
(FPCore (f n) :precision binary64 (/ (- (+ f n)) (- f n)))
double code(double f, double n) {
return -(f + n) / (f - n);
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = -(f + n) / (f - n)
end function
public static double code(double f, double n) {
return -(f + n) / (f - n);
}
def code(f, n): return -(f + n) / (f - n)
function code(f, n) return Float64(Float64(-Float64(f + n)) / Float64(f - n)) end
function tmp = code(f, n) tmp = -(f + n) / (f - n); end
code[f_, n_] := N[((-N[(f + n), $MachinePrecision]) / N[(f - n), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-\left(f + n\right)}{f - n}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (f n) :precision binary64 (/ (- (+ f n)) (- f n)))
double code(double f, double n) {
return -(f + n) / (f - n);
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = -(f + n) / (f - n)
end function
public static double code(double f, double n) {
return -(f + n) / (f - n);
}
def code(f, n): return -(f + n) / (f - n)
function code(f, n) return Float64(Float64(-Float64(f + n)) / Float64(f - n)) end
function tmp = code(f, n) tmp = -(f + n) / (f - n); end
code[f_, n_] := N[((-N[(f + n), $MachinePrecision]) / N[(f - n), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-\left(f + n\right)}{f - n}
\end{array}
(FPCore (f n) :precision binary64 (+ (/ n (- n f)) (/ f (- n f))))
double code(double f, double n) {
return (n / (n - f)) + (f / (n - f));
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = (n / (n - f)) + (f / (n - f))
end function
public static double code(double f, double n) {
return (n / (n - f)) + (f / (n - f));
}
def code(f, n): return (n / (n - f)) + (f / (n - f))
function code(f, n) return Float64(Float64(n / Float64(n - f)) + Float64(f / Float64(n - f))) end
function tmp = code(f, n) tmp = (n / (n - f)) + (f / (n - f)); end
code[f_, n_] := N[(N[(n / N[(n - f), $MachinePrecision]), $MachinePrecision] + N[(f / N[(n - f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{n}{n - f} + \frac{f}{n - f}
\end{array}
Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
clear-num100.0%
inv-pow100.0%
Applied egg-rr100.0%
unpow-1100.0%
associate-/r/99.7%
+-commutative99.7%
distribute-rgt-in99.7%
un-div-inv99.8%
un-div-inv100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (f n)
:precision binary64
(if (<= f -1.45e+81)
-1.0
(if (<= f -1.45e+41)
1.0
(if (<= f -4100000000.0)
-1.0
(if (<= f 2e-45) (+ 1.0 (* 2.0 (/ f n))) -1.0)))))
double code(double f, double n) {
double tmp;
if (f <= -1.45e+81) {
tmp = -1.0;
} else if (f <= -1.45e+41) {
tmp = 1.0;
} else if (f <= -4100000000.0) {
tmp = -1.0;
} else if (f <= 2e-45) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
real(8) :: tmp
if (f <= (-1.45d+81)) then
tmp = -1.0d0
else if (f <= (-1.45d+41)) then
tmp = 1.0d0
else if (f <= (-4100000000.0d0)) then
tmp = -1.0d0
else if (f <= 2d-45) then
tmp = 1.0d0 + (2.0d0 * (f / n))
else
tmp = -1.0d0
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if (f <= -1.45e+81) {
tmp = -1.0;
} else if (f <= -1.45e+41) {
tmp = 1.0;
} else if (f <= -4100000000.0) {
tmp = -1.0;
} else if (f <= 2e-45) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -1.45e+81: tmp = -1.0 elif f <= -1.45e+41: tmp = 1.0 elif f <= -4100000000.0: tmp = -1.0 elif f <= 2e-45: tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -1.45e+81) tmp = -1.0; elseif (f <= -1.45e+41) tmp = 1.0; elseif (f <= -4100000000.0) tmp = -1.0; elseif (f <= 2e-45) tmp = Float64(1.0 + Float64(2.0 * Float64(f / n))); else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (f <= -1.45e+81) tmp = -1.0; elseif (f <= -1.45e+41) tmp = 1.0; elseif (f <= -4100000000.0) tmp = -1.0; elseif (f <= 2e-45) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -1.45e+81], -1.0, If[LessEqual[f, -1.45e+41], 1.0, If[LessEqual[f, -4100000000.0], -1.0, If[LessEqual[f, 2e-45], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.45 \cdot 10^{+81}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq -1.45 \cdot 10^{+41}:\\
