
(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 5 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_2 (* 4.0 (* t_1 t_1)))) (/ (+ 1.0 t_2) (+ t_2 2.0))))
double code(double t) {
double t_1 = t / (1.0 + t);
double t_2 = 4.0 * (t_1 * t_1);
return (1.0 + t_2) / (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 / (1.0d0 + t)
t_2 = 4.0d0 * (t_1 * t_1)
code = (1.0d0 + t_2) / (t_2 + 2.0d0)
end function
public static double code(double t) {
double t_1 = t / (1.0 + t);
double t_2 = 4.0 * (t_1 * t_1);
return (1.0 + t_2) / (t_2 + 2.0);
}
def code(t): t_1 = t / (1.0 + t) t_2 = 4.0 * (t_1 * t_1) return (1.0 + t_2) / (t_2 + 2.0)
function code(t) t_1 = Float64(t / Float64(1.0 + t)) t_2 = Float64(4.0 * Float64(t_1 * t_1)) return Float64(Float64(1.0 + t_2) / Float64(t_2 + 2.0)) end
function tmp = code(t) t_1 = t / (1.0 + t); t_2 = 4.0 * (t_1 * t_1); tmp = (1.0 + t_2) / (t_2 + 2.0); end
code[t_] := Block[{t$95$1 = N[(t / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(4.0 * N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 + t$95$2), $MachinePrecision] / N[(t$95$2 + 2.0), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_1 := \frac{t}{1 + t}\\
t_2 := 4 \cdot \left(t\_1 \cdot t\_1\right)\\
\frac{1 + t\_2}{t\_2 + 2}
\end{array}
\end{array}
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%
Final simplification100.0%
(FPCore (t) :precision binary64 (if (or (<= t -0.58) (not (<= t 0.75))) (- 0.8333333333333334 (/ 0.2222222222222222 t)) (/ (+ 1.0 (* 4.0 (* t (/ t (+ 1.0 t))))) (+ 2.0 (* 4.0 (* t t))))))
double code(double t) {
double tmp;
if ((t <= -0.58) || !(t <= 0.75)) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else {
tmp = (1.0 + (4.0 * (t * (t / (1.0 + t))))) / (2.0 + (4.0 * (t * t)));
}
return tmp;
}
real(8) function code(t)
real(8), intent (in) :: t
real(8) :: tmp
if ((t <= (-0.58d0)) .or. (.not. (t <= 0.75d0))) then
tmp = 0.8333333333333334d0 - (0.2222222222222222d0 / t)
else
tmp = (1.0d0 + (4.0d0 * (t * (t / (1.0d0 + t))))) / (2.0d0 + (4.0d0 * (t * t)))
end if
code = tmp
end function
public static double code(double t) {
double tmp;
if ((t <= -0.58) || !(t <= 0.75)) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else {
tmp = (1.0 + (4.0 * (t * (t / (1.0 + t))))) / (2.0 + (4.0 * (t * t)));
}
return tmp;
}
def code(t): tmp = 0 if (t <= -0.58) or not (t <= 0.75): tmp = 0.8333333333333334 - (0.2222222222222222 / t) else: tmp = (1.0 + (4.0 * (t * (t / (1.0 + t))))) / (2.0 + (4.0 * (t * t))) return tmp
function code(t) tmp = 0.0 if ((t <= -0.58) || !(t <= 0.75)) tmp = Float64(0.8333333333333334 - Float64(0.2222222222222222 / t)); else tmp = Float64(Float64(1.0 + Float64(4.0 * Float64(t * Float64(t / Float64(1.0 + t))))) / Float64(2.0 + Float64(4.0 * Float64(t * t)))); end return tmp end
function tmp_2 = code(t) tmp = 0.0; if ((t <= -0.58) || ~((t <= 0.75))) tmp = 0.8333333333333334 - (0.2222222222222222 / t); else tmp = (1.0 + (4.0 * (t * (t / (1.0 + t))))) / (2.0 + (4.0 * (t * t))); end tmp_2 = tmp; end
code[t_] := If[Or[LessEqual[t, -0.58], N[Not[LessEqual[t, 0.75]], $MachinePrecision]], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 + N[(4.0 * N[(t * N[(t / N[(1.0 + t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 + N[(4.0 * N[(t * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.58 \lor \neg \left(t \leq 0.75\right):\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\mathbf{else}:\\
\;\;\;\;\frac{1 + 4 \cdot \left(t \cdot \frac{t}{1 + t}\right)}{2 + 4 \cdot \left(t \cdot t\right)}\\
\end{array}
\end{array}
if t < -0.57999999999999996 or 0.75 < 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 97.7%
associate-*r/97.7%
metadata-eval97.7%
Simplified97.7%
Taylor expanded in t around inf 98.1%
associate-*r/98.1%
metadata-eval98.1%
Simplified98.1%
if -0.57999999999999996 < t < 0.75Initial 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 99.7%
Taylor expanded in t around 0 99.7%
Taylor expanded in t around 0 99.8%
Final simplification99.0%
(FPCore (t) :precision binary64 (if (or (<= t -0.48) (not (<= t 0.67))) (- 0.8333333333333334 (/ 0.2222222222222222 t)) 0.5))
double code(double t) {
double tmp;
if ((t <= -0.48) || !(t <= 0.67)) {
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 <= (-0.48d0)) .or. (.not. (t <= 0.67d0))) 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 <= -0.48) || !(t <= 0.67)) {
tmp = 0.8333333333333334 - (0.2222222222222222 / t);
} else {
tmp = 0.5;
}
return tmp;
}
def code(t): tmp = 0 if (t <= -0.48) or not (t <= 0.67): tmp = 0.8333333333333334 - (0.2222222222222222 / t) else: tmp = 0.5 return tmp
function code(t) tmp = 0.0 if ((t <= -0.48) || !(t <= 0.67)) 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 <= -0.48) || ~((t <= 0.67))) tmp = 0.8333333333333334 - (0.2222222222222222 / t); else tmp = 0.5; end tmp_2 = tmp; end
code[t_] := If[Or[LessEqual[t, -0.48], N[Not[LessEqual[t, 0.67]], $MachinePrecision]], N[(0.8333333333333334 - N[(0.2222222222222222 / t), $MachinePrecision]), $MachinePrecision], 0.5]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;t \leq -0.48 \lor \neg \left(t \leq 0.67\right):\\
\;\;\;\;0.8333333333333334 - \frac{0.2222222222222222}{t}\\
\mathbf{else}:\\
\;\;\;\;0.5\\
\end{array}
\end{array}
if t < -0.47999999999999998 or 0.67000000000000004 < 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 97.7%
associate-*r/97.7%
metadata-eval97.7%
Simplified97.7%
Taylor expanded in t around inf 98.1%
associate-*r/98.1%
metadata-eval98.1%
Simplified98.1%
if -0.47999999999999998 < t < 0.67000000000000004Initial 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 99.7%
Taylor expanded in t around 0 99.6%
Final simplification98.9%
(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 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 97.7%
Taylor expanded in t around inf 97.9%
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 99.1%
Taylor expanded in t around 0 99.0%
Final simplification98.5%
(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-/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 54.4%
Taylor expanded in t around 0 61.8%
Final simplification61.8%
herbie shell --seed 2024039
(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))))))