
(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 74.9%
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 71.5%
Taylor expanded in x around 0 99.4%
log-rec99.4%
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 1e+307))) (- 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 <= 1e+307)) {
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 <= 1e+307)) {
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 <= 1e+307): 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 <= 1e+307)) 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 <= 1e+307))) 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, 1e+307]], $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 10^{+307}\right):\\
\;\;\;\;-z\\
\mathbf{else}:\\
\;\;\;\;t\_0 - z\\
\end{array}
\end{array}
if (*.f64 x (log.f64 (/.f64 x y))) < -inf.0 or 9.99999999999999986e306 < (*.f64 x (log.f64 (/.f64 x y))) Initial program 5.9%
Taylor expanded in x around 0 66.2%
mul-1-neg66.2%
Simplified66.2%
if -inf.0 < (*.f64 x (log.f64 (/.f64 x y))) < 9.99999999999999986e306Initial program 99.8%
Final simplification90.2%
(FPCore (x y z) :precision binary64 (if (<= x -3.1e-91) (- (* x (- (log (/ y x)))) z) (if (<= x -1e-308) (- z) (- (* x (- (log x) (log y))) z))))
double code(double x, double y, double z) {
double tmp;
if (x <= -3.1e-91) {
tmp = (x * -log((y / x))) - z;
} else if (x <= -1e-308) {
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 <= (-3.1d-91)) then
tmp = (x * -log((y / x))) - z
else if (x <= (-1d-308)) 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 <= -3.1e-91) {
tmp = (x * -Math.log((y / x))) - z;
} else if (x <= -1e-308) {
tmp = -z;
} else {
tmp = (x * (Math.log(x) - Math.log(y))) - z;
}
return tmp;
}
def code(x, y, z): tmp = 0 if x <= -3.1e-91: tmp = (x * -math.log((y / x))) - z elif x <= -1e-308: tmp = -z else: tmp = (x * (math.log(x) - math.log(y))) - z return tmp
function code(x, y, z) tmp = 0.0 if (x <= -3.1e-91) tmp = Float64(Float64(x * Float64(-log(Float64(y / x)))) - z); elseif (x <= -1e-308) 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 <= -3.1e-91) tmp = (x * -log((y / x))) - z; elseif (x <= -1e-308) tmp = -z; else tmp = (x * (log(x) - log(y))) - z; end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[x, -3.1e-91], N[(N[(x * (-N[Log[N[(y / x), $MachinePrecision]], $MachinePrecision])), $MachinePrecision] - z), $MachinePrecision], If[LessEqual[x, -1e-308], (-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 -3.1 \cdot 10^{-91}:\\
\;\;\;\;x \cdot \left(-\log \left(\frac{y}{x}\right)\right) - z\\
\mathbf{elif}\;x \leq -1 \cdot 10^{-308}:\\
\;\;\;\;-z\\
\mathbf{else}:\\
\;\;\;\;x \cdot \left(\log x - \log y\right) - z\\
\end{array}
\end{array}
if x < -3.09999999999999981e-91Initial program 78.7%
clear-num78.8%
neg-log80.3%
Applied egg-rr80.3%
if -3.09999999999999981e-91 < x < -9.9999999999999991e-309Initial program 68.1%
Taylor expanded in x around 0 88.0%
mul-1-neg88.0%
Simplified88.0%
if -9.9999999999999991e-309 < x Initial program 71.5%
Taylor expanded in x around 0 99.4%
log-rec99.4%
sub-neg99.4%
Simplified99.4%
(FPCore (x y z) :precision binary64 (if (or (<= z -1.3e-61) (not (<= z 5.8e-16))) (- z) (* x (log (/ x y)))))
double code(double x, double y, double z) {
double tmp;
if ((z <= -1.3e-61) || !(z <= 5.8e-16)) {
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 <= (-1.3d-61)) .or. (.not. (z <= 5.8d-16))) 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 <= -1.3e-61) || !(z <= 5.8e-16)) {
tmp = -z;
} else {
tmp = x * Math.log((x / y));
}
return tmp;
}
def code(x, y, z): tmp = 0 if (z <= -1.3e-61) or not (z <= 5.8e-16): tmp = -z else: tmp = x * math.log((x / y)) return tmp
function code(x, y, z) tmp = 0.0 if ((z <= -1.3e-61) || !(z <= 5.8e-16)) 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 <= -1.3e-61) || ~((z <= 5.8e-16))) tmp = -z; else tmp = x * log((x / y)); end tmp_2 = tmp; end
code[x_, y_, z_] := If[Or[LessEqual[z, -1.3e-61], N[Not[LessEqual[z, 5.8e-16]], $MachinePrecision]], (-z), N[(x * N[Log[N[(x / y), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq -1.3 \cdot 10^{-61} \lor \neg \left(z \leq 5.8 \cdot 10^{-16}\right):\\
\;\;\;\;-z\\
\mathbf{else}:\\
\;\;\;\;x \cdot \log \left(\frac{x}{y}\right)\\
\end{array}
\end{array}
if z < -1.30000000000000005e-61 or 5.7999999999999996e-16 < z Initial program 72.0%
Taylor expanded in x around 0 80.3%
mul-1-neg80.3%
Simplified80.3%
if -1.30000000000000005e-61 < z < 5.7999999999999996e-16Initial program 74.4%
Taylor expanded in z around 0 63.9%
Final simplification73.5%
(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 73.0%
Taylor expanded in x around 0 57.2%
mul-1-neg57.2%
Simplified57.2%
(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 73.0%
Taylor expanded in x around 0 57.2%
mul-1-neg57.2%
Simplified57.2%
neg-sub057.2%
sub-neg57.2%
add-sqr-sqrt28.4%
sqrt-unprod16.1%
sqr-neg16.1%
sqrt-unprod0.9%
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 2024111
(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))