\;\;\;\;1\\
\mathbf{elif}\;f \leq -4100000000:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 2 \cdot 10^{-45}:\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -1.45e81 or -1.44999999999999994e41 < f < -4.1e9 or 1.99999999999999997e-45 < f Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 84.2%
if -1.45e81 < f < -1.44999999999999994e41Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 100.0%
if -4.1e9 < f < 1.99999999999999997e-45Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 76.2%
Final simplification81.2%
(FPCore (f n)
:precision binary64
(let* ((t_0 (+ (* -2.0 (/ n f)) -1.0)))
(if (<= f -1.45e+81)
t_0
(if (<= f -1e+41)
1.0
(if (<= f -18500000000000.0)
-1.0
(if (<= f 1.45e-47) (+ 1.0 (* 2.0 (/ f n))) t_0))))))
double code(double f, double n) {
double t_0 = (-2.0 * (n / f)) + -1.0;
double tmp;
if (f <= -1.45e+81) {
tmp = t_0;
} else if (f <= -1e+41) {
tmp = 1.0;
} else if (f <= -18500000000000.0) {
tmp = -1.0;
} else if (f <= 1.45e-47) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = t_0;
}
return tmp;
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
real(8) :: t_0
real(8) :: tmp
t_0 = ((-2.0d0) * (n / f)) + (-1.0d0)
if (f <= (-1.45d+81)) then
tmp = t_0
else if (f <= (-1d+41)) then
tmp = 1.0d0
else if (f <= (-18500000000000.0d0)) then
tmp = -1.0d0
else if (f <= 1.45d-47) then
tmp = 1.0d0 + (2.0d0 * (f / n))
else
tmp = t_0
end if
code = tmp
end function
public static double code(double f, double n) {
double t_0 = (-2.0 * (n / f)) + -1.0;
double tmp;
if (f <= -1.45e+81) {
tmp = t_0;
} else if (f <= -1e+41) {
tmp = 1.0;
} else if (f <= -18500000000000.0) {
tmp = -1.0;
} else if (f <= 1.45e-47) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = t_0;
}
return tmp;
}
def code(f, n): t_0 = (-2.0 * (n / f)) + -1.0 tmp = 0 if f <= -1.45e+81: tmp = t_0 elif f <= -1e+41: tmp = 1.0 elif f <= -18500000000000.0: tmp = -1.0 elif f <= 1.45e-47: tmp = 1.0 + (2.0 * (f / n)) else: tmp = t_0 return tmp
function code(f, n) t_0 = Float64(Float64(-2.0 * Float64(n / f)) + -1.0) tmp = 0.0 if (f <= -1.45e+81) tmp = t_0; elseif (f <= -1e+41) tmp = 1.0; elseif (f <= -18500000000000.0) tmp = -1.0; elseif (f <= 1.45e-47) tmp = Float64(1.0 + Float64(2.0 * Float64(f / n))); else tmp = t_0; end return tmp end
function tmp_2 = code(f, n) t_0 = (-2.0 * (n / f)) + -1.0; tmp = 0.0; if (f <= -1.45e+81) tmp = t_0; elseif (f <= -1e+41) tmp = 1.0; elseif (f <= -18500000000000.0) tmp = -1.0; elseif (f <= 1.45e-47) tmp = 1.0 + (2.0 * (f / n)); else tmp = t_0; end tmp_2 = tmp; end
code[f_, n_] := Block[{t$95$0 = N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]}, If[LessEqual[f, -1.45e+81], t$95$0, If[LessEqual[f, -1e+41], 1.0, If[LessEqual[f, -18500000000000.0], -1.0, If[LessEqual[f, 1.45e-47], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := -2 \cdot \frac{n}{f} + -1\\
\mathbf{if}\;f \leq -1.45 \cdot 10^{+81}:\\
\;\;\;\;t_0\\
\mathbf{elif}\;f \leq -1 \cdot 10^{+41}:\\
\;\;\;\;1\\
\mathbf{elif}\;f \leq -18500000000000:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 1.45 \cdot 10^{-47}:\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;t_0\\
\end{array}
\end{array}
if f < -1.45e81 or 1.45e-47 < f Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in n around 0 84.3%
if -1.45e81 < f < -1.00000000000000001e41Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 100.0%
if -1.00000000000000001e41 < f < -1.85e13Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 100.0%
if -1.85e13 < f < 1.45e-47Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 76.2%
Final simplification81.7%
(FPCore (f n)
:precision binary64
(if (<= f -1.5e+82)
-1.0
(if (<= f -4e+39)
1.0
(if (<= f -128000000000.0) -1.0 (if (<= f 1.7e-47) 1.0 -1.0)))))
double code(double f, double n) {
double tmp;
if (f <= -1.5e+82) {
tmp = -1.0;
