
(FPCore (x y) :precision binary64 (- (log (+ 1.0 (exp x))) (* x y)))
double code(double x, double y) {
return log((1.0 + exp(x))) - (x * y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = log((1.0d0 + exp(x))) - (x * y)
end function
public static double code(double x, double y) {
return Math.log((1.0 + Math.exp(x))) - (x * y);
}
def code(x, y): return math.log((1.0 + math.exp(x))) - (x * y)
function code(x, y) return Float64(log(Float64(1.0 + exp(x))) - Float64(x * y)) end
function tmp = code(x, y) tmp = log((1.0 + exp(x))) - (x * y); end
code[x_, y_] := N[(N[Log[N[(1.0 + N[Exp[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(1 + e^{x}\right) - x \cdot y
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 9 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y) :precision binary64 (- (log (+ 1.0 (exp x))) (* x y)))
double code(double x, double y) {
return log((1.0 + exp(x))) - (x * y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = log((1.0d0 + exp(x))) - (x * y)
end function
public static double code(double x, double y) {
return Math.log((1.0 + Math.exp(x))) - (x * y);
}
def code(x, y): return math.log((1.0 + math.exp(x))) - (x * y)
function code(x, y) return Float64(log(Float64(1.0 + exp(x))) - Float64(x * y)) end
function tmp = code(x, y) tmp = log((1.0 + exp(x))) - (x * y); end
code[x_, y_] := N[(N[Log[N[(1.0 + N[Exp[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\log \left(1 + e^{x}\right) - x \cdot y
\end{array}
(FPCore (x y) :precision binary64 (- (log1p (exp x)) (* x y)))
double code(double x, double y) {
return log1p(exp(x)) - (x * y);
}
public static double code(double x, double y) {
return Math.log1p(Math.exp(x)) - (x * y);
}
def code(x, y): return math.log1p(math.exp(x)) - (x * y)
function code(x, y) return Float64(log1p(exp(x)) - Float64(x * y)) end
code[x_, y_] := N[(N[Log[1 + N[Exp[x], $MachinePrecision]], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\mathsf{log1p}\left(e^{x}\right) - x \cdot y
\end{array}
(FPCore (x y)
:precision binary64
(if (<= x -8.2e-8)
(* x (- y))
(if (or (<= x 2.2e-76) (and (not (<= x 6.5e-37)) (<= x 4.4e-20)))
(log 2.0)
(* x (- 0.5 y)))))
double code(double x, double y) {
double tmp;
if (x <= -8.2e-8) {
tmp = x * -y;
} else if ((x <= 2.2e-76) || (!(x <= 6.5e-37) && (x <= 4.4e-20))) {
tmp = log(2.0);
} else {
tmp = x * (0.5 - y);
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-8.2d-8)) then
tmp = x * -y
else if ((x <= 2.2d-76) .or. (.not. (x <= 6.5d-37)) .and. (x <= 4.4d-20)) then
tmp = log(2.0d0)
else
tmp = x * (0.5d0 - y)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -8.2e-8) {
tmp = x * -y;
} else if ((x <= 2.2e-76) || (!(x <= 6.5e-37) && (x <= 4.4e-20))) {
tmp = Math.log(2.0);
} else {
tmp = x * (0.5 - y);
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -8.2e-8: tmp = x * -y elif (x <= 2.2e-76) or (not (x <= 6.5e-37) and (x <= 4.4e-20)): tmp = math.log(2.0) else: tmp = x * (0.5 - y) return tmp
function code(x, y) tmp = 0.0 if (x <= -8.2e-8) tmp = Float64(x * Float64(-y)); elseif ((x <= 2.2e-76) || (!(x <= 6.5e-37) && (x <= 4.4e-20))) tmp = log(2.0); else tmp = Float64(x * Float64(0.5 - y)); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -8.2e-8) tmp = x * -y; elseif ((x <= 2.2e-76) || (~((x <= 6.5e-37)) && (x <= 4.4e-20))) tmp = log(2.0); else tmp = x * (0.5 - y); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -8.2e-8], N[(x * (-y)), $MachinePrecision], If[Or[LessEqual[x, 2.2e-76], And[N[Not[LessEqual[x, 6.5e-37]], $MachinePrecision], LessEqual[x, 4.4e-20]]], N[Log[2.0], $MachinePrecision], N[(x * N[(0.5 - y), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -8.2 \cdot 10^{-8}:\\
