
(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 (/ (+ 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%
(FPCore (f n) :precision binary64 (if (or (<= n -140000000.0) (not (<= n 1.4e-47))) (+ 1.0 (/ (* f 2.0) n)) (+ (* -2.0 (/ n f)) -1.0)))
double code(double f, double n) {
double tmp;
if ((n <= -140000000.0) || !(n <= 1.4e-47)) {
tmp = 1.0 + ((f * 2.0) / 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 <= (-140000000.0d0)) .or. (.not. (n <= 1.4d-47))) then
tmp = 1.0d0 + ((f * 2.0d0) / 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 <= -140000000.0) || !(n <= 1.4e-47)) {
tmp = 1.0 + ((f * 2.0) / n);
} else {
tmp = (-2.0 * (n / f)) + -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -140000000.0) or not (n <= 1.4e-47): tmp = 1.0 + ((f * 2.0) / n) else: tmp = (-2.0 * (n / f)) + -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -140000000.0) || !(n <= 1.4e-47)) tmp = Float64(1.0 + Float64(Float64(f * 2.0) / 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 <= -140000000.0) || ~((n <= 1.4e-47))) tmp = 1.0 + ((f * 2.0) / n); else tmp = (-2.0 * (n / f)) + -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -140000000.0], N[Not[LessEqual[n, 1.4e-47]], $MachinePrecision]], N[(1.0 + N[(N[(f * 2.0), $MachinePrecision] / n), $MachinePrecision]), $MachinePrecision], N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -140000000 \lor \neg \left(n \leq 1.4 \cdot 10^{-47}\right):\\
\;\;\;\;1 + \frac{f \cdot 2}{n}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\
\end{array}
\end{array}
if n < -1.4e8 or 1.39999999999999996e-47 < 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 82.0%
associate-*r/82.0%
Simplified82.0%
if -1.4e8 < n < 1.39999999999999996e-47Initial 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 n around 0 82.9%
Final simplification82.4%
(FPCore (f n) :precision binary64 (if (or (<= n -75000000000.0) (not (<= n 3.8e-45))) (+ 1.0 (/ (* f 2.0) n)) (/ f (- n f))))
double code(double f, double n) {
double tmp;
if ((n <= -75000000000.0) || !(n <= 3.8e-45)) {
tmp = 1.0 + ((f * 2.0) / n);
} else {
tmp = f / (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 <= (-75000000000.0d0)) .or. (.not. (n <= 3.8d-45))) then
tmp = 1.0d0 + ((f * 2.0d0) / n)
else
tmp = f / (n - f)
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((n <= -75000000000.0) || !(n <= 3.8e-45)) {
tmp = 1.0 + ((f * 2.0) / n);
} else {
tmp = f / (n - f);
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -75000000000.0) or not (n <= 3.8e-45): tmp = 1.0 + ((f * 2.0) / n) else: tmp = f / (n - f) return tmp
function code(f, n) tmp = 0.0 if ((n <= -75000000000.0) || !(n <= 3.8e-45)) tmp = Float64(1.0 + Float64(Float64(f * 2.0) / n)); else tmp = Float64(f / Float64(n - f)); end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((n <= -75000000000.0) || ~((n <= 3.8e-45))) tmp = 1.0 + ((f * 2.0) / n); else tmp = f / (n - f); end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -75000000000.0], N[Not[LessEqual[n, 3.8e-45]], $MachinePrecision]], N[(1.0 + N[(N[(f * 2.0), $MachinePrecision] / n), $MachinePrecision]), $MachinePrecision], N[(f / N[(n - f), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -75000000000 \lor \neg \left(n \leq 3.8 \cdot 10^{-45}\right):\\
\;\;\;\;1 + \frac{f \cdot 2}{n}\\
\mathbf{else}:\\
\;\;\;\;\frac{f}{n - f}\\
\end{array}
\end{array}
if n < -7.5e10 or 3.79999999999999997e-45 < 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 82.0%
associate-*r/82.0%
Simplified82.0%
if -7.5e10 < n < 3.79999999999999997e-45Initial 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 82.6%
Final simplification82.3%
(FPCore (f n) :precision binary64 (if (or (<= n -130000000000.0) (not (<= n 1.02e-42))) (+ 1.0 (/ f n)) (/ f (- n f))))
double code(double f, double n) {
double tmp;
if ((n <= -130000000000.0) || !(n <= 1.02e-42)) {
tmp = 1.0 + (f / n);
} else {
tmp = f / (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 <= (-130000000000.0d0)) .or. (.not. (n <= 1.02d-42))) then
tmp = 1.0d0 + (f / n)
else
tmp = f / (n - f)
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((n <= -130000000000.0) || !(n <= 1.02e-42)) {
