Curve intersection, scale width based on ribbon orientation

Percentage Accurate: 97.1% → 98.8%
Time: 17.5s
Alternatives: 8
Speedup: 60.1×

Specification

?
\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0_i \land n0_i \leq 1\right)\right) \land \left(-1 \leq n1_i \land n1_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t_0\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot t_0\right) \cdot n1_i \end{array} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (let* ((t_0 (/ 1.0 (sin normAngle))))
   (+
    (* (* (sin (* (- 1.0 u) normAngle)) t_0) n0_i)
    (* (* (sin (* u normAngle)) t_0) n1_i))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float t_0 = 1.0f / sinf(normAngle);
	return ((sinf(((1.0f - u) * normAngle)) * t_0) * n0_i) + ((sinf((u * normAngle)) * t_0) * n1_i);
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    real(4) :: t_0
    t_0 = 1.0e0 / sin(normangle)
    code = ((sin(((1.0e0 - u) * normangle)) * t_0) * n0_i) + ((sin((u * normangle)) * t_0) * n1_i)
end function
function code(normAngle, u, n0_i, n1_i)
	t_0 = Float32(Float32(1.0) / sin(normAngle))
	return Float32(Float32(Float32(sin(Float32(Float32(Float32(1.0) - u) * normAngle)) * t_0) * n0_i) + Float32(Float32(sin(Float32(u * normAngle)) * t_0) * n1_i))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	t_0 = single(1.0) / sin(normAngle);
	tmp = ((sin(((single(1.0) - u) * normAngle)) * t_0) * n0_i) + ((sin((u * normAngle)) * t_0) * n1_i);
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{\sin normAngle}\\
\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t_0\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot t_0\right) \cdot n1_i
\end{array}
\end{array}

Sampling outcomes in binary32 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 8 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 97.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t_0\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot t_0\right) \cdot n1_i \end{array} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (let* ((t_0 (/ 1.0 (sin normAngle))))
   (+
    (* (* (sin (* (- 1.0 u) normAngle)) t_0) n0_i)
    (* (* (sin (* u normAngle)) t_0) n1_i))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float t_0 = 1.0f / sinf(normAngle);
	return ((sinf(((1.0f - u) * normAngle)) * t_0) * n0_i) + ((sinf((u * normAngle)) * t_0) * n1_i);
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    real(4) :: t_0
    t_0 = 1.0e0 / sin(normangle)
    code = ((sin(((1.0e0 - u) * normangle)) * t_0) * n0_i) + ((sin((u * normangle)) * t_0) * n1_i)
end function
function code(normAngle, u, n0_i, n1_i)
	t_0 = Float32(Float32(1.0) / sin(normAngle))
	return Float32(Float32(Float32(sin(Float32(Float32(Float32(1.0) - u) * normAngle)) * t_0) * n0_i) + Float32(Float32(sin(Float32(u * normAngle)) * t_0) * n1_i))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	t_0 = single(1.0) / sin(normAngle);
	tmp = ((sin(((single(1.0) - u) * normAngle)) * t_0) * n0_i) + ((sin((u * normAngle)) * t_0) * n1_i);
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{\sin normAngle}\\
\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t_0\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot t_0\right) \cdot n1_i
\end{array}
\end{array}

Alternative 1: 98.8% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \frac{n0_i}{\frac{\sin normAngle}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (+
  (/ n0_i (/ (sin normAngle) (sin (* normAngle (- 1.0 u)))))
  (* (/ normAngle (/ (sin normAngle) u)) n1_i)))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return (n0_i / (sinf(normAngle) / sinf((normAngle * (1.0f - u))))) + ((normAngle / (sinf(normAngle) / u)) * n1_i);
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = (n0_i / (sin(normangle) / sin((normangle * (1.0e0 - u))))) + ((normangle / (sin(normangle) / u)) * n1_i)
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(Float32(n0_i / Float32(sin(normAngle) / sin(Float32(normAngle * Float32(Float32(1.0) - u))))) + Float32(Float32(normAngle / Float32(sin(normAngle) / u)) * n1_i))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = (n0_i / (sin(normAngle) / sin((normAngle * (single(1.0) - u))))) + ((normAngle / (sin(normAngle) / u)) * n1_i);
end
\begin{array}{l}

