
(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 (+ 1.0 t)) (* t 4.0)) (+ 1.0 t)))) (/ (+ 1.0 t_1) (+ t_1 2.0))))
double code(double t) {
double t_1 = ((t / (1.0 + t)) * (t * 4.0)) / (1.0 + t);
return (1.0 + t_1) / (t_1 + 2.0);
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
t_1 = ((t / (1.0d0 + t)) * (t * 4.0d0)) / (1.0d0 + t)
code = (1.0d0 + t_1) / (t_1 + 2.0d0)
end function
public static double code(double t) {
double t_1 = ((t / (1.0 + t)) * (t * 4.0)) / (1.0 + t);
return (1.0 + t_1) / (t_1 + 2.0);
}
def code(t): t_1 = ((t / (1.0 + t)) * (t * 4.0)) / (1.0 + t) return (1.0 + t_1) / (t_1 + 2.0)
function code(t) t_1 = Float64(Float64(Float64(t / Float64(1.0 + t)) * Float64(t * 4.0)) / Float64(1.0 + t)) return Float64(Float64(1.0 + t_1) / Float64(t_1 + 2.0)) end
function tmp = code(t) t_1 = ((t / (1.0 + t)) * (t * 4.0)) / (1.0 + t); tmp = (1.0 + t_1) / (t_1 + 2.0); end
code[t_] := Block[{t$95$1 = N[(N[(N[(t / N[(1.0 + t), $MachinePrecision]), $MachinePrecision] * N[(t * 4.0), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 + t$95$1), $MachinePrecision] / N[(t$95$1 + 2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{\frac{t}{1 + t} \cdot \left(t \cdot 4\right)}{1 + t}\\
\frac{1 + t_1}{t_1 + 2}
\end{array}
\end{array}
Initial program 100.0%
frac-times73.4%
swap-sqr73.4%
metadata-eval73.4%
*-commutative73.4%
associate-*r*73.4%
times-frac100.0%
associate-*r/100.0%
+-commutative100.0%
+-commutative100.0%
Applied egg-rr100.0%
frac-times73.4%
swap-sqr73.4%
metadata-eval73.4%
*-commutative73.4%
associate-*r*73.4%
times-frac100.0%
associate-*r/100.0%
+-commutative100.0%
+-commutative100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (t)
:precision binary64
(let* ((t_1 (/ (* t (* t 4.0)) (* (+ 1.0 t) (+ 1.0 t)))))
(if (<= (/ (* t 2.0) (+ 1.0 t)) 2.0)
(/ (+ 1.0 t_1) (+ 2.0 t_1))
(- 0.8333333333333334 (/ 0.2222222222222222 t)))))
double code(double t) {
double t_1 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t));
double tmp;
if (((t * 2.0) / (1.0 + t)) <= 2.0) {
tmp = (1.0 + t_1) / (2.0 + t_1);
} else {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: tmp
t_1 = (t * (t * 4.0d0)) / ((1.0d0 + t) * (1.0d0 + t))
if (((t * 2.0d0) / (1.0d0 + t)) <= 2.0d0) then
tmp = (1.0d0 + t_1) / (2.0d0 + t_1)
else
tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
end if
code = tmp
end function
public static double code(double t) {
double t_1 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t));
double tmp;
if (((t * 2.0) / (1.0 + t)) <= 2.0) {
tmp = (1.0 + t_1) / (2.0 + t_1);
} else {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
}
return tmp;
}
def code(t): t_1 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t)) tmp = 0 if ((t * 2.0) / (1.0 + t)) <= 2.0: tmp = (1.0 + t_1) / (2.0 + t_1) else: tmp = 0.8333333333333334 - (0.2222222222222222 / t) return tmp
function code(t) t_1 = Float64(Float64(t * Float64(t * 4.0)) / Float64(Float64(1.0 + t) * Float64(1.0 + t))) tmp = 0.0 if (Float64(Float64(t * 2.0) / Float64(1.0 + t)) <= 2.0) tmp = Float64(Float64(1.0 + t_1) / Float64(2.0 + t_1)); else tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t)); end return tmp end
function tmp_2 = code(t) t_1 = (t * (t * 4.0)) / ((1.0 + t) * (1.0 + t)); tmp = 0.0; if (((t * 2.0) / (1.0 + t)) <= 2.0) tmp = (1.0 + t_1) / (2.0 + t_1); else tmp = 0.8333333333333334 - (0.2222222222222222 / t); end tmp_2 = tmp; end
code[t_] := Block[{t$95$1 = N[(N[(t * N[(t * 4.0), $MachinePrecision]), $MachinePrecision] / N[(N[(1.0 + t), $MachinePrecision] * N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision], 2.0], N[(N[(1.0 + t$95$1), $MachinePrecision] / N[(2.0 + t$95$1), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{t \cdot \left(t \cdot 4\right)}{\left(1 + t\right) \cdot \left(1 + t\right)}\\