\;\;\;\;x \cdot \left(-y\right)\\
\mathbf{elif}\;x \leq 2.2 \cdot 10^{-76} \lor \neg \left(x \leq 6.5 \cdot 10^{-37}\right) \land x \leq 4.4 \cdot 10^{-20}:\\
\;\;\;\;\log 2\\
\mathbf{else}:\\
\;\;\;\;x \cdot \left(0.5 - y\right)\\
\end{array}
\end{array}
(FPCore (x y)
:precision binary64
(if (<= x -2.9e-8)
(* x (- y))
(if (or (<= x 5e-76) (not (<= x 1.4e-37)))
(log (+ x 2.0))
(* x (- 0.5 y)))))
double code(double x, double y) {
double tmp;
if (x <= -2.9e-8) {
tmp = x * -y;
} else if ((x <= 5e-76) || !(x <= 1.4e-37)) {
tmp = log((x + 2.0));
} else {
tmp = x * (0.5 - y);
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-2.9d-8)) then
tmp = x * -y
else if ((x <= 5d-76) .or. (.not. (x <= 1.4d-37))) then
tmp = log((x + 2.0d0))
else
tmp = x * (0.5d0 - y)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -2.9e-8) {
tmp = x * -y;
} else if ((x <= 5e-76) || !(x <= 1.4e-37)) {
tmp = Math.log((x + 2.0));
} else {
tmp = x * (0.5 - y);
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -2.9e-8: tmp = x * -y elif (x <= 5e-76) or not (x <= 1.4e-37): tmp = math.log((x + 2.0)) else: tmp = x * (0.5 - y) return tmp
function code(x, y) tmp = 0.0 if (x <= -2.9e-8) tmp = Float64(x * Float64(-y)); elseif ((x <= 5e-76) || !(x <= 1.4e-37)) tmp = log(Float64(x + 2.0)); else tmp = Float64(x * Float64(0.5 - y)); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -2.9e-8) tmp = x * -y; elseif ((x <= 5e-76) || ~((x <= 1.4e-37))) tmp = log((x + 2.0)); else tmp = x * (0.5 - y); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -2.9e-8], N[(x * (-y)), $MachinePrecision], If[Or[LessEqual[x, 5e-76], N[Not[LessEqual[x, 1.4e-37]], $MachinePrecision]], N[Log[N[(x + 2.0), $MachinePrecision]], $MachinePrecision], N[(x * N[(0.5 - y), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.9 \cdot 10^{-8}:\\
\;\;\;\;x \cdot \left(-y\right)\\
\mathbf{elif}\;x \leq 5 \cdot 10^{-76} \lor \neg \left(x \leq 1.4 \cdot 10^{-37}\right):\\
\;\;\;\;\log \left(x + 2\right)\\
\mathbf{else}:\\
\;\;\;\;x \cdot \left(0.5 - y\right)\\
\end{array}
\end{array}
(FPCore (x y)
:precision binary64
(if (<= x -1.85e-6)
(* x (- y))
(if (<= x 2.8e-75)
(log1p (+ x 1.0))
(if (<= x 4.3e-38) (* x (- 0.5 y)) (log (+ x 2.0))))))
double code(double x, double y) {
double tmp;
if (x <= -1.85e-6) {
tmp = x * -y;
} else if (x <= 2.8e-75) {
tmp = log1p((x + 1.0));
} else if (x <= 4.3e-38) {
tmp = x * (0.5 - y);
} else {
tmp = log((x + 2.0));
}
return tmp;
}
public static double code(double x, double y) {
double tmp;
if (x <= -1.85e-6) {
tmp = x * -y;
} else if (x <= 2.8e-75) {
tmp = Math.log1p((x + 1.0));
} else if (x <= 4.3e-38) {
tmp = x * (0.5 - y);
} else {
tmp = Math.log((x + 2.0));
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -1.85e-6: tmp = x * -y elif x <= 2.8e-75: tmp = math.log1p((x + 1.0)) elif x <= 4.3e-38: tmp = x * (0.5 - y) else: tmp = math.log((x + 2.0)) return tmp
function code(x, y) tmp = 0.0 if (x <= -1.85e-6) tmp = Float64(x * Float64(-y)); elseif (x <= 2.8e-75) tmp = log1p(Float64(x + 1.0)); elseif (x <= 4.3e-38) tmp = Float64(x * Float64(0.5 - y)); else tmp = log(Float64(x + 2.0)); end return tmp end