\\
\frac{n0_i}{\frac{\sin normAngle}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0 96.4%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle \cdot u}{\sin normAngle}} \cdot n1_i \]
  4. Step-by-step derivation
    1. associate-/l*98.7%

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  5. Simplified98.7%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  6. Step-by-step derivation
    1. *-commutative98.7%

      \[\leadsto \color{blue}{n0_i \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right)} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    2. associate-*r*82.2%

      \[\leadsto \color{blue}{\left(n0_i \cdot \sin \left(\left(1 - u\right) \cdot normAngle\right)\right) \cdot \frac{1}{\sin normAngle}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    3. div-inv82.4%

      \[\leadsto \color{blue}{\frac{n0_i \cdot \sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    4. associate-/l*98.9%

      \[\leadsto \color{blue}{\frac{n0_i}{\frac{\sin normAngle}{\sin \left(\left(1 - u\right) \cdot normAngle\right)}}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    5. *-commutative98.9%

      \[\leadsto \frac{n0_i}{\frac{\sin normAngle}{\sin \color{blue}{\left(normAngle \cdot \left(1 - u\right)\right)}}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  7. Applied egg-rr98.9%

    \[\leadsto \color{blue}{\frac{n0_i}{\frac{\sin normAngle}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  8. Final simplification98.9%

    \[\leadsto \frac{n0_i}{\frac{\sin normAngle}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  9. Add Preprocessing

Alternative 2: 98.9% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + \sin \left(normAngle \cdot \left(1 - u\right)\right) \cdot \frac{n0_i}{\sin normAngle} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (+
  (* (/ normAngle (/ (sin normAngle) u)) n1_i)
  (* (sin (* normAngle (- 1.0 u))) (/ n0_i (sin normAngle)))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return ((normAngle / (sinf(normAngle) / u)) * n1_i) + (sinf((normAngle * (1.0f - u))) * (n0_i / sinf(normAngle)));
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = ((normangle / (sin(normangle) / u)) * n1_i) + (sin((normangle * (1.0e0 - u))) * (n0_i / sin(normangle)))
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(Float32(Float32(normAngle / Float32(sin(normAngle) / u)) * n1_i) + Float32(sin(Float32(normAngle * Float32(Float32(1.0) - u))) * Float32(n0_i / sin(normAngle))))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = ((normAngle / (sin(normAngle) / u)) * n1_i) + (sin((normAngle * (single(1.0) - u))) * (n0_i / sin(normAngle)));
end
\begin{array}{l}

\\
\frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + \sin \left(normAngle \cdot \left(1 - u\right)\right) \cdot \frac{n0_i}{\sin normAngle}
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0 96.4%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle \cdot u}{\sin normAngle}} \cdot n1_i \]
  4. Step-by-step derivation
    1. associate-/l*98.7%

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  5. Simplified98.7%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  6. Taylor expanded in u around inf 82.4%

    \[\leadsto \color{blue}{\frac{n0_i \cdot \sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  7. Step-by-step derivation
    1. *-commutative82.4%

      \[\leadsto \frac{\color{blue}{\sin \left(normAngle \cdot \left(1 - u\right)\right) \cdot n0_i}}{\sin normAngle} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    2. associate-*r/98.8%

      \[\leadsto \color{blue}{\sin \left(normAngle \cdot \left(1 - u\right)\right) \cdot \frac{n0_i}{\sin normAngle}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  8. Simplified98.8%

    \[\leadsto \color{blue}{\sin \left(normAngle \cdot \left(1 - u\right)\right) \cdot \frac{n0_i}{\sin normAngle}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  9. Final simplification98.8%

    \[\leadsto \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + \sin \left(normAngle \cdot \left(1 - u\right)\right) \cdot \frac{n0_i}{\sin normAngle} \]
  10. Add Preprocessing

