Curve intersection, scale width based on ribbon orientation

Percentage Accurate: 97.2% → 98.9%
Time: 37.3s
Alternatives: 7
Speedup: 18.2×

Specification

?
\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i \end{array} \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (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)
use fmin_fmax_functions
    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}
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}

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 7 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: 97.2% accurate, 1.0× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i \end{array} \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (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)
use fmin_fmax_functions
    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}
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}

Alternative 1: 98.9% accurate, 1.6× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\mathsf{fma}\left(n0\_i, 1 - u, \mathsf{fma}\left(n1\_i, u, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot {\left(1 - u\right)}^{3}, -0.16666666666666666 \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot \left(1 - u\right), -0.16666666666666666 \cdot \left(n1\_i \cdot u\right)\right)\right)\right)\right) \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (fma
 n0_i
 (- 1.0 u)
 (fma
  n1_i
  u
  (*
   (pow normAngle 2.0)
   (-
    (fma
     -0.16666666666666666
     (* n0_i (pow (- 1.0 u) 3.0))
     (* -0.16666666666666666 (* n1_i (pow u 3.0))))
    (fma
     -0.16666666666666666
     (* n0_i (- 1.0 u))
     (* -0.16666666666666666 (* n1_i u))))))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return fmaf(n0_i, (1.0f - u), fmaf(n1_i, u, (powf(normAngle, 2.0f) * (fmaf(-0.16666666666666666f, (n0_i * powf((1.0f - u), 3.0f)), (-0.16666666666666666f * (n1_i * powf(u, 3.0f)))) - fmaf(-0.16666666666666666f, (n0_i * (1.0f - u)), (-0.16666666666666666f * (n1_i * u)))))));
}
function code(normAngle, u, n0_i, n1_i)
	return fma(n0_i, Float32(Float32(1.0) - u), fma(n1_i, u, Float32((normAngle ^ Float32(2.0)) * Float32(fma(Float32(-0.16666666666666666), Float32(n0_i * (Float32(Float32(1.0) - u) ^ Float32(3.0))), Float32(Float32(-0.16666666666666666) * Float32(n1_i * (u ^ Float32(3.0))))) - fma(Float32(-0.16666666666666666), Float32(n0_i * Float32(Float32(1.0) - u)), Float32(Float32(-0.16666666666666666) * Float32(n1_i * u)))))))
end
\mathsf{fma}\left(n0\_i, 1 - u, \mathsf{fma}\left(n1\_i, u, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot {\left(1 - u\right)}^{3}, -0.16666666666666666 \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot \left(1 - u\right), -0.16666666666666666 \cdot \left(n1\_i \cdot u\right)\right)\right)\right)\right)
Derivation
  1. Initial program 97.2%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Taylor expanded in normAngle around 0

    \[\leadsto n0\_i \cdot \left(1 - u\right) + \left(n1\_i \cdot u + {normAngle}^{2} \cdot \left(\left(\frac{-1}{6} \cdot \left(n0\_i \cdot {\left(1 - u\right)}^{3}\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \left(\frac{-1}{6} \cdot \left(n0\_i \cdot \left(1 - u\right)\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot u\right)\right)\right)\right) \]
  3. Applied rewrites98.9%

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \mathsf{fma}\left(n1\_i, u, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot {\left(1 - u\right)}^{3}, -0.16666666666666666 \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot \left(1 - u\right), -0.16666666666666666 \cdot \left(n1\_i \cdot u\right)\right)\right)\right)\right) \]
  4. Add Preprocessing

Alternative 2: 98.9% accurate, 5.1× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[n0\_i + u \cdot \mathsf{fma}\left(\mathsf{fma}\left(u, -0.5 \cdot n0\_i, \mathsf{fma}\left(n0\_i, 0.3333333333333333, n1\_i \cdot 0.16666666666666666\right)\right), normAngle \cdot normAngle, n1\_i - n0\_i\right) \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (+
 n0_i
 (*
  u
  (fma
   (fma
    u
    (* -0.5 n0_i)
    (fma n0_i 0.3333333333333333 (* n1_i 0.16666666666666666)))
   (* normAngle normAngle)
   (- n1_i n0_i)))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return n0_i + (u * fmaf(fmaf(u, (-0.5f * n0_i), fmaf(n0_i, 0.3333333333333333f, (n1_i * 0.16666666666666666f))), (normAngle * normAngle), (n1_i - n0_i)));
}
function code(normAngle, u, n0_i, n1_i)
	return Float32(n0_i + Float32(u * fma(fma(u, Float32(Float32(-0.5) * n0_i), fma(n0_i, Float32(0.3333333333333333), Float32(n1_i * Float32(0.16666666666666666)))), Float32(normAngle * normAngle), Float32(n1_i - n0_i))))
end
n0\_i + u \cdot \mathsf{fma}\left(\mathsf{fma}\left(u, -0.5 \cdot n0\_i, \mathsf{fma}\left(n0\_i, 0.3333333333333333, n1\_i \cdot 0.16666666666666666\right)\right), normAngle \cdot normAngle, n1\_i - n0\_i\right)
Derivation
  1. Initial program 97.2%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Taylor expanded in u around 0

