math.square on complex, imaginary part

Average Error: 0.2 → 0.1

Time: 4.8s

Precision: 64

Math

\[\frac{\left(re \cdot im\right)}{\left(im \cdot re\right)}\]

↓

\[\left(\left(im \cdot \left(re + re\right)\right)\right)\]

C

double f(double re, double im) {
        double r10958 = re;
        double r10959 = im;
        double r10960 = r10958 * r10959;
        double r10961 = r10959 * r10958;
        double r10962 = r10960 + r10961;
        return r10962;
}

↓

double f(double re, double im) {
        double r10963 = im;
        double r10964 = re;
        double r10965 = r10964 + r10964;
        double r10966 = r10963 * r10965;
        double r10967 = /*Error: no posit support in C */;
        double r10968 = /*Error: no posit support in C */;
        return r10968;
}

Error

Bits error versus re

Bits error versus im

Derivation

1. Initial program 0.2

   \[\frac{\left(re \cdot im\right)}{\left(im \cdot re\right)}\]
2. Using strategy rm

3. Applied introduce-quire 0.2

   \[\leadsto \color{blue}{\left(\left(\frac{\left(re \cdot im\right)}{\left(im \cdot re\right)}\right)\right)}\]

4. Simplified 0.1

   \[\leadsto \color{blue}{\left(\left(im \cdot \left(\frac{re}{re}\right)\right)\right)}\]

5. Final simplification 0.1

   \[\leadsto \left(\left(im \cdot \left(re + re\right)\right)\right)\]

Reproduce

herbie shell --seed 2019146 +o rules:numerics
(FPCore (re im)
  :name "math.square on complex, imaginary part"
  (+.p16 (*.p16 re im) (*.p16 im re)))