original	0.4
Target	0.2
Herbie	0.0

\[\left(d + \left(c + \left(a + b\right)\right)\right) + e\]

Derivation

1. Initial program 0.4

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

3. Applied add-log-exp 0.4

   \[\leadsto \left(\left(\left(e + d\right) + c\right) + b\right) + \color{blue}{\log \left(e^{a}\right)}\]

4. Applied add-log-exp 0.4

   \[\leadsto \left(\left(\left(e + d\right) + c\right) + \color{blue}{\log \left(e^{b}\right)}\right) + \log \left(e^{a}\right)\]

5. Applied add-log-exp 0.4

   \[\leadsto \left(\left(\left(e + d\right) + \color{blue}{\log \left(e^{c}\right)}\right) + \log \left(e^{b}\right)\right) + \log \left(e^{a}\right)\]

6. Applied add-log-exp 0.4

   \[\leadsto \left(\left(\color{blue}{\log \left(e^{e + d}\right)} + \log \left(e^{c}\right)\right) + \log \left(e^{b}\right)\right) + \log \left(e^{a}\right)\]

7. Applied sum-log 0.4

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

8. Applied sum-log 0.3

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

9. Applied sum-log 0.2

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

10. Simplified 0.3

    \[\leadsto \log \color{blue}{\left(e^{\left(d + e\right) + \left(\left(c + a\right) + b\right)}\right)}\]
11. Using strategy rm

12. Applied add-log-exp 0.3

    \[\leadsto \log \left(e^{\left(d + e\right) + \left(\left(c + a\right) + \color{blue}{\log \left(e^{b}\right)}\right)}\right)\]

13. Applied add-log-exp 0.3

    \[\leadsto \log \left(e^{\left(d + e\right) + \left(\left(c + \color{blue}{\log \left(e^{a}\right)}\right) + \log \left(e^{b}\right)\right)}\right)\]

14. Applied add-log-exp 0.3

    \[\leadsto \log \left(e^{\left(d + e\right) + \left(\left(\color{blue}{\log \left(e^{c}\right)} + \log \left(e^{a}\right)\right) + \log \left(e^{b}\right)\right)}\right)\]

15. Applied sum-log 0.3

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

16. Applied sum-log 0.3

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

17. Applied add-log-exp 0.3

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

18. Applied add-log-exp 0.3

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

19. Applied sum-log 0.3

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

20. Applied sum-log 0.0

    \[\leadsto \log \left(e^{\color{blue}{\log \left(\left(e^{d} \cdot e^{e}\right) \cdot \left(\left(e^{c} \cdot e^{a}\right) \cdot e^{b}\right)\right)}}\right)\]

21. Applied rem-exp-log 0.0

    \[\leadsto \log \color{blue}{\left(\left(e^{d} \cdot e^{e}\right) \cdot \left(\left(e^{c} \cdot e^{a}\right) \cdot e^{b}\right)\right)}\]

22. Final simplification 0.0

    \[\leadsto \log \left(\left(e^{e} \cdot e^{d}\right) \cdot \left(e^{b} \cdot \left(e^{c} \cdot e^{a}\right)\right)\right)\]

Reproduce

herbie shell --seed 2019125 
(FPCore (a b c d e)
  :name "Expression 1, p15"
  :pre (<= 1 a 2 b 4 c 8 d 16 e 32)

  :herbie-target
  (+ (+ d (+ c (+ a b))) e)

  (+ (+ (+ (+ e d) c) b) a))