xlohi (overflows)

Percentage Accurate: 3.1% → 99.0%
Time: 14.7s
Alternatives: 8
Speedup: 7.0×

Specification

?
\[lo < -1 \cdot 10^{+308} \land hi > 10^{+308}\]
\[\begin{array}{l} \\ \frac{x - lo}{hi - lo} \end{array} \]
(FPCore (lo hi x) :precision binary64 (/ (- x lo) (- hi lo)))
double code(double lo, double hi, double x) {
	return (x - lo) / (hi - lo);
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = (x - lo) / (hi - lo)
end function
public static double code(double lo, double hi, double x) {
	return (x - lo) / (hi - lo);
}
def code(lo, hi, x):
	return (x - lo) / (hi - lo)
function code(lo, hi, x)
	return Float64(Float64(x - lo) / Float64(hi - lo))
end
function tmp = code(lo, hi, x)
	tmp = (x - lo) / (hi - lo);
end
code[lo_, hi_, x_] := N[(N[(x - lo), $MachinePrecision] / N[(hi - lo), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x - lo}{hi - lo}
\end{array}

Sampling outcomes in binary64 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: 3.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{x - lo}{hi - lo} \end{array} \]
(FPCore (lo hi x) :precision binary64 (/ (- x lo) (- hi lo)))
double code(double lo, double hi, double x) {
	return (x - lo) / (hi - lo);
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = (x - lo) / (hi - lo)
end function
public static double code(double lo, double hi, double x) {
	return (x - lo) / (hi - lo);
}
def code(lo, hi, x):
	return (x - lo) / (hi - lo)
function code(lo, hi, x)
	return Float64(Float64(x - lo) / Float64(hi - lo))
end
function tmp = code(lo, hi, x)
	tmp = (x - lo) / (hi - lo);
end
code[lo_, hi_, x_] := N[(N[(x - lo), $MachinePrecision] / N[(hi - lo), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x - lo}{hi - lo}
\end{array}

Alternative 1: 99.0% accurate, 0.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := -1 - \frac{hi}{lo}\\ \left({\left(t\_0 \cdot \frac{x}{lo}\right)}^{3} + 1\right) \cdot \frac{1}{\left({\left(\frac{x - hi}{lo}\right)}^{2} + t\_0 \cdot \frac{hi - x}{lo}\right) + 1} \end{array} \end{array} \]
(FPCore (lo hi x)
 :precision binary64
 (let* ((t_0 (- -1.0 (/ hi lo))))
   (*
    (+ (pow (* t_0 (/ x lo)) 3.0) 1.0)
    (/ 1.0 (+ (+ (pow (/ (- x hi) lo) 2.0) (* t_0 (/ (- hi x) lo))) 1.0)))))
double code(double lo, double hi, double x) {
	double t_0 = -1.0 - (hi / lo);
	return (pow((t_0 * (x / lo)), 3.0) + 1.0) * (1.0 / ((pow(((x - hi) / lo), 2.0) + (t_0 * ((hi - x) / lo))) + 1.0));
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    real(8) :: t_0
    t_0 = (-1.0d0) - (hi / lo)
    code = (((t_0 * (x / lo)) ** 3.0d0) + 1.0d0) * (1.0d0 / (((((x - hi) / lo) ** 2.0d0) + (t_0 * ((hi - x) / lo))) + 1.0d0))
end function
public static double code(double lo, double hi, double x) {
	double t_0 = -1.0 - (hi / lo);
	return (Math.pow((t_0 * (x / lo)), 3.0) + 1.0) * (1.0 / ((Math.pow(((x - hi) / lo), 2.0) + (t_0 * ((hi - x) / lo))) + 1.0));
}
def code(lo, hi, x):
	t_0 = -1.0 - (hi / lo)
	return (math.pow((t_0 * (x / lo)), 3.0) + 1.0) * (1.0 / ((math.pow(((x - hi) / lo), 2.0) + (t_0 * ((hi - x) / lo))) + 1.0))
function code(lo, hi, x)
	t_0 = Float64(-1.0 - Float64(hi / lo))
	return Float64(Float64((Float64(t_0 * Float64(x / lo)) ^ 3.0) + 1.0) * Float64(1.0 / Float64(Float64((Float64(Float64(x - hi) / lo) ^ 2.0) + Float64(t_0 * Float64(Float64(hi - x) / lo))) + 1.0)))
end
function tmp = code(lo, hi, x)
	t_0 = -1.0 - (hi / lo);
	tmp = (((t_0 * (x / lo)) ^ 3.0) + 1.0) * (1.0 / (((((x - hi) / lo) ^ 2.0) + (t_0 * ((hi - x) / lo))) + 1.0));
end
code[lo_, hi_, x_] := Block[{t$95$0 = N[(-1.0 - N[(hi / lo), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[N[(t$95$0 * N[(x / lo), $MachinePrecision]), $MachinePrecision], 3.0], $MachinePrecision] + 1.0), $MachinePrecision] * N[(1.0 / N[(N[(N[Power[N[(N[(x - hi), $MachinePrecision] / lo), $MachinePrecision], 2.0], $MachinePrecision] + N[(t$95$0 * N[(N[(hi - x), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := -1 - \frac{hi}{lo}\\
\left({\left(t\_0 \cdot \frac{x}{lo}\right)}^{3} + 1\right) \cdot \frac{1}{\left({\left(\frac{x - hi}{lo}\right)}^{2} + t\_0 \cdot \frac{hi - x}{lo}\right) + 1}
\end{array}
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in lo around inf 0.0%