Alternative 3: 98.8% accurate, 1.8× speedup?

\[\begin{array}{l} \\ \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + \frac{n0_i}{\frac{1}{1 - u} + {normAngle}^{2} \cdot \left(-0.16666666666666666 \cdot \left(u + -1\right) + 0.16666666666666666 \cdot \frac{-1}{1 - u}\right)} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (+
  (* (/ normAngle (/ (sin normAngle) u)) n1_i)
  (/
   n0_i
   (+
    (/ 1.0 (- 1.0 u))
    (*
     (pow normAngle 2.0)
     (+
      (* -0.16666666666666666 (+ u -1.0))
      (* 0.16666666666666666 (/ -1.0 (- 1.0 u)))))))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return ((normAngle / (sinf(normAngle) / u)) * n1_i) + (n0_i / ((1.0f / (1.0f - u)) + (powf(normAngle, 2.0f) * ((-0.16666666666666666f * (u + -1.0f)) + (0.16666666666666666f * (-1.0f / (1.0f - u)))))));
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = ((normangle / (sin(normangle) / u)) * n1_i) + (n0_i / ((1.0e0 / (1.0e0 - u)) + ((normangle ** 2.0e0) * (((-0.16666666666666666e0) * (u + (-1.0e0))) + (0.16666666666666666e0 * ((-1.0e0) / (1.0e0 - u)))))))
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(Float32(Float32(normAngle / Float32(sin(normAngle) / u)) * n1_i) + Float32(n0_i / Float32(Float32(Float32(1.0) / Float32(Float32(1.0) - u)) + Float32((normAngle ^ Float32(2.0)) * Float32(Float32(Float32(-0.16666666666666666) * Float32(u + Float32(-1.0))) + Float32(Float32(0.16666666666666666) * Float32(Float32(-1.0) / Float32(Float32(1.0) - u))))))))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = ((normAngle / (sin(normAngle) / u)) * n1_i) + (n0_i / ((single(1.0) / (single(1.0) - u)) + ((normAngle ^ single(2.0)) * ((single(-0.16666666666666666) * (u + single(-1.0))) + (single(0.16666666666666666) * (single(-1.0) / (single(1.0) - u)))))));
end
\begin{array}{l}

\\
\frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + \frac{n0_i}{\frac{1}{1 - u} + {normAngle}^{2} \cdot \left(-0.16666666666666666 \cdot \left(u + -1\right) + 0.16666666666666666 \cdot \frac{-1}{1 - u}\right)}
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0 96.4%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle \cdot u}{\sin normAngle}} \cdot n1_i \]
  4. Step-by-step derivation
    1. associate-/l*98.7%

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  5. Simplified98.7%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  6. Step-by-step derivation
    1. *-commutative98.7%

      \[\leadsto \color{blue}{n0_i \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right)} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    2. associate-*r*82.2%

      \[\leadsto \color{blue}{\left(n0_i \cdot \sin \left(\left(1 - u\right) \cdot normAngle\right)\right) \cdot \frac{1}{\sin normAngle}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    3. div-inv82.4%

      \[\leadsto \color{blue}{\frac{n0_i \cdot \sin \left(\left(1 - u\right) \cdot normAngle\right)}{\sin normAngle}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    4. associate-/l*98.9%

      \[\leadsto \color{blue}{\frac{n0_i}{\frac{\sin normAngle}{\sin \left(\left(1 - u\right) \cdot normAngle\right)}}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
    5. *-commutative98.9%

      \[\leadsto \frac{n0_i}{\frac{\sin normAngle}{\sin \color{blue}{\left(normAngle \cdot \left(1 - u\right)\right)}}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  7. Applied egg-rr98.9%

    \[\leadsto \color{blue}{\frac{n0_i}{\frac{\sin normAngle}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  8. Taylor expanded in normAngle around 0 98.5%

