
(FPCore (t) :precision binary64 (let* ((t_1 (/ (* 2.0 t) (+ 1.0 t))) (t_2 (* t_1 t_1))) (/ (+ 1.0 t_2) (+ 2.0 t_2))))
double code(double t) {
double t_1 = (2.0 * t) / (1.0 + t);
double t_2 = t_1 * t_1;
return (1.0 + t_2) / (2.0 + t_2);
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: t_2
t_1 = (2.0d0 * t) / (1.0d0 + t)
t_2 = t_1 * t_1
code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function
public static double code(double t) {
double t_1 = (2.0 * t) / (1.0 + t);
double t_2 = t_1 * t_1;
return (1.0 + t_2) / (2.0 + t_2);
}
def code(t): t_1 = (2.0 * t) / (1.0 + t) t_2 = t_1 * t_1 return (1.0 + t_2) / (2.0 + t_2)
function code(t) t_1 = Float64(Float64(2.0 * t) / Float64(1.0 + t)) t_2 = Float64(t_1 * t_1) return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2)) end
function tmp = code(t) t_1 = (2.0 * t) / (1.0 + t); t_2 = t_1 * t_1; tmp = (1.0 + t_2) / (2.0 + t_2); end
code[t_] := Block[{t$95$1 = N[(N[(2.0 * t), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{2 \cdot t}{1 + t}\\
t_2 := t\_1 \cdot t\_1\\
\frac{1 + t\_2}{2 + t\_2}
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (t) :precision binary64 (let* ((t_1 (/ (* 2.0 t) (+ 1.0 t))) (t_2 (* t_1 t_1))) (/ (+ 1.0 t_2) (+ 2.0 t_2))))
double code(double t) {
double t_1 = (2.0 * t) / (1.0 + t);
double t_2 = t_1 * t_1;
return (1.0 + t_2) / (2.0 + t_2);
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: t_2
t_1 = (2.0d0 * t) / (1.0d0 + t)
t_2 = t_1 * t_1
code = (1.0d0 + t_2) / (2.0d0 + t_2)
end function
public static double code(double t) {
double t_1 = (2.0 * t) / (1.0 + t);
double t_2 = t_1 * t_1;
return (1.0 + t_2) / (2.0 + t_2);
}
def code(t): t_1 = (2.0 * t) / (1.0 + t) t_2 = t_1 * t_1 return (1.0 + t_2) / (2.0 + t_2)
function code(t) t_1 = Float64(Float64(2.0 * t) / Float64(1.0 + t)) t_2 = Float64(t_1 * t_1) return Float64(Float64(1.0 + t_2) / Float64(2.0 + t_2)) end
function tmp = code(t) t_1 = (2.0 * t) / (1.0 + t); t_2 = t_1 * t_1; tmp = (1.0 + t_2) / (2.0 + t_2); end
code[t_] := Block[{t$95$1 = N[(N[(2.0 * t), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 * t$95$1), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(2.0 + t$95$2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{2 \cdot t}{1 + t}\\
t_2 := t\_1 \cdot t\_1\\
\frac{1 + t\_2}{2 + t\_2}
\end{array}
\end{array}
(FPCore (t) :precision binary64 (let* ((t_1 (/ t (+ t 1.0))) (t_2 (* 4.0 (* t_1 t_1)))) (/ (+ t_2 1.0) (+ t_2 2.0))))
double code(double t) {
double t_1 = t / (t + 1.0);
double t_2 = 4.0 * (t_1 * t_1);
return (t_2 + 1.0) / (t_2 + 2.0);
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: t_2
t_1 = t / (t + 1.0d0)
t_2 = 4.0d0 * (t_1 * t_1)
code = (t_2 + 1.0d0) / (t_2 + 2.0d0)
end function
public static double code(double t) {
double t_1 = t / (t + 1.0);
double t_2 = 4.0 * (t_1 * t_1);
return (t_2 + 1.0) / (t_2 + 2.0);
}
def code(t): t_1 = t / (t + 1.0) t_2 = 4.0 * (t_1 * t_1) return (t_2 + 1.0) / (t_2 + 2.0)
function code(t) t_1 = Float64(t / Float64(t + 1.0)) t_2 = Float64(4.0 * Float64(t_1 * t_1)) return Float64(Float64(t_2 + 1.0) / Float64(t_2 + 2.0)) end
function tmp = code(t) t_1 = t / (t + 1.0); t_2 = 4.0 * (t_1 * t_1); tmp = (t_2 + 1.0) / (t_2 + 2.0); end
code[t_] := Block[{t$95$1 = N[(t / N[(t + 1.0), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(4.0 * N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$2 + 1.0), $MachinePrecision] / N[(t$95$2 + 2.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{t}{t + 1}\\