    \[\leadsto \color{blue}{\left(1 + \left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right)\right) - -1 \cdot \frac{hi}{lo}} \]
  4. Step-by-step derivation
    1. associate--l+0.0%

      \[\leadsto \color{blue}{1 + \left(\left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right) - -1 \cdot \frac{hi}{lo}\right)} \]
    2. +-commutative0.0%

      \[\leadsto 1 + \left(\color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + -1 \cdot \frac{x}{lo}\right)} - -1 \cdot \frac{hi}{lo}\right) \]
    3. associate--l+0.0%

      \[\leadsto 1 + \color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right)} \]
    4. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot x - -1 \cdot hi\right) \cdot hi}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    5. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot \left(x - hi\right)\right)} \cdot hi}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    6. associate-*r*0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{-1 \cdot \left(\left(x - hi\right) \cdot hi\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    7. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{-1 \cdot \color{blue}{\left(hi \cdot \left(x - hi\right)\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    8. associate-*r/0.0%

      \[\leadsto 1 + \left(\color{blue}{-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    9. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + \color{blue}{-1 \cdot \left(\frac{x}{lo} - \frac{hi}{lo}\right)}\right) \]
    10. div-sub0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + -1 \cdot \color{blue}{\frac{x - hi}{lo}}\right) \]
    11. +-commutative0.0%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{x - hi}{lo} + -1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)} \]
    12. mul-1-neg0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{x - hi}{lo} + \color{blue}{\left(-\frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)}\right) \]
  5. Simplified18.8%

    \[\leadsto \color{blue}{1 + \frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)} \]
  6. Step-by-step derivation
    1. flip3-+18.8%

      \[\leadsto \color{blue}{\frac{{1}^{3} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)}} \]
    2. div-inv18.8%

      \[\leadsto \color{blue}{\left({1}^{3} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)}} \]
    3. metadata-eval18.8%

      \[\leadsto \left(\color{blue}{1} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
    4. *-commutative18.8%

      \[\leadsto \left(1 + {\color{blue}{\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
    5. metadata-eval18.8%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{\color{blue}{1} + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
  7. Applied egg-rr18.8%

    \[\leadsto \color{blue}{\left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left({\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{2} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}} \]
  8. Taylor expanded in lo around inf 0.0%

    \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{\frac{{\left(x - hi\right)}^{2}}{{lo}^{2}}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  9. Step-by-step derivation
    1. unpow20.0%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\frac{\color{blue}{\left(x - hi\right) \cdot \left(x - hi\right)}}{{lo}^{2}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
    2. unpow20.0%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\frac{\left(x - hi\right) \cdot \left(x - hi\right)}{\color{blue}{lo \cdot lo}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
    3. times-frac32.2%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{\frac{x - hi}{lo} \cdot \frac{x - hi}{lo}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
    4. unpow232.2%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{{\left(\frac{x - hi}{lo}\right)}^{2}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  10. Simplified32.2%

    \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{{\left(\frac{x - hi}{lo}\right)}^{2}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  11. Taylor expanded in x around inf 99.4%

    \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \color{blue}{\frac{x}{lo}}\right)}^{3}\right) \cdot \frac{1}{1 + \left({\left(\frac{x - hi}{lo}\right)}^{2} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  12. Final simplification99.4%

    \[\leadsto \left({\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x}{lo}\right)}^{3} + 1\right) \cdot \frac{1}{\left({\left(\frac{x - hi}{lo}\right)}^{2} + \left(-1 - \frac{hi}{lo}\right) \cdot \frac{hi - x}{lo}\right) + 1} \]
  13. Add Preprocessing