tmp = 1.0 + (f / n);
} else {
tmp = f / (n - f);
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -130000000000.0) or not (n <= 1.02e-42): tmp = 1.0 + (f / n) else: tmp = f / (n - f) return tmp
function code(f, n) tmp = 0.0 if ((n <= -130000000000.0) || !(n <= 1.02e-42)) tmp = Float64(1.0 + Float64(f / n)); else tmp = Float64(f / Float64(n - f)); end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((n <= -130000000000.0) || ~((n <= 1.02e-42))) tmp = 1.0 + (f / n); else tmp = f / (n - f); end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -130000000000.0], N[Not[LessEqual[n, 1.02e-42]], $MachinePrecision]], N[(1.0 + N[(f / n), $MachinePrecision]), $MachinePrecision], N[(f / N[(n - f), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -130000000000 \lor \neg \left(n \leq 1.02 \cdot 10^{-42}\right):\\
\;\;\;\;1 + \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;\frac{f}{n - f}\\
\end{array}
\end{array}
if n < -1.3e11 or 1.0199999999999999e-42 < 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 81.5%
Taylor expanded in n around inf 81.8%
+-commutative81.8%
Simplified81.8%
if -1.3e11 < n < 1.0199999999999999e-42Initial 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 82.6%
Final simplification82.2%
(FPCore (f n) :precision binary64 (if (or (<= n -29000000.0) (not (<= n 2.8e-41))) (+ 1.0 (/ f n)) -1.0))
double code(double f, double n) {
double tmp;
if ((n <= -29000000.0) || !(n <= 2.8e-41)) {
tmp = 1.0 + (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 <= (-29000000.0d0)) .or. (.not. (n <= 2.8d-41))) then
tmp = 1.0d0 + (f / n)
else
tmp = -1.0d0
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((n <= -29000000.0) || !(n <= 2.8e-41)) {
tmp = 1.0 + (f / n);
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -29000000.0) or not (n <= 2.8e-41): tmp = 1.0 + (f / n) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -29000000.0) || !(n <= 2.8e-41)) tmp = Float64(1.0 + Float64(f / n)); else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((n <= -29000000.0) || ~((n <= 2.8e-41))) tmp = 1.0 + (f / n); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -29000000.0], N[Not[LessEqual[n, 2.8e-41]], $MachinePrecision]], N[(1.0 + N[(f / n), $MachinePrecision]), $MachinePrecision], -1.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -29000000 \lor \neg \left(n \leq 2.8 \cdot 10^{-41}\right):\\
\;\;\;\;1 + \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if n < -2.9e7 or 2.8000000000000002e-41 < 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 81.5%
Taylor expanded in n around inf 81.8%
+-commutative81.8%
Simplified81.8%
if -2.9e7 < n < 2.8000000000000002e-41Initial 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 82.1%
Final simplification81.9%
(FPCore (f n) :precision binary64 (if (<= n -48000000.0) 1.0 (if (<= n 1e-60) -1.0 1.0)))
double code(double f, double n) {
double tmp;
if (n <= -48000000.0) {
tmp = 1.0;
} else if (n <= 1e-60) {
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 <= (-48000000.0d0)) then
tmp = 1.0d0
else if (n <= 1d-60) 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 <= -48000000.0) {
tmp = 1.0;
} else if (n <= 1e-60) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -48000000.0: tmp = 1.0 elif n <= 1e-60: tmp = -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -48000000.0) tmp = 1.0; elseif (n <= 1e-60) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -48000000.0) tmp = 1.0; elseif (n <= 1e-60) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -48000000.0], 1.0, If[LessEqual[n, 1e-60], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -48000000:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 10^{-60}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -4.8e7 or 9.9999999999999997e-61 < 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 80.7%
if -4.8e7 < n < 9.9999999999999997e-61Initial 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 82.6%
(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 51.2%
herbie shell --seed 2024148
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))