Curve intersection, scale width based on ribbon orientation

Percentage Accurate: 97.2% → 98.0%
Time: 11.2s
Alternatives: 4
Speedup: 38.3×

Specification

?
\[\left(\left(\left(0 \leq normAngle \land normAngle \leq \frac{\mathsf{PI}\left(\right)}{2}\right) \land \left(-1 \leq n0\_i \land n0\_i \leq 1\right)\right) \land \left(-1 \leq n1\_i \land n1\_i \leq 1\right)\right) \land \left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right)\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i \end{array} \end{array} \]
(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 4 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?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{\sin normAngle}\\ \left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot t\_0\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot t\_0\right) \cdot n1\_i \end{array} \end{array} \]
(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: 98.0% accurate, 38.3× 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 97.6%

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

    \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
  4. Step-by-step derivation
    1. lower-fma.f32N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(n0\_i, 1 - u, n1\_i \cdot u\right)} \]
    2. lower--.f32N/A

      \[\leadsto \mathsf{fma}\left(n0\_i, \color{blue}{1 - u}, n1\_i \cdot u\right) \]
    3. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \color{blue}{u \cdot n1\_i}\right) \]
    4. lower-*.f3248.4

      \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \color{blue}{u \cdot n1\_i}\right) \]
  5. Applied rewrites48.3%

    \[\leadsto \color{blue}{\mathsf{fma}\left(n0\_i, 1 - u, u \cdot n1\_i\right)} \]
  6. Step-by-step derivation
    1. lift--.f32N/A

      \[\leadsto n0\_i \cdot \color{blue}{\left(1 - u\right)} + u \cdot n1\_i \]
    2. lift-*.f32N/A

      \[\leadsto n0\_i \cdot \left(1 - u\right) + \color{blue}{u \cdot n1\_i} \]
    3. *-commutativeN/A

      \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + u \cdot n1\_i \]
    4. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i} + u \cdot n1\_i \]
    5. lower-+.f3298.2

      \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i + u \cdot n1\_i} \]
  7. Applied rewrites98.2%

    \[\leadsto \color{blue}{\left(1 - u\right) \cdot n0\_i + u \cdot n1\_i} \]
  8. Step-by-step derivation
    1. sub-negN/A

      \[\leadsto \color{blue}{\left(1 + \left(\mathsf{neg}\left(u\right)\right)\right)} \cdot n0\_i + u \cdot n1\_i \]
    2. lift-neg.f32N/A

      \[\leadsto \left(1 + \color{blue}{\left(\mathsf{neg}\left(u\right)\right)}\right) \cdot n0\_i + u \cdot n1\_i \]
    3. +-commutativeN/A

      \[\leadsto \color{blue}{\left(\left(\mathsf{neg}\left(u\right)\right) + 1\right)} \cdot n0\_i + u \cdot n1\_i \]
    4. distribute-rgt1-inN/A

      \[\leadsto \color{blue}{\left(n0\_i + \left(\mathsf{neg}\left(u\right)\right) \cdot n0\_i\right)} + u \cdot n1\_i \]
    5. lift-neg.f32N/A

      \[\leadsto \left(n0\_i + \color{blue}{\left(\mathsf{neg}\left(u\right)\right)} \cdot n0\_i\right) + u \cdot n1\_i \]
    6. distribute-lft-neg-outN/A

      \[\leadsto \left(n0\_i + \color{blue}{\left(\mathsf{neg}\left(u \cdot n0\_i\right)\right)}\right) + u \cdot n1\_i \]
    7. unsub-negN/A

      \[\leadsto \color{blue}{\left(n0\_i - u \cdot n0\_i\right)} + u \cdot n1\_i \]
    8. lower--.f32N/A

      \[\leadsto \color{blue}{\left(n0\_i - u \cdot n0\_i\right)} + u \cdot n1\_i \]
    9. lower-*.f3298.4

      \[\leadsto \left(n0\_i - \color{blue}{u \cdot n0\_i}\right) + u \cdot n1\_i \]
  9. Applied rewrites98.4%

    \[\leadsto \color{blue}{\left(n0\_i - u \cdot n0\_i\right)} + u \cdot n1\_i \]
  10. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \left(n0\_i - \color{blue}{u \cdot n0\_i}\right) + u \cdot n1\_i \]
    2. lift-*.f32N/A

      \[\leadsto \left(n0\_i - u \cdot n0\_i\right) + \color{blue}{u \cdot n1\_i} \]
    3. associate-+l-N/A

      \[\leadsto \color{blue}{n0\_i - \left(u \cdot n0\_i - u \cdot n1\_i\right)} \]
    4. lower--.f32N/A

