
(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 4 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 (/ (+ 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%
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 (if (or (<= n -1.35e+119) (not (<= n 1.8e-73))) (+ 1.0 (* 2.0 (/ f n))) -1.0))
double code(double f, double n) {
double tmp;
if ((n <= -1.35e+119) || !(n <= 1.8e-73)) {
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 <= (-1.35d+119)) .or. (.not. (n <= 1.8d-73))) 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 <= -1.35e+119) || !(n <= 1.8e-73)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -1.35e+119) or not (n <= 1.8e-73): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -1.35e+119) || !(n <= 1.8e-73)) 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 <= -1.35e+119) || ~((n <= 1.8e-73))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -1.35e+119], N[Not[LessEqual[n, 1.8e-73]], $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 -1.35 \cdot 10^{+119} \lor \neg \left(n \leq 1.8 \cdot 10^{-73}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if n < -1.3499999999999999e119 or 1.8e-73 < n 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 0 82.7%
if -1.3499999999999999e119 < n < 1.8e-73Initial 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 80.0%
Final simplification81.3%
(FPCore (f n) :precision binary64 (if (<= n -4.8e+115) 1.0 (if (<= n 1.75e-73) -1.0 1.0)))
double code(double f, double n) {
double tmp;
if (n <= -4.8e+115) {
tmp = 1.0;
} else if (n <= 1.75e-73) {
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 <= (-4.8d+115)) then
tmp = 1.0d0
else if (n <= 1.75d-73) 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 <= -4.8e+115) {
tmp = 1.0;
} else if (n <= 1.75e-73) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -4.8e+115: tmp = 1.0 elif n <= 1.75e-73: tmp = -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -4.8e+115) tmp = 1.0; elseif (n <= 1.75e-73) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -4.8e+115) tmp = 1.0; elseif (n <= 1.75e-73) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -4.8e+115], 1.0, If[LessEqual[n, 1.75e-73], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -4.8 \cdot 10^{+115}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 1.75 \cdot 10^{-73}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -4.8000000000000001e115 or 1.7499999999999999e-73 < n 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 0 81.8%
if -4.8000000000000001e115 < n < 1.7499999999999999e-73Initial 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 80.0%
Final simplification80.8%
(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 51.1%
Final simplification51.1%
herbie shell --seed 2023309
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))