\mathbf{if}\;\frac{t \cdot 2}{1 + t} \leq 2:\\
\;\;\;\;\frac{1 + t_1}{2 + t_1}\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\end{array}
\end{array}
if (/.f64 (*.f64 2 t) (+.f64 1 t)) < 2Initial program 100.0%
times-frac72.8%
sqr-neg72.8%
distribute-rgt-neg-out72.8%
distribute-rgt-neg-out72.8%
swap-sqr72.8%
*-commutative72.8%
sqr-neg72.8%
associate-*r*72.8%
metadata-eval72.8%
times-frac72.8%
Simplified72.8%
if 2 < (/.f64 (*.f64 2 t) (+.f64 1 t)) Initial program 100.0%
Taylor expanded in t around inf 75.6%
associate-*r/75.6%
metadata-eval75.6%
Simplified75.6%
Taylor expanded in t around inf 80.6%
associate-*r/80.6%
metadata-eval80.6%
Simplified80.6%
Final simplification73.0%
(FPCore (t)
:precision binary64
(let* ((t_1 (/ (* t (* t 4.0)) (+ 1.0 (* t 2.0)))))
(if (<= (/ (* t 2.0) (+ 1.0 t)) 0.005)
(/ (+ 1.0 t_1) (+ 2.0 t_1))
(- 0.8333333333333334 (/ 0.2222222222222222 t)))))
double code(double t) {
double t_1 = (t * (t * 4.0)) / (1.0 + (t * 2.0));
double tmp;
if (((t * 2.0) / (1.0 + t)) <= 0.005) {
tmp = (1.0 + t_1) / (2.0 + t_1);
} else {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
real(8) :: tmp
t_1 = (t * (t * 4.0d0)) / (1.0d0 + (t * 2.0d0))
if (((t * 2.0d0) / (1.0d0 + t)) <= 0.005d0) then
tmp = (1.0d0 + t_1) / (2.0d0 + t_1)
else
tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
end if
code = tmp
end function
public static double code(double t) {
double t_1 = (t * (t * 4.0)) / (1.0 + (t * 2.0));
double tmp;
if (((t * 2.0) / (1.0 + t)) <= 0.005) {
tmp = (1.0 + t_1) / (2.0 + t_1);
} else {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
}
return tmp;
}
def code(t): t_1 = (t * (t * 4.0)) / (1.0 + (t * 2.0)) tmp = 0 if ((t * 2.0) / (1.0 + t)) <= 0.005: tmp = (1.0 + t_1) / (2.0 + t_1) else: tmp = 0.8333333333333334 - (0.2222222222222222 / t) return tmp
function code(t) t_1 = Float64(Float64(t * Float64(t * 4.0)) / Float64(1.0 + Float64(t * 2.0))) tmp = 0.0 if (Float64(Float64(t * 2.0) / Float64(1.0 + t)) <= 0.005) tmp = Float64(Float64(1.0 + t_1) / Float64(2.0 + t_1)); else tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t)); end return tmp end
function tmp_2 = code(t) t_1 = (t * (t * 4.0)) / (1.0 + (t * 2.0)); tmp = 0.0; if (((t * 2.0) / (1.0 + t)) <= 0.005) tmp = (1.0 + t_1) / (2.0 + t_1); else tmp = 0.8333333333333334 - (0.2222222222222222 / t); end tmp_2 = tmp; end
code[t_] := Block[{t$95$1 = N[(N[(t * N[(t * 4.0), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(t * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision], 0.005], N[(N[(1.0 + t$95$1), $MachinePrecision] / N[(2.0 + t$95$1), $MachinePrecision]), $MachinePrecision], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{t \cdot \left(t \cdot 4\right)}{1 + t \cdot 2}\\
\mathbf{if}\;\frac{t \cdot 2}{1 + t} \leq 0.005:\\
\;\;\;\;\frac{1 + t_1}{2 + t_1}\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\end{array}
\end{array}
if (/.f64 (*.f64 2 t) (+.f64 1 t)) < 0.0050000000000000001Initial program 100.0%
times-frac100.0%
sqr-neg100.0%
distribute-rgt-neg-out100.0%
distribute-rgt-neg-out100.0%
swap-sqr100.0%
*-commutative100.0%
sqr-neg100.0%
associate-*r*100.0%
metadata-eval100.0%
times-frac100.0%
Simplified100.0%
Taylor expanded in t around 0 99.7%
*-commutative99.7%
Simplified99.7%
Taylor expanded in t around 0 99.7%
*-commutative99.7%
Simplified99.7%
if 0.0050000000000000001 < (/.f64 (*.f64 2 t) (+.f64 1 t)) Initial program 100.0%
Taylor expanded in t around inf 98.2%
