
(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%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
(FPCore (f n)
:precision binary64
(if (<= n -3e+14)
1.0
(if (<= n -2.5e-12)
-1.0
(if (<= n -1.85e-13)
1.0
(if (<= n 4.3e+45)
-1.0
(if (<= n 3e+63) 1.0 (if (<= n 4.2e+65) -1.0 1.0)))))))
double code(double f, double n) {
double tmp;
if (n <= -3e+14) {
tmp = 1.0;
} else if (n <= -2.5e-12) {
tmp = -1.0;
} else if (n <= -1.85e-13) {
tmp = 1.0;
} else if (n <= 4.3e+45) {
tmp = -1.0;
} else if (n <= 3e+63) {
tmp = 1.0;
} else if (n <= 4.2e+65) {
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 <= (-3d+14)) then
tmp = 1.0d0
else if (n <= (-2.5d-12)) then
tmp = -1.0d0
else if (n <= (-1.85d-13)) then
tmp = 1.0d0
else if (n <= 4.3d+45) then
tmp = -1.0d0
else if (n <= 3d+63) then
tmp = 1.0d0
else if (n <= 4.2d+65) 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 <= -3e+14) {
tmp = 1.0;
} else if (n <= -2.5e-12) {
tmp = -1.0;
} else if (n <= -1.85e-13) {
tmp = 1.0;
} else if (n <= 4.3e+45) {
tmp = -1.0;
} else if (n <= 3e+63) {
tmp = 1.0;
} else if (n <= 4.2e+65) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -3e+14: tmp = 1.0 elif n <= -2.5e-12: tmp = -1.0 elif n <= -1.85e-13: tmp = 1.0 elif n <= 4.3e+45: tmp = -1.0 elif n <= 3e+63: tmp = 1.0 elif n <= 4.2e+65: tmp = -1.0 else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -3e+14) tmp = 1.0; elseif (n <= -2.5e-12) tmp = -1.0; elseif (n <= -1.85e-13) tmp = 1.0; elseif (n <= 4.3e+45) tmp = -1.0; elseif (n <= 3e+63) tmp = 1.0; elseif (n <= 4.2e+65) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -3e+14) tmp = 1.0; elseif (n <= -2.5e-12) tmp = -1.0; elseif (n <= -1.85e-13) tmp = 1.0; elseif (n <= 4.3e+45) tmp = -1.0; elseif (n <= 3e+63) tmp = 1.0; elseif (n <= 4.2e+65) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -3e+14], 1.0, If[LessEqual[n, -2.5e-12], -1.0, If[LessEqual[n, -1.85e-13], 1.0, If[LessEqual[n, 4.3e+45], -1.0, If[LessEqual[n, 3e+63], 1.0, If[LessEqual[n, 4.2e+65], -1.0, 1.0]]]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -3 \cdot 10^{+14}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq -2.5 \cdot 10^{-12}:\\
\;\;\;\;-1\\
\mathbf{elif}\;n \leq -1.85 \cdot 10^{-13}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 4.3 \cdot 10^{+45}:\\
\;\;\;\;-1\\
\mathbf{elif}\;n \leq 3 \cdot 10^{+63}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 4.2 \cdot 10^{+65}:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -3e14 or -2.49999999999999985e-12 < n < -1.84999999999999994e-13 or 4.3000000000000003e45 < n < 2.99999999999999999e63 or 4.19999999999999983e65 < n Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around 0 79.9%
if -3e14 < n < -2.49999999999999985e-12 or -1.84999999999999994e-13 < n < 4.3000000000000003e45 or 2.99999999999999999e63 < n < 4.19999999999999983e65Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 76.7%
(FPCore (f n)
:precision binary64
(if (<= n -3.3e+14)
1.0
(if (<= n -5e-13)
-1.0
(if (<= n -3.5e-13)
1.0
(if (<= n 4.3e+45) (+ -1.0 (* -2.0 (/ n f))) 1.0)))))
double code(double f, double n) {
double tmp;
if (n <= -3.3e+14) {
tmp = 1.0;
} else if (n <= -5e-13) {
tmp = -1.0;
} else if (n <= -3.5e-13) {
tmp = 1.0;
} else if (n <= 4.3e+45) {
tmp = -1.0 + (-2.0 * (n / f));
} 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 <= (-3.3d+14)) then
tmp = 1.0d0
else if (n <= (-5d-13)) then
tmp = -1.0d0
else if (n <= (-3.5d-13)) then
tmp = 1.0d0
else if (n <= 4.3d+45) then
tmp = (-1.0d0) + ((-2.0d0) * (n / f))
else
tmp = 1.0d0
end if
code = tmp
end function
public static double code(double f, double n) {
double tmp;
if (n <= -3.3e+14) {
tmp = 1.0;
} else if (n <= -5e-13) {
tmp = -1.0;
} else if (n <= -3.5e-13) {
tmp = 1.0;
} else if (n <= 4.3e+45) {
tmp = -1.0 + (-2.0 * (n / f));
} else {
tmp = 1.0;
}
return tmp;
}
def code(f, n): tmp = 0 if n <= -3.3e+14: tmp = 1.0 elif n <= -5e-13: tmp = -1.0 elif n <= -3.5e-13: tmp = 1.0 elif n <= 4.3e+45: tmp = -1.0 + (-2.0 * (n / f)) else: tmp = 1.0 return tmp
function code(f, n) tmp = 0.0 if (n <= -3.3e+14) tmp = 1.0; elseif (n <= -5e-13) tmp = -1.0; elseif (n <= -3.5e-13) tmp = 1.0; elseif (n <= 4.3e+45) tmp = Float64(-1.0 + Float64(-2.0 * Float64(n / f))); else tmp = 1.0; end return tmp end
function tmp_2 = code(f, n) tmp = 0.0; if (n <= -3.3e+14) tmp = 1.0; elseif (n <= -5e-13) tmp = -1.0; elseif (n <= -3.5e-13) tmp = 1.0; elseif (n <= 4.3e+45) tmp = -1.0 + (-2.0 * (n / f)); else tmp = 1.0; end tmp_2 = tmp; end
code[f_, n_] := If[LessEqual[n, -3.3e+14], 1.0, If[LessEqual[n, -5e-13], -1.0, If[LessEqual[n, -3.5e-13], 1.0, If[LessEqual[n, 4.3e+45], N[(-1.0 + N[(-2.0 * N[(n / f), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.0]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;n \leq -3.3 \cdot 10^{+14}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq -5 \cdot 10^{-13}:\\
\;\;\;\;-1\\
\mathbf{elif}\;n \leq -3.5 \cdot 10^{-13}:\\
\;\;\;\;1\\
\mathbf{elif}\;n \leq 4.3 \cdot 10^{+45}:\\
\;\;\;\;-1 + -2 \cdot \frac{n}{f}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if n < -3.3e14 or -4.9999999999999999e-13 < n < -3.5000000000000002e-13 or 4.3000000000000003e45 < n Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
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 -3.3e14 < n < -4.9999999999999999e-13Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 100.0%
if -3.5000000000000002e-13 < n < 4.3000000000000003e45Initial program 100.0%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in n around 0 76.7%
Final simplification78.2%
(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%
distribute-frac-neg100.0%
distribute-neg-frac2100.0%
sub-neg100.0%
+-commutative100.0%
distribute-neg-in100.0%
remove-double-neg100.0%
sub-neg100.0%
Simplified100.0%
Taylor expanded in f around inf 53.5%
herbie shell --seed 2024105
(FPCore (f n)
:name "subtraction fraction"
:precision binary64
(/ (- (+ f n)) (- f n)))