
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + log(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 * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z): return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * ((1.0 - z) + log(z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + log(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 * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z): return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z) return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z)))) end
function tmp = code(x, y, z) tmp = (x * 0.5) + (y * ((1.0 - z) + log(z))); end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}
(FPCore (x y z) :precision binary64 (fma (- (+ 1.0 (log z)) z) y (* x 0.5)))
double code(double x, double y, double z) {
return fma(((1.0 + log(z)) - z), y, (x * 0.5));
}
function code(x, y, z) return fma(Float64(Float64(1.0 + log(z)) - z), y, Float64(x * 0.5)) end
code[x_, y_, z_] := N[(N[(N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision] * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\left(1 + \log z\right) - z, y, x \cdot 0.5\right)
\end{array}
Initial program 99.9%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f6499.9
lift-+.f64N/A
+-commutativeN/A
lift--.f64N/A
associate-+r-N/A
lower--.f64N/A
lower-+.f6499.9
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.9
Applied rewrites99.9%
Final simplification99.9%
(FPCore (x y z) :precision binary64 (let* ((t_0 (fma (- (log z) z) y y))) (if (<= y -3.1e+145) t_0 (if (<= y 2e+74) (fma (- z) y (* x 0.5)) t_0))))
double code(double x, double y, double z) {
double t_0 = fma((log(z) - z), y, y);
double tmp;
if (y <= -3.1e+145) {
tmp = t_0;
} else if (y <= 2e+74) {
tmp = fma(-z, y, (x * 0.5));
} else {
tmp = t_0;
}
return tmp;
}
function code(x, y, z) t_0 = fma(Float64(log(z) - z), y, y) tmp = 0.0 if (y <= -3.1e+145) tmp = t_0; elseif (y <= 2e+74) tmp = fma(Float64(-z), y, Float64(x * 0.5)); else tmp = t_0; end return tmp end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + y), $MachinePrecision]}, If[LessEqual[y, -3.1e+145], t$95$0, If[LessEqual[y, 2e+74], N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(\log z - z, y, y\right)\\
\mathbf{if}\;y \leq -3.1 \cdot 10^{+145}:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;y \leq 2 \cdot 10^{+74}:\\
\;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if y < -3.09999999999999988e145 or 1.9999999999999999e74 < y Initial program 99.8%
Taylor expanded in y around inf
sub-negN/A
associate-+r+N/A
mul-1-negN/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
mul-1-negN/A
sub-negN/A
lower--.f64N/A
lower-log.f6491.6
Applied rewrites91.6%
if -3.09999999999999988e145 < y < 1.9999999999999999e74Initial program 99.9%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f6499.9
lift-+.f64N/A
+-commutativeN/A
lift--.f64N/A
associate-+r-N/A
lower--.f64N/A
lower-+.f6499.9
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.9
Applied rewrites99.9%
Taylor expanded in z around inf
mul-1-negN/A
lower-neg.f6490.2
Applied rewrites90.2%
Final simplification90.7%
(FPCore (x y z) :precision binary64 (if (<= z 0.28) (fma (+ 1.0 (log z)) y (* x 0.5)) (fma (- z) y (* x 0.5))))
double code(double x, double y, double z) {
double tmp;
if (z <= 0.28) {
tmp = fma((1.0 + log(z)), y, (x * 0.5));
} else {
tmp = fma(-z, y, (x * 0.5));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (z <= 0.28) tmp = fma(Float64(1.0 + log(z)), y, Float64(x * 0.5)); else tmp = fma(Float64(-z), y, Float64(x * 0.5)); end return tmp end
code[x_, y_, z_] := If[LessEqual[z, 0.28], N[(N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision] * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 0.28:\\
