
(FPCore (x y z) :precision binary64 (- (* x (log (/ x y))) z))
double code(double x, double y, double z) {
return (x * log((x / y))) - z;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * log((x / y))) - z
end function
public static double code(double x, double y, double z) {
return (x * Math.log((x / y))) - z;
}
def code(x, y, z): return (x * math.log((x / y))) - z
function code(x, y, z) return Float64(Float64(x * log(Float64(x / y))) - z) end
function tmp = code(x, y, z) tmp = (x * log((x / y))) - z; end
code[x_, y_, z_] := N[(N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \log \left(\frac{x}{y}\right) - z
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (- (* x (log (/ x y))) z))
double code(double x, double y, double z) {
return (x * log((x / y))) - z;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (x * log((x / y))) - z
end function
public static double code(double x, double y, double z) {
return (x * Math.log((x / y))) - z;
}
def code(x, y, z): return (x * math.log((x / y))) - z
function code(x, y, z) return Float64(Float64(x * log(Float64(x / y))) - z) end
function tmp = code(x, y, z) tmp = (x * log((x / y))) - z; end
code[x_, y_, z_] := N[(N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \log \left(\frac{x}{y}\right) - z
\end{array}
(FPCore (x y z) :precision binary64 (if (<= y -2e-310) (- (* x (- (log (- x)) (log (- y)))) z) (- (* x (- (log x) (log y))) z)))
double code(double x, double y, double z) {
double tmp;
if (y <= -2e-310) {
tmp = (x * (log(-x) - log(-y))) - z;
} else {
tmp = (x * (log(x) - log(y))) - z;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if (y <= (-2d-310)) then
tmp = (x * (log(-x) - log(-y))) - z
else
tmp = (x * (log(x) - log(y))) - z
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (y <= -2e-310) {
tmp = (x * (Math.log(-x) - Math.log(-y))) - z;
} else {
tmp = (x * (Math.log(x) - Math.log(y))) - z;
}
return tmp;
}
def code(x, y, z): tmp = 0 if y <= -2e-310: tmp = (x * (math.log(-x) - math.log(-y))) - z else: tmp = (x * (math.log(x) - math.log(y))) - z return tmp
function code(x, y, z) tmp = 0.0 if (y <= -2e-310) tmp = Float64(Float64(x * Float64(log(Float64(-x)) - log(Float64(-y)))) - z); else tmp = Float64(Float64(x * Float64(log(x) - log(y))) - z); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (y <= -2e-310) tmp = (x * (log(-x) - log(-y))) - z; else tmp = (x * (log(x) - log(y))) - z; end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[y, -2e-310], N[(N[(x * N[(N[Log[(-x)], $MachinePrecision] - N[Log[(-y)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], N[(N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y \leq -2 \cdot 10^{-310}:\\
\;\;\;\;x \cdot \left(\log \left(-x\right) - \log \left(-y\right)\right) - z\\
\mathbf{else}:\\
\;\;\;\;x \cdot \left(\log x - \log y\right) - z\\
\end{array}
\end{array}
if y < -1.999999999999994e-310Initial program 71.8%
Taylor expanded in y around -inf 99.6%
metadata-eval99.6%
distribute-neg-frac99.6%
distribute-frac-neg299.6%
neg-mul-199.6%
log-rec99.6%
sub-neg99.6%
Simplified99.6%
if -1.999999999999994e-310 < y Initial program 77.0%
Taylor expanded in x around 0 99.4%
log-rec99.4%
neg-mul-199.4%
neg-mul-199.4%
sub-neg99.4%
Simplified99.4%
(FPCore (x y z) :precision binary64 (let* ((t_0 (* x (log (/ x y))))) (if (or (<= t_0 (- INFINITY)) (not (<= t_0 5e+304))) (- z) (- t_0 z))))
double code(double x, double y, double z) {
double t_0 = x * log((x / y));
double tmp;
if ((t_0 <= -((double) INFINITY)) || !(t_0 <= 5e+304)) {
tmp = -z;
} else {
tmp = t_0 - z;
}
return tmp;
}
public static double code(double x, double y, double z) {
double t_0 = x * Math.log((x / y));
double tmp;
if ((t_0 <= -Double.POSITIVE_INFINITY) || !(t_0 <= 5e+304)) {
tmp = -z;
} else {
tmp = t_0 - z;
}
return tmp;
}
def code(x, y, z): t_0 = x * math.log((x / y)) tmp = 0 if (t_0 <= -math.inf) or not (t_0 <= 5e+304): tmp = -z else: tmp = t_0 - z return tmp