    \[\leadsto \frac{n0_i}{\color{blue}{-1 \cdot \left({normAngle}^{2} \cdot \left(-0.16666666666666666 \cdot \left(1 - u\right) + 0.16666666666666666 \cdot \frac{1}{1 - u}\right)\right) + \frac{1}{1 - u}}} + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  9. Final simplification98.5%

    \[\leadsto \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + \frac{n0_i}{\frac{1}{1 - u} + {normAngle}^{2} \cdot \left(-0.16666666666666666 \cdot \left(u + -1\right) + 0.16666666666666666 \cdot \frac{-1}{1 - u}\right)} \]
  10. Add Preprocessing

Alternative 4: 98.8% accurate, 3.7× speedup?

\[\begin{array}{l} \\ \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + n0_i \cdot \left(1 - u\right) \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (+ (* (/ normAngle (/ (sin normAngle) u)) n1_i) (* n0_i (- 1.0 u))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return ((normAngle / (sinf(normAngle) / u)) * n1_i) + (n0_i * (1.0f - u));
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = ((normangle / (sin(normangle) / u)) * n1_i) + (n0_i * (1.0e0 - u))
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(Float32(Float32(normAngle / Float32(sin(normAngle) / u)) * n1_i) + Float32(n0_i * Float32(Float32(1.0) - u)))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = ((normAngle / (sin(normAngle) / u)) * n1_i) + (n0_i * (single(1.0) - u));
end
\begin{array}{l}

\\
\frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + n0_i \cdot \left(1 - u\right)
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0 96.4%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle \cdot u}{\sin normAngle}} \cdot n1_i \]
  4. Step-by-step derivation
    1. associate-/l*98.7%

      \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  5. Simplified98.7%

    \[\leadsto \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \color{blue}{\frac{normAngle}{\frac{\sin normAngle}{u}}} \cdot n1_i \]
  6. Taylor expanded in normAngle around 0 98.1%

    \[\leadsto \color{blue}{\left(1 - u\right)} \cdot n0_i + \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i \]
  7. Final simplification98.1%

    \[\leadsto \frac{normAngle}{\frac{\sin normAngle}{u}} \cdot n1_i + n0_i \cdot \left(1 - u\right) \]
  8. Add Preprocessing

Alternative 5: 98.1% accurate, 4.0× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(u, n1_i - n0_i, n0_i\right) \end{array} \]
(FPCore (normAngle u n0_i n1_i) :precision binary32 (fma u (- n1_i n0_i) n0_i))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return fmaf(u, (n1_i - n0_i), n0_i);
}
function code(normAngle, u, n0_i, n1_i)
	return fma(u, Float32(n1_i - n0_i), n0_i)
end
\begin{array}{l}

\\
\mathsf{fma}\left(u, n1_i - n0_i, n0_i\right)
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Step-by-step derivation
    1. *-commutative96.5%

      \[\leadsto \color{blue}{\left(\frac{1}{\sin normAngle} \cdot \sin \left(\left(1 - u\right) \cdot normAngle\right)\right)} \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
    2. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right)} + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
    3. *-commutative80.2%

      \[\leadsto \frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right) + \color{blue}{\left(\frac{1}{\sin normAngle} \cdot \sin \left(u \cdot normAngle\right)\right)} \cdot n1_i \]
    4. associate-*l*73.6%

      \[\leadsto \frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right) + \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
    5. distribute-lft-out73.5%

      \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i + \sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
  3. Simplified73.5%