Alternative 2: 31.8% accurate, 0.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{hi - x}{lo}\\ t_1 := \left(\frac{hi}{lo} + 1\right) \cdot t\_0\\ \left({t\_1}^{3} + 1\right) \cdot \frac{1}{\left(t\_0 \cdot t\_0 - t\_1\right) + 1} \end{array} \end{array} \]
(FPCore (lo hi x)
 :precision binary64
 (let* ((t_0 (/ (- hi x) lo)) (t_1 (* (+ (/ hi lo) 1.0) t_0)))
   (* (+ (pow t_1 3.0) 1.0) (/ 1.0 (+ (- (* t_0 t_0) t_1) 1.0)))))
double code(double lo, double hi, double x) {
	double t_0 = (hi - x) / lo;
	double t_1 = ((hi / lo) + 1.0) * t_0;
	return (pow(t_1, 3.0) + 1.0) * (1.0 / (((t_0 * t_0) - t_1) + 1.0));
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    real(8) :: t_0
    real(8) :: t_1
    t_0 = (hi - x) / lo
    t_1 = ((hi / lo) + 1.0d0) * t_0
    code = ((t_1 ** 3.0d0) + 1.0d0) * (1.0d0 / (((t_0 * t_0) - t_1) + 1.0d0))
end function
public static double code(double lo, double hi, double x) {
	double t_0 = (hi - x) / lo;
	double t_1 = ((hi / lo) + 1.0) * t_0;
	return (Math.pow(t_1, 3.0) + 1.0) * (1.0 / (((t_0 * t_0) - t_1) + 1.0));
}
def code(lo, hi, x):
	t_0 = (hi - x) / lo
	t_1 = ((hi / lo) + 1.0) * t_0
	return (math.pow(t_1, 3.0) + 1.0) * (1.0 / (((t_0 * t_0) - t_1) + 1.0))
function code(lo, hi, x)
	t_0 = Float64(Float64(hi - x) / lo)
	t_1 = Float64(Float64(Float64(hi / lo) + 1.0) * t_0)
	return Float64(Float64((t_1 ^ 3.0) + 1.0) * Float64(1.0 / Float64(Float64(Float64(t_0 * t_0) - t_1) + 1.0)))
end
function tmp = code(lo, hi, x)
	t_0 = (hi - x) / lo;
	t_1 = ((hi / lo) + 1.0) * t_0;
	tmp = ((t_1 ^ 3.0) + 1.0) * (1.0 / (((t_0 * t_0) - t_1) + 1.0));
end
code[lo_, hi_, x_] := Block[{t$95$0 = N[(N[(hi - x), $MachinePrecision] / lo), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(hi / lo), $MachinePrecision] + 1.0), $MachinePrecision] * t$95$0), $MachinePrecision]}, N[(N[(N[Power[t$95$1, 3.0], $MachinePrecision] + 1.0), $MachinePrecision] * N[(1.0 / N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] - t$95$1), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{hi - x}{lo}\\
t_1 := \left(\frac{hi}{lo} + 1\right) \cdot t\_0\\
\left({t\_1}^{3} + 1\right) \cdot \frac{1}{\left(t\_0 \cdot t\_0 - t\_1\right) + 1}
\end{array}
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in lo around inf 0.0%

    \[\leadsto \color{blue}{\left(1 + \left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right)\right) - -1 \cdot \frac{hi}{lo}} \]
  4. Step-by-step derivation
    1. associate--l+0.0%

      \[\leadsto \color{blue}{1 + \left(\left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right) - -1 \cdot \frac{hi}{lo}\right)} \]
    2. +-commutative0.0%

      \[\leadsto 1 + \left(\color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + -1 \cdot \frac{x}{lo}\right)} - -1 \cdot \frac{hi}{lo}\right) \]
    3. associate--l+0.0%

      \[\leadsto 1 + \color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right)} \]
    4. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot x - -1 \cdot hi\right) \cdot hi}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    5. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot \left(x - hi\right)\right)} \cdot hi}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    6. associate-*r*0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{-1 \cdot \left(\left(x - hi\right) \cdot hi\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    7. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{-1 \cdot \color{blue}{\left(hi \cdot \left(x - hi\right)\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    8. associate-*r/0.0%

      \[\leadsto 1 + \left(\color{blue}{-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    9. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + \color{blue}{-1 \cdot \left(\frac{x}{lo} - \frac{hi}{lo}\right)}\right) \]
    10. div-sub0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + -1 \cdot \color{blue}{\frac{x - hi}{lo}}\right) \]
    11. +-commutative0.0%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{x - hi}{lo} + -1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)} \]
    12. mul-1-neg0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{x - hi}{lo} + \color{blue}{\left(-\frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)}\right) \]
  5. Simplified18.8%