code[x_, y_] := If[LessEqual[x, -1.85e-6], N[(x * (-y)), $MachinePrecision], If[LessEqual[x, 2.8e-75], N[Log[1 + N[(x + 1.0), $MachinePrecision]], $MachinePrecision], If[LessEqual[x, 4.3e-38], N[(x * N[(0.5 - y), $MachinePrecision]), $MachinePrecision], N[Log[N[(x + 2.0), $MachinePrecision]], $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.85 \cdot 10^{-6}:\\
\;\;\;\;x \cdot \left(-y\right)\\
\mathbf{elif}\;x \leq 2.8 \cdot 10^{-75}:\\
\;\;\;\;\mathsf{log1p}\left(x + 1\right)\\
\mathbf{elif}\;x \leq 4.3 \cdot 10^{-38}:\\
\;\;\;\;x \cdot \left(0.5 - y\right)\\
\mathbf{else}:\\
\;\;\;\;\log \left(x + 2\right)\\
\end{array}
\end{array}
(FPCore (x y) :precision binary64 (if (<= x -26.5) (* x (- y)) (+ (log 2.0) (* x (- 0.5 y)))))
double code(double x, double y) {
double tmp;
if (x <= -26.5) {
tmp = x * -y;
} else {
tmp = log(2.0) + (x * (0.5 - y));
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-26.5d0)) then
tmp = x * -y
else
tmp = log(2.0d0) + (x * (0.5d0 - y))
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -26.5) {
tmp = x * -y;
} else {
tmp = Math.log(2.0) + (x * (0.5 - y));
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -26.5: tmp = x * -y else: tmp = math.log(2.0) + (x * (0.5 - y)) return tmp
function code(x, y) tmp = 0.0 if (x <= -26.5) tmp = Float64(x * Float64(-y)); else tmp = Float64(log(2.0) + Float64(x * Float64(0.5 - y))); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -26.5) tmp = x * -y; else tmp = log(2.0) + (x * (0.5 - y)); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -26.5], N[(x * (-y)), $MachinePrecision], N[(N[Log[2.0], $MachinePrecision] + N[(x * N[(0.5 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -26.5:\\
\;\;\;\;x \cdot \left(-y\right)\\
\mathbf{else}:\\
\;\;\;\;\log 2 + x \cdot \left(0.5 - y\right)\\
\end{array}
\end{array}
(FPCore (x y) :precision binary64 (if (<= x -1.5) (* x (- y)) (- (log (+ x 2.0)) (* x y))))
double code(double x, double y) {
double tmp;
if (x <= -1.5) {
tmp = x * -y;
} else {
tmp = log((x + 2.0)) - (x * y);
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-1.5d0)) then
tmp = x * -y
else
tmp = log((x + 2.0d0)) - (x * y)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -1.5) {
tmp = x * -y;
} else {
tmp = Math.log((x + 2.0)) - (x * y);
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -1.5: tmp = x * -y else: tmp = math.log((x + 2.0)) - (x * y) return tmp
function code(x, y) tmp = 0.0 if (x <= -1.5) tmp = Float64(x * Float64(-y)); else tmp = Float64(log(Float64(x + 2.0)) - Float64(x * y)); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -1.5) tmp = x * -y; else tmp = log((x + 2.0)) - (x * y); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -1.5], N[(x * (-y)), $MachinePrecision], N[(N[Log[N[(x + 2.0), $MachinePrecision]], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.5:\\
\;\;\;\;x \cdot \left(-y\right)\\
\mathbf{else}:\\
\;\;\;\;\log \left(x + 2\right) - x \cdot y\\
\end{array}
\end{array}
(FPCore (x y) :precision binary64 (if (<= x -106.0) (* x (- y)) (- (log 2.0) (* x y))))
double code(double x, double y) {
double tmp;
if (x <= -106.0) {
tmp = x * -y;
} else {
tmp = log(2.0) - (x * y);
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-106.0d0)) then
tmp = x * -y
else
tmp = log(2.0d0) - (x * y)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -106.0) {
tmp = x * -y;
} else {
tmp = Math.log(2.0) - (x * y);
