
(FPCore (x) :precision binary64 (let* ((t_0 (* (tan x) (tan x)))) (/ (- 1.0 t_0) (+ 1.0 t_0))))
double code(double x) {
double t_0 = tan(x) * tan(x);
return (1.0 - t_0) / (1.0 + t_0);
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
t_0 = tan(x) * tan(x)
code = (1.0d0 - t_0) / (1.0d0 + t_0)
end function
public static double code(double x) {
double t_0 = Math.tan(x) * Math.tan(x);
return (1.0 - t_0) / (1.0 + t_0);
}
def code(x): t_0 = math.tan(x) * math.tan(x) return (1.0 - t_0) / (1.0 + t_0)
function code(x) t_0 = Float64(tan(x) * tan(x)) return Float64(Float64(1.0 - t_0) / Float64(1.0 + t_0)) end
function tmp = code(x) t_0 = tan(x) * tan(x); tmp = (1.0 - t_0) / (1.0 + t_0); end
code[x_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - t$95$0), $MachinePrecision] / N[(1.0 + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \tan x \cdot \tan x\\
\frac{1 - t\_0}{1 + t\_0}
\end{array}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (let* ((t_0 (* (tan x) (tan x)))) (/ (- 1.0 t_0) (+ 1.0 t_0))))
double code(double x) {
double t_0 = tan(x) * tan(x);
return (1.0 - t_0) / (1.0 + t_0);
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
t_0 = tan(x) * tan(x)
code = (1.0d0 - t_0) / (1.0d0 + t_0)
end function
public static double code(double x) {
double t_0 = Math.tan(x) * Math.tan(x);
return (1.0 - t_0) / (1.0 + t_0);
}
def code(x): t_0 = math.tan(x) * math.tan(x) return (1.0 - t_0) / (1.0 + t_0)
function code(x) t_0 = Float64(tan(x) * tan(x)) return Float64(Float64(1.0 - t_0) / Float64(1.0 + t_0)) end
function tmp = code(x) t_0 = tan(x) * tan(x); tmp = (1.0 - t_0) / (1.0 + t_0); end
code[x_] := Block[{t$95$0 = N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision]}, N[(N[(1.0 - t$95$0), $MachinePrecision] / N[(1.0 + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \tan x \cdot \tan x\\
\frac{1 - t\_0}{1 + t\_0}
\end{array}
\end{array}
(FPCore (x) :precision binary64 (let* ((t_0 (pow (tan x) 2.0))) (/ (- 1.0 t_0) (+ 1.0 t_0))))
double code(double x) {
double t_0 = pow(tan(x), 2.0);
return (1.0 - t_0) / (1.0 + t_0);
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
t_0 = tan(x) ** 2.0d0
code = (1.0d0 - t_0) / (1.0d0 + t_0)
end function
public static double code(double x) {
double t_0 = Math.pow(Math.tan(x), 2.0);
return (1.0 - t_0) / (1.0 + t_0);
}
def code(x): t_0 = math.pow(math.tan(x), 2.0) return (1.0 - t_0) / (1.0 + t_0)
function code(x) t_0 = tan(x) ^ 2.0 return Float64(Float64(1.0 - t_0) / Float64(1.0 + t_0)) end
function tmp = code(x) t_0 = tan(x) ^ 2.0; tmp = (1.0 - t_0) / (1.0 + t_0); end
code[x_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, N[(N[(1.0 - t$95$0), $MachinePrecision] / N[(1.0 + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
\frac{1 - t\_0}{1 + t\_0}
\end{array}
\end{array}
Initial program 99.5%
add-log-exp99.3%
*-un-lft-identity99.3%
log-prod99.3%
metadata-eval99.3%
add-log-exp99.5%
pow299.5%
pow299.5%
Applied egg-rr99.5%
+-lft-identity99.5%
Simplified99.5%
(FPCore (x) :precision binary64 (if (or (<= (tan x) -1.0) (not (<= (tan x) 1.0))) (+ -1.0 (exp (- (log 2.0) (pow x 2.0)))) (/ (log1p (expm1 1.0)) (+ 1.0 (pow (tan x) 2.0)))))
double code(double x) {
double tmp;
if ((tan(x) <= -1.0) || !(tan(x) <= 1.0)) {
tmp = -1.0 + exp((log(2.0) - pow(x, 2.0)));
} else {
tmp = log1p(expm1(1.0)) / (1.0 + pow(tan(x), 2.0));
}
return tmp;
}