\;\;\;\;\mathsf{fma}\left(1 + \log z, y, x \cdot 0.5\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\
\end{array}
\end{array}
if z < 0.28000000000000003Initial program 99.8%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lift-+.f64N/A
flip-+N/A
div-invN/A
associate-*l*N/A
lower-fma.f64N/A
Applied rewrites99.6%
Taylor expanded in z around 0
+-commutativeN/A
associate-/l*N/A
*-commutativeN/A
lower-fma.f64N/A
remove-double-negN/A
log-recN/A
mul-1-negN/A
lower-/.f64N/A
lower--.f64N/A
lower-pow.f64N/A
lower-log.f64N/A
mul-1-negN/A
log-recN/A
remove-double-negN/A
lower--.f64N/A
lower-log.f64N/A
*-commutativeN/A
lower-*.f6498.7
Applied rewrites98.7%
Applied rewrites98.7%
if 0.28000000000000003 < z Initial program 100.0%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f64100.0
lift-+.f64N/A
+-commutativeN/A
lift--.f64N/A
associate-+r-N/A
lower--.f64N/A
lower-+.f64100.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f64100.0
Applied rewrites100.0%
Taylor expanded in z around inf
mul-1-negN/A
lower-neg.f6499.0
Applied rewrites99.0%
Final simplification98.8%
(FPCore (x y z) :precision binary64 (if (<= (+ (- 1.0 z) (log z)) -2e+21) (* (- z) y) (* x 0.5)))
double code(double x, double y, double z) {
double tmp;
if (((1.0 - z) + log(z)) <= -2e+21) {
tmp = -z * y;
} else {
tmp = x * 0.5;
}
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 (((1.0d0 - z) + log(z)) <= (-2d+21)) then
tmp = -z * y
else
tmp = x * 0.5d0
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double tmp;
if (((1.0 - z) + Math.log(z)) <= -2e+21) {
tmp = -z * y;
} else {
tmp = x * 0.5;
}
return tmp;
}
def code(x, y, z): tmp = 0 if ((1.0 - z) + math.log(z)) <= -2e+21: tmp = -z * y else: tmp = x * 0.5 return tmp
function code(x, y, z) tmp = 0.0 if (Float64(Float64(1.0 - z) + log(z)) <= -2e+21) tmp = Float64(Float64(-z) * y); else tmp = Float64(x * 0.5); end return tmp end
function tmp_2 = code(x, y, z) tmp = 0.0; if (((1.0 - z) + log(z)) <= -2e+21) tmp = -z * y; else tmp = x * 0.5; end tmp_2 = tmp; end
code[x_, y_, z_] := If[LessEqual[N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision], -2e+21], N[((-z) * y), $MachinePrecision], N[(x * 0.5), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left(1 - z\right) + \log z \leq -2 \cdot 10^{+21}:\\
\;\;\;\;\left(-z\right) \cdot y\\
\mathbf{else}:\\
\;\;\;\;x \cdot 0.5\\
\end{array}
\end{array}
if (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) < -2e21Initial program 100.0%
Taylor expanded in z around inf
mul-1-negN/A
*-commutativeN/A
distribute-lft-neg-inN/A
lower-*.f64N/A
lower-neg.f6480.0
Applied rewrites80.0%
if -2e21 < (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) Initial program 99.8%
Taylor expanded in y around 0
*-commutativeN/A
lower-*.f6456.2
Applied rewrites56.2%
(FPCore (x y z) :precision binary64 (if (<= z 0.28) (fma x 0.5 (fma (log z) y y)) (fma (- z) y (* x 0.5))))
double code(double x, double y, double z) {
double tmp;
if (z <= 0.28) {
tmp = fma(x, 0.5, fma(log(z), y, y));
} else {
tmp = fma(-z, y, (x * 0.5));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (z <= 0.28) tmp = fma(x, 0.5, fma(log(z), y, y)); else tmp = fma(Float64(-z), y, Float64(x * 0.5)); end return tmp end
code[x_, y_, z_] := If[LessEqual[z, 0.28], N[(x * 0.5 + N[(N[Log[z], $MachinePrecision] * y + y), $MachinePrecision]), $MachinePrecision], N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 0.28:\\
\;\;\;\;\mathsf{fma}\left(x, 0.5, \mathsf{fma}\left(\log z, y, y\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\
\end{array}
\end{array}
if z < 0.28000000000000003Initial program 99.8%