function code(x, y, z) t_0 = Float64(x * log(Float64(x / y))) tmp = 0.0 if ((t_0 <= Float64(-Inf)) || !(t_0 <= 5e+304)) tmp = Float64(-z); else tmp = Float64(t_0 - z); end return tmp end
function tmp_2 = code(x, y, z) t_0 = x * log((x / y)); tmp = 0.0; if ((t_0 <= -Inf) || ~((t_0 <= 5e+304))) tmp = -z; else tmp = t_0 - z; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$0, (-Infinity)], N[Not[LessEqual[t$95$0, 5e+304]], $MachinePrecision]], (-z), N[(t$95$0 - z), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := x \cdot \log \left(\frac{x}{y}\right)\\
\mathbf{if}\;t\_0 \leq -\infty \lor \neg \left(t\_0 \leq 5 \cdot 10^{+304}\right):\\
\;\;\;\;-z\\
\mathbf{else}:\\
\;\;\;\;t\_0 - z\\
\end{array}
\end{array}
if (*.f64 x (log.f64 (/.f64 x y))) < -inf.0 or 4.9999999999999997e304 < (*.f64 x (log.f64 (/.f64 x y))) Initial program 4.3%
Taylor expanded in x around 0 55.7%
neg-mul-155.7%
Simplified55.7%
if -inf.0 < (*.f64 x (log.f64 (/.f64 x y))) < 4.9999999999999997e304Initial program 99.8%
Final simplification88.1%
(FPCore (x y z) :precision binary64 (if (<= x -4.3e-147) (- (* x (- (log (/ y x)))) z) (if (<= x -2e-307) (- z) (- (* x (- (log x) (log y))) z))))
double code(double x, double y, double z) {
double tmp;
if (x <= -4.3e-147) {
tmp = (x * -log((y / x))) - z;
} else if (x <= -2e-307) {
tmp = -z;
} else {
tmp = (x * (log(x) - log(y))) - z;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if (x <= (-4.3d-147)) then
tmp = (x * -log((y / x))) - z
else if (x <= (-2d-307)) then
tmp = -z
else
tmp = (x * (log(x) - log(y))) - z
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (x <= -4.3e-147) {
tmp = (x * -Math.log((y / x))) - z;
} else if (x <= -2e-307) {
tmp = -z;
} else {
tmp = (x * (Math.log(x) - Math.log(y))) - z;
}
return tmp;
}
def code(x, y, z): tmp = 0 if x <= -4.3e-147: tmp = (x * -math.log((y / x))) - z elif x <= -2e-307: tmp = -z else: tmp = (x * (math.log(x) - math.log(y))) - z return tmp
function code(x, y, z) tmp = 0.0 if (x <= -4.3e-147) tmp = Float64(Float64(x * Float64(-log(Float64(y / x)))) - z); elseif (x <= -2e-307) tmp = Float64(-z); else tmp = Float64(Float64(x * Float64(log(x) - log(y))) - z); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (x <= -4.3e-147) tmp = (x * -log((y / x))) - z; elseif (x <= -2e-307) tmp = -z; else tmp = (x * (log(x) - log(y))) - z; end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[x, -4.3e-147], N[(N[(x * (-N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision])), $MachinePrecision] - z), $MachinePrecision], If[LessEqual[x, -2e-307], (-z), N[(N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.3 \cdot 10^{-147}:\\
\;\;\;\;x \cdot \left(-\log \left(\frac{y}{x}\right)\right) - z\\
\mathbf{elif}\;x \leq -2 \cdot 10^{-307}:\\
\;\;\;\;-z\\
\mathbf{else}:\\
\;\;\;\;x \cdot \left(\log x - \log y\right) - z\\
\end{array}
\end{array}
if x < -4.3000000000000001e-147Initial program 78.7%
clear-num78.7%
neg-log79.4%
Applied egg-rr79.4%
if -4.3000000000000001e-147 < x < -1.99999999999999982e-307Initial program 51.4%
Taylor expanded in x around 0 94.7%
neg-mul-194.7%
Simplified94.7%
if -1.99999999999999982e-307 < x Initial program 77.0%
Taylor expanded in x around 0 99.4%
log-rec99.4%
neg-mul-199.4%
neg-mul-199.4%
sub-neg99.4%
Simplified99.4%
(FPCore (x y z) :precision binary64 (if (or (<= z -3.1e-138) (not (<= z 1.05e-62))) (- z) (* x (log (/ x y)))))
double code(double x, double y, double z) {
double tmp;
if ((z <= -3.1e-138) || !(z <= 1.05e-62)) {
tmp = -z;
} else {
tmp = x * log((x / y));
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if ((z <= (-3.1d-138)) .or. (.not. (z <= 1.05d-62))) then
tmp = -z
else
tmp = x * log((x / y))
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if ((z <= -3.1e-138) || !(z <= 1.05e-62)) {
tmp = -z;
} else {
tmp = x * Math.log((x / y));
}
return tmp;
}
def code(x, y, z): tmp = 0 if (z <= -3.1e-138) or not (z <= 1.05e-62): tmp = -z else: tmp = x * math.log((x / y)) return tmp