    \[\leadsto \color{blue}{1 + \frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)} \]
  6. Step-by-step derivation
    1. flip3-+18.8%

      \[\leadsto \color{blue}{\frac{{1}^{3} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)}} \]
    2. div-inv18.8%

      \[\leadsto \color{blue}{\left({1}^{3} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)}} \]
    3. metadata-eval18.8%

      \[\leadsto \left(\color{blue}{1} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
    4. *-commutative18.8%

      \[\leadsto \left(1 + {\color{blue}{\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
    5. metadata-eval18.8%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{\color{blue}{1} + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
  7. Applied egg-rr18.8%

    \[\leadsto \color{blue}{\left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left({\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{2} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}} \]
  8. Taylor expanded in lo around inf 0.0%

    \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{\frac{{\left(x - hi\right)}^{2}}{{lo}^{2}}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  9. Step-by-step derivation
    1. unpow20.0%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\frac{\color{blue}{\left(x - hi\right) \cdot \left(x - hi\right)}}{{lo}^{2}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
    2. unpow20.0%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\frac{\left(x - hi\right) \cdot \left(x - hi\right)}{\color{blue}{lo \cdot lo}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
    3. times-frac32.2%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{\frac{x - hi}{lo} \cdot \frac{x - hi}{lo}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
    4. unpow232.2%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{{\left(\frac{x - hi}{lo}\right)}^{2}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  10. Simplified32.2%

    \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{{\left(\frac{x - hi}{lo}\right)}^{2}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  11. Step-by-step derivation
    1. unpow232.2%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{\frac{x - hi}{lo} \cdot \frac{x - hi}{lo}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  12. Applied egg-rr32.2%

    \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left(\color{blue}{\frac{x - hi}{lo} \cdot \frac{x - hi}{lo}} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)} \]
  13. Final simplification32.2%

    \[\leadsto \left({\left(\left(\frac{hi}{lo} + 1\right) \cdot \frac{hi - x}{lo}\right)}^{3} + 1\right) \cdot \frac{1}{\left(\frac{hi - x}{lo} \cdot \frac{hi - x}{lo} - \left(\frac{hi}{lo} + 1\right) \cdot \frac{hi - x}{lo}\right) + 1} \]
  14. Add Preprocessing

Alternative 3: 31.8% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \left({\left(\left(\frac{hi}{lo} + 1\right) \cdot \frac{hi - x}{lo}\right)}^{3} + 1\right) \cdot \frac{1}{\frac{x - hi}{lo} + 1} \end{array} \]
(FPCore (lo hi x)
 :precision binary64
 (*
  (+ (pow (* (+ (/ hi lo) 1.0) (/ (- hi x) lo)) 3.0) 1.0)
  (/ 1.0 (+ (/ (- x hi) lo) 1.0))))
double code(double lo, double hi, double x) {
	return (pow((((hi / lo) + 1.0) * ((hi - x) / lo)), 3.0) + 1.0) * (1.0 / (((x - hi) / lo) + 1.0));
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = (((((hi / lo) + 1.0d0) * ((hi - x) / lo)) ** 3.0d0) + 1.0d0) * (1.0d0 / (((x - hi) / lo) + 1.0d0))
end function
public static double code(double lo, double hi, double x) {
	return (Math.pow((((hi / lo) + 1.0) * ((hi - x) / lo)), 3.0) + 1.0) * (1.0 / (((x - hi) / lo) + 1.0));
}
def code(lo, hi, x):
	return (math.pow((((hi / lo) + 1.0) * ((hi - x) / lo)), 3.0) + 1.0) * (1.0 / (((x - hi) / lo) + 1.0))
function code(lo, hi, x)
	return Float64(Float64((Float64(Float64(Float64(hi / lo) + 1.0) * Float64(Float64(hi - x) / lo)) ^ 3.0) + 1.0) * Float64(1.0 / Float64(Float64(Float64(x - hi) / lo) + 1.0)))
end
function tmp = code(lo, hi, x)
	tmp = (((((hi / lo) + 1.0) * ((hi - x) / lo)) ^ 3.0) + 1.0) * (1.0 / (((x - hi) / lo) + 1.0));
end
code[lo_, hi_, x_] := N[(N[(N[Power[N[(N[(N[(hi / lo), $MachinePrecision] + 1.0), $MachinePrecision] * N[(N[(hi - x), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision], 3.0], $MachinePrecision] + 1.0), $MachinePrecision] * N[(1.0 / N[(N[(N[(x - hi), $MachinePrecision] / lo), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left({\left(\left(\frac{hi}{lo} + 1\right) \cdot \frac{hi - x}{lo}\right)}^{3} + 1\right) \cdot \frac{1}{\frac{x - hi}{lo} + 1}
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in lo around inf 0.0%