Taylor expanded in z around 0
*-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
lower-log.f6498.7
Applied rewrites98.7%
if 0.28000000000000003 < z Initial program 100.0%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f64100.0
lift-+.f64N/A
+-commutativeN/A
lift--.f64N/A
associate-+r-N/A
lower--.f64N/A
lower-+.f64100.0
lift-*.f64N/A
*-commutativeN/A
lower-*.f64100.0
Applied rewrites100.0%
Taylor expanded in z around inf
mul-1-negN/A
lower-neg.f6499.0
Applied rewrites99.0%
Final simplification98.8%
(FPCore (x y z) :precision binary64 (fma x 0.5 (fma (- (log z) z) y y)))
double code(double x, double y, double z) {
return fma(x, 0.5, fma((log(z) - z), y, y));
}
function code(x, y, z) return fma(x, 0.5, fma(Float64(log(z) - z), y, y)) end
code[x_, y_, z_] := N[(x * 0.5 + N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(x, 0.5, \mathsf{fma}\left(\log z - z, y, y\right)\right)
\end{array}
Initial program 99.9%
Taylor expanded in z around 0
+-commutativeN/A
associate-+l+N/A
mul-1-negN/A
unsub-negN/A
distribute-lft-out--N/A
*-commutativeN/A
lower-fma.f64N/A
sub-negN/A
associate-+r+N/A
mul-1-negN/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
mul-1-negN/A
sub-negN/A
lower--.f64N/A
lower-log.f6499.9
Applied rewrites99.9%
(FPCore (x y z) :precision binary64 (fma (- z) y (* x 0.5)))
double code(double x, double y, double z) {
return fma(-z, y, (x * 0.5));
}
function code(x, y, z) return fma(Float64(-z), y, Float64(x * 0.5)) end
code[x_, y_, z_] := N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-z, y, x \cdot 0.5\right)
\end{array}
Initial program 99.9%
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f6499.9
lift-+.f64N/A
+-commutativeN/A
lift--.f64N/A
associate-+r-N/A
lower--.f64N/A
lower-+.f6499.9
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.9
Applied rewrites99.9%
Taylor expanded in z around inf
mul-1-negN/A
lower-neg.f6479.4
Applied rewrites79.4%
Final simplification79.4%
(FPCore (x y z) :precision binary64 (* x 0.5))
double code(double x, double y, double z) {
return x * 0.5;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x * 0.5d0
end function
public static double code(double x, double y, double z) {
return x * 0.5;
}
def code(x, y, z): return x * 0.5
function code(x, y, z) return Float64(x * 0.5) end
function tmp = code(x, y, z) tmp = x * 0.5; end
code[x_, y_, z_] := N[(x * 0.5), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5
\end{array}
Initial program 99.9%
Taylor expanded in y around 0
*-commutativeN/A
lower-*.f6438.5
Applied rewrites38.5%
(FPCore (x y z) :precision binary64 (- (+ y (* 0.5 x)) (* y (- z (log z)))))
double code(double x, double y, double z) {
return (y + (0.5 * x)) - (y * (z - log(z)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = (y + (0.5d0 * x)) - (y * (z - log(z)))
end function
public static double code(double x, double y, double z) {
return (y + (0.5 * x)) - (y * (z - Math.log(z)));
}
def code(x, y, z): return (y + (0.5 * x)) - (y * (z - math.log(z)))
function code(x, y, z) return Float64(Float64(y + Float64(0.5 * x)) - Float64(y * Float64(z - log(z)))) end
function tmp = code(x, y, z) tmp = (y + (0.5 * x)) - (y * (z - log(z))); end
code[x_, y_, z_] := N[(N[(y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision] - N[(y * N[(z - N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(y + 0.5 \cdot x\right) - y \cdot \left(z - \log z\right)
\end{array}
herbie shell --seed 2024243
(FPCore (x y z)
:name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
:precision binary64
:alt
(! :herbie-platform default (- (+ y (* 1/2 x)) (* y (- z (log z)))))
(+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))