    \[\leadsto n0\_i + u \cdot \left(-1 \cdot \frac{n0\_i \cdot \left(normAngle \cdot \cos normAngle\right)}{\sin normAngle} + \left(\frac{-1}{2} \cdot \left(n0\_i \cdot \left({normAngle}^{2} \cdot u\right)\right) + \frac{n1\_i \cdot normAngle}{\sin normAngle}\right)\right) \]
  3. Applied rewrites88.4%

    \[\leadsto n0\_i + u \cdot \mathsf{fma}\left(-1, \frac{n0\_i \cdot \left(normAngle \cdot \cos normAngle\right)}{\sin normAngle}, \mathsf{fma}\left(-0.5, n0\_i \cdot \left({normAngle}^{2} \cdot u\right), \frac{n1\_i \cdot normAngle}{\sin normAngle}\right)\right) \]
  4. Taylor expanded in normAngle around 0

    \[\leadsto n0\_i + u \cdot \left(n1\_i + \left(-1 \cdot n0\_i + {normAngle}^{2} \cdot \left(\left(-1 \cdot \left(\frac{-1}{2} \cdot n0\_i - \frac{-1}{6} \cdot n0\_i\right) + \frac{-1}{2} \cdot \left(n0\_i \cdot u\right)\right) - \frac{-1}{6} \cdot n1\_i\right)\right)\right) \]
  5. Applied rewrites98.9%

    \[\leadsto n0\_i + u \cdot \left(n1\_i + \mathsf{fma}\left(-1, n0\_i, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-1, -0.5 \cdot n0\_i - -0.16666666666666666 \cdot n0\_i, -0.5 \cdot \left(n0\_i \cdot u\right)\right) - -0.16666666666666666 \cdot n1\_i\right)\right)\right) \]
  6. Applied rewrites98.9%

    \[\leadsto n0\_i + u \cdot \mathsf{fma}\left(\mathsf{fma}\left(u, -0.5 \cdot n0\_i, \mathsf{fma}\left(n0\_i, 0.3333333333333333, n1\_i \cdot 0.16666666666666666\right)\right), normAngle \cdot normAngle, n1\_i - n0\_i\right) \]
  7. Add Preprocessing

Alternative 3: 98.9% accurate, 6.7× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[n0\_i + u \cdot \mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, n1\_i, 0.3333333333333333 \cdot n0\_i\right), normAngle \cdot normAngle, n1\_i - n0\_i\right) \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (+
 n0_i
 (*
  u
  (fma
   (fma 0.16666666666666666 n1_i (* 0.3333333333333333 n0_i))
   (* normAngle normAngle)
   (- n1_i n0_i)))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return n0_i + (u * fmaf(fmaf(0.16666666666666666f, n1_i, (0.3333333333333333f * n0_i)), (normAngle * normAngle), (n1_i - n0_i)));
}
function code(normAngle, u, n0_i, n1_i)
	return Float32(n0_i + Float32(u * fma(fma(Float32(0.16666666666666666), n1_i, Float32(Float32(0.3333333333333333) * n0_i)), Float32(normAngle * normAngle), Float32(n1_i - n0_i))))
end
n0\_i + u \cdot \mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, n1\_i, 0.3333333333333333 \cdot n0\_i\right), normAngle \cdot normAngle, n1\_i - n0\_i\right)
Derivation
  1. Initial program 97.2%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Taylor expanded in u around 0

    \[\leadsto n0\_i + u \cdot \left(-1 \cdot \frac{n0\_i \cdot \left(normAngle \cdot \cos normAngle\right)}{\sin normAngle} + \left(\frac{-1}{2} \cdot \left(n0\_i \cdot \left({normAngle}^{2} \cdot u\right)\right) + \frac{n1\_i \cdot normAngle}{\sin normAngle}\right)\right) \]
  3. Applied rewrites88.4%

    \[\leadsto n0\_i + u \cdot \mathsf{fma}\left(-1, \frac{n0\_i \cdot \left(normAngle \cdot \cos normAngle\right)}{\sin normAngle}, \mathsf{fma}\left(-0.5, n0\_i \cdot \left({normAngle}^{2} \cdot u\right), \frac{n1\_i \cdot normAngle}{\sin normAngle}\right)\right) \]
  4. Taylor expanded in normAngle around 0