      \[\leadsto \color{blue}{n0\_i - \left(u \cdot n0\_i - u \cdot n1\_i\right)} \]
    5. lift-*.f32N/A

      \[\leadsto n0\_i - \left(\color{blue}{u \cdot n0\_i} - u \cdot n1\_i\right) \]
    6. lift-*.f32N/A

      \[\leadsto n0\_i - \left(u \cdot n0\_i - \color{blue}{u \cdot n1\_i}\right) \]
    7. distribute-lft-out--N/A

      \[\leadsto n0\_i - \color{blue}{u \cdot \left(n0\_i - n1\_i\right)} \]
    8. lower-*.f32N/A

      \[\leadsto n0\_i - \color{blue}{u \cdot \left(n0\_i - n1\_i\right)} \]
    9. lower--.f3298.5

      \[\leadsto n0\_i - u \cdot \color{blue}{\left(n0\_i - n1\_i\right)} \]
  11. Applied rewrites98.5%

    \[\leadsto \color{blue}{n0\_i - u \cdot \left(n0\_i - n1\_i\right)} \]
  12. Final simplification98.5%

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

Alternative 2: 70.5% accurate, 21.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := n0\_i \cdot \left(1 - u\right)\\ \mathbf{if}\;n0\_i \leq -1.4999999523982838 \cdot 10^{-21}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;n0\_i \leq 4.999999841327613 \cdot 10^{-22}:\\ \;\;\;\;u \cdot n1\_i\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (let* ((t_0 (* n0_i (- 1.0 u))))
   (if (<= n0_i -1.4999999523982838e-21)
     t_0
     (if (<= n0_i 4.999999841327613e-22) (* u n1_i) t_0))))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float t_0 = n0_i * (1.0f - u);
	float tmp;
	if (n0_i <= -1.4999999523982838e-21f) {
		tmp = t_0;
	} else if (n0_i <= 4.999999841327613e-22f) {
		tmp = u * n1_i;
	} else {
		tmp = t_0;
	}
	return tmp;
}
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
    real(4) :: tmp
    t_0 = n0_i * (1.0e0 - u)
    if (n0_i <= (-1.4999999523982838e-21)) then
        tmp = t_0
    else if (n0_i <= 4.999999841327613e-22) then
        tmp = u * n1_i
    else
        tmp = t_0
    end if
    code = tmp
end function
function code(normAngle, u, n0_i, n1_i)
	t_0 = Float32(n0_i * Float32(Float32(1.0) - u))
	tmp = Float32(0.0)
	if (n0_i <= Float32(-1.4999999523982838e-21))
		tmp = t_0;
	elseif (n0_i <= Float32(4.999999841327613e-22))
		tmp = Float32(u * n1_i);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(normAngle, u, n0_i, n1_i)
	t_0 = n0_i * (single(1.0) - u);
	tmp = single(0.0);
	if (n0_i <= single(-1.4999999523982838e-21))
		tmp = t_0;
	elseif (n0_i <= single(4.999999841327613e-22))
		tmp = u * n1_i;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := n0\_i \cdot \left(1 - u\right)\\
\mathbf{if}\;n0\_i \leq -1.4999999523982838 \cdot 10^{-21}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;n0\_i \leq 4.999999841327613 \cdot 10^{-22}:\\
\;\;\;\;u \cdot n1\_i\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n0_i < -1.5e-21 or 4.9999998e-22 < n0_i

    1. Initial program 98.4%

      \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    2. Add Preprocessing
    3. Taylor expanded in n0_i around inf

      \[\leadsto \color{blue}{\frac{n0\_i \cdot \sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
    4. Step-by-step derivation
      1. associate-/l*N/A

        \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      2. lower-*.f32N/A

        \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      3. lower-/.f32N/A

        \[\leadsto n0\_i \cdot \color{blue}{\frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      4. lower-sin.f32N/A

