
(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 (pow (* (/ 1.0 (+ n f)) (- n f)) -1.0))
double code(double f, double n) {
return pow(((1.0 / (n + f)) * (n - f)), -1.0);
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = ((1.0d0 / (n + f)) * (n - f)) ** (-1.0d0)
end function
public static double code(double f, double n) {
return Math.pow(((1.0 / (n + f)) * (n - f)), -1.0);
}
def code(f, n): return math.pow(((1.0 / (n + f)) * (n - f)), -1.0)
function code(f, n) return Float64(Float64(1.0 / Float64(n + f)) * Float64(n - f)) ^ -1.0 end
function tmp = code(f, n) tmp = ((1.0 / (n + f)) * (n - f)) ^ -1.0; end
code[f_, n_] := N[Power[N[(N[(1.0 / N[(n + f), $MachinePrecision]), $MachinePrecision] * N[(n - f), $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]
\begin{array}{l}
\\
{\left(\frac{1}{n + f} \cdot \left(n - f\right)\right)}^{-1}
\end{array}
Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
clear-num100.0%
inv-pow100.0%
Applied egg-rr100.0%
clear-num100.0%
associate-/r/100.0%
+-commutative100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 (if (or (<= n -4.8e+104) (not (<= n 4.4e-31))) (+ 1.0 (* 2.0 (/ f n))) -1.0))
double code(double f, double n) {
double tmp;
if ((n <= -4.8e+104) || !(n <= 4.4e-31)) {
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 <= (-4.8d+104)) .or. (.not. (n <= 4.4d-31))) 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 <= -4.8e+104) || !(n <= 4.4e-31)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -4.8e+104) or not (n <= 4.4e-31): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -4.8e+104) || !(n <= 4.4e-31)) 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 <= -4.8e+104) || ~((n <= 4.4e-31))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -4.8e+104], N[Not[LessEqual[n, 4.4e-31]], $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 -4.8 \cdot 10^{+104} \lor \neg \left(n \leq 4.4 \cdot 10^{-31}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if n < -4.8e104 or 4.40000000000000019e-31 < n Initial program 100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
div-sub100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
div-sub100.0%
unsub-neg100.0%
remove-double-neg100.0%
+-commutative100.0%
sub-neg100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in f around 0 82.5%
if -4.8e104 < n < 4.40000000000000019e-31Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in f around inf 74.9%
Final simplification78.3%
(FPCore (f n) :precision binary64 (if (or (<= n -2.45e+104) (not (<= n 4.4e-31))) (+ 1.0 (* 2.0 (/ f n))) (+ -1.0 (* -2.0 (/ n f)))))
double code(double f, double n) {
double tmp;
if ((n <= -2.45e+104) || !(n <= 4.4e-31)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0 + (-2.0 * (n / f));
}
return tmp;
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
real(8) :: tmp
if ((n <= (-2.45d+104)) .or. (.not. (n <= 4.4d-31))) then
tmp = 1.0d0 + (2.0d0 * (f / n))
else
tmp = (-1.0d0) + ((-2.0d0) * (n / f))
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((n <= -2.45e+104) || !(n <= 4.4e-31)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0 + (-2.0 * (n / f));
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -2.45e+104) or not (n <= 4.4e-31): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 + (-2.0 * (n / f)) return tmp
function code(f, n) tmp = 0.0 if ((n <= -2.45e+104) || !(n <= 4.4e-31)) tmp = Float64(1.0 + Float64(2.0 * Float64(f / n))); else tmp = Float64(-1.0 + Float64(-2.0 * Float64(n / f))); end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((n <= -2.45e+104) || ~((n <= 4.4e-31))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0 + (-2.0 * (n / f)); end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -2.45e+104], N[Not[LessEqual[n, 4.4e-31]], $MachinePrecision]], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(-1.0 + N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -2.45 \cdot 10^{+104} \lor \neg \left(n \leq 4.4 \cdot 10^{-31}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1 + -2 \cdot \frac{n}{f}\\
\end{array}
\end{array}
if n < -2.44999999999999993e104 or 4.40000000000000019e-31 < n Initial program 100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
div-sub100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
div-sub100.0%
unsub-neg100.0%
remove-double-neg100.0%
+-commutative100.0%
sub-neg100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in f around 0 82.5%
if -2.44999999999999993e104 < n < 4.40000000000000019e-31Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in n around 0 75.8%
Final simplification78.8%
(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 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
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 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Final simplification99.9%
(FPCore (f n) :precision binary64 (if (<= n -2.05e+104) 1.0 (if (<= n 3.9e-31) -1.0 1.0)))
double code(double f, double n) {
double tmp;
if (n <= -2.05e+104) {
tmp = 1.0;
} else if (n <= 3.9e-31) {
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 <= (-2.05d+104)) then
tmp = 1.0d0
else if (n <= 3.9d-31) 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 <= -2.05e+104) {
tmp = 1.0;
} else if (n <= 3.9e-31) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -2.05e+104: tmp = 1.0 elif n <= 3.9e-31: tmp = -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -2.05e+104) tmp = 1.0; elseif (n <= 3.9e-31) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -2.05e+104) tmp = 1.0; elseif (n <= 3.9e-31) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -2.05e+104], 1.0, If[LessEqual[n, 3.9e-31], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -2.05 \cdot 10^{+104}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 3.9 \cdot 10^{-31}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -2.04999999999999992e104 or 3.9000000000000001e-31 < n Initial program 100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
div-sub100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
div-sub100.0%
unsub-neg100.0%
remove-double-neg100.0%
+-commutative100.0%
sub-neg100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in f around 0 82.0%
if -2.04999999999999992e104 < n < 3.9000000000000001e-31Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in f around inf 74.9%
Final simplification78.1%
(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 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in f around inf 49.5%
Final simplification49.5%
herbie shell --seed 2023257
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))