    \[\leadsto \color{blue}{\left(1 + \left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right)\right) - -1 \cdot \frac{hi}{lo}} \]
  4. Step-by-step derivation
    1. associate--l+0.0%

      \[\leadsto \color{blue}{1 + \left(\left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right) - -1 \cdot \frac{hi}{lo}\right)} \]
    2. +-commutative0.0%

      \[\leadsto 1 + \left(\color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + -1 \cdot \frac{x}{lo}\right)} - -1 \cdot \frac{hi}{lo}\right) \]
    3. associate--l+0.0%

      \[\leadsto 1 + \color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right)} \]
    4. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot x - -1 \cdot hi\right) \cdot hi}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    5. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot \left(x - hi\right)\right)} \cdot hi}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    6. associate-*r*0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{-1 \cdot \left(\left(x - hi\right) \cdot hi\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    7. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{-1 \cdot \color{blue}{\left(hi \cdot \left(x - hi\right)\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    8. associate-*r/0.0%

      \[\leadsto 1 + \left(\color{blue}{-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    9. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + \color{blue}{-1 \cdot \left(\frac{x}{lo} - \frac{hi}{lo}\right)}\right) \]
    10. div-sub0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + -1 \cdot \color{blue}{\frac{x - hi}{lo}}\right) \]
    11. +-commutative0.0%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{x - hi}{lo} + -1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)} \]
    12. mul-1-neg0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{x - hi}{lo} + \color{blue}{\left(-\frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)}\right) \]
  5. Simplified18.8%

    \[\leadsto \color{blue}{1 + \frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)} \]
  6. Step-by-step derivation
    1. flip3-+18.8%

      \[\leadsto \color{blue}{\frac{{1}^{3} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)}} \]
    2. div-inv18.8%

      \[\leadsto \color{blue}{\left({1}^{3} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)}} \]
    3. metadata-eval18.8%

      \[\leadsto \left(\color{blue}{1} + {\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
    4. *-commutative18.8%

      \[\leadsto \left(1 + {\color{blue}{\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}}^{3}\right) \cdot \frac{1}{1 \cdot 1 + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
    5. metadata-eval18.8%

      \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{\color{blue}{1} + \left(\left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right) - 1 \cdot \left(\frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)\right)\right)} \]
  7. Applied egg-rr18.8%

    \[\leadsto \color{blue}{\left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \left({\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{2} - \left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}} \]
  8. Taylor expanded in lo around inf 32.1%

    \[\leadsto \left(1 + {\left(\left(-1 - \frac{hi}{lo}\right) \cdot \frac{x - hi}{lo}\right)}^{3}\right) \cdot \frac{1}{1 + \color{blue}{\frac{x - hi}{lo}}} \]
  9. Final simplification32.1%

    \[\leadsto \left({\left(\left(\frac{hi}{lo} + 1\right) \cdot \frac{hi - x}{lo}\right)}^{3} + 1\right) \cdot \frac{1}{\frac{x - hi}{lo} + 1} \]
  10. Add Preprocessing

Alternative 4: 18.9% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \left(hi \cdot \frac{\frac{hi}{lo} + 1}{lo} - \frac{x}{lo}\right) + 1 \end{array} \]
(FPCore (lo hi x)
 :precision binary64
 (+ (- (* hi (/ (+ (/ hi lo) 1.0) lo)) (/ x lo)) 1.0))
double code(double lo, double hi, double x) {
	return ((hi * (((hi / lo) + 1.0) / lo)) - (x / lo)) + 1.0;
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = ((hi * (((hi / lo) + 1.0d0) / lo)) - (x / lo)) + 1.0d0
end function
public static double code(double lo, double hi, double x) {
	return ((hi * (((hi / lo) + 1.0) / lo)) - (x / lo)) + 1.0;
}
def code(lo, hi, x):
	return ((hi * (((hi / lo) + 1.0) / lo)) - (x / lo)) + 1.0
function code(lo, hi, x)
	return Float64(Float64(Float64(hi * Float64(Float64(Float64(hi / lo) + 1.0) / lo)) - Float64(x / lo)) + 1.0)
end
function tmp = code(lo, hi, x)
	tmp = ((hi * (((hi / lo) + 1.0) / lo)) - (x / lo)) + 1.0;
end
code[lo_, hi_, x_] := N[(N[(N[(hi * N[(N[(N[(hi / lo), $MachinePrecision] + 1.0), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision] - N[(x / lo), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]
\begin{array}{l}

