
(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 (/ (+ 1.0 t) t)))
(/
(+ 1.0 (/ (/ (* t 4.0) t_1) (+ 1.0 t)))
(+ 2.0 (+ (+ 1.0 (/ 4.0 (pow t_1 2.0))) -1.0)))))
double code(double t) {
double t_1 = (1.0 + t) / t;
return (1.0 + (((t * 4.0) / t_1) / (1.0 + t))) / (2.0 + ((1.0 + (4.0 / pow(t_1, 2.0))) + -1.0));
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: t_1
t_1 = (1.0d0 + t) / t
code = (1.0d0 + (((t * 4.0d0) / t_1) / (1.0d0 + t))) / (2.0d0 + ((1.0d0 + (4.0d0 / (t_1 ** 2.0d0))) + (-1.0d0)))
end function
public static double code(double t) {
double t_1 = (1.0 + t) / t;
return (1.0 + (((t * 4.0) / t_1) / (1.0 + t))) / (2.0 + ((1.0 + (4.0 / Math.pow(t_1, 2.0))) + -1.0));
}
def code(t): t_1 = (1.0 + t) / t return (1.0 + (((t * 4.0) / t_1) / (1.0 + t))) / (2.0 + ((1.0 + (4.0 / math.pow(t_1, 2.0))) + -1.0))
function code(t) t_1 = Float64(Float64(1.0 + t) / t) return Float64(Float64(1.0 + Float64(Float64(Float64(t * 4.0) / t_1) / Float64(1.0 + t))) / Float64(2.0 + Float64(Float64(1.0 + Float64(4.0 / (t_1 ^ 2.0))) + -1.0))) end
function tmp = code(t) t_1 = (1.0 + t) / t; tmp = (1.0 + (((t * 4.0) / t_1) / (1.0 + t))) / (2.0 + ((1.0 + (4.0 / (t_1 ^ 2.0))) + -1.0)); end
code[t_] := Block[{t$95$1 = N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]}, N[(N[(1.0 + N[(N[(N[(t * 4.0), $MachinePrecision] / t$95$1), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(N[(1.0 + N[(4.0 / N[Power[t$95$1, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{1 + t}{t}\\
\frac{1 + \frac{\frac{t \cdot 4}{t\_1}}{1 + t}}{2 + \left(\left(1 + \frac{4}{{t\_1}^{2}}\right) + -1\right)}
\end{array}
\end{array}
Initial program 100.0%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*99.9%
associate-*l/99.9%
associate-*r/99.9%
metadata-eval99.9%
associate-*r/100.0%
Simplified100.0%
expm1-log1p-u100.0%
expm1-udef99.2%
log1p-udef99.3%
add-exp-log100.0%
associate-/l/100.0%
*-commutative100.0%
associate-/l*100.0%
associate-*l/100.0%
pow2100.0%
+-commutative100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (t)
:precision binary64
(if (or (<= t -0.51) (not (<= t 0.75)))
(- 0.8333333333333334 (/ 0.2222222222222222 t))
(/
(+ 1.0 (/ (/ (* t 4.0) (/ (+ 1.0 t) t)) (+ 1.0 t)))
(+ 2.0 (/ (* t (* t 4.0)) (+ 1.0 t))))))
double code(double t) {
double tmp;
if ((t <= -0.51) || !(t <= 0.75)) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else {
tmp = (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * (t * 4.0)) / (1.0 + t)));
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: tmp
if ((t <= (-0.51d0)) .or. (.not. (t <= 0.75d0))) then
tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
else
tmp = (1.0d0 + (((t * 4.0d0) / ((1.0d0 + t) / t)) / (1.0d0 + t))) / (2.0d0 + ((t * (t * 4.0d0)) / (1.0d0 + t)))
end if
code = tmp
end function
public static double code(double t) {
double tmp;
if ((t <= -0.51) || !(t <= 0.75)) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else {
tmp = (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * (t * 4.0)) / (1.0 + t)));
}
return tmp;
}
def code(t): tmp = 0 if (t <= -0.51) or not (t <= 0.75): tmp = 0.8333333333333334 - (0.2222222222222222 / t) else: tmp = (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * (t * 4.0)) / (1.0 + t))) return tmp
function code(t) tmp = 0.0 if ((t <= -0.51) || !(t <= 0.75)) tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t)); else tmp = Float64(Float64(1.0 + Float64(Float64(Float64(t * 4.0) / Float64(Float64(1.0 + t) / t)) / Float64(1.0 + t))) / Float64(2.0 + Float64(Float64(t * Float64(t * 4.0)) / Float64(1.0 + t)))); end return tmp end
function tmp_2 = code(t) tmp = 0.0; if ((t <= -0.51) || ~((t <= 0.75))) tmp = 0.8333333333333334 - (0.2222222222222222 / t); else tmp = (1.0 + (((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t))) / (2.0 + ((t * (t * 4.0)) / (1.0 + t))); end tmp_2 = tmp; end
code[t_] := If[Or[LessEqual[t, -0.51], N[Not[LessEqual[t, 0.75]], $MachinePrecision]], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + N[(N[(N[(t * 4.0), $MachinePrecision] / N[(N[(1.0 + t), $MachinePrecision] / t), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(N[(t * N[(t * 4.0), $MachinePrecision]), $MachinePrecision] / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.51 \lor \neg \left(t \leq 0.75\right):\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\mathbf{else}:\\
\;\;\;\;\frac{1 + \frac{\frac{t \cdot 4}{\frac{1 + t}{t}}}{1 + t}}{2 + \frac{t \cdot \left(t \cdot 4\right)}{1 + t}}\\
\end{array}
\end{array}
if t < -0.51000000000000001 or 0.75 < t Initial program 100.0%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*99.9%
associate-*l/99.9%
associate-*r/99.9%
metadata-eval99.9%
associate-*r/100.0%
Simplified100.0%