function code(x, y, z) tmp = 0.0 if ((z <= -3.1e-138) || !(z <= 1.05e-62)) tmp = Float64(-z); else tmp = Float64(x * log(Float64(x / y))); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if ((z <= -3.1e-138) || ~((z <= 1.05e-62))) tmp = -z; else tmp = x * log((x / y)); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[z, -3.1e-138], N[Not[LessEqual[z, 1.05e-62]], $MachinePrecision]], (-z), N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -3.1 \cdot 10^{-138} \lor \neg \left(z \leq 1.05 \cdot 10^{-62}\right):\\
\;\;\;\;-z\\
\mathbf{else}:\\
\;\;\;\;x \cdot \log \left(\frac{x}{y}\right)\\
\end{array}
\end{array}
if z < -3.0999999999999998e-138 or 1.05e-62 < z Initial program 73.5%
Taylor expanded in x around 0 70.3%
neg-mul-170.3%
Simplified70.3%
if -3.0999999999999998e-138 < z < 1.05e-62Initial program 76.4%
Taylor expanded in z around 0 68.8%
Final simplification69.8%
(FPCore (x y z) :precision binary64 (- z))
double code(double x, double y, double z) {
return -z;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = -z
end function
public static double code(double x, double y, double z) {
return -z;
}
def code(x, y, z): return -z
function code(x, y, z) return Float64(-z) end
function tmp = code(x, y, z) tmp = -z; end
code[x_, y_, z_] := (-z)
\begin{array}{l}
\\
-z
\end{array}
Initial program 74.4%
Taylor expanded in x around 0 52.2%
neg-mul-152.2%
Simplified52.2%
(FPCore (x y z) :precision binary64 z)
double code(double x, double y, double z) {
return z;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = z
end function
public static double code(double x, double y, double z) {
return z;
}
def code(x, y, z): return z
function code(x, y, z) return z end
function tmp = code(x, y, z) tmp = z; end
code[x_, y_, z_] := z
\begin{array}{l}
\\
z
\end{array}
Initial program 74.4%
Taylor expanded in x around 0 52.2%
neg-mul-152.2%
Simplified52.2%
neg-sub052.2%
sub-neg52.2%
add-sqr-sqrt25.8%
sqrt-unprod15.0%
sqr-neg15.0%
sqrt-unprod1.0%
add-sqr-sqrt2.1%
Applied egg-rr2.1%
+-lft-identity2.1%
Simplified2.1%
(FPCore (x y z) :precision binary64 (if (< y 7.595077799083773e-308) (- (* x (log (/ x y))) z) (- (* x (- (log x) (log y))) z)))
double code(double x, double y, double z) {
double tmp;
if (y < 7.595077799083773e-308) {
tmp = (x * log((x / y))) - z;
} else {
tmp = (x * (log(x) - log(y))) - z;
}
return tmp;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
real(8) :: tmp
if (y < 7.595077799083773d-308) then
tmp = (x * log((x / y))) - z
else
tmp = (x * (log(x) - log(y))) - z
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (y < 7.595077799083773e-308) {
tmp = (x * Math.log((x / y))) - z;
} else {
tmp = (x * (Math.log(x) - Math.log(y))) - z;
}
return tmp;
}
def code(x, y, z): tmp = 0 if y < 7.595077799083773e-308: tmp = (x * math.log((x / y))) - z else: tmp = (x * (math.log(x) - math.log(y))) - z return tmp
function code(x, y, z) tmp = 0.0 if (y < 7.595077799083773e-308) tmp = Float64(Float64(x * log(Float64(x / y))) - z); else tmp = Float64(Float64(x * Float64(log(x) - log(y))) - z); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (y < 7.595077799083773e-308) tmp = (x * log((x / y))) - z; else tmp = (x * (log(x) - log(y))) - z; end tmp_2 = tmp; end
code[x_, y_, z_] := If[Less[y, 7.595077799083773e-308], N[(N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision], N[(N[(x * N[(N[Log[x], $MachinePrecision] - N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;y < 7.595077799083773 \cdot 10^{-308}:\\
\;\;\;\;x \cdot \log \left(\frac{x}{y}\right) - z\\
\mathbf{else}:\\
\;\;\;\;x \cdot \left(\log x - \log y\right) - z\\
\end{array}
\end{array}
herbie shell --seed 2024170
(FPCore (x y z)
:name "Numeric.SpecFunctions.Extra:bd0 from math-functions-0.1.5.2"
:precision binary64
:alt
(! :herbie-platform default (if (< y 7595077799083773/100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (- (* x (log (/ x y))) z) (- (* x (- (log x) (log y))) z)))
(- (* x (log (/ x y))) z))