
(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 (log1p (expm1 (/ (+ f n) (- n f)))))
double code(double f, double n) {
return log1p(expm1(((f + n) / (n - f))));
}
public static double code(double f, double n) {
return Math.log1p(Math.expm1(((f + n) / (n - f))));
}
def code(f, n): return math.log1p(math.expm1(((f + n) / (n - f))))
function code(f, n) return log1p(expm1(Float64(Float64(f + n) / Float64(n - f)))) end
code[f_, n_] := N[Log[1 + N[(Exp[N[(N[(f + n), $MachinePrecision] / N[(n - f), $MachinePrecision]), $MachinePrecision]] - 1), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\mathsf{log1p}\left(\mathsf{expm1}\left(\frac{f + n}{n - f}\right)\right)
\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%
log1p-expm1-u100.0%
Applied egg-rr100.0%
(FPCore (f n) :precision binary64 (if (or (<= f -1.32e-65) (not (<= f 7e-30))) (+ (* -2.0 (/ n f)) -1.0) (+ 1.0 (/ f n))))
double code(double f, double n) {
double tmp;
if ((f <= -1.32e-65) || !(f <= 7e-30)) {
tmp = (-2.0 * (n / f)) + -1.0;
} else {
tmp = 1.0 + (f / n);
}
return tmp;
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
real(8) :: tmp
if ((f <= (-1.32d-65)) .or. (.not. (f <= 7d-30))) then
tmp = ((-2.0d0) * (n / f)) + (-1.0d0)
else
tmp = 1.0d0 + (f / n)
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((f <= -1.32e-65) || !(f <= 7e-30)) {
tmp = (-2.0 * (n / f)) + -1.0;
} else {
tmp = 1.0 + (f / n);
}
return tmp;
}
def code(f, n): tmp = 0 if (f <= -1.32e-65) or not (f <= 7e-30): tmp = (-2.0 * (n / f)) + -1.0 else: tmp = 1.0 + (f / n) return tmp
function code(f, n) tmp = 0.0 if ((f <= -1.32e-65) || !(f <= 7e-30)) tmp = Float64(Float64(-2.0 * Float64(n / f)) + -1.0); else tmp = Float64(1.0 + Float64(f / n)); end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((f <= -1.32e-65) || ~((f <= 7e-30))) tmp = (-2.0 * (n / f)) + -1.0; else tmp = 1.0 + (f / n); end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[f, -1.32e-65], N[Not[LessEqual[f, 7e-30]], $MachinePrecision]], N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(1.0 + N[(f / n), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.32 \cdot 10^{-65} \lor \neg \left(f \leq 7 \cdot 10^{-30}\right):\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\
\mathbf{else}:\\
\;\;\;\;1 + \frac{f}{n}\\
\end{array}
\end{array}
if f < -1.32e-65 or 7.0000000000000006e-30 < f 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 n around 0 74.9%
if -1.32e-65 < f < 7.0000000000000006e-30Initial 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 84.6%
Taylor expanded in n around inf 84.9%
Final simplification78.9%
(FPCore (f n) :precision binary64 (if (or (<= f -1.36e-68) (not (<= f 1.02e-30))) (/ f (- n f)) (+ 1.0 (/ f n))))
double code(double f, double n) {
double tmp;
if ((f <= -1.36e-68) || !(f <= 1.02e-30)) {
tmp = f / (n - f);
} else {
tmp = 1.0 + (f / n);
}
return tmp;
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
real(8) :: tmp
if ((f <= (-1.36d-68)) .or. (.not. (f <= 1.02d-30))) then
tmp = f / (n - f)
else
tmp = 1.0d0 + (f / n)
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((f <= -1.36e-68) || !(f <= 1.02e-30)) {
tmp = f / (n - f);
} else {
tmp = 1.0 + (f / n);
}
return tmp;
}
def code(f, n): tmp = 0 if (f <= -1.36e-68) or not (f <= 1.02e-30): tmp = f / (n - f) else: tmp = 1.0 + (f / n) return tmp