    \[\leadsto n0\_i + u \cdot \left(n1\_i + \left(-1 \cdot n0\_i + {normAngle}^{2} \cdot \left(\left(-1 \cdot \left(\frac{-1}{2} \cdot n0\_i - \frac{-1}{6} \cdot n0\_i\right) + \frac{-1}{2} \cdot \left(n0\_i \cdot u\right)\right) - \frac{-1}{6} \cdot n1\_i\right)\right)\right) \]
  5. Applied rewrites98.9%

    \[\leadsto n0\_i + u \cdot \left(n1\_i + \mathsf{fma}\left(-1, n0\_i, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-1, -0.5 \cdot n0\_i - -0.16666666666666666 \cdot n0\_i, -0.5 \cdot \left(n0\_i \cdot u\right)\right) - -0.16666666666666666 \cdot n1\_i\right)\right)\right) \]
  6. Applied rewrites98.9%

    \[\leadsto n0\_i + u \cdot \mathsf{fma}\left(\mathsf{fma}\left(u, -0.5 \cdot n0\_i, \mathsf{fma}\left(n0\_i, 0.3333333333333333, n1\_i \cdot 0.16666666666666666\right)\right), normAngle \cdot normAngle, n1\_i - n0\_i\right) \]
  7. Taylor expanded in u around 0

    \[\leadsto n0\_i + u \cdot \mathsf{fma}\left(\frac{1}{6} \cdot n1\_i + \frac{1}{3} \cdot n0\_i, normAngle \cdot normAngle, n1\_i - n0\_i\right) \]
  8. Applied rewrites98.9%

    \[\leadsto n0\_i + u \cdot \mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, n1\_i, 0.3333333333333333 \cdot n0\_i\right), normAngle \cdot normAngle, n1\_i - n0\_i\right) \]
  9. Add Preprocessing

Alternative 4: 98.5% accurate, 7.2× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\mathsf{fma}\left(n0\_i, 1 - u, u \cdot \left(n1\_i - \left(-0.16666666666666666 \cdot n1\_i\right) \cdot \left(normAngle \cdot normAngle\right)\right)\right) \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (fma
 n0_i
 (- 1.0 u)
 (*
  u
  (- n1_i (* (* -0.16666666666666666 n1_i) (* normAngle normAngle))))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return fmaf(n0_i, (1.0f - u), (u * (n1_i - ((-0.16666666666666666f * n1_i) * (normAngle * normAngle)))));
}
function code(normAngle, u, n0_i, n1_i)
	return fma(n0_i, Float32(Float32(1.0) - u), Float32(u * Float32(n1_i - Float32(Float32(Float32(-0.16666666666666666) * n1_i) * Float32(normAngle * normAngle)))))
end
\mathsf{fma}\left(n0\_i, 1 - u, u \cdot \left(n1\_i - \left(-0.16666666666666666 \cdot n1\_i\right) \cdot \left(normAngle \cdot normAngle\right)\right)\right)
Derivation
  1. Initial program 97.2%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Taylor expanded in normAngle around 0

    \[\leadsto n0\_i \cdot \left(1 - u\right) + \left(n1\_i \cdot u + {normAngle}^{2} \cdot \left(\left(\frac{-1}{6} \cdot \left(n0\_i \cdot {\left(1 - u\right)}^{3}\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \left(\frac{-1}{6} \cdot \left(n0\_i \cdot \left(1 - u\right)\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot u\right)\right)\right)\right) \]
  3. Applied rewrites98.9%

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \mathsf{fma}\left(n1\_i, u, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot {\left(1 - u\right)}^{3}, -0.16666666666666666 \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot \left(1 - u\right), -0.16666666666666666 \cdot \left(n1\_i \cdot u\right)\right)\right)\right)\right) \]
  4. Taylor expanded in u around 0

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, u \cdot \left(n1\_i + {normAngle}^{2} \cdot \left(\frac{1}{2} \cdot n0\_i - \left(\frac{-1}{6} \cdot n1\_i + \frac{1}{6} \cdot n0\_i\right)\right)\right)\right) \]
  5. Applied rewrites98.7%

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, u \cdot \left(n1\_i + {normAngle}^{2} \cdot \left(0.5 \cdot n0\_i - \mathsf{fma}\left(-0.16666666666666666, n1\_i, 0.16666666666666666 \cdot n0\_i\right)\right)\right)\right) \]
  6. Applied rewrites98.7%

