
(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 4 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) (- 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%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (f n) :precision binary64 (if (<= f -6.5e+25) -1.0 (if (<= f 4.2e-37) (+ 1.0 (* 2.0 (/ f n))) -1.0)))
double code(double f, double n) {
double tmp;
if (f <= -6.5e+25) {
tmp = -1.0;
} else if (f <= 4.2e-37) {
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 <= (-6.5d+25)) then
tmp = -1.0d0
else if (f <= 4.2d-37) 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 <= -6.5e+25) {
tmp = -1.0;
} else if (f <= 4.2e-37) {
tmp = 1.0 + (2.0 * (f / n));
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -6.5e+25: tmp = -1.0 elif f <= 4.2e-37: tmp = 1.0 + (2.0 * (f / n)) else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -6.5e+25) tmp = -1.0; elseif (f <= 4.2e-37) 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 <= -6.5e+25) tmp = -1.0; elseif (f <= 4.2e-37) tmp = 1.0 + (2.0 * (f / n)); else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -6.5e+25], -1.0, If[LessEqual[f, 4.2e-37], N[(1.0 + N[(2.0 * N[(f / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -6.5 \cdot 10^{+25}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 4.2 \cdot 10^{-37}:\\
\;\;\;\;1 + 2 \cdot \frac{f}{n}\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -6.50000000000000005e25 or 4.2000000000000002e-37 < f Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 82.3%
if -6.50000000000000005e25 < f < 4.2000000000000002e-37Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 83.1%
Final simplification82.7%
(FPCore (f n) :precision binary64 (if (<= f -5e+26) -1.0 (if (<= f 2.5e-36) 1.0 -1.0)))
double code(double f, double n) {
double tmp;
if (f <= -5e+26) {
tmp = -1.0;
} else if (f <= 2.5e-36) {
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 <= (-5d+26)) then
tmp = -1.0d0
else if (f <= 2.5d-36) 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 <= -5e+26) {
tmp = -1.0;
} else if (f <= 2.5e-36) {
tmp = 1.0;
} else {
tmp = -1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if f <= -5e+26: tmp = -1.0 elif f <= 2.5e-36: tmp = 1.0 else: tmp = -1.0 return tmp
function code(f, n) tmp = 0.0 if (f <= -5e+26) tmp = -1.0; elseif (f <= 2.5e-36) tmp = 1.0; else tmp = -1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (f <= -5e+26) tmp = -1.0; elseif (f <= 2.5e-36) tmp = 1.0; else tmp = -1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[f, -5e+26], -1.0, If[LessEqual[f, 2.5e-36], 1.0, -1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;f \leq -5 \cdot 10^{+26}:\\
\;\;\;\;-1\\
\mathbf{elif}\;f \leq 2.5 \cdot 10^{-36}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;-1\\
\end{array}
\end{array}
if f < -5.0000000000000001e26 or 2.50000000000000002e-36 < f Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 82.3%
if -5.0000000000000001e26 < f < 2.50000000000000002e-36Initial program 100.0%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 82.0%
Final simplification82.2%
(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%
sub-neg100.0%
remove-double-neg100.0%
distribute-neg-in100.0%
neg-mul-1100.0%
associate-/r*100.0%
neg-mul-1100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
/-rgt-identity100.0%
+-commutative100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 52.0%
Final simplification52.0%
herbie shell --seed 2023280
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))