t_2 := 4 \cdot \left(t\_1 \cdot t\_1\right)\\
\frac{t\_2 + 1}{t\_2 + 2}
\end{array}
\end{array}
Initial program 99.6%
associate-/l*99.6%
associate-/l*99.6%
swap-sqr99.6%
metadata-eval99.6%
associate-/l*99.6%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (t)
:precision binary64
(let* ((t_1 (/ t (+ t 1.0))))
(if (<= t -0.52)
(+
0.8333333333333334
(/ (- (/ 0.037037037037037035 t) 0.2222222222222222) t))
(if (<= t 1.0)
(/ (+ (* 4.0 (* t_1 t_1)) 1.0) (+ 2.0 (* 4.0 (* t t_1))))
0.8333333333333334))))
double code(double t) {
double t_1 = t / (t + 1.0);
double tmp;
if (t <= -0.52) {
tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t);
} else if (t <= 1.0) {
tmp = ((4.0 * (t_1 * t_1)) + 1.0) / (2.0 + (4.0 * (t * t_1)));
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: tmp
t_1 = t / (t + 1.0d0)
if (t <= (-0.52d0)) then
tmp = 0.8333333333333334d0 + (((0.037037037037037035d0 / t) - 0.2222222222222222d0) / t)
else if (t <= 1.0d0) then
tmp = ((4.0d0 * (t_1 * t_1)) + 1.0d0) / (2.0d0 + (4.0d0 * (t * t_1)))
else
tmp = 0.8333333333333334d0
end if
code = tmp
end function
public static double code(double t) {
double t_1 = t / (t + 1.0);
double tmp;
if (t <= -0.52) {
tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t);
} else if (t <= 1.0) {
tmp = ((4.0 * (t_1 * t_1)) + 1.0) / (2.0 + (4.0 * (t * t_1)));
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
def code(t): t_1 = t / (t + 1.0) tmp = 0 if t <= -0.52: tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t) elif t <= 1.0: tmp = ((4.0 * (t_1 * t_1)) + 1.0) / (2.0 + (4.0 * (t * t_1))) else: tmp = 0.8333333333333334 return tmp
function code(t) t_1 = Float64(t / Float64(t + 1.0)) tmp = 0.0 if (t <= -0.52) tmp = Float64(0.8333333333333334 + Float64(Float64(Float64(0.037037037037037035 / t) - 0.2222222222222222) / t)); elseif (t <= 1.0) tmp = Float64(Float64(Float64(4.0 * Float64(t_1 * t_1)) + 1.0) / Float64(2.0 + Float64(4.0 * Float64(t * t_1)))); else tmp = 0.8333333333333334; end return tmp end
function tmp_2 = code(t) t_1 = t / (t + 1.0); tmp = 0.0; if (t <= -0.52) tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t); elseif (t <= 1.0) tmp = ((4.0 * (t_1 * t_1)) + 1.0) / (2.0 + (4.0 * (t * t_1))); else tmp = 0.8333333333333334; end tmp_2 = tmp; end
code[t_] := Block[{t$95$1 = N[(t / N[(t + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, -0.52], N[(0.8333333333333334 + N[(N[(N[(0.037037037037037035 / t), $MachinePrecision] - 0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 1.0], N[(N[(N[(4.0 * N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / N[(2.0 + N[(4.0 * N[(t * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.8333333333333334]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{t}{t + 1}\\
\mathbf{if}\;t \leq -0.52:\\
\;\;\;\;0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} - 0.2222222222222222}{t}\\
\mathbf{elif}\;t \leq 1:\\
\;\;\;\;\frac{4 \cdot \left(t\_1 \cdot t\_1\right) + 1}{2 + 4 \cdot \left(t \cdot t\_1\right)}\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334\\
\end{array}
\end{array}
if t < -0.52000000000000002Initial program 98.3%
associate-/l*98.3%
associate-/l*98.4%
swap-sqr98.4%
metadata-eval98.4%
associate-/l*98.4%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around -inf 100.0%
mul-1-neg100.0%
unsub-neg100.0%
associate-*r/100.0%
metadata-eval100.0%
Simplified100.0%
if -0.52000000000000002 < t < 1Initial program 100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around 0 98.3%
