
(FPCore (x) :precision binary64 (- (/ x x) (* (/ 1.0 x) (sqrt (* x x)))))
double code(double x) {
return (x / x) - ((1.0 / x) * sqrt((x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x / x) - ((1.0d0 / x) * sqrt((x * x)))
end function
public static double code(double x) {
return (x / x) - ((1.0 / x) * Math.sqrt((x * x)));
}
def code(x): return (x / x) - ((1.0 / x) * math.sqrt((x * x)))
function code(x) return Float64(Float64(x / x) - Float64(Float64(1.0 / x) * sqrt(Float64(x * x)))) end
function tmp = code(x) tmp = (x / x) - ((1.0 / x) * sqrt((x * x))); end
code[x_] := N[(N[(x / x), $MachinePrecision] - N[(N[(1.0 / x), $MachinePrecision] * N[Sqrt[N[(x * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{x} - \frac{1}{x} \cdot \sqrt{x \cdot x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ x x) (* (/ 1.0 x) (sqrt (* x x)))))
double code(double x) {
return (x / x) - ((1.0 / x) * sqrt((x * x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x / x) - ((1.0d0 / x) * sqrt((x * x)))
end function
public static double code(double x) {
return (x / x) - ((1.0 / x) * Math.sqrt((x * x)));
}
def code(x): return (x / x) - ((1.0 / x) * math.sqrt((x * x)))
function code(x) return Float64(Float64(x / x) - Float64(Float64(1.0 / x) * sqrt(Float64(x * x)))) end
function tmp = code(x) tmp = (x / x) - ((1.0 / x) * sqrt((x * x))); end
code[x_] := N[(N[(x / x), $MachinePrecision] - N[(N[(1.0 / x), $MachinePrecision] * N[Sqrt[N[(x * x), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{x} - \frac{1}{x} \cdot \sqrt{x \cdot x}
\end{array}
(FPCore (x) :precision binary64 (- 1.0 (/ (fabs x) x)))
double code(double x) {
return 1.0 - (fabs(x) / x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 - (abs(x) / x)
end function
public static double code(double x) {
return 1.0 - (Math.abs(x) / x);
}
def code(x): return 1.0 - (math.fabs(x) / x)
function code(x) return Float64(1.0 - Float64(abs(x) / x)) end
function tmp = code(x) tmp = 1.0 - (abs(x) / x); end
code[x_] := N[(1.0 - N[(N[Abs[x], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \frac{\left|x\right|}{x}
\end{array}
Initial program 52.2%
cancel-sign-sub-inv52.2%
*-inverses52.2%
distribute-frac-neg252.2%
sqr-neg52.2%
*-inverses52.2%
cancel-sign-sub52.2%
*-inverses52.2%
*-inverses52.2%
distribute-neg-frac52.2%
*-inverses52.2%
metadata-eval52.2%
associate-*l/57.1%
neg-mul-157.1%
distribute-neg-frac57.1%
distribute-neg-frac257.1%
Simplified100.0%
(FPCore (x) :precision binary64 (if (<= x -2e-310) 1.0 0.0))
double code(double x) {
double tmp;
if (x <= -2e-310) {
tmp = 1.0;
} else {
tmp = 0.0;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-2d-310)) then
tmp = 1.0d0
else
tmp = 0.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -2e-310) {
tmp = 1.0;
} else {
tmp = 0.0;
}
return tmp;
}
def code(x): tmp = 0 if x <= -2e-310: tmp = 1.0 else: tmp = 0.0 return tmp
function code(x) tmp = 0.0 if (x <= -2e-310) tmp = 1.0; else tmp = 0.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -2e-310) tmp = 1.0; else tmp = 0.0; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -2e-310], 1.0, 0.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2 \cdot 10^{-310}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}
\end{array}
if x < -1.999999999999994e-310Initial program 59.3%
cancel-sign-sub-inv59.3%
*-inverses59.3%
distribute-frac-neg259.3%
sqr-neg59.3%
*-inverses59.3%
cancel-sign-sub59.3%
*-inverses59.3%
*-inverses59.3%
distribute-neg-frac59.3%
*-inverses59.3%
metadata-eval59.3%
associate-*l/59.3%
neg-mul-159.3%
distribute-neg-frac59.3%
distribute-neg-frac259.3%
Simplified100.0%
Taylor expanded in x around inf 18.8%
if -1.999999999999994e-310 < x Initial program 45.1%
cancel-sign-sub-inv45.1%
*-inverses45.1%
distribute-frac-neg245.1%
sqr-neg45.1%
*-inverses45.1%
cancel-sign-sub45.1%
*-inverses45.1%
*-inverses45.1%
distribute-neg-frac45.1%
*-inverses45.1%
metadata-eval45.1%
associate-*l/55.0%
neg-mul-155.0%
distribute-neg-frac55.0%
distribute-neg-frac255.0%
Simplified100.0%
Taylor expanded in x around 0 100.0%
div-sub100.0%
*-inverses100.0%
rem-square-sqrt51.6%
fabs-sqr51.6%
rem-square-sqrt100.0%
*-inverses100.0%
metadata-eval100.0%
Simplified100.0%
(FPCore (x) :precision binary64 0.0)
double code(double x) {
return 0.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.0d0
end function
public static double code(double x) {
return 0.0;
}
def code(x): return 0.0
function code(x) return 0.0 end
function tmp = code(x) tmp = 0.0; end
code[x_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 52.2%
cancel-sign-sub-inv52.2%
*-inverses52.2%
distribute-frac-neg252.2%
sqr-neg52.2%
*-inverses52.2%
cancel-sign-sub52.2%
*-inverses52.2%
*-inverses52.2%
distribute-neg-frac52.2%
*-inverses52.2%
metadata-eval52.2%
associate-*l/57.1%
neg-mul-157.1%
distribute-neg-frac57.1%
distribute-neg-frac257.1%
Simplified100.0%
Taylor expanded in x around 0 100.0%
div-sub100.0%
*-inverses100.0%
rem-square-sqrt25.8%
fabs-sqr25.8%
rem-square-sqrt51.6%
*-inverses51.6%
metadata-eval51.6%
Simplified51.6%
(FPCore (x) :precision binary64 (if (< x 0.0) 2.0 0.0))
double code(double x) {
double tmp;
if (x < 0.0) {
tmp = 2.0;
} else {
tmp = 0.0;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x < 0.0d0) then
tmp = 2.0d0
else
tmp = 0.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x < 0.0) {
tmp = 2.0;
} else {
tmp = 0.0;
}
return tmp;
}
def code(x): tmp = 0 if x < 0.0: tmp = 2.0 else: tmp = 0.0 return tmp
function code(x) tmp = 0.0 if (x < 0.0) tmp = 2.0; else tmp = 0.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x < 0.0) tmp = 2.0; else tmp = 0.0; end tmp_2 = tmp; end
code[x_] := If[Less[x, 0.0], 2.0, 0.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x < 0:\\
\;\;\;\;2\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}
\end{array}
herbie shell --seed 2024165
(FPCore (x)
:name "sqrt sqr"
:precision binary64
:alt
(! :herbie-platform default (if (< x 0) 2 0))
(- (/ x x) (* (/ 1.0 x) (sqrt (* x x)))))