
(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 (+ (/ 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 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%
add-cbrt-cube99.9%
pow399.9%
Applied egg-rr99.9%
rem-cbrt-cube100.0%
clear-num100.0%
Applied egg-rr100.0%
clear-num99.9%
associate-/r/99.7%
Applied egg-rr99.7%
associate-*l/100.0%
*-un-lft-identity100.0%
associate-/r/99.7%
+-commutative99.7%
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 (<= f -3.4e-69) (not (<= f 2.6e-32))) (+ (* -2.0 (/ n f)) -1.0) 1.0))
double code(double f, double n) {
double tmp;
if ((f <= -3.4e-69) || !(f <= 2.6e-32)) {
tmp = (-2.0 * (n / f)) + -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 <= (-3.4d-69)) .or. (.not. (f <= 2.6d-32))) then
tmp = ((-2.0d0) * (n / f)) + (-1.0d0)
else
tmp = 1.0d0
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((f <= -3.4e-69) || !(f <= 2.6e-32)) {
tmp = (-2.0 * (n / f)) + -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if (f <= -3.4e-69) or not (f <= 2.6e-32): tmp = (-2.0 * (n / f)) + -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if ((f <= -3.4e-69) || !(f <= 2.6e-32)) tmp = Float64(Float64(-2.0 * Float64(n / f)) + -1.0); else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((f <= -3.4e-69) || ~((f <= 2.6e-32))) tmp = (-2.0 * (n / f)) + -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[f, -3.4e-69], N[Not[LessEqual[f, 2.6e-32]], $MachinePrecision]], N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], 1.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -3.4 \cdot 10^{-69} \lor \neg \left(f \leq 2.6 \cdot 10^{-32}\right):\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if f < -3.40000000000000008e-69 or 2.5999999999999997e-32 < f 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 n around 0 79.6%
if -3.40000000000000008e-69 < f < 2.5999999999999997e-32Initial 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 84.0%
Final simplification81.5%
(FPCore (f n) :precision binary64 (if (<= f -4.9e-62) -1.0 (if (<= f 6e-33) 1.0 -1.0)))
double code(double f, double n) {
double tmp;
if (f <= -4.9e-62) {
tmp = -1.0;
} else if (f <= 6e-33) {
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 <= (-4.9d-62)) then
tmp = -1.0d0
else if (f <= 6d-33) 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 <= -4.9e-62) {
tmp = -1.0;
} else if (f <= 6e-33) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -4.9e-62: tmp = -1.0 elif f <= 6e-33: tmp = 1.0 else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -4.9e-62) tmp = -1.0; elseif (f <= 6e-33) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (f <= -4.9e-62) tmp = -1.0; elseif (f <= 6e-33) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -4.9e-62], -1.0, If[LessEqual[f, 6e-33], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -4.9 \cdot 10^{-62}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 6 \cdot 10^{-33}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -4.9000000000000004e-62 or 6.0000000000000003e-33 < f 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 79.2%
if -4.9000000000000004e-62 < f < 6.0000000000000003e-33Initial 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 83.4%
Final simplification81.1%
(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 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%
Final simplification100.0%
(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%
/-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 inf 51.0%
Final simplification51.0%
herbie shell --seed 2024022
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))