
(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 f)) (/ n (- n f))))
double code(double f, double n) {
return (f / (n - f)) + (n / (n - f));
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = (f / (n - f)) + (n / (n - f))
end function
public static double code(double f, double n) {
return (f / (n - f)) + (n / (n - f));
}
def code(f, n): return (f / (n - f)) + (n / (n - f))
function code(f, n) return Float64(Float64(f / Float64(n - f)) + Float64(n / Float64(n - f))) end
function tmp = code(f, n) tmp = (f / (n - f)) + (n / (n - f)); end
code[f_, n_] := N[(N[(f / N[(n - f), $MachinePrecision]), $MachinePrecision] + N[(n / N[(n - f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{f}{n - f} + \frac{n}{n - f}
\end{array}
Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
log1p-expm1-u100.0%
Applied egg-rr100.0%
log1p-expm1-u99.9%
*-un-lft-identity99.9%
associate-*l/99.7%
distribute-rgt-in99.7%
un-div-inv99.9%
un-div-inv100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (f n)
:precision binary64
(if (or (<= f -1.6e+53)
(and (not (<= f -1.3e-22)) (or (<= f -1.3e-107) (not (<= f 2e-47)))))
(+ (* -2.0 (/ n f)) -1.0)
(+ 1.0 (* 2.0 (/ f n)))))
double code(double f, double n) {
double tmp;
if ((f <= -1.6e+53) || (!(f <= -1.3e-22) && ((f <= -1.3e-107) || !(f <= 2e-47)))) {
tmp = (-2.0 * (n / f)) + -1.0;
} else {
tmp = 1.0 + (2.0 * (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 <= (-1.6d+53)) .or. (.not. (f <= (-1.3d-22))) .and. (f <= (-1.3d-107)) .or. (.not. (f <= 2d-47))) then
tmp = ((-2.0d0) * (n / f)) + (-1.0d0)
else
tmp = 1.0d0 + (2.0d0 * (f / n))
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if ((f <= -1.6e+53) || (!(f <= -1.3e-22) && ((f <= -1.3e-107) || !(f <= 2e-47)))) {
tmp = (-2.0 * (n / f)) + -1.0;
} else {
tmp = 1.0 + (2.0 * (f / n));
}
return tmp;
}
def code(f, n): tmp = 0 if (f <= -1.6e+53) or (not (f <= -1.3e-22) and ((f <= -1.3e-107) or not (f <= 2e-47))): tmp = (-2.0 * (n / f)) + -1.0 else: tmp = 1.0 + (2.0 * (f / n)) return tmp
function code(f, n) tmp = 0.0 if ((f <= -1.6e+53) || (!(f <= -1.3e-22) && ((f <= -1.3e-107) || !(f <= 2e-47)))) tmp = Float64(Float64(-2.0 * Float64(n / f)) + -1.0); else tmp = Float64(1.0 + Float64(2.0 * Float64(f / n))); end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if ((f <= -1.6e+53) || (~((f <= -1.3e-22)) && ((f <= -1.3e-107) || ~((f <= 2e-47))))) tmp = (-2.0 * (n / f)) + -1.0; else tmp = 1.0 + (2.0 * (f / n)); end tmp_2 = tmp; end
code[f_, n_] := If[Or[LessEqual[f, -1.6e+53], And[N[Not[LessEqual[f, -1.3e-22]], $MachinePrecision], Or[LessEqual[f, -1.3e-107], N[Not[LessEqual[f, 2e-47]], $MachinePrecision]]]], N[(N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.6 \cdot 10^{+53} \lor \neg \left(f \leq -1.3 \cdot 10^{-22}\right) \land \left(f \leq -1.3 \cdot 10^{-107} \lor \neg \left(f \leq 2 \cdot 10^{-47}\right)\right):\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\
\mathbf{else}:\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\end{array}
\end{array}
if f < -1.6e53 or -1.3e-22 < f < -1.3e-107 or 1.9999999999999999e-47 < f Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in n around 0 76.4%
if -1.6e53 < f < -1.3e-22 or -1.3e-107 < f < 1.9999999999999999e-47Initial program 100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
div-sub100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
div-sub100.0%
unsub-neg100.0%
remove-double-neg100.0%
+-commutative100.0%
sub-neg100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in f around 0 86.3%
Final simplification80.6%
(FPCore (f n)
:precision binary64
(if (<= f -5.8e+49)
-1.0
(if (or (<= f -1.6e-19) (and (not (<= f -1.3e-107)) (<= f 7.2e-53)))
(+ 1.0 (* 2.0 (/ f n)))
-1.0)))
double code(double f, double n) {
double tmp;
if (f <= -5.8e+49) {
tmp = -1.0;
} else if ((f <= -1.6e-19) || (!(f <= -1.3e-107) && (f <= 7.2e-53))) {
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 (f <= (-5.8d+49)) then
tmp = -1.0d0
else if ((f <= (-1.6d-19)) .or. (.not. (f <= (-1.3d-107))) .and. (f <= 7.2d-53)) 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 (f <= -5.8e+49) {
tmp = -1.0;
} else if ((f <= -1.6e-19) || (!(f <= -1.3e-107) && (f <= 7.2e-53))) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -5.8e+49: tmp = -1.0 elif (f <= -1.6e-19) or (not (f <= -1.3e-107) and (f <= 7.2e-53)): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -5.8e+49) tmp = -1.0; elseif ((f <= -1.6e-19) || (!(f <= -1.3e-107) && (f <= 7.2e-53))) 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 (f <= -5.8e+49) tmp = -1.0; elseif ((f <= -1.6e-19) || (~((f <= -1.3e-107)) && (f <= 7.2e-53))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -5.8e+49], -1.0, If[Or[LessEqual[f, -1.6e-19], And[N[Not[LessEqual[f, -1.3e-107]], $MachinePrecision], LessEqual[f, 7.2e-53]]], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -5.8 \cdot 10^{+49}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq -1.6 \cdot 10^{-19} \lor \neg \left(f \leq -1.3 \cdot 10^{-107}\right) \land f \leq 7.2 \cdot 10^{-53}:\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -5.8e49 or -1.59999999999999991e-19 < f < -1.3e-107 or 7.1999999999999998e-53 < f Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in f around inf 74.6%
