\[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
Test:
Complex division, real part
Bits:
128 bits
Bits error versus a
Bits error versus b
Bits error versus c
Bits error versus d
Time: 10.9 s
Input Error: 15.7
Output Error: 0.6
Log:
Profile: 🕒
\(\begin{cases} \frac{a}{c} + \frac{b}{c} \cdot \frac{d}{c} & \text{when } c \le -0.0047717416f0 \\ \frac{c}{d} \cdot \frac{a}{d} + \frac{b}{d} & \text{when } c \le 183.04706f0 \\ \frac{a}{c} + \frac{b}{c} \cdot \frac{d}{c} & \text{otherwise} \end{cases}\)

    if c < -0.0047717416f0 or 183.04706f0 < c

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      18.4
    2. Using strategy rm
      18.4
    3. Applied add-sqr-sqrt to get
      \[\frac{a \cdot c + b \cdot d}{\color{red}{{c}^2 + {d}^2}} \leadsto \frac{a \cdot c + b \cdot d}{\color{blue}{{\left(\sqrt{{c}^2 + {d}^2}\right)}^2}}\]
      18.4
    4. Using strategy rm
      18.4
    5. Applied add-exp-log to get
      \[\frac{a \cdot c + b \cdot d}{{\color{red}{\left(\sqrt{{c}^2 + {d}^2}\right)}}^2} \leadsto \frac{a \cdot c + b \cdot d}{{\color{blue}{\left(e^{\log \left(\sqrt{{c}^2 + {d}^2}\right)}\right)}}^2}\]
      19.0
    6. Applied taylor to get
      \[\frac{a \cdot c + b \cdot d}{{\left(e^{\log \left(\sqrt{{c}^2 + {d}^2}\right)}\right)}^2} \leadsto \frac{a}{c} + \frac{b \cdot d}{{c}^2}\]
      4.8
    7. Taylor expanded around inf to get
      \[\color{red}{\frac{a}{c} + \frac{b \cdot d}{{c}^2}} \leadsto \color{blue}{\frac{a}{c} + \frac{b \cdot d}{{c}^2}}\]
      4.8
    8. Applied simplify to get
      \[\frac{a}{c} + \frac{b \cdot d}{{c}^2} \leadsto \frac{a}{c} + \frac{b}{c} \cdot \frac{d}{c}\]
      0.4

    9. Applied final simplification

    if -0.0047717416f0 < c < 183.04706f0

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      12.3
    2. Using strategy rm
      12.3
    3. Applied add-cube-cbrt to get
      \[\color{red}{\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}} \leadsto \color{blue}{{\left(\sqrt[3]{\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}}\right)}^3}\]
      12.4
    4. Using strategy rm
      12.4
    5. Applied div-inv to get
      \[{\left(\sqrt[3]{\color{red}{\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}}}\right)}^3 \leadsto {\left(\sqrt[3]{\color{blue}{\left(a \cdot c + b \cdot d\right) \cdot \frac{1}{{c}^2 + {d}^2}}}\right)}^3\]
      12.7
    6. Applied cbrt-prod to get
      \[{\color{red}{\left(\sqrt[3]{\left(a \cdot c + b \cdot d\right) \cdot \frac{1}{{c}^2 + {d}^2}}\right)}}^3 \leadsto {\color{blue}{\left(\sqrt[3]{a \cdot c + b \cdot d} \cdot \sqrt[3]{\frac{1}{{c}^2 + {d}^2}}\right)}}^3\]
      12.8
    7. Applied cube-prod to get
      \[\color{red}{{\left(\sqrt[3]{a \cdot c + b \cdot d} \cdot \sqrt[3]{\frac{1}{{c}^2 + {d}^2}}\right)}^3} \leadsto \color{blue}{{\left(\sqrt[3]{a \cdot c + b \cdot d}\right)}^3 \cdot {\left(\sqrt[3]{\frac{1}{{c}^2 + {d}^2}}\right)}^3}\]
      12.8
    8. Applied simplify to get
      \[\color{red}{{\left(\sqrt[3]{a \cdot c + b \cdot d}\right)}^3} \cdot {\left(\sqrt[3]{\frac{1}{{c}^2 + {d}^2}}\right)}^3 \leadsto \color{blue}{\left(c \cdot a + d \cdot b\right)} \cdot {\left(\sqrt[3]{\frac{1}{{c}^2 + {d}^2}}\right)}^3\]
      12.7
    9. Applied taylor to get
      \[\left(c \cdot a + d \cdot b\right) \cdot {\left(\sqrt[3]{\frac{1}{{c}^2 + {d}^2}}\right)}^3 \leadsto \frac{c \cdot a}{{d}^2} + \frac{b}{d}\]
      2.9
    10. Taylor expanded around inf to get
      \[\color{red}{\frac{c \cdot a}{{d}^2} + \frac{b}{d}} \leadsto \color{blue}{\frac{c \cdot a}{{d}^2} + \frac{b}{d}}\]
      2.9
    11. Applied simplify to get
      \[\frac{c \cdot a}{{d}^2} + \frac{b}{d} \leadsto \frac{c}{d} \cdot \frac{a}{d} + \frac{b}{d}\]
      0.8

    12. Applied final simplification

  1. Removed slow pow expressions

Original test:


(lambda ((a default) (b default) (c default) (d default))
  #:name "Complex division, real part"
  (/ (+ (* a c) (* b d)) (+ (sqr c) (sqr d)))
  #:target
  (if (< (fabs d) (fabs c)) (/ (+ a (* b (/ d c))) (+ c (* d (/ d c)))) (/ (+ b (* a (/ c d))) (+ d (* c (/ c d))))))