Taylor expanded in t around inf 99.6%
associate-*r/99.6%
metadata-eval99.6%
Simplified99.6%
if -0.51000000000000001 < t < 0.75Initial program 100.0%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*100.0%
associate-*l/100.0%
associate-*r/100.0%
metadata-eval100.0%
associate-*r/100.0%
Simplified100.0%
Taylor expanded in t around 0 99.1%
associate-/r/99.1%
/-rgt-identity99.1%
*-commutative99.1%
Applied egg-rr99.1%
Final simplification99.4%
(FPCore (t) :precision binary64 (let* ((t_1 (/ (/ (* t 4.0) (/ (+ 1.0 t) t)) (+ 1.0 t)))) (/ (+ 1.0 t_1) (+ t_1 2.0))))
double code(double t) {
double t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (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 * 4.0d0) / ((1.0d0 + t) / t)) / (1.0d0 + t)
code = (1.0d0 + t_1) / (t_1 + 2.0d0)
end function
public static double code(double t) {
double t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t);
return (1.0 + t_1) / (t_1 + 2.0);
}
def code(t): t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t) return (1.0 + t_1) / (t_1 + 2.0)
function code(t) t_1 = Float64(Float64(Float64(t * 4.0) / Float64(Float64(1.0 + t) / t)) / Float64(1.0 + t)) return Float64(Float64(1.0 + t_1) / Float64(t_1 + 2.0)) end
function tmp = code(t) t_1 = ((t * 4.0) / ((1.0 + t) / t)) / (1.0 + t); tmp = (1.0 + t_1) / (t_1 + 2.0); end
code[t_] := Block[{t$95$1 = N[(N[(N[(t * 4.0), $MachinePrecision] / N[(N[(1.0 + t), $MachinePrecision] / t), $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 \cdot 4}{\frac{1 + t}{t}}}{1 + t}\\
\frac{1 + t\_1}{t\_1 + 2}
\end{array}
\end{array}
Initial program 100.0%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*99.9%
associate-*l/99.9%
associate-*r/99.9%
metadata-eval99.9%
associate-*r/100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (t) :precision binary64 (if (or (<= t -0.49) (not (<= t 0.65))) (- 0.8333333333333334 (/ 0.2222222222222222 t)) 0.5))
double code(double t) {
double tmp;
if ((t <= -0.49) || !(t <= 0.65)) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else {
tmp = 0.5;
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: tmp
if ((t <= (-0.49d0)) .or. (.not. (t <= 0.65d0))) then
tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
else
tmp = 0.5d0
end if
code = tmp
end function
public static double code(double t) {
double tmp;
if ((t <= -0.49) || !(t <= 0.65)) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else {
tmp = 0.5;
}
return tmp;
}
def code(t): tmp = 0 if (t <= -0.49) or not (t <= 0.65): tmp = 0.8333333333333334 - (0.2222222222222222 / t) else: tmp = 0.5 return tmp
function code(t) tmp = 0.0 if ((t <= -0.49) || !(t <= 0.65)) tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t)); else tmp = 0.5; end return tmp end
function tmp_2 = code(t) tmp = 0.0; if ((t <= -0.49) || ~((t <= 0.65))) tmp = 0.8333333333333334 - (0.2222222222222222 / t); else tmp = 0.5; end tmp_2 = tmp; end
code[t_] := If[Or[LessEqual[t, -0.49], N[Not[LessEqual[t, 0.65]], $MachinePrecision]], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.49 \lor \neg \left(t \leq 0.65\right):\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\mathbf{else}:\\
\;\;\;\;0.5\\
\end{array}
\end{array}
if t < -0.48999999999999999 or 0.650000000000000022 < t Initial program 100.0%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*99.9%
associate-*l/99.9%
associate-*r/99.9%
metadata-eval99.9%
associate-*r/100.0%
Simplified100.0%
Taylor expanded in t around inf 99.6%
associate-*r/99.6%
metadata-eval99.6%
Simplified99.6%
if -0.48999999999999999 < t < 0.650000000000000022Initial program 100.0%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*100.0%
associate-*l/100.0%
associate-*r/100.0%
metadata-eval100.0%
associate-*r/100.0%
Simplified100.0%
Taylor expanded in t around 0 98.5%
Final simplification99.1%
(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%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*99.9%
associate-*l/99.9%
associate-*r/99.9%
metadata-eval99.9%
associate-*r/100.0%
Simplified100.0%
Taylor expanded in t around inf 98.6%
if -0.330000000000000016 < t < 1Initial program 100.0%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*100.0%
associate-*l/100.0%
associate-*r/100.0%
metadata-eval100.0%
associate-*r/100.0%
Simplified100.0%
Taylor expanded in t around 0 98.5%
Final simplification98.6%
(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%
associate-*r/100.0%
associate-*r*100.0%
*-commutative100.0%
associate-/l*99.9%
associate-*l/99.9%
associate-*r/99.9%
metadata-eval99.9%
associate-*r/100.0%
Simplified100.0%
Taylor expanded in t around 0 60.0%
Final simplification60.0%
herbie shell --seed 2024027
(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))))))