
(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 5 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}
Initial program 99.5%
accelerator-lowering-log1p.f64N/A
exp-lowering-exp.f6499.6%
Applied egg-rr99.6%
(FPCore (x y) :precision binary64 (if (<= x -1.4) (- 0.0 (* x y)) (+ (log 2.0) (* x (- 0.5 y)))))
double code(double x, double y) {
double tmp;
if (x <= -1.4) {
tmp = 0.0 - (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 <= (-1.4d0)) then
tmp = 0.0d0 - (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 <= -1.4) {
tmp = 0.0 - (x * y);
} else {
tmp = Math.log(2.0) + (x * (0.5 - y));
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -1.4: tmp = 0.0 - (x * y) else: tmp = math.log(2.0) + (x * (0.5 - y)) return tmp
function code(x, y) tmp = 0.0 if (x <= -1.4) tmp = Float64(0.0 - Float64(x * 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 <= -1.4) tmp = 0.0 - (x * y); else tmp = log(2.0) + (x * (0.5 - y)); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -1.4], N[(0.0 - N[(x * y), $MachinePrecision]), $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 -1.4:\\
\;\;\;\;0 - x \cdot y\\
\mathbf{else}:\\
\;\;\;\;\log 2 + x \cdot \left(0.5 - y\right)\\
\end{array}
\end{array}
if x < -1.3999999999999999Initial program 99.7%
Taylor expanded in x around inf
mul-1-negN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
neg-sub0N/A
--lowering--.f6498.2%
Simplified98.2%
sub0-negN/A
neg-lowering-neg.f6498.2%
Applied egg-rr98.2%
if -1.3999999999999999 < x Initial program 99.4%
Taylor expanded in x around 0
+-lowering-+.f64N/A
log-lowering-log.f64N/A
*-lowering-*.f64N/A
--lowering--.f6499.8%
Simplified99.8%
Final simplification99.2%
(FPCore (x y) :precision binary64 (if (<= x -18.0) (- 0.0 (* x y)) (- (log 2.0) (* x y))))
double code(double x, double y) {
double tmp;
if (x <= -18.0) {
tmp = 0.0 - (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 <= (-18.0d0)) then
tmp = 0.0d0 - (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 <= -18.0) {
tmp = 0.0 - (x * y);
} else {
tmp = Math.log(2.0) - (x * y);
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -18.0: tmp = 0.0 - (x * y) else: tmp = math.log(2.0) - (x * y) return tmp
function code(x, y) tmp = 0.0 if (x <= -18.0) tmp = Float64(0.0 - Float64(x * 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 <= -18.0) tmp = 0.0 - (x * y); else tmp = log(2.0) - (x * y); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -18.0], N[(0.0 - N[(x * y), $MachinePrecision]), $MachinePrecision], N[(N[Log[2.0], $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -18:\\
\;\;\;\;0 - x \cdot y\\
\mathbf{else}:\\
\;\;\;\;\log 2 - x \cdot y\\
\end{array}
\end{array}
if x < -18Initial program 99.7%
Taylor expanded in x around inf
mul-1-negN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
neg-sub0N/A
--lowering--.f6499.2%
Simplified99.2%
sub0-negN/A
neg-lowering-neg.f6499.2%
Applied egg-rr99.2%
if -18 < x Initial program 99.4%
Taylor expanded in x around 0
log-lowering-log.f6499.1%
Simplified99.1%
Final simplification99.1%
(FPCore (x y) :precision binary64 (if (<= x -8.4e-82) (- 0.0 (* x y)) (log 2.0)))
double code(double x, double y) {
double tmp;
if (x <= -8.4e-82) {
tmp = 0.0 - (x * y);
} else {
tmp = log(2.0);
}
return tmp;
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8) :: tmp
if (x <= (-8.4d-82)) then
tmp = 0.0d0 - (x * y)
else
tmp = log(2.0d0)
end if
code = tmp
end function
public static double code(double x, double y) {
double tmp;
if (x <= -8.4e-82) {
tmp = 0.0 - (x * y);
} else {
tmp = Math.log(2.0);
}
return tmp;
}
def code(x, y): tmp = 0 if x <= -8.4e-82: tmp = 0.0 - (x * y) else: tmp = math.log(2.0) return tmp
function code(x, y) tmp = 0.0 if (x <= -8.4e-82) tmp = Float64(0.0 - Float64(x * y)); else tmp = log(2.0); end return tmp end
function tmp_2 = code(x, y) tmp = 0.0; if (x <= -8.4e-82) tmp = 0.0 - (x * y); else tmp = log(2.0); end tmp_2 = tmp; end
code[x_, y_] := If[LessEqual[x, -8.4e-82], N[(0.0 - N[(x * y), $MachinePrecision]), $MachinePrecision], N[Log[2.0], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -8.4 \cdot 10^{-82}:\\
\;\;\;\;0 - x \cdot y\\
\mathbf{else}:\\
\;\;\;\;\log 2\\
\end{array}
\end{array}
if x < -8.4000000000000001e-82Initial program 99.7%
Taylor expanded in x around inf
mul-1-negN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
neg-sub0N/A
--lowering--.f6491.8%
Simplified91.8%
sub0-negN/A
neg-lowering-neg.f6491.8%
Applied egg-rr91.8%
if -8.4000000000000001e-82 < x Initial program 99.3%
Taylor expanded in x around 0
log-lowering-log.f6477.6%
Simplified77.6%
Final simplification84.1%
(FPCore (x y) :precision binary64 (- 0.0 (* x y)))
double code(double x, double y) {
return 0.0 - (x * y);
}
real(8) function code(x, y)
real(8), intent (in) :: x
real(8), intent (in) :: y
code = 0.0d0 - (x * y)
end function
public static double code(double x, double y) {
return 0.0 - (x * y);
}
def code(x, y): return 0.0 - (x * y)
function code(x, y) return Float64(0.0 - Float64(x * y)) end
function tmp = code(x, y) tmp = 0.0 - (x * y); end
code[x_, y_] := N[(0.0 - N[(x * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0 - x \cdot y
\end{array}
Initial program 99.5%
Taylor expanded in x around inf
mul-1-negN/A
distribute-rgt-neg-inN/A
*-lowering-*.f64N/A
neg-sub0N/A
--lowering--.f6454.7%
Simplified54.7%
sub0-negN/A
neg-lowering-neg.f6454.7%
Applied egg-rr54.7%
Final simplification54.7%
(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 2024191
(FPCore (x y)
:name "Logistic regression 2"
:precision binary64
:alt
(! :herbie-platform default (if (<= x 0) (- (log (+ 1 (exp x))) (* x y)) (- (log (+ 1 (exp (- x)))) (* (- x) (- 1 y)))))
(- (log (+ 1.0 (exp x))) (* x y)))