    \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i + \sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in normAngle around 0 97.1%

    \[\leadsto \color{blue}{n0_i \cdot \left(1 - u\right) + n1_i \cdot u} \]
  6. Taylor expanded in u around 0 97.3%

    \[\leadsto \color{blue}{n0_i + u \cdot \left(n1_i + -1 \cdot n0_i\right)} \]
  7. Step-by-step derivation
    1. +-commutative97.3%

      \[\leadsto \color{blue}{u \cdot \left(n1_i + -1 \cdot n0_i\right) + n0_i} \]
    2. fma-def97.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(u, n1_i + -1 \cdot n0_i, n0_i\right)} \]
    3. mul-1-neg97.4%

      \[\leadsto \mathsf{fma}\left(u, n1_i + \color{blue}{\left(-n0_i\right)}, n0_i\right) \]
    4. unsub-neg97.4%

      \[\leadsto \mathsf{fma}\left(u, \color{blue}{n1_i - n0_i}, n0_i\right) \]
  8. Simplified97.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(u, n1_i - n0_i, n0_i\right)} \]
  9. Final simplification97.4%

    \[\leadsto \mathsf{fma}\left(u, n1_i - n0_i, n0_i\right) \]
  10. Add Preprocessing

Alternative 6: 98.0% accurate, 60.1× speedup?

\[\begin{array}{l} \\ n0_i + u \cdot \left(n1_i - n0_i\right) \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (+ n0_i (* u (- n1_i n0_i))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return n0_i + (u * (n1_i - n0_i));
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = n0_i + (u * (n1_i - n0_i))
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(n0_i + Float32(u * Float32(n1_i - n0_i)))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = n0_i + (u * (n1_i - n0_i));
end
\begin{array}{l}

\\
n0_i + u \cdot \left(n1_i - n0_i\right)
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Step-by-step derivation
    1. *-commutative96.5%

      \[\leadsto \color{blue}{\left(\frac{1}{\sin normAngle} \cdot \sin \left(\left(1 - u\right) \cdot normAngle\right)\right)} \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
    2. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right)} + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
    3. *-commutative80.2%

      \[\leadsto \frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right) + \color{blue}{\left(\frac{1}{\sin normAngle} \cdot \sin \left(u \cdot normAngle\right)\right)} \cdot n1_i \]
    4. associate-*l*73.6%

      \[\leadsto \frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right) + \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
    5. distribute-lft-out73.5%

      \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i + \sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
  3. Simplified73.5%

    \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i + \sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in normAngle around 0 97.1%

    \[\leadsto \color{blue}{n0_i \cdot \left(1 - u\right) + n1_i \cdot u} \]
  6. Taylor expanded in u around -inf 97.3%

    \[\leadsto \color{blue}{n0_i + -1 \cdot \left(u \cdot \left(n0_i + -1 \cdot n1_i\right)\right)} \]
  7. Step-by-step derivation
    1. mul-1-neg97.3%

      \[\leadsto n0_i + \color{blue}{\left(-u \cdot \left(n0_i + -1 \cdot n1_i\right)\right)} \]
    2. unsub-neg97.3%

      \[\leadsto \color{blue}{n0_i - u \cdot \left(n0_i + -1 \cdot n1_i\right)} \]
    3. mul-1-neg97.3%

      \[\leadsto n0_i - u \cdot \left(n0_i + \color{blue}{\left(-n1_i\right)}\right) \]
    4. unsub-neg97.3%

      \[\leadsto n0_i - u \cdot \color{blue}{\left(n0_i - n1_i\right)} \]
  8. Simplified97.3%

    \[\leadsto \color{blue}{n0_i - u \cdot \left(n0_i - n1_i\right)} \]
  9. Final simplification97.3%

    \[\leadsto n0_i + u \cdot \left(n1_i - n0_i\right) \]
  10. Add Preprocessing

Alternative 7: 82.2% accurate, 84.2× speedup?

\[\begin{array}{l} \\ n0_i + u \cdot n1_i \end{array} \]
(FPCore (normAngle u n0_i n1_i) :precision binary32 (+ n0_i (* u n1_i)))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return n0_i + (u * n1_i);
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = n0_i + (u * n1_i)
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(n0_i + Float32(u * n1_i))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = n0_i + (u * n1_i);
end
\begin{array}{l}