associate-*r/98.2%
metadata-eval98.2%
Simplified98.2%
Taylor expanded in t around inf 98.5%
associate-*r/98.5%
metadata-eval98.5%
Simplified98.5%
Final simplification99.1%
(FPCore (t) :precision binary64 (if (<= (/ (* t 2.0) (+ 1.0 t)) 0.005) 0.5 (- 0.8333333333333334 (/ 0.2222222222222222 t))))
double code(double t) {
double tmp;
if (((t * 2.0) / (1.0 + t)) <= 0.005) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: tmp
if (((t * 2.0d0) / (1.0d0 + t)) <= 0.005d0) then
tmp = 0.5d0
else
tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
end if
code = tmp
end function
public static double code(double t) {
double tmp;
if (((t * 2.0) / (1.0 + t)) <= 0.005) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
}
return tmp;
}
def code(t): tmp = 0 if ((t * 2.0) / (1.0 + t)) <= 0.005: tmp = 0.5 else: tmp = 0.8333333333333334 - (0.2222222222222222 / t) return tmp
function code(t) tmp = 0.0 if (Float64(Float64(t * 2.0) / Float64(1.0 + t)) <= 0.005) tmp = 0.5; else tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t)); end return tmp end
function tmp_2 = code(t) tmp = 0.0; if (((t * 2.0) / (1.0 + t)) <= 0.005) tmp = 0.5; else tmp = 0.8333333333333334 - (0.2222222222222222 / t); end tmp_2 = tmp; end
code[t_] := If[LessEqual[N[(N[(t * 2.0), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision], 0.005], 0.5, N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{t \cdot 2}{1 + t} \leq 0.005:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\end{array}
\end{array}
if (/.f64 (*.f64 2 t) (+.f64 1 t)) < 0.0050000000000000001Initial program 100.0%
Taylor expanded in t around 0 98.6%
Taylor expanded in t around 0 98.7%
if 0.0050000000000000001 < (/.f64 (*.f64 2 t) (+.f64 1 t)) Initial program 100.0%
Taylor expanded in t around inf 98.2%
associate-*r/98.2%
metadata-eval98.2%
Simplified98.2%
Taylor expanded in t around inf 98.5%
associate-*r/98.5%
metadata-eval98.5%
Simplified98.5%
Final simplification98.6%
(FPCore (t) :precision binary64 (if (<= t -0.33) 0.8333333333333334 (if (<= t 1.0) 0.5 0.8333333333333334)))
double code(double t) {
double tmp;
if (t <= -0.33) {
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 <= (-0.33d0)) 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 <= -0.33) {
tmp = 0.8333333333333334;
} else if (t <= 1.0) {
tmp = 0.5;
} else {
tmp = 0.8333333333333334;
}
return tmp;
}
def code(t): tmp = 0 if t <= -0.33: tmp = 0.8333333333333334 elif t <= 1.0: tmp = 0.5 else: tmp = 0.8333333333333334 return tmp
function code(t) tmp = 0.0 if (t <= -0.33) 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 <= -0.33) tmp = 0.8333333333333334; elseif (t <= 1.0) tmp = 0.5; else tmp = 0.8333333333333334; end tmp_2 = tmp; end
code[t_] := If[LessEqual[t, -0.33], 0.8333333333333334, If[LessEqual[t, 1.0], 0.5, 0.8333333333333334]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.33:\\
\;\;\;\;0.8333333333333334\\
\mathbf{elif}\;t \leq 1:\\
\;\;\;\;0.5\\
\mathbf{else}:\\
\;\;\;\;0.8333333333333334\\
\end{array}
\end{array}
if t < -0.330000000000000016 or 1 < t Initial program 100.0%
Taylor expanded in t around inf 98.2%
associate-*r/98.2%
metadata-eval98.2%
Simplified98.2%
Taylor expanded in t around inf 97.1%
if -0.330000000000000016 < t < 1Initial program 100.0%
Taylor expanded in t around 0 98.6%
Taylor expanded in t around 0 98.7%
Final simplification97.9%
(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 100.0%
Taylor expanded in t around 0 56.4%
Taylor expanded in t around 0 57.9%
Final simplification57.9%
herbie shell --seed 2024019
(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))))))