
(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 6 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 (let* ((t_0 (/ n (- n f))) (t_1 (/ f (- n f)))) (/ (* (/ (- f n) (- n f)) (+ t_0 t_1)) (- t_1 t_0))))
double code(double f, double n) {
double t_0 = n / (n - f);
double t_1 = f / (n - f);
return (((f - n) / (n - f)) * (t_0 + t_1)) / (t_1 - t_0);
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
real(8) :: t_0
real(8) :: t_1
t_0 = n / (n - f)
t_1 = f / (n - f)
code = (((f - n) / (n - f)) * (t_0 + t_1)) / (t_1 - t_0)
end function
public static double code(double f, double n) {
double t_0 = n / (n - f);
double t_1 = f / (n - f);
return (((f - n) / (n - f)) * (t_0 + t_1)) / (t_1 - t_0);
}
def code(f, n): t_0 = n / (n - f) t_1 = f / (n - f) return (((f - n) / (n - f)) * (t_0 + t_1)) / (t_1 - t_0)
function code(f, n) t_0 = Float64(n / Float64(n - f)) t_1 = Float64(f / Float64(n - f)) return Float64(Float64(Float64(Float64(f - n) / Float64(n - f)) * Float64(t_0 + t_1)) / Float64(t_1 - t_0)) end
function tmp = code(f, n) t_0 = n / (n - f); t_1 = f / (n - f); tmp = (((f - n) / (n - f)) * (t_0 + t_1)) / (t_1 - t_0); end
code[f_, n_] := Block[{t$95$0 = N[(n / N[(n - f), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(f / N[(n - f), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(f - n), $MachinePrecision] / N[(n - f), $MachinePrecision]), $MachinePrecision] * N[(t$95$0 + t$95$1), $MachinePrecision]), $MachinePrecision] / N[(t$95$1 - t$95$0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{n}{n - f}\\
t_1 := \frac{f}{n - f}\\
\frac{\frac{f - n}{n - f} \cdot \left(t_0 + t_1\right)}{t_1 - t_0}
\end{array}
\end{array}
Initial program 100.0%
neg-mul-1100.0%
remove-double-neg100.0%
unsub-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
times-frac100.0%
metadata-eval100.0%
+-commutative100.0%
+-commutative100.0%
sub-neg100.0%
*-lft-identity100.0%
+-commutative100.0%
Simplified100.0%
clear-num100.0%
inv-pow100.0%
Applied egg-rr100.0%
unpow-1100.0%
associate-/r/99.7%
distribute-lft-in99.7%
flip-+99.7%
associate-*l/99.8%
*-un-lft-identity99.8%
associate-*l/99.7%
*-un-lft-identity99.7%
associate-*l/99.9%
*-un-lft-identity99.9%
associate-*l/99.7%
*-un-lft-identity99.7%
associate-*l/99.8%
*-un-lft-identity99.8%
associate-*l/100.0%
Applied egg-rr100.0%
difference-of-squares100.0%
div-inv99.9%
div-inv99.7%
distribute-rgt-in99.7%
+-commutative99.7%
associate-/r/100.0%
clear-num100.0%
*-commutative100.0%
sub-div100.0%
Applied egg-rr100.0%
clear-num100.0%
associate-/r/99.7%
distribute-rgt-in99.7%
div-inv99.9%
div-inv100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 (if (or (<= n -8.8e-20) (not (<= n 1.02e+18))) (+ 1.0 (* 2.0 (/ f n))) -1.0))
double code(double f, double n) {
double tmp;
if ((n <= -8.8e-20) || !(n <= 1.02e+18)) {
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 ((n <= (-8.8d-20)) .or. (.not. (n <= 1.02d+18))) 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 ((n <= -8.8e-20) || !(n <= 1.02e+18)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -8.8e-20) or not (n <= 1.02e+18): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -8.8e-20) || !(n <= 1.02e+18)) 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 ((n <= -8.8e-20) || ~((n <= 1.02e+18))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -8.8e-20], N[Not[LessEqual[n, 1.02e+18]], $MachinePrecision]], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -8.8 \cdot 10^{-20} \lor \neg \left(n \leq 1.02 \cdot 10^{+18}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if n < -8.79999999999999964e-20 or 1.02e18 < n Initial program 100.0%
neg-mul-1100.0%
remove-double-neg100.0%
unsub-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
times-frac100.0%
metadata-eval100.0%
+-commutative100.0%
+-commutative100.0%
sub-neg100.0%
*-lft-identity100.0%
+-commutative100.0%
Simplified100.0%
Taylor expanded in f around 0 83.2%
if -8.79999999999999964e-20 < n < 1.02e18Initial program 99.9%
neg-mul-199.9%
remove-double-neg99.9%
unsub-neg99.9%
distribute-neg-in99.9%
neg-mul-199.9%
times-frac99.9%
metadata-eval99.9%
+-commutative99.9%