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -106.0: tmp = x * -y else: tmp = math.log(2.0) - (x * y) return tmp
function code(x, y) tmp = 0.0 if (x <= -106.0) tmp = Float64(x * Float64(-y)); else tmp = Float64(log(2.0) - Float64(x * y)); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -106.0) tmp = x * -y; else tmp = log(2.0) - (x * y); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -106.0], N[(x * (-y)), $MachinePrecision], N[(N[Log[2.0], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -106:\\
\;\;\;\;x \cdot \left(-y\right)\\
\mathbf{else}:\\
\;\;\;\;\log 2 - x \cdot y\\
\end{array}
\end{array}
(FPCore (x y) :precision binary64 (* x (- y)))
double code(double x, double y) {
return x * -y;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x * -y
end function
public static double code(double x, double y) {
return x * -y;
}
def code(x, y): return x * -y
function code(x, y) return Float64(x * Float64(-y)) end
function tmp = code(x, y) tmp = x * -y; end
code[x_, y_] := N[(x * (-y)), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(-y\right)
\end{array}
(FPCore (x y) :precision binary64 (* x 0.5))
double code(double x, double y) {
return x * 0.5;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = x * 0.5d0
end function
public static double code(double x, double y) {
return x * 0.5;
}
def code(x, y): return x * 0.5
function code(x, y) return Float64(x * 0.5) end
function tmp = code(x, y) tmp = x * 0.5; end
code[x_, y_] := N[(x * 0.5), $MachinePrecision]
\begin{array}{l}
\\
x \cdot 0.5
\end{array}
(FPCore (x y) :precision binary64 (if (<= x 0.0) (- (log (+ 1.0 (exp x))) (* x y)) (- (log (+ 1.0 (exp (- x)))) (* (- x) (- 1.0 y)))))
double code(double x, double y) {
double tmp;
if (x <= 0.0) {
tmp = log((1.0 + exp(x))) - (x * y);
} else {
tmp = log((1.0 + exp(-x))) - (-x * (1.0 - y));
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= 0.0d0) then
tmp = log((1.0d0 + exp(x))) - (x * y)
else
tmp = log((1.0d0 + exp(-x))) - (-x * (1.0d0 - y))
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= 0.0) {
tmp = Math.log((1.0 + Math.exp(x))) - (x * y);
} else {
tmp = Math.log((1.0 + Math.exp(-x))) - (-x * (1.0 - y));
}
return tmp;
}
def code(x, y): tmp = 0 if x <= 0.0: tmp = math.log((1.0 + math.exp(x))) - (x * y) else: tmp = math.log((1.0 + math.exp(-x))) - (-x * (1.0 - y)) return tmp
function code(x, y) tmp = 0.0 if (x <= 0.0) tmp = Float64(log(Float64(1.0 + exp(x))) - Float64(x * y)); else tmp = Float64(log(Float64(1.0 + exp(Float64(-x)))) - Float64(Float64(-x) * Float64(1.0 - y))); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= 0.0) tmp = log((1.0 + exp(x))) - (x * y); else tmp = log((1.0 + exp(-x))) - (-x * (1.0 - y)); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, 0.0], N[(N[Log[N[(1.0 + N[Exp[x], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision], N[(N[Log[N[(1.0 + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - N[((-x) * N[(1.0 - y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 0:\\
\;\;\;\;\log \left(1 + e^{x}\right) - x \cdot y\\
\mathbf{else}:\\
\;\;\;\;\log \left(1 + e^{-x}\right) - \left(-x\right) \cdot \left(1 - y\right)\\
\end{array}
\end{array}
herbie shell --seed 2024006
(FPCore (x y)
:name "Logistic regression 2"
:precision binary64
:herbie-target
(if (<= x 0.0) (- (log (+ 1.0 (exp x))) (* x y)) (- (log (+ 1.0 (exp (- x)))) (* (- x) (- 1.0 y))))
(- (log (+ 1.0 (exp x))) (* x y)))