if 1 < t Initial program 100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around inf 100.0%
Final simplification99.1%
(FPCore (t)
:precision binary64
(if (<= t -0.52)
(+
0.8333333333333334
(/ (- (/ 0.037037037037037035 t) 0.2222222222222222) t))
(if (<= t 1.0) 0.5 0.8333333333333334)))
double code(double t) {
double tmp;
if (t <= -0.52) {
tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t);
} else if (t <= 1.0) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: tmp
if (t <= (-0.52d0)) then
tmp = 0.8333333333333334d0 + (((0.037037037037037035d0 / t) - 0.2222222222222222d0) / t)
else if (t <= 1.0d0) then
tmp = 0.5d0
else
tmp = 0.8333333333333334d0
end if
code = tmp
end function
public static double code(double t) {
double tmp;
if (t <= -0.52) {
tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t);
} else if (t <= 1.0) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
def code(t): tmp = 0 if t <= -0.52: tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t) elif t <= 1.0: tmp = 0.5 else: tmp = 0.8333333333333334 return tmp
function code(t) tmp = 0.0 if (t <= -0.52) tmp = Float64(0.8333333333333334 + Float64(Float64(Float64(0.037037037037037035 / t) - 0.2222222222222222) / t)); elseif (t <= 1.0) tmp = 0.5; else tmp = 0.8333333333333334; end return tmp end
function tmp_2 = code(t) tmp = 0.0; if (t <= -0.52) tmp = 0.8333333333333334 + (((0.037037037037037035 / t) - 0.2222222222222222) / t); elseif (t <= 1.0) tmp = 0.5; else tmp = 0.8333333333333334; end tmp_2 = tmp; end
code[t_] := If[LessEqual[t, -0.52], N[(0.8333333333333334 + N[(N[(N[(0.037037037037037035 / t), $MachinePrecision] - 0.2222222222222222), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 1.0], 0.5, 0.8333333333333334]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.52:\\
\;\;\;\;0.8333333333333334 + \frac{\frac{0.037037037037037035}{t} - 0.2222222222222222}{t}\\
\mathbf{elif}\;t \leq 1:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334\\
\end{array}
\end{array}
if t < -0.52000000000000002Initial program 98.3%
associate-/l*98.3%
associate-/l*98.4%
swap-sqr98.4%
metadata-eval98.4%
associate-/l*98.4%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around -inf 100.0%
mul-1-neg100.0%
unsub-neg100.0%
associate-*r/100.0%
metadata-eval100.0%
Simplified100.0%
if -0.52000000000000002 < t < 1Initial program 100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around 0 97.8%
if 1 < t Initial program 100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around inf 100.0%
Final simplification98.9%
(FPCore (t) :precision binary64 (if (<= t -0.48) (- 0.8333333333333334 (/ 0.2222222222222222 t)) (if (<= t 1.0) 0.5 0.8333333333333334)))
double code(double t) {
double tmp;
if (t <= -0.48) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else if (t <= 1.0) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: tmp
if (t <= (-0.48d0)) then
tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
else if (t <= 1.0d0) then
tmp = 0.5d0
else
tmp = 0.8333333333333334d0
end if
code = tmp
end function
public static double code(double t) {
double tmp;
if (t <= -0.48) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else if (t <= 1.0) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
def code(t): tmp = 0 if t <= -0.48: tmp = 0.8333333333333334 - (0.2222222222222222 / t) elif t <= 1.0: tmp = 0.5 else: tmp = 0.8333333333333334 return tmp
function code(t) tmp = 0.0 if (t <= -0.48) tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t)); elseif (t <= 1.0) tmp = 0.5; else tmp = 0.8333333333333334; end return tmp end
