
(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 (+ (/ 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 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%
flip--53.5%
+-commutative53.5%
associate-/r/53.3%
Applied egg-rr53.3%
distribute-rgt-in53.3%
clear-num53.3%
un-div-inv53.4%
+-commutative53.4%
flip--74.7%
clear-num74.7%
un-div-inv74.8%
+-commutative74.8%
flip--100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (f n)
:precision binary64
(if (<= f -1.6e+58)
-1.0
(if (or (<= f 1.6e-20) (and (not (<= f 2.25e+17)) (<= f 7.8e+73)))
(+ 1.0 (* 2.0 (/ f n)))
-1.0)))
double code(double f, double n) {
double tmp;
if (f <= -1.6e+58) {
tmp = -1.0;
} else if ((f <= 1.6e-20) || (!(f <= 2.25e+17) && (f <= 7.8e+73))) {
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 <= (-1.6d+58)) then
tmp = -1.0d0
else if ((f <= 1.6d-20) .or. (.not. (f <= 2.25d+17)) .and. (f <= 7.8d+73)) 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 <= -1.6e+58) {
tmp = -1.0;
} else if ((f <= 1.6e-20) || (!(f <= 2.25e+17) && (f <= 7.8e+73))) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -1.6e+58: tmp = -1.0 elif (f <= 1.6e-20) or (not (f <= 2.25e+17) and (f <= 7.8e+73)): tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -1.6e+58) tmp = -1.0; elseif ((f <= 1.6e-20) || (!(f <= 2.25e+17) && (f <= 7.8e+73))) 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 <= -1.6e+58) tmp = -1.0; elseif ((f <= 1.6e-20) || (~((f <= 2.25e+17)) && (f <= 7.8e+73))) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -1.6e+58], -1.0, If[Or[LessEqual[f, 1.6e-20], And[N[Not[LessEqual[f, 2.25e+17]], $MachinePrecision], LessEqual[f, 7.8e+73]]], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.6 \cdot 10^{+58}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 1.6 \cdot 10^{-20} \lor \neg \left(f \leq 2.25 \cdot 10^{+17}\right) \land f \leq 7.8 \cdot 10^{+73}:\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -1.60000000000000008e58 or 1.59999999999999985e-20 < f < 2.25e17 or 7.8000000000000002e73 < f Initial 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 inf 90.8%
if -1.60000000000000008e58 < f < 1.59999999999999985e-20 or 2.25e17 < f < 7.8000000000000002e73Initial 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 77.6%
Final simplification83.0%
(FPCore (f n) :precision binary64 (if (or (<= f -1.18e+58) (not (<= f 3.4e-19))) (+ (* -2.0 (/ n f)) -1.0) (+ 1.0 (* 2.0 (/ f n)))))
double code(double f, double n) {
double tmp;
if ((f <= -1.18e+58) || !(f <= 3.4e-19)) {
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 <= (-1.18d+58)) .or. (.not. (f <= 3.4d-19))) 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 <= -1.18e+58) || !(f <= 3.4e-19)) {
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 <= -1.18e+58) or not (f <= 3.4e-19): 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 <= -1.18e+58) || !(f <= 3.4e-19)) 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 <= -1.18e+58) || ~((f <= 3.4e-19))) 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, -1.18e+58], N[Not[LessEqual[f, 3.4e-19]], $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 -1.18 \cdot 10^{+58} \lor \neg \left(f \leq 3.4 \cdot 10^{-19}\right):\\
\;\;\;\;-2 \cdot \frac{n}{f} + -1\\
\mathbf{else}:\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\end{array}
\end{array}
if f < -1.18000000000000003e58 or 3.4000000000000002e-19 < 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 85.8%
if -1.18000000000000003e58 < f < 3.4000000000000002e-19Initial 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 78.5%
Final simplification81.8%
(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%
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%
Final simplification100.0%
(FPCore (f n) :precision binary64 (if (<= f -1.2e+58) -1.0 (if (<= f 1.7e-24) 1.0 -1.0)))
double code(double f, double n) {
double tmp;
if (f <= -1.2e+58) {
tmp = -1.0;
} else if (f <= 1.7e-24) {
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 <= (-1.2d+58)) then
tmp = -1.0d0
else if (f <= 1.7d-24) 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 <= -1.2e+58) {
tmp = -1.0;
} else if (f <= 1.7e-24) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -1.2e+58: tmp = -1.0 elif f <= 1.7e-24: tmp = 1.0 else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -1.2e+58) tmp = -1.0; elseif (f <= 1.7e-24) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (f <= -1.2e+58) tmp = -1.0; elseif (f <= 1.7e-24) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -1.2e+58], -1.0, If[LessEqual[f, 1.7e-24], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -1.2 \cdot 10^{+58}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 1.7 \cdot 10^{-24}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -1.2e58 or 1.69999999999999996e-24 < 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 85.0%
if -1.2e58 < f < 1.69999999999999996e-24Initial 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 77.6%
Final simplification81.0%
(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%
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 inf 51.3%
Final simplification51.3%
herbie shell --seed 2023213
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))