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, u \cdot \left(n1\_i - \left(-0.16666666666666666 \cdot n1\_i - n0\_i \cdot 0.3333333333333333\right) \cdot \left(normAngle \cdot normAngle\right)\right)\right) \]
  7. Taylor expanded in n0_i around 0

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, u \cdot \left(n1\_i - \left(\frac{-1}{6} \cdot n1\_i\right) \cdot \left(normAngle \cdot normAngle\right)\right)\right) \]
  8. Applied rewrites98.5%

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, u \cdot \left(n1\_i - \left(-0.16666666666666666 \cdot n1\_i\right) \cdot \left(normAngle \cdot normAngle\right)\right)\right) \]
  9. Add Preprocessing

Alternative 5: 98.0% accurate, 18.2× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[n0\_i + u \cdot \left(n1\_i - n0\_i\right) \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (+ 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)
use fmin_fmax_functions
    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
n0\_i + u \cdot \left(n1\_i - n0\_i\right)
Derivation
  1. Initial program 97.2%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Taylor expanded in u around 0

    \[\leadsto n0\_i + u \cdot \left(-1 \cdot \frac{n0\_i \cdot \left(normAngle \cdot \cos normAngle\right)}{\sin normAngle} + \frac{n1\_i \cdot normAngle}{\sin normAngle}\right) \]
  3. Applied rewrites88.3%

    \[\leadsto n0\_i + u \cdot \mathsf{fma}\left(-1, \frac{n0\_i \cdot \left(normAngle \cdot \cos normAngle\right)}{\sin normAngle}, \frac{n1\_i \cdot normAngle}{\sin normAngle}\right) \]
  4. Taylor expanded in normAngle around 0

    \[\leadsto n0\_i + u \cdot \left(n1\_i + -1 \cdot n0\_i\right) \]
  5. Applied rewrites98.0%

    \[\leadsto n0\_i + u \cdot \left(n1\_i + -1 \cdot n0\_i\right) \]
  6. Applied rewrites98.0%

    \[\leadsto n0\_i + u \cdot \left(n1\_i - n0\_i\right) \]
  7. Add Preprocessing

Alternative 6: 83.9% accurate, 16.1× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\begin{array}{l} \mathbf{if}\;n0\_i \leq 3.5105799560744555 \cdot 10^{-13}:\\ \;\;\;\;n0\_i + u \cdot n1\_i\\ \mathbf{else}:\\ \;\;\;\;n0\_i \cdot \left(1 - u\right)\\ \end{array} \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (if (<= n0_i 3.5105799560744555e-13)
  (+ n0_i (* u n1_i))
  (* n0_i (- 1.0 u))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float tmp;
	if (n0_i <= 3.5105799560744555e-13f) {
		tmp = n0_i + (u * n1_i);
	} else {
		tmp = n0_i * (1.0f - u);
	}
	return tmp;
}
real(4) function code(normangle, u, n0_i, n1_i)
use fmin_fmax_functions
    real(4), intent (in) :: normangle
    real(4), intent (in) :: u
    real(4), intent (in) :: n0_i
    real(4), intent (in) :: n1_i
    real(4) :: tmp
    if (n0_i <= 3.5105799560744555e-13) then
        tmp = n0_i + (u * n1_i)
    else
        tmp = n0_i * (1.0e0 - u)
    end if
    code = tmp
end function
function code(normAngle, u, n0_i, n1_i)
	tmp = Float32(0.0)
	if (n0_i <= Float32(3.5105799560744555e-13))
		tmp = Float32(n0_i + Float32(u * n1_i));
	else
		tmp = Float32(n0_i * Float32(Float32(1.0) - u));
	end
	return tmp
end
function tmp_2 = code(normAngle, u, n0_i, n1_i)
	tmp = single(0.0);
	if (n0_i <= single(3.5105799560744555e-13))
		tmp = n0_i + (u * n1_i);
	else
		tmp = n0_i * (single(1.0) - u);
	end
	tmp_2 = tmp;
end
\begin{array}{l}
\mathbf{if}\;n0\_i \leq 3.5105799560744555 \cdot 10^{-13}:\\
\;\;\;\;n0\_i + u \cdot n1\_i\\

\mathbf{else}:\\
\;\;\;\;n0\_i \cdot \left(1 - u\right)\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n0_i < 3.51057996e-13