} else if (f <= -4e+39) {
tmp = 1.0;
} else if (f <= -128000000000.0) {
tmp = -1.0;
} else if (f <= 1.7e-47) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
real(8) :: tmp
if (f <= (-1.5d+82)) then
tmp = -1.0d0
else if (f <= (-4d+39)) then
tmp = 1.0d0
else if (f <= (-128000000000.0d0)) then
tmp = -1.0d0
else if (f <= 1.7d-47) then
tmp = 1.0d0
else
tmp = -1.0d0
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if (f <= -1.5e+82) {
tmp = -1.0;
} else if (f <= -4e+39) {
tmp = 1.0;
} else if (f <= -128000000000.0) {
tmp = -1.0;
} else if (f <= 1.7e-47) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -1.5e+82: tmp = -1.0 elif f <= -4e+39: tmp = 1.0 elif f <= -128000000000.0: tmp = -1.0 elif f <= 1.7e-47: tmp = 1.0 else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -1.5e+82) tmp = -1.0; elseif (f <= -4e+39) tmp = 1.0; elseif (f <= -128000000000.0) tmp = -1.0; elseif (f <= 1.7e-47) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (f <= -1.5e+82) tmp = -1.0; elseif (f <= -4e+39) tmp = 1.0; elseif (f <= -128000000000.0) tmp = -1.0; elseif (f <= 1.7e-47) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -1.5e+82], -1.0, If[LessEqual[f, -4e+39], 1.0, If[LessEqual[f, -128000000000.0], -1.0, If[LessEqual[f, 1.7e-47], 1.0, -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.5 \cdot 10^{+82}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq -4 \cdot 10^{+39}:\\
\;\;\;\;1\\
\mathbf{elif}\;f \leq -128000000000:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 1.7 \cdot 10^{-47}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -1.49999999999999995e82 or -3.99999999999999976e39 < f < -1.28e11 or 1.7000000000000001e-47 < f Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 84.2%
if -1.49999999999999995e82 < f < -3.99999999999999976e39 or -1.28e11 < f < 1.7000000000000001e-47Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 76.6%
Final simplification80.6%
(FPCore (f n) :precision binary64 (/ 1.0 (/ (- n f) (+ n f))))
double code(double f, double n) {
return 1.0 / ((n - f) / (n + f));
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = 1.0d0 / ((n - f) / (n + f))
end function
public static double code(double f, double n) {
return 1.0 / ((n - f) / (n + f));
}
def code(f, n): return 1.0 / ((n - f) / (n + f))
function code(f, n) return Float64(1.0 / Float64(Float64(n - f) / Float64(n + f))) end
function tmp = code(f, n) tmp = 1.0 / ((n - f) / (n + f)); end
code[f_, n_] := N[(1.0 / N[(N[(n - f), $MachinePrecision] / N[(n + f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{n - f}{n + f}}
\end{array}
Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
clear-num100.0%
inv-pow100.0%
Applied egg-rr100.0%
unpow-1100.0%
+-commutative100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 (/ (+ n f) (- n f)))
double code(double f, double n) {
return (n + f) / (n - f);
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = (n + f) / (n - f)
end function
public static double code(double f, double n) {
return (n + f) / (n - f);
}
def code(f, n): return (n + f) / (n - f)
function code(f, n) return Float64(Float64(n + f) / Float64(n - f)) end
function tmp = code(f, n) tmp = (n + f) / (n - f); end
code[f_, n_] := N[(N[(n + f), $MachinePrecision] / N[(n - f), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{n + f}{n - f}
\end{array}
Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 -1.0)
double code(double f, double n) {
return -1.0;
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = -1.0d0
end function
public static double code(double f, double n) {
return -1.0;
}
def code(f, n): return -1.0
function code(f, n) return -1.0 end
function tmp = code(f, n) tmp = -1.0; end
code[f_, n_] := -1.0
\begin{array}{l}
\\
-1
\end{array}
Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 54.8%
Final simplification54.8%
herbie shell --seed 2023305
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))