
(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 (- (+ (log z) 1.0) z) y (* 0.5 x)))
double code(double x, double y, double z) {
return fma(((log(z) + 1.0) - z), y, (0.5 * x));
}
function code(x, y, z) return fma(Float64(Float64(log(z) + 1.0) - z), y, Float64(0.5 * x)) end
code[x_, y_, z_] := N[(N[(N[(N[Log[z], $MachinePrecision] + 1.0), $MachinePrecision] - z), $MachinePrecision] * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(\left(\log z + 1\right) - z, y, 0.5 \cdot x\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%
(FPCore (x y z) :precision binary64 (let* ((t_0 (* y (+ (- 1.0 z) (log z))))) (if (or (<= t_0 -1e+172) (not (<= t_0 4e-10))) (* (- y) z) (* 0.5 x))))
double code(double x, double y, double z) {
double t_0 = y * ((1.0 - z) + log(z));
double tmp;
if ((t_0 <= -1e+172) || !(t_0 <= 4e-10)) {
tmp = -y * z;
} else {
tmp = 0.5 * x;
}
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) :: t_0
real(8) :: tmp
t_0 = y * ((1.0d0 - z) + log(z))
if ((t_0 <= (-1d+172)) .or. (.not. (t_0 <= 4d-10))) then
tmp = -y * z
else
tmp = 0.5d0 * x
end if
code = tmp
end function
public static double code(double x, double y, double z) {
double t_0 = y * ((1.0 - z) + Math.log(z));
double tmp;
if ((t_0 <= -1e+172) || !(t_0 <= 4e-10)) {
tmp = -y * z;
} else {
tmp = 0.5 * x;
}
return tmp;
}
def code(x, y, z): t_0 = y * ((1.0 - z) + math.log(z)) tmp = 0 if (t_0 <= -1e+172) or not (t_0 <= 4e-10): tmp = -y * z else: tmp = 0.5 * x return tmp
function code(x, y, z) t_0 = Float64(y * Float64(Float64(1.0 - z) + log(z))) tmp = 0.0 if ((t_0 <= -1e+172) || !(t_0 <= 4e-10)) tmp = Float64(Float64(-y) * z); else tmp = Float64(0.5 * x); end return tmp end
function tmp_2 = code(x, y, z) t_0 = y * ((1.0 - z) + log(z)); tmp = 0.0; if ((t_0 <= -1e+172) || ~((t_0 <= 4e-10))) tmp = -y * z; else tmp = 0.5 * x; end tmp_2 = tmp; end
code[x_, y_, z_] := Block[{t$95$0 = N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$0, -1e+172], N[Not[LessEqual[t$95$0, 4e-10]], $MachinePrecision]], N[((-y) * z), $MachinePrecision], N[(0.5 * x), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := y \cdot \left(\left(1 - z\right) + \log z\right)\\
\mathbf{if}\;t\_0 \leq -1 \cdot 10^{+172} \lor \neg \left(t\_0 \leq 4 \cdot 10^{-10}\right):\\
\;\;\;\;\left(-y\right) \cdot z\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot x\\
\end{array}
\end{array}
if (*.f64 y (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z))) < -1.0000000000000001e172 or 4.00000000000000015e-10 < (*.f64 y (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z))) Initial program 99.9%
Taylor expanded in z around inf
associate-*r*N/A
lower-*.f64N/A
mul-1-negN/A
lower-neg.f6463.4
Applied rewrites63.4%
if -1.0000000000000001e172 < (*.f64 y (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z))) < 4.00000000000000015e-10Initial 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 x around inf
Applied rewrites95.1%
Taylor expanded in x around inf
Applied rewrites65.8%
Final simplification64.7%
(FPCore (x y z) :precision binary64 (if (or (<= x -4.3e-95) (not (<= x 3.4e-49))) (fma (- z) y (* 0.5 x)) (fma (- (log z) z) y y)))
double code(double x, double y, double z) {
double tmp;
if ((x <= -4.3e-95) || !(x <= 3.4e-49)) {
tmp = fma(-z, y, (0.5 * x));
} else {
tmp = fma((log(z) - z), y, y);
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if ((x <= -4.3e-95) || !(x <= 3.4e-49)) tmp = fma(Float64(-z), y, Float64(0.5 * x)); else tmp = fma(Float64(log(z) - z), y, y); end return tmp end
code[x_, y_, z_] := If[Or[LessEqual[x, -4.3e-95], N[Not[LessEqual[x, 3.4e-49]], $MachinePrecision]], N[((-z) * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision], N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + y), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -4.3 \cdot 10^{-95} \lor \neg \left(x \leq 3.4 \cdot 10^{-49}\right):\\
\;\;\;\;\mathsf{fma}\left(-z, y, 0.5 \cdot x\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\log z - z, y, y\right)\\
\end{array}
\end{array}
if x < -4.29999999999999997e-95 or 3.40000000000000005e-49 < x 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.f6489.0
Applied rewrites89.0%
if -4.29999999999999997e-95 < x < 3.40000000000000005e-49Initial program 99.8%
Taylor expanded in x around 0
associate--l+N/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
lower--.f64N/A
lower-log.f6491.9
Applied rewrites91.9%
Final simplification90.1%
