
(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 5 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%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 (if (or (<= n -2.45e-17) (not (<= n 8e-50))) (+ 1.0 (* 2.0 (/ f n))) -1.0))
double code(double f, double n) {
double tmp;
if ((n <= -2.45e-17) || !(n <= 8e-50)) {
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 <= (-2.45d-17)) .or. (.not. (n <= 8d-50))) 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 <= -2.45e-17) || !(n <= 8e-50)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -2.45e-17) or not (n <= 8e-50): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -2.45e-17) || !(n <= 8e-50)) 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 <= -2.45e-17) || ~((n <= 8e-50))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -2.45e-17], N[Not[LessEqual[n, 8e-50]], $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 -2.45 \cdot 10^{-17} \lor \neg \left(n \leq 8 \cdot 10^{-50}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if n < -2.45000000000000006e-17 or 8.00000000000000006e-50 < n Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 78.2%
if -2.45000000000000006e-17 < n < 8.00000000000000006e-50Initial program 99.9%
distribute-frac-neg99.9%
distribute-neg-frac299.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Taylor expanded in f around inf 85.5%
Final simplification81.4%
(FPCore (f n) :precision binary64 (if (or (<= n -2e-17) (not (<= n 2e-50))) (+ 1.0 (* 2.0 (/ f n))) (+ (* -2.0 (/ n f)) -1.0)))
double code(double f, double n) {
double tmp;
if ((n <= -2e-17) || !(n <= 2e-50)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = (-2.0 * (n / f)) + -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 <= (-2d-17)) .or. (.not. (n <= 2d-50))) then
tmp = 1.0d0 + (2.0d0 * (f / n))
else
tmp = ((-2.0d0) * (n / f)) + (-1.0d0)
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((n <= -2e-17) || !(n <= 2e-50)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = (-2.0 * (n / f)) + -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -2e-17) or not (n <= 2e-50): tmp = 1.0 + (2.0 * (f / n)) else: tmp = (-2.0 * (n / f)) + -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -2e-17) || !(n <= 2e-50)) tmp = Float64(1.0 + Float64(2.0 * Float64(f / n))); else tmp = Float64(Float64(-2.0 * Float64(n / f)) + -1.0); end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((n <= -2e-17) || ~((n <= 2e-50))) tmp = 1.0 + (2.0 * (f / n)); else tmp = (-2.0 * (n / f)) + -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -2e-17], N[Not[LessEqual[n, 2e-50]], $MachinePrecision]], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -2 \cdot 10^{-17} \lor \neg \left(n \leq 2 \cdot 10^{-50}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\
\end{array}
\end{array}
if n < -2.00000000000000014e-17 or 2.00000000000000002e-50 < n Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 78.2%
if -2.00000000000000014e-17 < n < 2.00000000000000002e-50Initial program 99.9%
distribute-frac-neg99.9%
distribute-neg-frac299.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Taylor expanded in n around 0 86.0%
Final simplification81.6%
(FPCore (f n) :precision binary64 (if (<= n -8e-15) 1.0 (if (<= n 9e-50) -1.0 1.0)))
double code(double f, double n) {
double tmp;
if (n <= -8e-15) {
tmp = 1.0;
} else if (n <= 9e-50) {
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 <= (-8d-15)) then
tmp = 1.0d0
else if (n <= 9d-50) 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 <= -8e-15) {
tmp = 1.0;
} else if (n <= 9e-50) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -8e-15: tmp = 1.0 elif n <= 9e-50: tmp = -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -8e-15) tmp = 1.0; elseif (n <= 9e-50) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -8e-15) tmp = 1.0; elseif (n <= 9e-50) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -8e-15], 1.0, If[LessEqual[n, 9e-50], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -8 \cdot 10^{-15}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 9 \cdot 10^{-50}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -8.0000000000000006e-15 or 8.99999999999999924e-50 < n Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 77.3%
if -8.0000000000000006e-15 < n < 8.99999999999999924e-50Initial program 99.9%
distribute-frac-neg99.9%
distribute-neg-frac299.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Taylor expanded in f around inf 85.5%
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%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 49.2%
Final simplification49.2%
herbie shell --seed 2024078
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))