public static double code(double x) {
double tmp;
if ((Math.tan(x) <= -1.0) || !(Math.tan(x) <= 1.0)) {
tmp = -1.0 + Math.exp((Math.log(2.0) - Math.pow(x, 2.0)));
} else {
tmp = Math.log1p(Math.expm1(1.0)) / (1.0 + Math.pow(Math.tan(x), 2.0));
}
return tmp;
}
def code(x): tmp = 0 if (math.tan(x) <= -1.0) or not (math.tan(x) <= 1.0): tmp = -1.0 + math.exp((math.log(2.0) - math.pow(x, 2.0))) else: tmp = math.log1p(math.expm1(1.0)) / (1.0 + math.pow(math.tan(x), 2.0)) return tmp
function code(x) tmp = 0.0 if ((tan(x) <= -1.0) || !(tan(x) <= 1.0)) tmp = Float64(-1.0 + exp(Float64(log(2.0) - (x ^ 2.0)))); else tmp = Float64(log1p(expm1(1.0)) / Float64(1.0 + (tan(x) ^ 2.0))); end return tmp end
code[x_] := If[Or[LessEqual[N[Tan[x], $MachinePrecision], -1.0], N[Not[LessEqual[N[Tan[x], $MachinePrecision], 1.0]], $MachinePrecision]], N[(-1.0 + N[Exp[N[(N[Log[2.0], $MachinePrecision] - N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(N[Log[1 + N[(Exp[1.0] - 1), $MachinePrecision]], $MachinePrecision] / N[(1.0 + N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\tan x \leq -1 \lor \neg \left(\tan x \leq 1\right):\\
\;\;\;\;-1 + e^{\log 2 - {x}^{2}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{log1p}\left(\mathsf{expm1}\left(1\right)\right)}{1 + {\tan x}^{2}}\\
\end{array}
\end{array}
if (tan.f64 x) < -1 or 1 < (tan.f64 x) Initial program 99.2%
expm1-log1p-u99.2%
expm1-undefine99.2%
div-inv99.0%
div-inv99.2%
pow299.2%
pow299.2%
Applied egg-rr99.2%
Taylor expanded in x around 0 21.0%
mul-1-neg21.0%
unsub-neg21.0%
Simplified21.0%
if -1 < (tan.f64 x) < 1Initial program 99.6%
add-log-exp99.5%
*-un-lft-identity99.5%
log-prod99.5%
metadata-eval99.5%
add-log-exp99.6%
pow299.6%
pow299.6%
Applied egg-rr99.6%
+-lft-identity99.6%
Simplified99.6%
log1p-expm1-u99.6%
Applied egg-rr99.6%
Taylor expanded in x around 0 73.1%
expm1-define73.1%
Simplified73.1%
Final simplification58.7%
(FPCore (x) :precision binary64 (+ -1.0 (exp (- (log 2.0) (pow x 2.0)))))
double code(double x) {
return -1.0 + exp((log(2.0) - pow(x, 2.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.0d0) + exp((log(2.0d0) - (x ** 2.0d0)))
end function
public static double code(double x) {
return -1.0 + Math.exp((Math.log(2.0) - Math.pow(x, 2.0)));
}
def code(x): return -1.0 + math.exp((math.log(2.0) - math.pow(x, 2.0)))
function code(x) return Float64(-1.0 + exp(Float64(log(2.0) - (x ^ 2.0)))) end
function tmp = code(x) tmp = -1.0 + exp((log(2.0) - (x ^ 2.0))); end
code[x_] := N[(-1.0 + N[Exp[N[(N[Log[2.0], $MachinePrecision] - N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
-1 + e^{\log 2 - {x}^{2}}
\end{array}
Initial program 99.5%
expm1-log1p-u99.5%
expm1-undefine99.4%
div-inv99.3%
div-inv99.4%
pow299.4%
pow299.4%
Applied egg-rr99.4%
Taylor expanded in x around 0 53.6%
mul-1-neg53.6%
unsub-neg53.6%
Simplified53.6%
Final simplification53.6%
(FPCore (x) :precision binary64 1.0)
double code(double x) {
return 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double x) {
return 1.0;
}
def code(x): return 1.0
function code(x) return 1.0 end
function tmp = code(x) tmp = 1.0; end
code[x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 99.5%
Taylor expanded in x around 0 52.9%
herbie shell --seed 2024119
(FPCore (x)
:name "Trigonometry B"
:precision binary64
(/ (- 1.0 (* (tan x) (tan x))) (+ 1.0 (* (tan x) (tan x)))))