        \[\leadsto n0\_i \cdot \frac{\color{blue}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}}{\sin normAngle} \]
      5. *-commutativeN/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\left(1 - u\right) \cdot normAngle\right)}}{\sin normAngle} \]
      6. sub-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(u\right)\right)\right)} \cdot normAngle\right)}{\sin normAngle} \]
      7. +-commutativeN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(\left(\mathsf{neg}\left(u\right)\right) + 1\right)} \cdot normAngle\right)}{\sin normAngle} \]
      8. distribute-lft1-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\left(\mathsf{neg}\left(u\right)\right) \cdot normAngle + normAngle\right)}}{\sin normAngle} \]
      9. distribute-lft-neg-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(\mathsf{neg}\left(u \cdot normAngle\right)\right)} + normAngle\right)}{\sin normAngle} \]
      10. distribute-rgt-neg-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{u \cdot \left(\mathsf{neg}\left(normAngle\right)\right)} + normAngle\right)}{\sin normAngle} \]
      11. mul-1-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(u \cdot \color{blue}{\left(-1 \cdot normAngle\right)} + normAngle\right)}{\sin normAngle} \]
      12. lower-fma.f32N/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\mathsf{fma}\left(u, -1 \cdot normAngle, normAngle\right)\right)}}{\sin normAngle} \]
      13. mul-1-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, \color{blue}{\mathsf{neg}\left(normAngle\right)}, normAngle\right)\right)}{\sin normAngle} \]
      14. lower-neg.f32N/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, \color{blue}{\mathsf{neg}\left(normAngle\right)}, normAngle\right)\right)}{\sin normAngle} \]
      15. lower-sin.f3261.7

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, -normAngle, normAngle\right)\right)}{\color{blue}{\sin normAngle}} \]
    5. Applied rewrites61.7%

      \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, -normAngle, normAngle\right)\right)}{\sin normAngle}} \]
    6. Taylor expanded in normAngle around 0

      \[\leadsto n0\_i \cdot \color{blue}{\left(1 + -1 \cdot u\right)} \]
    7. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto n0\_i \cdot \left(1 + \color{blue}{\left(\mathsf{neg}\left(u\right)\right)}\right) \]
      2. sub-negN/A

        \[\leadsto n0\_i \cdot \color{blue}{\left(1 - u\right)} \]
      3. lower--.f3286.1

        \[\leadsto n0\_i \cdot \color{blue}{\left(1 - u\right)} \]
    8. Applied rewrites86.1%

      \[\leadsto n0\_i \cdot \color{blue}{\left(1 - u\right)} \]

    if -1.5e-21 < n0_i < 4.9999998e-22

    1. Initial program 96.8%

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

      \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
    4. Step-by-step derivation
      1. lower-fma.f32N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(n0\_i, 1 - u, n1\_i \cdot u\right)} \]
      2. lower--.f32N/A

        \[\leadsto \mathsf{fma}\left(n0\_i, \color{blue}{1 - u}, n1\_i \cdot u\right) \]
      3. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \color{blue}{u \cdot n1\_i}\right) \]
      4. lower-*.f3229.1

        \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \color{blue}{u \cdot n1\_i}\right) \]
    5. Applied rewrites28.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(n0\_i, 1 - u, u \cdot n1\_i\right)} \]
    6. Taylor expanded in n0_i around 0

      \[\leadsto \color{blue}{n1\_i \cdot u} \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{u \cdot n1\_i} \]
      2. lower-*.f3264.0

        \[\leadsto \color{blue}{u \cdot n1\_i} \]
    8. Applied rewrites64.0%

      \[\leadsto \color{blue}{u \cdot n1\_i} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 60.6% accurate, 25.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n0\_i \leq -1.4999999523982838 \cdot 10^{-21}:\\ \;\;\;\;n0\_i\\ \mathbf{elif}\;n0\_i \leq 4.999999841327613 \cdot 10^{-22}:\\ \;\;\;\;u \cdot n1\_i\\ \mathbf{else}:\\ \;\;\;\;n0\_i\\ \end{array} \end{array} \]
(FPCore (normAngle u n0_i n1_i)
 :precision binary32
 (if (<= n0_i -1.4999999523982838e-21)
   n0_i
   (if (<= n0_i 4.999999841327613e-22) (* u n1_i) n0_i)))
float code(float normAngle, float u, float n0_i, float n1_i) {
	float tmp;
	if (n0_i <= -1.4999999523982838e-21f) {
		tmp = n0_i;
	} else if (n0_i <= 4.999999841327613e-22f) {
		tmp = u * n1_i;
	} else {
		tmp = n0_i;
	}
	return tmp;
}
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) :: tmp
    if (n0_i <= (-1.4999999523982838e-21)) then
        tmp = n0_i
    else if (n0_i <= 4.999999841327613e-22) then
        tmp = u * n1_i
    else
        tmp = n0_i
    end if
    code = tmp
end function
function code(normAngle, u, n0_i, n1_i)
	tmp = Float32(0.0)
	if (n0_i <= Float32(-1.4999999523982838e-21))
		tmp = n0_i;
	elseif (n0_i <= Float32(4.999999841327613e-22))
		tmp = Float32(u * n1_i);
	else
		tmp = n0_i;
	end
	return tmp
end
function tmp_2 = code(normAngle, u, n0_i, n1_i)
	tmp = single(0.0);
	if (n0_i <= single(-1.4999999523982838e-21))
		tmp = n0_i;
	elseif (n0_i <= single(4.999999841327613e-22))
		tmp = u * n1_i;
	else
		tmp = n0_i;
	end
	tmp_2 = tmp;
end
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;n0\_i \leq -1.4999999523982838 \cdot 10^{-21}:\\
\;\;\;\;n0\_i\\

