\[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
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: 15.4 s
Input Error: 13.1
Output Error: 4.9
Log:
Profile: 🕒
\(\begin{cases} \left(\frac{a}{c} + \frac{d \cdot b}{c \cdot c}\right) - \frac{\left(d \cdot b\right) \cdot {\left(\left|\frac{1}{d}\right|\right)}^2}{{c}^{4}} & \text{when } c \le -1.674345f+14 \\ \frac{a \cdot c + b \cdot d}{{c}^2 + {\left(\left|d\right|\right)}^2} & \text{when } c \le -1.8106279f-24 \\ \frac{c}{d} \cdot \frac{a}{d} + \frac{b}{d} & \text{when } c \le 9.359174f-16 \\ \frac{a \cdot c + b \cdot d}{{c}^2 + {\left(\left|d\right|\right)}^2} & \text{when } c \le 6.144087f+15 \\ \left(\frac{a}{c} + \frac{d \cdot b}{c \cdot c}\right) - \frac{\left(d \cdot b\right) \cdot {\left(\left|\frac{1}{d}\right|\right)}^2}{{c}^{4}} & \text{otherwise} \end{cases}\)

    if c < -1.674345f+14 or 6.144087f+15 < c

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      21.8
    2. Using strategy rm
      21.8
    3. Applied add-sqr-sqrt to get
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + \color{red}{{d}^2}} \leadsto \frac{a \cdot c + b \cdot d}{{c}^2 + \color{blue}{{\left(\sqrt{{d}^2}\right)}^2}}\]
      21.8
    4. Applied simplify to get
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {\color{red}{\left(\sqrt{{d}^2}\right)}}^2} \leadsto \frac{a \cdot c + b \cdot d}{{c}^2 + {\color{blue}{\left(\left|d\right|\right)}}^2}\]
      21.8
    5. Applied taylor to get
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {\left(\left|d\right|\right)}^2} \leadsto \left(\frac{a}{c} + \frac{b \cdot d}{{c}^2}\right) - \frac{b \cdot \left(d \cdot {\left(\left|\frac{1}{d}\right|\right)}^2\right)}{{c}^{4}}\]
      6.5
    6. Taylor expanded around inf to get
      \[\color{red}{\left(\frac{a}{c} + \frac{b \cdot d}{{c}^2}\right) - \frac{b \cdot \left(d \cdot {\left(\left|\frac{1}{d}\right|\right)}^2\right)}{{c}^{4}}} \leadsto \color{blue}{\left(\frac{a}{c} + \frac{b \cdot d}{{c}^2}\right) - \frac{b \cdot \left(d \cdot {\left(\left|\frac{1}{d}\right|\right)}^2\right)}{{c}^{4}}}\]
      6.5
    7. Applied simplify to get
      \[\left(\frac{a}{c} + \frac{b \cdot d}{{c}^2}\right) - \frac{b \cdot \left(d \cdot {\left(\left|\frac{1}{d}\right|\right)}^2\right)}{{c}^{4}} \leadsto \left(\frac{a}{c} + \frac{d \cdot b}{c \cdot c}\right) - \frac{\left(d \cdot b\right) \cdot {\left(\left|\frac{1}{d}\right|\right)}^2}{{c}^{4}}\]
      6.5

    8. Applied final simplification

    if -1.674345f+14 < c < -1.8106279f-24 or 9.359174f-16 < c < 6.144087f+15

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      8.0
    2. Using strategy rm
      8.0
    3. Applied add-sqr-sqrt to get
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + \color{red}{{d}^2}} \leadsto \frac{a \cdot c + b \cdot d}{{c}^2 + \color{blue}{{\left(\sqrt{{d}^2}\right)}^2}}\]
      7.9
    4. Applied simplify to get
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {\color{red}{\left(\sqrt{{d}^2}\right)}}^2} \leadsto \frac{a \cdot c + b \cdot d}{{c}^2 + {\color{blue}{\left(\left|d\right|\right)}}^2}\]
      5.6

    if -1.8106279f-24 < c < 9.359174f-16

    1. Started with
      \[\frac{a \cdot c + b \cdot d}{{c}^2 + {d}^2}\]
      10.8
    2. Using strategy rm
      10.8
    3. Applied add-sqr-sqrt to get
      \[\frac{a \cdot c + b \cdot d}{\color{red}{{c}^2} + {d}^2} \leadsto \frac{a \cdot c + b \cdot d}{\color{blue}{{\left(\sqrt{{c}^2}\right)}^2} + {d}^2}\]
      10.8
    4. Applied simplify to get
      \[\frac{a \cdot c + b \cdot d}{{\color{red}{\left(\sqrt{{c}^2}\right)}}^2 + {d}^2} \leadsto \frac{a \cdot c + b \cdot d}{{\color{blue}{\left(\left|c\right|\right)}}^2 + {d}^2}\]
      10.8
    5. Applied taylor to get
      \[\frac{a \cdot c + b \cdot d}{{\left(\left|c\right|\right)}^2 + {d}^2} \leadsto \frac{c \cdot a}{{d}^2} + \frac{b}{d}\]
      3.0
    6. Taylor expanded around inf to get
      \[\color{red}{\frac{c \cdot a}{{d}^2} + \frac{b}{d}} \leadsto \color{blue}{\frac{c \cdot a}{{d}^2} + \frac{b}{d}}\]
      3.0
    7. Applied taylor to get
      \[\frac{c \cdot a}{{d}^2} + \frac{b}{d} \leadsto \frac{c \cdot a}{{d}^2} + \frac{b}{d}\]
      3.0
    8. Taylor expanded around 0 to get
      \[\frac{c \cdot a}{{d}^2} + \color{red}{\frac{b}{d}} \leadsto \frac{c \cdot a}{{d}^2} + \color{blue}{\frac{b}{d}}\]
      3.0
    9. Applied simplify to get
      \[\frac{c \cdot a}{{d}^2} + \frac{b}{d} \leadsto \frac{c}{d} \cdot \frac{a}{d} + \frac{b}{d}\]
      1.0

    10. 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))))))