    1. Initial program 97.2%

      \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    2. Taylor expanded in u around 0

      \[\leadsto n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    3. Applied rewrites81.2%

      \[\leadsto n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    4. Taylor expanded in normAngle around 0

      \[\leadsto n0\_i + u \cdot n1\_i \]
    5. Applied rewrites81.7%

      \[\leadsto n0\_i + u \cdot n1\_i \]

    if 3.51057996e-13 < n0_i

    1. Initial program 97.2%

      \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    2. Taylor expanded in normAngle around 0

      \[\leadsto n0\_i \cdot \left(1 - u\right) + \left(n1\_i \cdot u + {normAngle}^{2} \cdot \left(\left(\frac{-1}{6} \cdot \left(n0\_i \cdot {\left(1 - u\right)}^{3}\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \left(\frac{-1}{6} \cdot \left(n0\_i \cdot \left(1 - u\right)\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot u\right)\right)\right)\right) \]
    3. Applied rewrites98.9%

      \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \mathsf{fma}\left(n1\_i, u, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot {\left(1 - u\right)}^{3}, -0.16666666666666666 \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot \left(1 - u\right), -0.16666666666666666 \cdot \left(n1\_i \cdot u\right)\right)\right)\right)\right) \]
    4. Taylor expanded in n0_i around inf

      \[\leadsto n0\_i \cdot \left(\left(1 + {normAngle}^{2} \cdot \left(\frac{-1}{6} \cdot {\left(1 - u\right)}^{3} - \frac{-1}{6} \cdot \left(1 - u\right)\right)\right) - u\right) \]
    5. Applied rewrites59.0%

      \[\leadsto n0\_i \cdot \left(\left(1 + {normAngle}^{2} \cdot \left(-0.16666666666666666 \cdot {\left(1 - u\right)}^{3} - -0.16666666666666666 \cdot \left(1 - u\right)\right)\right) - u\right) \]
    6. Taylor expanded in normAngle around 0

      \[\leadsto n0\_i \cdot \left(1 - u\right) \]
    7. Applied rewrites58.8%

      \[\leadsto n0\_i \cdot \left(1 - u\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 7: 58.8% accurate, 25.4× speedup?

\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\pi}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[n0\_i \cdot \left(1 - u\right) \]
(FPCore (normAngle u n0_i n1_i)
  :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)))
  (* n0_i (- 1.0 u)))
float code(float normAngle, float u, float n0_i, float n1_i) {
	return n0_i * (1.0f - u);
}
real(4) function code(normangle, u, n0_i, n1_i)
use fmin_fmax_functions
    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 * (1.0e0 - u)
end function
function code(normAngle, u, n0_i, n1_i)
	return Float32(n0_i * Float32(Float32(1.0) - u))
end
function tmp = code(normAngle, u, n0_i, n1_i)
	tmp = n0_i * (single(1.0) - u);
end
n0\_i \cdot \left(1 - u\right)
Derivation
  1. Initial program 97.2%

    \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
  2. Taylor expanded in normAngle around 0

    \[\leadsto n0\_i \cdot \left(1 - u\right) + \left(n1\_i \cdot u + {normAngle}^{2} \cdot \left(\left(\frac{-1}{6} \cdot \left(n0\_i \cdot {\left(1 - u\right)}^{3}\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \left(\frac{-1}{6} \cdot \left(n0\_i \cdot \left(1 - u\right)\right) + \frac{-1}{6} \cdot \left(n1\_i \cdot u\right)\right)\right)\right) \]
  3. Applied rewrites98.9%

    \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \mathsf{fma}\left(n1\_i, u, {normAngle}^{2} \cdot \left(\mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot {\left(1 - u\right)}^{3}, -0.16666666666666666 \cdot \left(n1\_i \cdot {u}^{3}\right)\right) - \mathsf{fma}\left(-0.16666666666666666, n0\_i \cdot \left(1 - u\right), -0.16666666666666666 \cdot \left(n1\_i \cdot u\right)\right)\right)\right)\right) \]
  4. Taylor expanded in n0_i around inf

    \[\leadsto n0\_i \cdot \left(\left(1 + {normAngle}^{2} \cdot \left(\frac{-1}{6} \cdot {\left(1 - u\right)}^{3} - \frac{-1}{6} \cdot \left(1 - u\right)\right)\right) - u\right) \]
  5. Applied rewrites59.0%

    \[\leadsto n0\_i \cdot \left(\left(1 + {normAngle}^{2} \cdot \left(-0.16666666666666666 \cdot {\left(1 - u\right)}^{3} - -0.16666666666666666 \cdot \left(1 - u\right)\right)\right) - u\right) \]
  6. Taylor expanded in normAngle around 0

    \[\leadsto n0\_i \cdot \left(1 - u\right) \]
  7. Applied rewrites58.8%

    \[\leadsto n0\_i \cdot \left(1 - u\right) \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2026089 +o generate:egglog
(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)))