function code(f, n) tmp = 0.0 if ((f <= -1.36e-68) || !(f <= 1.02e-30)) tmp = Float64(f / Float64(n - f)); else tmp = Float64(1.0 + Float64(f / n)); end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((f <= -1.36e-68) || ~((f <= 1.02e-30))) tmp = f / (n - f); else tmp = 1.0 + (f / n); end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[f, -1.36e-68], N[Not[LessEqual[f, 1.02e-30]], $MachinePrecision]], N[(f / N[(n - f), $MachinePrecision]), $MachinePrecision], N[(1.0 + N[(f / n), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.36 \cdot 10^{-68} \lor \neg \left(f \leq 1.02 \cdot 10^{-30}\right):\\
\;\;\;\;\frac{f}{n - f}\\
\mathbf{else}:\\
\;\;\;\;1 + \frac{f}{n}\\
\end{array}
\end{array}
if f < -1.36000000000000003e-68 or 1.0199999999999999e-30 < f 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 74.7%
if -1.36000000000000003e-68 < f < 1.0199999999999999e-30Initial 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 84.6%
Taylor expanded in n around inf 84.9%
Final simplification78.8%
(FPCore (f n) :precision binary64 (if (<= f -8.5e-83) -1.0 (if (<= f 3.1e-26) (+ 1.0 (/ f n)) -1.0)))
double code(double f, double n) {
double tmp;
if (f <= -8.5e-83) {
tmp = -1.0;
} else if (f <= 3.1e-26) {
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 (f <= (-8.5d-83)) then
tmp = -1.0d0
else if (f <= 3.1d-26) 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 (f <= -8.5e-83) {
tmp = -1.0;
} else if (f <= 3.1e-26) {
tmp = 1.0 + (f / n);
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -8.5e-83: tmp = -1.0 elif f <= 3.1e-26: tmp = 1.0 + (f / n) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -8.5e-83) tmp = -1.0; elseif (f <= 3.1e-26) 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 (f <= -8.5e-83) tmp = -1.0; elseif (f <= 3.1e-26) tmp = 1.0 + (f / n); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -8.5e-83], -1.0, If[LessEqual[f, 3.1e-26], N[(1.0 + N[(f / n), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -8.5 \cdot 10^{-83}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 3.1 \cdot 10^{-26}:\\
\;\;\;\;1 + \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -8.49999999999999938e-83 or 3.09999999999999983e-26 < f 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 73.8%
if -8.49999999999999938e-83 < f < 3.09999999999999983e-26Initial 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 84.6%
Taylor expanded in n around inf 84.9%
(FPCore (f n) :precision binary64 (if (<= f -1.7e-68) -1.0 (if (<= f 3.5e-32) 1.0 -1.0)))
double code(double f, double n) {
double tmp;
if (f <= -1.7e-68) {
tmp = -1.0;
} else if (f <= 3.5e-32) {
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 (f <= (-1.7d-68)) then
tmp = -1.0d0
else if (f <= 3.5d-32) 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 (f <= -1.7e-68) {
tmp = -1.0;
} else if (f <= 3.5e-32) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -1.7e-68: tmp = -1.0 elif f <= 3.5e-32: tmp = 1.0 else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -1.7e-68) tmp = -1.0; elseif (f <= 3.5e-32) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (f <= -1.7e-68) tmp = -1.0; elseif (f <= 3.5e-32) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -1.7e-68], -1.0, If[LessEqual[f, 3.5e-32], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.7 \cdot 10^{-68}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 3.5 \cdot 10^{-32}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -1.70000000000000009e-68 or 3.4999999999999999e-32 < f 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 73.8%
if -1.70000000000000009e-68 < f < 3.4999999999999999e-32Initial 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 84.3%
(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 -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 50.2%
herbie shell --seed 2024141
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))