\mathbf{elif}\;n0\_i \leq 4.999999841327613 \cdot 10^{-22}:\\
\;\;\;\;u \cdot n1\_i\\

\mathbf{else}:\\
\;\;\;\;n0\_i\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n0_i < -1.5e-21 or 4.9999998e-22 < n0_i

    1. Initial program 98.4%

      \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    2. Add Preprocessing
    3. Taylor expanded in n0_i around inf

      \[\leadsto \color{blue}{\frac{n0\_i \cdot \sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
    4. Step-by-step derivation
      1. associate-/l*N/A

        \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      2. lower-*.f32N/A

        \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      3. lower-/.f32N/A

        \[\leadsto n0\_i \cdot \color{blue}{\frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      4. lower-sin.f32N/A

        \[\leadsto n0\_i \cdot \frac{\color{blue}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}}{\sin normAngle} \]
      5. *-commutativeN/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\left(1 - u\right) \cdot normAngle\right)}}{\sin normAngle} \]
      6. sub-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(u\right)\right)\right)} \cdot normAngle\right)}{\sin normAngle} \]
      7. +-commutativeN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(\left(\mathsf{neg}\left(u\right)\right) + 1\right)} \cdot normAngle\right)}{\sin normAngle} \]
      8. distribute-lft1-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\left(\mathsf{neg}\left(u\right)\right) \cdot normAngle + normAngle\right)}}{\sin normAngle} \]
      9. distribute-lft-neg-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(\mathsf{neg}\left(u \cdot normAngle\right)\right)} + normAngle\right)}{\sin normAngle} \]
      10. distribute-rgt-neg-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{u \cdot \left(\mathsf{neg}\left(normAngle\right)\right)} + normAngle\right)}{\sin normAngle} \]
      11. mul-1-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(u \cdot \color{blue}{\left(-1 \cdot normAngle\right)} + normAngle\right)}{\sin normAngle} \]
      12. lower-fma.f32N/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\mathsf{fma}\left(u, -1 \cdot normAngle, normAngle\right)\right)}}{\sin normAngle} \]
      13. mul-1-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, \color{blue}{\mathsf{neg}\left(normAngle\right)}, normAngle\right)\right)}{\sin normAngle} \]
      14. lower-neg.f32N/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, \color{blue}{\mathsf{neg}\left(normAngle\right)}, normAngle\right)\right)}{\sin normAngle} \]
      15. lower-sin.f3261.7

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, -normAngle, normAngle\right)\right)}{\color{blue}{\sin normAngle}} \]
    5. Applied rewrites61.7%

      \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, -normAngle, normAngle\right)\right)}{\sin normAngle}} \]
    6. Taylor expanded in u around 0

      \[\leadsto n0\_i \cdot \color{blue}{1} \]
    7. Step-by-step derivation
      1. Applied rewrites67.7%

        \[\leadsto n0\_i \cdot \color{blue}{1} \]
      2. Step-by-step derivation
        1. *-rgt-identity67.7

          \[\leadsto \color{blue}{n0\_i} \]
      3. Applied rewrites67.7%

        \[\leadsto \color{blue}{n0\_i} \]

      if -1.5e-21 < n0_i < 4.9999998e-22

      1. Initial program 96.8%

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

        \[\leadsto \color{blue}{n0\_i \cdot \left(1 - u\right) + n1\_i \cdot u} \]
      4. Step-by-step derivation
        1. lower-fma.f32N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(n0\_i, 1 - u, n1\_i \cdot u\right)} \]
        2. lower--.f32N/A

          \[\leadsto \mathsf{fma}\left(n0\_i, \color{blue}{1 - u}, n1\_i \cdot u\right) \]
        3. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \color{blue}{u \cdot n1\_i}\right) \]
        4. lower-*.f3229.1

          \[\leadsto \mathsf{fma}\left(n0\_i, 1 - u, \color{blue}{u \cdot n1\_i}\right) \]
      5. Applied rewrites28.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(n0\_i, 1 - u, u \cdot n1\_i\right)} \]
      6. Taylor expanded in n0_i around 0

        \[\leadsto \color{blue}{n1\_i \cdot u} \]
      7. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{u \cdot n1\_i} \]
        2. lower-*.f3264.0

          \[\leadsto \color{blue}{u \cdot n1\_i} \]
      8. Applied rewrites64.0%

        \[\leadsto \color{blue}{u \cdot n1\_i} \]
    8. Recombined 2 regimes into one program.
    9. Add Preprocessing