\\
n0_i + u \cdot n1_i
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Step-by-step derivation
    1. fma-def96.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}, n0_i, \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i\right)} \]
    2. associate-*l*96.3%

      \[\leadsto \mathsf{fma}\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}, n0_i, \color{blue}{\sin \left(u \cdot normAngle\right) \cdot \left(\frac{1}{\sin normAngle} \cdot n1_i\right)}\right) \]
  3. Simplified96.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}, n0_i, \sin \left(u \cdot normAngle\right) \cdot \left(\frac{1}{\sin normAngle} \cdot n1_i\right)\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in u around 0 81.9%

    \[\leadsto \mathsf{fma}\left(\color{blue}{1}, n0_i, \sin \left(u \cdot normAngle\right) \cdot \left(\frac{1}{\sin normAngle} \cdot n1_i\right)\right) \]
  6. Taylor expanded in normAngle around 0 83.4%

    \[\leadsto \color{blue}{n0_i + n1_i \cdot u} \]
  7. Step-by-step derivation
    1. *-commutative83.4%

      \[\leadsto n0_i + \color{blue}{u \cdot n1_i} \]
  8. Simplified83.4%

    \[\leadsto \color{blue}{n0_i + u \cdot n1_i} \]
  9. Final simplification83.4%

    \[\leadsto n0_i + u \cdot n1_i \]
  10. Add Preprocessing

Alternative 8: 38.1% accurate, 140.3× speedup?

\[\begin{array}{l} \\ u \cdot n1_i \end{array} \]
(FPCore (normAngle u n0_i n1_i) :precision binary32 (* u n1_i))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return u * n1_i;
}
real(4) function code(normangle, u, n0_i, n1_i)
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    code = u * n1_i
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(u * n1_i)
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = u * n1_i;
end
\begin{array}{l}

\\
u \cdot n1_i
\end{array}
Derivation
  1. Initial program 96.5%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
  2. Step-by-step derivation
    1. *-commutative96.5%

      \[\leadsto \color{blue}{\left(\frac{1}{\sin normAngle} \cdot \sin \left(\left(1 - u\right) \cdot normAngle\right)\right)} \cdot n0_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
    2. associate-*l*80.2%

      \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right)} + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1_i \]
    3. *-commutative80.2%

      \[\leadsto \frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right) + \color{blue}{\left(\frac{1}{\sin normAngle} \cdot \sin \left(u \cdot normAngle\right)\right)} \cdot n1_i \]
    4. associate-*l*73.6%

      \[\leadsto \frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i\right) + \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
    5. distribute-lft-out73.5%

      \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i + \sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
  3. Simplified73.5%

    \[\leadsto \color{blue}{\frac{1}{\sin normAngle} \cdot \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot n0_i + \sin \left(u \cdot normAngle\right) \cdot n1_i\right)} \]
  4. Add Preprocessing
  5. Taylor expanded in normAngle around 0 97.1%

    \[\leadsto \color{blue}{n0_i \cdot \left(1 - u\right) + n1_i \cdot u} \]
  6. Taylor expanded in n0_i around 0 40.1%

    \[\leadsto \color{blue}{n1_i \cdot u} \]
  7. Step-by-step derivation
    1. *-commutative40.1%

      \[\leadsto \color{blue}{u \cdot n1_i} \]
  8. Simplified40.1%

    \[\leadsto \color{blue}{u \cdot n1_i} \]
  9. Final simplification40.1%

    \[\leadsto u \cdot n1_i \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2024020 
(FPCore (normAngle u n0_i n1_i)
  :name "Curve intersection, scale width based on ribbon orientation"
  :precision binary32
  :pre (and (and (and (and (<= 0.0 normAngle) (<= normAngle (/ PI 2.0))) (and (<= -1.0 n0_i) (<= n0_i 1.0))) (and (<= -1.0 n1_i) (<= n1_i 1.0))) (and (<= 2.328306437e-10 u) (<= u 1.0)))
  (+ (* (* (sin (* (- 1.0 u) normAngle)) (/ 1.0 (sin normAngle))) n0_i) (* (* (sin (* u normAngle)) (/ 1.0 (sin normAngle))) n1_i)))