
(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 6 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 (+ (/ n (- n f)) (/ f (- n f))))
double code(double f, double n) {
return (n / (n - f)) + (f / (n - f));
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = (n / (n - f)) + (f / (n - f))
end function
public static double code(double f, double n) {
return (n / (n - f)) + (f / (n - f));
}
def code(f, n): return (n / (n - f)) + (f / (n - f))
function code(f, n) return Float64(Float64(n / Float64(n - f)) + Float64(f / Float64(n - f))) end
function tmp = code(f, n) tmp = (n / (n - f)) + (f / (n - f)); end
code[f_, n_] := N[(N[(n / N[(n - f), $MachinePrecision]), $MachinePrecision] + N[(f / N[(n - f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{n}{n - f} + \frac{f}{n - f}
\end{array}
Initial program 99.9%
/-rgt-identity99.9%
metadata-eval99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/r*99.9%
neg-mul-199.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
add-cbrt-cube100.0%
pow3100.0%
Applied egg-rr100.0%
rem-cbrt-cube99.9%
clear-num99.9%
Applied egg-rr99.9%
clear-num99.9%
associate-/r/99.7%
+-commutative99.7%
Applied egg-rr99.7%
associate-*l/99.9%
*-un-lft-identity99.9%
associate-/r/99.7%
distribute-lft-out99.7%
associate-*l/99.8%
*-un-lft-identity99.8%
associate-*l/100.0%
*-un-lft-identity100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 (if (or (<= n -7.2e-57) (not (<= n 3.6e-49))) (+ 1.0 (* 2.0 (/ f n))) -1.0))
double code(double f, double n) {
double tmp;
if ((n <= -7.2e-57) || !(n <= 3.6e-49)) {
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 <= (-7.2d-57)) .or. (.not. (n <= 3.6d-49))) 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 <= -7.2e-57) || !(n <= 3.6e-49)) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (n <= -7.2e-57) or not (n <= 3.6e-49): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if ((n <= -7.2e-57) || !(n <= 3.6e-49)) 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 <= -7.2e-57) || ~((n <= 3.6e-49))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[n, -7.2e-57], N[Not[LessEqual[n, 3.6e-49]], $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 -7.2 \cdot 10^{-57} \lor \neg \left(n \leq 3.6 \cdot 10^{-49}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if n < -7.2000000000000005e-57 or 3.5999999999999997e-49 < n Initial program 100.0%
/-rgt-identity100.0%
metadata-eval100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/r*100.0%
neg-mul-1100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 79.2%
if -7.2000000000000005e-57 < n < 3.5999999999999997e-49Initial program 99.9%
/-rgt-identity99.9%
metadata-eval99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/r*99.9%
neg-mul-199.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Taylor expanded in f around inf 80.8%
Final simplification79.9%
(FPCore (f n) :precision binary64 (if (or (<= n -1.05e-55) (not (<= n 1.46e-50))) (+ 1.0 (* 2.0 (/ f n))) (+ (* -2.0 (/ n f)) -1.0)))
double code(double f, double n) {
double tmp;
if ((n <= -1.05e-55) || !(n <= 1.46e-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 <= (-1.05d-55)) .or. (.not. (n <= 1.46d-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 <= -1.05e-55) || !(n <= 1.46e-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 <= -1.05e-55) or not (n <= 1.46e-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 <= -1.05e-55) || !(n <= 1.46e-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 <= -1.05e-55) || ~((n <= 1.46e-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, -1.05e-55], N[Not[LessEqual[n, 1.46e-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 -1.05 \cdot 10^{-55} \lor \neg \left(n \leq 1.46 \cdot 10^{-50}\right):\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\
\end{array}
\end{array}
if n < -1.0500000000000001e-55 or 1.4600000000000001e-50 < n Initial program 100.0%
/-rgt-identity100.0%
metadata-eval100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/r*100.0%
neg-mul-1100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 79.2%
if -1.0500000000000001e-55 < n < 1.4600000000000001e-50Initial program 99.9%
/-rgt-identity99.9%
metadata-eval99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/r*99.9%
neg-mul-199.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Taylor expanded in n around 0 82.3%
Final simplification80.5%
(FPCore (f n) :precision binary64 (if (<= n -2e-57) 1.0 (if (<= n 1.2e-48) -1.0 1.0)))
double code(double f, double n) {
double tmp;
if (n <= -2e-57) {
tmp = 1.0;
} else if (n <= 1.2e-48) {
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 <= (-2d-57)) then
tmp = 1.0d0
else if (n <= 1.2d-48) 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 <= -2e-57) {
tmp = 1.0;
} else if (n <= 1.2e-48) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -2e-57: tmp = 1.0 elif n <= 1.2e-48: tmp = -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -2e-57) tmp = 1.0; elseif (n <= 1.2e-48) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -2e-57) tmp = 1.0; elseif (n <= 1.2e-48) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -2e-57], 1.0, If[LessEqual[n, 1.2e-48], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -2 \cdot 10^{-57}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 1.2 \cdot 10^{-48}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -1.99999999999999991e-57 or 1.2e-48 < n Initial program 100.0%
/-rgt-identity100.0%
metadata-eval100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/r*100.0%
neg-mul-1100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 77.7%
if -1.99999999999999991e-57 < n < 1.2e-48Initial program 99.9%
/-rgt-identity99.9%
metadata-eval99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/r*99.9%
neg-mul-199.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Taylor expanded in f around inf 80.8%
Final simplification79.0%
(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%
/-rgt-identity99.9%
metadata-eval99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/r*99.9%
neg-mul-199.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Final simplification99.9%
(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%
/-rgt-identity99.9%
metadata-eval99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/r*99.9%
neg-mul-199.9%
sub-neg99.9%
+-commutative99.9%
distribute-neg-in99.9%
remove-double-neg99.9%
sub-neg99.9%
Simplified99.9%
Taylor expanded in f around inf 45.5%
Final simplification45.5%
herbie shell --seed 2024031
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))