    Alternative 4: 47.5% accurate, 459.0× speedup?

    \[\begin{array}{l} \\ n0\_i \end{array} \]
    (FPCore (normAngle u n0_i n1_i) :precision binary32 n0_i)
    float code(float normAngle, float u, float n0_i, float n1_i) {
    	return 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
    end function
    
    function code(normAngle, u, n0_i, n1_i)
    	return n0_i
    end
    
    function tmp = code(normAngle, u, n0_i, n1_i)
    	tmp = n0_i;
    end
    
    \begin{array}{l}
    
    \\
    n0\_i
    \end{array}
    
    Derivation
    1. Initial program 97.6%

      \[\left(\sin \left(\left(1 - u\right) \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n0\_i + \left(\sin \left(u \cdot normAngle\right) \cdot \frac{1}{\sin normAngle}\right) \cdot n1\_i \]
    2. Add Preprocessing
    3. Taylor expanded in n0_i around inf

      \[\leadsto \color{blue}{\frac{n0\_i \cdot \sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
    4. Step-by-step derivation
      1. associate-/l*N/A

        \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      2. lower-*.f32N/A

        \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      3. lower-/.f32N/A

        \[\leadsto n0\_i \cdot \color{blue}{\frac{\sin \left(normAngle \cdot \left(1 - u\right)\right)}{\sin normAngle}} \]
      4. lower-sin.f32N/A

        \[\leadsto n0\_i \cdot \frac{\color{blue}{\sin \left(normAngle \cdot \left(1 - u\right)\right)}}{\sin normAngle} \]
      5. *-commutativeN/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\left(1 - u\right) \cdot normAngle\right)}}{\sin normAngle} \]
      6. sub-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(1 + \left(\mathsf{neg}\left(u\right)\right)\right)} \cdot normAngle\right)}{\sin normAngle} \]
      7. +-commutativeN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(\left(\mathsf{neg}\left(u\right)\right) + 1\right)} \cdot normAngle\right)}{\sin normAngle} \]
      8. distribute-lft1-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\left(\mathsf{neg}\left(u\right)\right) \cdot normAngle + normAngle\right)}}{\sin normAngle} \]
      9. distribute-lft-neg-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{\left(\mathsf{neg}\left(u \cdot normAngle\right)\right)} + normAngle\right)}{\sin normAngle} \]
      10. distribute-rgt-neg-inN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\color{blue}{u \cdot \left(\mathsf{neg}\left(normAngle\right)\right)} + normAngle\right)}{\sin normAngle} \]
      11. mul-1-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(u \cdot \color{blue}{\left(-1 \cdot normAngle\right)} + normAngle\right)}{\sin normAngle} \]
      12. lower-fma.f32N/A

        \[\leadsto n0\_i \cdot \frac{\sin \color{blue}{\left(\mathsf{fma}\left(u, -1 \cdot normAngle, normAngle\right)\right)}}{\sin normAngle} \]
      13. mul-1-negN/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, \color{blue}{\mathsf{neg}\left(normAngle\right)}, normAngle\right)\right)}{\sin normAngle} \]
      14. lower-neg.f32N/A

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, \color{blue}{\mathsf{neg}\left(normAngle\right)}, normAngle\right)\right)}{\sin normAngle} \]
      15. lower-sin.f3245.6

        \[\leadsto n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, -normAngle, normAngle\right)\right)}{\color{blue}{\sin normAngle}} \]
    5. Applied rewrites45.6%

      \[\leadsto \color{blue}{n0\_i \cdot \frac{\sin \left(\mathsf{fma}\left(u, -normAngle, normAngle\right)\right)}{\sin normAngle}} \]
    6. Taylor expanded in u around 0

      \[\leadsto n0\_i \cdot \color{blue}{1} \]
    7. Step-by-step derivation
      1. Applied rewrites48.4%

        \[\leadsto n0\_i \cdot \color{blue}{1} \]
      2. Step-by-step derivation
        1. *-rgt-identity48.4

          \[\leadsto \color{blue}{n0\_i} \]
      3. Applied rewrites48.4%

        \[\leadsto \color{blue}{n0\_i} \]
      4. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024216 
      (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)))