+-commutative99.9%
sub-neg99.9%
*-lft-identity99.9%
+-commutative99.9%
Simplified99.9%
Taylor expanded in f around inf 74.4%
Final simplification78.2%
(FPCore (f n) :precision binary64 (/ 1.0 (/ (- n f) (+ f n))))
double code(double f, double n) {
return 1.0 / ((n - f) / (f + n));
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = 1.0d0 / ((n - f) / (f + n))
end function
public static double code(double f, double n) {
return 1.0 / ((n - f) / (f + n));
}
def code(f, n): return 1.0 / ((n - f) / (f + n))
function code(f, n) return Float64(1.0 / Float64(Float64(n - f) / Float64(f + n))) end
function tmp = code(f, n) tmp = 1.0 / ((n - f) / (f + n)); end
code[f_, n_] := N[(1.0 / N[(N[(n - f), $MachinePrecision] / N[(f + n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{n - f}{f + n}}
\end{array}
Initial program 100.0%
neg-mul-1100.0%
remove-double-neg100.0%
unsub-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
times-frac100.0%
metadata-eval100.0%
+-commutative100.0%
+-commutative100.0%
sub-neg100.0%
*-lft-identity100.0%
+-commutative100.0%
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 (/ (+ f n) (- n f)))
double code(double f, double n) {
return (f + n) / (n - f);
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = (f + n) / (n - f)
end function
public static double code(double f, double n) {
return (f + n) / (n - f);
}
def code(f, n): return (f + n) / (n - f)
function code(f, n) return Float64(Float64(f + n) / Float64(n - f)) end
function tmp = code(f, n) tmp = (f + n) / (n - f); end
code[f_, n_] := N[(N[(f + n), $MachinePrecision] / N[(n - f), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{f + n}{n - f}
\end{array}
Initial program 100.0%
neg-mul-1100.0%
remove-double-neg100.0%
unsub-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
times-frac100.0%
metadata-eval100.0%
+-commutative100.0%
+-commutative100.0%
sub-neg100.0%
*-lft-identity100.0%
+-commutative100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 (if (<= n -3.9e-19) 1.0 (if (<= n 4.4e+17) -1.0 1.0)))
double code(double f, double n) {
double tmp;
if (n <= -3.9e-19) {
tmp = 1.0;
} else if (n <= 4.4e+17) {
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 (n <= (-3.9d-19)) then
tmp = 1.0d0
else if (n <= 4.4d+17) 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 (n <= -3.9e-19) {
tmp = 1.0;
} else if (n <= 4.4e+17) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -3.9e-19: tmp = 1.0 elif n <= 4.4e+17: tmp = -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -3.9e-19) tmp = 1.0; elseif (n <= 4.4e+17) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -3.9e-19) tmp = 1.0; elseif (n <= 4.4e+17) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -3.9e-19], 1.0, If[LessEqual[n, 4.4e+17], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -3.9 \cdot 10^{-19}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 4.4 \cdot 10^{+17}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -3.89999999999999995e-19 or 4.4e17 < n Initial program 100.0%
neg-mul-1100.0%
remove-double-neg100.0%
unsub-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
times-frac100.0%
metadata-eval100.0%
+-commutative100.0%
+-commutative100.0%
sub-neg100.0%
*-lft-identity100.0%
+-commutative100.0%
Simplified100.0%
Taylor expanded in f around 0 82.7%
if -3.89999999999999995e-19 < n < 4.4e17Initial program 99.9%
neg-mul-199.9%
remove-double-neg99.9%
unsub-neg99.9%
distribute-neg-in99.9%
neg-mul-199.9%
times-frac99.9%
metadata-eval99.9%
+-commutative99.9%
+-commutative99.9%
sub-neg99.9%
*-lft-identity99.9%
+-commutative99.9%
Simplified99.9%
Taylor expanded in f around inf 74.4%
Final simplification78.0%
(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%
neg-mul-1100.0%
remove-double-neg100.0%
unsub-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
times-frac100.0%
metadata-eval100.0%
+-commutative100.0%
+-commutative100.0%
sub-neg100.0%
*-lft-identity100.0%
+-commutative100.0%
Simplified100.0%
Taylor expanded in f around inf 50.7%
Final simplification50.7%
herbie shell --seed 2023334
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))