(FPCore (x y z) :precision binary64 (if (or (<= x -2.3e-252) (not (<= x 1.66e-183))) (fma (- z) y (* 0.5 x)) (fma (log z) y y)))
double code(double x, double y, double z) {
double tmp;
if ((x <= -2.3e-252) || !(x <= 1.66e-183)) {
tmp = fma(-z, y, (0.5 * x));
} else {
tmp = fma(log(z), y, y);
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if ((x <= -2.3e-252) || !(x <= 1.66e-183)) tmp = fma(Float64(-z), y, Float64(0.5 * x)); else tmp = fma(log(z), y, y); end return tmp end
code[x_, y_, z_] := If[Or[LessEqual[x, -2.3e-252], N[Not[LessEqual[x, 1.66e-183]], $MachinePrecision]], N[((-z) * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision], N[(N[Log[z], $MachinePrecision] * y + y), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.3 \cdot 10^{-252} \lor \neg \left(x \leq 1.66 \cdot 10^{-183}\right):\\
\;\;\;\;\mathsf{fma}\left(-z, y, 0.5 \cdot x\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\log z, y, y\right)\\
\end{array}
\end{array}
if x < -2.2999999999999998e-252 or 1.66e-183 < x 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.f6482.6
Applied rewrites82.6%
if -2.2999999999999998e-252 < x < 1.66e-183Initial program 99.8%
Taylor expanded in x around 0
associate--l+N/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
lower--.f64N/A
lower-log.f6497.5
Applied rewrites97.5%
Taylor expanded in z around 0
Applied rewrites67.8%
Final simplification80.3%
(FPCore (x y z) :precision binary64 (if (<= z 0.28) (fma 0.5 x (fma (log z) y y)) (fma (- z) y (* 0.5 x))))
double code(double x, double y, double z) {
double tmp;
if (z <= 0.28) {
tmp = fma(0.5, x, fma(log(z), y, y));
} else {
tmp = fma(-z, y, (0.5 * x));
}
return tmp;
}
function code(x, y, z) tmp = 0.0 if (z <= 0.28) tmp = fma(0.5, x, fma(log(z), y, y)); else tmp = fma(Float64(-z), y, Float64(0.5 * x)); end return tmp end
code[x_, y_, z_] := If[LessEqual[z, 0.28], N[(0.5 * x + N[(N[Log[z], $MachinePrecision] * y + y), $MachinePrecision]), $MachinePrecision], N[((-z) * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;z \leq 0.28:\\
\;\;\;\;\mathsf{fma}\left(0.5, x, \mathsf{fma}\left(\log z, y, y\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(-z, y, 0.5 \cdot x\right)\\
\end{array}
\end{array}
if z < 0.28000000000000003Initial program 99.8%
Taylor expanded in z around 0
lower-fma.f64N/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
lower-log.f6498.9
Applied rewrites98.9%
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.f6497.6
Applied rewrites97.6%
(FPCore (x y z) :precision binary64 (fma 0.5 x (fma (- (log z) z) y y)))
double code(double x, double y, double z) {
return fma(0.5, x, fma((log(z) - z), y, y));
}
function code(x, y, z) return fma(0.5, x, fma(Float64(log(z) - z), y, y)) end
code[x_, y_, z_] := N[(0.5 * x + N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(0.5, x, \mathsf{fma}\left(\log z - z, y, y\right)\right)
\end{array}
Initial program 99.9%
Taylor expanded in x around 0
fp-cancel-sign-sub-invN/A
distribute-lft-neg-outN/A
distribute-rgt-neg-outN/A
mul-1-negN/A
fp-cancel-sub-sign-invN/A
mul-1-negN/A
lower-fma.f64N/A
mul-1-negN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-inN/A
distribute-lft-neg-inN/A
metadata-evalN/A
*-lft-identityN/A
associate--l+N/A
+-commutativeN/A
distribute-rgt-inN/A
*-lft-identityN/A
lower-fma.f64N/A
Applied rewrites99.9%
(FPCore (x y z) :precision binary64 (fma (- z) y (* 0.5 x)))
double code(double x, double y, double z) {
return fma(-z, y, (0.5 * x));
}
function code(x, y, z) return fma(Float64(-z), y, Float64(0.5 * x)) end
code[x_, y_, z_] := N[((-z) * y + N[(0.5 * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{fma}\left(-z, y, 0.5 \cdot x\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.f6475.1
Applied rewrites75.1%
(FPCore (x y z) :precision binary64 (* 0.5 x))
double code(double x, double y, double z) {
return 0.5 * x;
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = 0.5d0 * x
end function
public static double code(double x, double y, double z) {
return 0.5 * x;
}
def code(x, y, z): return 0.5 * x
function code(x, y, z) return Float64(0.5 * x) end
function tmp = code(x, y, z) tmp = 0.5 * x; end
code[x_, y_, z_] := N[(0.5 * x), $MachinePrecision]
\begin{array}{l}
\\
0.5 \cdot x
\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 x around inf
Applied rewrites88.8%
Taylor expanded in x around inf
Applied rewrites41.9%
Final simplification41.9%
(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 2024339
(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)))))