function tmp_2 = code(t) tmp = 0.0; if (t <= -0.48) tmp = 0.8333333333333334 - (0.2222222222222222 / t); elseif (t <= 1.0) tmp = 0.5; else tmp = 0.8333333333333334; end tmp_2 = tmp; end
code[t_] := If[LessEqual[t, -0.48], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 1.0], 0.5, 0.8333333333333334]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.48:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\mathbf{elif}\;t \leq 1:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334\\
\end{array}
\end{array}
if t < -0.47999999999999998Initial program 98.3%
associate-/l*98.3%
associate-/l*98.4%
swap-sqr98.4%
metadata-eval98.4%
associate-/l*98.4%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around inf 99.9%
associate-*r/99.9%
metadata-eval99.9%
Simplified99.9%
if -0.47999999999999998 < t < 1Initial program 100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around 0 97.8%
if 1 < t Initial program 100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around inf 100.0%
(FPCore (t) :precision binary64 (if (<= t -0.34) 0.8333333333333334 (if (<= t 1.0) 0.5 0.8333333333333334)))
double code(double t) {
double tmp;
if (t <= -0.34) {
tmp = 0.8333333333333334;
} else if (t <= 1.0) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: tmp
if (t <= (-0.34d0)) then
tmp = 0.8333333333333334d0
else if (t <= 1.0d0) then
tmp = 0.5d0
else
tmp = 0.8333333333333334d0
end if
code = tmp
end function
public static double code(double t) {
double tmp;
if (t <= -0.34) {
tmp = 0.8333333333333334;
} else if (t <= 1.0) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
def code(t): tmp = 0 if t <= -0.34: tmp = 0.8333333333333334 elif t <= 1.0: tmp = 0.5 else: tmp = 0.8333333333333334 return tmp
function code(t) tmp = 0.0 if (t <= -0.34) tmp = 0.8333333333333334; elseif (t <= 1.0) tmp = 0.5; else tmp = 0.8333333333333334; end return tmp end
function tmp_2 = code(t) tmp = 0.0; if (t <= -0.34) tmp = 0.8333333333333334; elseif (t <= 1.0) tmp = 0.5; else tmp = 0.8333333333333334; end tmp_2 = tmp; end
code[t_] := If[LessEqual[t, -0.34], 0.8333333333333334, If[LessEqual[t, 1.0], 0.5, 0.8333333333333334]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.34:\\
\;\;\;\;0.8333333333333334\\
\mathbf{elif}\;t \leq 1:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334\\
\end{array}
\end{array}
if t < -0.340000000000000024 or 1 < t Initial program 99.2%
associate-/l*99.2%
associate-/l*99.2%
swap-sqr99.2%
metadata-eval99.2%
associate-/l*99.2%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around inf 99.3%
if -0.340000000000000024 < t < 1Initial program 100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around 0 97.8%
(FPCore (t) :precision binary64 0.5)
double code(double t) {
return 0.5;
}
real(8) function code(t)
real(8), intent (in) :: t
code = 0.5d0
end function
public static double code(double t) {
return 0.5;
}
def code(t): return 0.5
function code(t) return 0.5 end
function tmp = code(t) tmp = 0.5; end
code[t_] := 0.5
\begin{array}{l}
\\
0.5
\end{array}
Initial program 99.6%
associate-/l*99.6%
associate-/l*99.6%
swap-sqr99.6%
metadata-eval99.6%
associate-/l*99.6%
associate-/l*100.0%
swap-sqr100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in t around 0 60.0%
herbie shell --seed 2024085
(FPCore (t)
:name "Kahan p13 Example 1"
:precision binary64
(/ (+ 1.0 (* (/ (* 2.0 t) (+ 1.0 t)) (/ (* 2.0 t) (+ 1.0 t)))) (+ 2.0 (* (/ (* 2.0 t) (+ 1.0 t)) (/ (* 2.0 t) (+ 1.0 t))))))