\\
\left(hi \cdot \frac{\frac{hi}{lo} + 1}{lo} - \frac{x}{lo}\right) + 1
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in lo around inf 0.0%

    \[\leadsto \color{blue}{\left(1 + \left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right)\right) - -1 \cdot \frac{hi}{lo}} \]
  4. Step-by-step derivation
    1. associate--l+0.0%

      \[\leadsto \color{blue}{1 + \left(\left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right) - -1 \cdot \frac{hi}{lo}\right)} \]
    2. +-commutative0.0%

      \[\leadsto 1 + \left(\color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + -1 \cdot \frac{x}{lo}\right)} - -1 \cdot \frac{hi}{lo}\right) \]
    3. associate--l+0.0%

      \[\leadsto 1 + \color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right)} \]
    4. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot x - -1 \cdot hi\right) \cdot hi}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    5. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot \left(x - hi\right)\right)} \cdot hi}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    6. associate-*r*0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{-1 \cdot \left(\left(x - hi\right) \cdot hi\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    7. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{-1 \cdot \color{blue}{\left(hi \cdot \left(x - hi\right)\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    8. associate-*r/0.0%

      \[\leadsto 1 + \left(\color{blue}{-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    9. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + \color{blue}{-1 \cdot \left(\frac{x}{lo} - \frac{hi}{lo}\right)}\right) \]
    10. div-sub0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + -1 \cdot \color{blue}{\frac{x - hi}{lo}}\right) \]
    11. +-commutative0.0%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{x - hi}{lo} + -1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)} \]
    12. mul-1-neg0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{x - hi}{lo} + \color{blue}{\left(-\frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)}\right) \]
  5. Simplified18.8%

    \[\leadsto \color{blue}{1 + \frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)} \]
  6. Taylor expanded in x around 0 18.8%

    \[\leadsto 1 + \color{blue}{\left(-1 \cdot \left(x \cdot \left(\frac{1}{lo} + \frac{hi}{{lo}^{2}}\right)\right) + \frac{hi \cdot \left(1 + \frac{hi}{lo}\right)}{lo}\right)} \]
  7. Step-by-step derivation
    1. +-commutative18.8%

      \[\leadsto 1 + \color{blue}{\left(\frac{hi \cdot \left(1 + \frac{hi}{lo}\right)}{lo} + -1 \cdot \left(x \cdot \left(\frac{1}{lo} + \frac{hi}{{lo}^{2}}\right)\right)\right)} \]
    2. mul-1-neg18.8%

      \[\leadsto 1 + \left(\frac{hi \cdot \left(1 + \frac{hi}{lo}\right)}{lo} + \color{blue}{\left(-x \cdot \left(\frac{1}{lo} + \frac{hi}{{lo}^{2}}\right)\right)}\right) \]
    3. unsub-neg18.8%

      \[\leadsto 1 + \color{blue}{\left(\frac{hi \cdot \left(1 + \frac{hi}{lo}\right)}{lo} - x \cdot \left(\frac{1}{lo} + \frac{hi}{{lo}^{2}}\right)\right)} \]
    4. associate-/l*18.8%

      \[\leadsto 1 + \left(\color{blue}{hi \cdot \frac{1 + \frac{hi}{lo}}{lo}} - x \cdot \left(\frac{1}{lo} + \frac{hi}{{lo}^{2}}\right)\right) \]
    5. +-commutative18.8%

      \[\leadsto 1 + \left(hi \cdot \frac{\color{blue}{\frac{hi}{lo} + 1}}{lo} - x \cdot \left(\frac{1}{lo} + \frac{hi}{{lo}^{2}}\right)\right) \]
  8. Simplified18.8%

    \[\leadsto 1 + \color{blue}{\left(hi \cdot \frac{\frac{hi}{lo} + 1}{lo} - x \cdot \left(\frac{1}{lo} + \frac{hi}{{lo}^{2}}\right)\right)} \]
  9. Taylor expanded in lo around inf 18.8%

    \[\leadsto 1 + \left(hi \cdot \frac{\frac{hi}{lo} + 1}{lo} - \color{blue}{\frac{x}{lo}}\right) \]
  10. Final simplification18.8%

    \[\leadsto \left(hi \cdot \frac{\frac{hi}{lo} + 1}{lo} - \frac{x}{lo}\right) + 1 \]
  11. Add Preprocessing

Alternative 5: 18.9% accurate, 0.6× speedup?