if -5.8e49 < f < -1.59999999999999991e-19 or -1.3e-107 < f < 7.1999999999999998e-53Initial program 100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
div-sub100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
div-sub100.0%
unsub-neg100.0%
remove-double-neg100.0%
+-commutative100.0%
sub-neg100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in f around 0 86.9%
Final simplification79.8%
(FPCore (f n)
:precision binary64
(if (<= f -1100000000000.0)
-1.0
(if (<= f -1e-19)
1.0
(if (<= f -1.3e-107) -1.0 (if (<= f 6.6e-68) 1.0 -1.0)))))
double code(double f, double n) {
double tmp;
if (f <= -1100000000000.0) {
tmp = -1.0;
} else if (f <= -1e-19) {
tmp = 1.0;
} else if (f <= -1.3e-107) {
tmp = -1.0;
} else if (f <= 6.6e-68) {
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 <= (-1100000000000.0d0)) then
tmp = -1.0d0
else if (f <= (-1d-19)) then
tmp = 1.0d0
else if (f <= (-1.3d-107)) then
tmp = -1.0d0
else if (f <= 6.6d-68) 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 <= -1100000000000.0) {
tmp = -1.0;
} else if (f <= -1e-19) {
tmp = 1.0;
} else if (f <= -1.3e-107) {
tmp = -1.0;
} else if (f <= 6.6e-68) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -1100000000000.0: tmp = -1.0 elif f <= -1e-19: tmp = 1.0 elif f <= -1.3e-107: tmp = -1.0 elif f <= 6.6e-68: tmp = 1.0 else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -1100000000000.0) tmp = -1.0; elseif (f <= -1e-19) tmp = 1.0; elseif (f <= -1.3e-107) tmp = -1.0; elseif (f <= 6.6e-68) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (f <= -1100000000000.0) tmp = -1.0; elseif (f <= -1e-19) tmp = 1.0; elseif (f <= -1.3e-107) tmp = -1.0; elseif (f <= 6.6e-68) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -1100000000000.0], -1.0, If[LessEqual[f, -1e-19], 1.0, If[LessEqual[f, -1.3e-107], -1.0, If[LessEqual[f, 6.6e-68], 1.0, -1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1100000000000:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq -1 \cdot 10^{-19}:\\
\;\;\;\;1\\
\mathbf{elif}\;f \leq -1.3 \cdot 10^{-107}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 6.6 \cdot 10^{-68}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -1.1e12 or -9.9999999999999998e-20 < f < -1.3e-107 or 6.5999999999999997e-68 < f Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in f around inf 72.8%
if -1.1e12 < f < -9.9999999999999998e-20 or -1.3e-107 < f < 6.5999999999999997e-68Initial program 100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
div-sub100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
*-commutative100.0%
neg-mul-1100.0%
div-sub100.0%
unsub-neg100.0%
remove-double-neg100.0%
+-commutative100.0%
sub-neg100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in f around 0 90.4%
Final simplification79.4%
(FPCore (f n) :precision binary64 (/ 1.0 (/ (- n f) (+ f n))))
double code(double f, double n) {
return 1.0 / ((n - f) / (f + n));
}
real(8) function code(f, n)
real(8), intent (in) :: f
real(8), intent (in) :: n
code = 1.0d0 / ((n - f) / (f + n))
end function
public static double code(double f, double n) {
return 1.0 / ((n - f) / (f + n));
}
def code(f, n): return 1.0 / ((n - f) / (f + n))
function code(f, n) return Float64(1.0 / Float64(Float64(n - f) / Float64(f + n))) end
function tmp = code(f, n) tmp = 1.0 / ((n - f) / (f + n)); end
code[f_, n_] := N[(1.0 / N[(N[(n - f), $MachinePrecision] / N[(f + n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{n - f}{f + n}}
\end{array}
Initial program 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
log1p-expm1-u100.0%
Applied egg-rr100.0%
log1p-expm1-u99.9%
clear-num99.9%
Applied egg-rr99.9%
Final simplification99.9%
(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 99.9%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
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%
neg-mul-199.9%
*-commutative99.9%
associate-/l*99.9%
div-sub99.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
metadata-eval99.9%
metadata-eval99.9%
associate-/l*99.9%
*-commutative99.9%
neg-mul-199.9%
div-sub99.9%
unsub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
sub-neg99.9%
metadata-eval99.9%
/-rgt-identity99.9%
Simplified99.9%
Taylor expanded in f around inf 48.9%
Final simplification48.9%
herbie shell --seed 2023189
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))