\[\begin{array}{l} \\ hi \cdot \frac{\frac{hi}{lo} + 1}{lo} + 1 \end{array} \]
(FPCore (lo hi x) :precision binary64 (+ (* hi (/ (+ (/ hi lo) 1.0) lo)) 1.0))
double code(double lo, double hi, double x) {
	return (hi * (((hi / lo) + 1.0) / lo)) + 1.0;
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = (hi * (((hi / lo) + 1.0d0) / lo)) + 1.0d0
end function
public static double code(double lo, double hi, double x) {
	return (hi * (((hi / lo) + 1.0) / lo)) + 1.0;
}
def code(lo, hi, x):
	return (hi * (((hi / lo) + 1.0) / lo)) + 1.0
function code(lo, hi, x)
	return Float64(Float64(hi * Float64(Float64(Float64(hi / lo) + 1.0) / lo)) + 1.0)
end
function tmp = code(lo, hi, x)
	tmp = (hi * (((hi / lo) + 1.0) / lo)) + 1.0;
end
code[lo_, hi_, x_] := N[(N[(hi * N[(N[(N[(hi / lo), $MachinePrecision] + 1.0), $MachinePrecision] / lo), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]
\begin{array}{l}

\\
hi \cdot \frac{\frac{hi}{lo} + 1}{lo} + 1
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in lo around inf 0.0%

    \[\leadsto \color{blue}{\left(1 + \left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right)\right) - -1 \cdot \frac{hi}{lo}} \]
  4. Step-by-step derivation
    1. associate--l+0.0%

      \[\leadsto \color{blue}{1 + \left(\left(-1 \cdot \frac{x}{lo} + \frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}}\right) - -1 \cdot \frac{hi}{lo}\right)} \]
    2. +-commutative0.0%

      \[\leadsto 1 + \left(\color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + -1 \cdot \frac{x}{lo}\right)} - -1 \cdot \frac{hi}{lo}\right) \]
    3. associate--l+0.0%

      \[\leadsto 1 + \color{blue}{\left(\frac{hi \cdot \left(-1 \cdot x - -1 \cdot hi\right)}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right)} \]
    4. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot x - -1 \cdot hi\right) \cdot hi}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    5. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{\left(-1 \cdot \left(x - hi\right)\right)} \cdot hi}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    6. associate-*r*0.0%

      \[\leadsto 1 + \left(\frac{\color{blue}{-1 \cdot \left(\left(x - hi\right) \cdot hi\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    7. *-commutative0.0%

      \[\leadsto 1 + \left(\frac{-1 \cdot \color{blue}{\left(hi \cdot \left(x - hi\right)\right)}}{{lo}^{2}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    8. associate-*r/0.0%

      \[\leadsto 1 + \left(\color{blue}{-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}} + \left(-1 \cdot \frac{x}{lo} - -1 \cdot \frac{hi}{lo}\right)\right) \]
    9. distribute-lft-out--0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + \color{blue}{-1 \cdot \left(\frac{x}{lo} - \frac{hi}{lo}\right)}\right) \]
    10. div-sub0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}} + -1 \cdot \color{blue}{\frac{x - hi}{lo}}\right) \]
    11. +-commutative0.0%

      \[\leadsto 1 + \color{blue}{\left(-1 \cdot \frac{x - hi}{lo} + -1 \cdot \frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)} \]
    12. mul-1-neg0.0%

      \[\leadsto 1 + \left(-1 \cdot \frac{x - hi}{lo} + \color{blue}{\left(-\frac{hi \cdot \left(x - hi\right)}{{lo}^{2}}\right)}\right) \]
  5. Simplified18.8%

    \[\leadsto \color{blue}{1 + \frac{x - hi}{lo} \cdot \left(-1 - \frac{hi}{lo}\right)} \]
  6. Taylor expanded in x around 0 18.8%

    \[\leadsto 1 + \color{blue}{\frac{hi \cdot \left(1 + \frac{hi}{lo}\right)}{lo}} \]
  7. Step-by-step derivation
    1. associate-/l*18.8%

      \[\leadsto 1 + \color{blue}{hi \cdot \frac{1 + \frac{hi}{lo}}{lo}} \]
    2. +-commutative18.8%

      \[\leadsto 1 + hi \cdot \frac{\color{blue}{\frac{hi}{lo} + 1}}{lo} \]
  8. Simplified18.8%

    \[\leadsto 1 + \color{blue}{hi \cdot \frac{\frac{hi}{lo} + 1}{lo}} \]
  9. Final simplification18.8%

    \[\leadsto hi \cdot \frac{\frac{hi}{lo} + 1}{lo} + 1 \]
  10. Add Preprocessing

Alternative 6: 18.7% accurate, 1.4× speedup?

\[\begin{array}{l} \\ 1 - \frac{x}{lo} \end{array} \]
(FPCore (lo hi x) :precision binary64 (- 1.0 (/ x lo)))
double code(double lo, double hi, double x) {
	return 1.0 - (x / lo);
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = 1.0d0 - (x / lo)
end function
public static double code(double lo, double hi, double x) {
	return 1.0 - (x / lo);
}
def code(lo, hi, x):
	return 1.0 - (x / lo)
function code(lo, hi, x)
	return Float64(1.0 - Float64(x / lo))
end
function tmp = code(lo, hi, x)
	tmp = 1.0 - (x / lo);
end
code[lo_, hi_, x_] := N[(1.0 - N[(x / lo), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 - \frac{x}{lo}
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in hi around 0 18.7%

    \[\leadsto \color{blue}{-1 \cdot \frac{x - lo}{lo}} \]
  4. Step-by-step derivation
    1. div-sub18.7%

      \[\leadsto -1 \cdot \color{blue}{\left(\frac{x}{lo} - \frac{lo}{lo}\right)} \]
    2. sub-neg18.7%

      \[\leadsto -1 \cdot \color{blue}{\left(\frac{x}{lo} + \left(-\frac{lo}{lo}\right)\right)} \]
    3. *-inverses18.7%

      \[\leadsto -1 \cdot \left(\frac{x}{lo} + \left(-\color{blue}{1}\right)\right) \]
    4. metadata-eval18.7%

      \[\leadsto -1 \cdot \left(\frac{x}{lo} + \color{blue}{-1}\right) \]
    5. distribute-lft-in18.7%

      \[\leadsto \color{blue}{-1 \cdot \frac{x}{lo} + -1 \cdot -1} \]
    6. metadata-eval18.7%

      \[\leadsto -1 \cdot \frac{x}{lo} + \color{blue}{1} \]
    7. +-commutative18.7%

      \[\leadsto \color{blue}{1 + -1 \cdot \frac{x}{lo}} \]
    8. mul-1-neg18.7%

      \[\leadsto 1 + \color{blue}{\left(-\frac{x}{lo}\right)} \]
    9. unsub-neg18.7%

      \[\leadsto \color{blue}{1 - \frac{x}{lo}} \]
  5. Simplified18.7%

    \[\leadsto \color{blue}{1 - \frac{x}{lo}} \]
  6. Final simplification18.7%

    \[\leadsto 1 - \frac{x}{lo} \]
  7. Add Preprocessing

Alternative 7: 18.8% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \frac{x - lo}{hi} \end{array} \]
(FPCore (lo hi x) :precision binary64 (/ (- x lo) hi))
double code(double lo, double hi, double x) {
	return (x - lo) / hi;
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = (x - lo) / hi
end function
public static double code(double lo, double hi, double x) {
	return (x - lo) / hi;
}
def code(lo, hi, x):
	return (x - lo) / hi
function code(lo, hi, x)
	return Float64(Float64(x - lo) / hi)
end
function tmp = code(lo, hi, x)
	tmp = (x - lo) / hi;
end
code[lo_, hi_, x_] := N[(N[(x - lo), $MachinePrecision] / hi), $MachinePrecision]
\begin{array}{l}

\\
\frac{x - lo}{hi}
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in hi around inf 18.8%

    \[\leadsto \color{blue}{\frac{x - lo}{hi}} \]
  4. Final simplification18.8%

    \[\leadsto \frac{x - lo}{hi} \]
  5. Add Preprocessing

Alternative 8: 18.7% accurate, 7.0× speedup?

\[\begin{array}{l} \\ 1 \end{array} \]
(FPCore (lo hi x) :precision binary64 1.0)
double code(double lo, double hi, double x) {
	return 1.0;
}
real(8) function code(lo, hi, x)
    real(8), intent (in) :: lo
    real(8), intent (in) :: hi
    real(8), intent (in) :: x
    code = 1.0d0
end function
public static double code(double lo, double hi, double x) {
	return 1.0;
}
def code(lo, hi, x):
	return 1.0
function code(lo, hi, x)
	return 1.0
end
function tmp = code(lo, hi, x)
	tmp = 1.0;
end
code[lo_, hi_, x_] := 1.0
\begin{array}{l}

\\
1
\end{array}
Derivation
  1. Initial program 3.1%

    \[\frac{x - lo}{hi - lo} \]
  2. Add Preprocessing
  3. Taylor expanded in lo around inf 18.7%

    \[\leadsto \color{blue}{1} \]
  4. Final simplification18.7%

    \[\leadsto 1 \]
  5. Add Preprocessing

Reproduce

?
herbie shell --seed 2024047 
(FPCore (lo hi x)
  :name "xlohi (overflows)"
  :precision binary64
  :pre (and (< lo -1e+308) (> hi 1e+308))
  (/ (- x lo) (- hi lo)))