
(FPCore (x) :precision binary32 (acosh x))
float code(float x) {
return acoshf(x);
}
function code(x) return acosh(x) end
function tmp = code(x) tmp = acosh(x); end
\begin{array}{l}
\\
\cosh^{-1} x
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 6 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary32 (log (+ x (sqrt (- (* x x) 1.0)))))
float code(float x) {
return logf((x + sqrtf(((x * x) - 1.0f))));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log((x + sqrt(((x * x) - 1.0e0))))
end function
function code(x) return log(Float32(x + sqrt(Float32(Float32(x * x) - Float32(1.0))))) end
function tmp = code(x) tmp = log((x + sqrt(((x * x) - single(1.0))))); end
\begin{array}{l}
\\
\log \left(x + \sqrt{x \cdot x - 1}\right)
\end{array}
(FPCore (x) :precision binary32 (log (+ x (* (sqrt (+ x 1.0)) (sqrt (+ x -1.0))))))
float code(float x) {
return logf((x + (sqrtf((x + 1.0f)) * sqrtf((x + -1.0f)))));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log((x + (sqrt((x + 1.0e0)) * sqrt((x + (-1.0e0))))))
end function
function code(x) return log(Float32(x + Float32(sqrt(Float32(x + Float32(1.0))) * sqrt(Float32(x + Float32(-1.0)))))) end
function tmp = code(x) tmp = log((x + (sqrt((x + single(1.0))) * sqrt((x + single(-1.0)))))); end
\begin{array}{l}
\\
\log \left(x + \sqrt{x + 1} \cdot \sqrt{x + -1}\right)
\end{array}
Initial program 57.2%
pow1/257.2%
difference-of-sqr-157.2%
unpow-prod-down99.2%
sub-neg99.2%
metadata-eval99.2%
Applied egg-rr99.2%
unpow1/299.2%
unpow1/299.2%
Simplified99.2%
(FPCore (x) :precision binary32 (log (+ x x)))
float code(float x) {
return logf((x + x));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log((x + x))
end function
function code(x) return log(Float32(x + x)) end
function tmp = code(x) tmp = log((x + x)); end
\begin{array}{l}
\\
\log \left(x + x\right)
\end{array}
Initial program 57.2%
Taylor expanded in x around inf 96.7%
(FPCore (x) :precision binary32 (log (* x 1.25)))
float code(float x) {
return logf((x * 1.25f));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log((x * 1.25e0))
end function
function code(x) return log(Float32(x * Float32(1.25))) end
function tmp = code(x) tmp = log((x * single(1.25))); end
\begin{array}{l}
\\
\log \left(x \cdot 1.25\right)
\end{array}
Initial program 57.2%
pow1/257.2%
difference-of-sqr-157.2%
unpow-prod-down99.2%
sub-neg99.2%
metadata-eval99.2%
Applied egg-rr99.2%
unpow1/299.2%
unpow1/299.2%
Simplified99.2%
Taylor expanded in x around inf 97.9%
Simplified45.5%
Taylor expanded in x around 0 45.5%
*-commutative45.5%
Simplified45.5%
(FPCore (x) :precision binary32 (log x))
float code(float x) {
return logf(x);
}
real(4) function code(x)
real(4), intent (in) :: x
code = log(x)
end function
function code(x) return log(x) end
function tmp = code(x) tmp = log(x); end
\begin{array}{l}
\\
\log x
\end{array}
Initial program 57.2%
Taylor expanded in x around inf 96.7%
Taylor expanded in x around 0 96.6%
Simplified43.7%
(FPCore (x) :precision binary32 (* x 0.8333333333333334))
float code(float x) {
return x * 0.8333333333333334f;
}
real(4) function code(x)
real(4), intent (in) :: x
code = x * 0.8333333333333334e0
end function
function code(x) return Float32(x * Float32(0.8333333333333334)) end
function tmp = code(x) tmp = x * single(0.8333333333333334); end
\begin{array}{l}
\\
x \cdot 0.8333333333333334
\end{array}
Initial program 57.2%
fma-neg57.2%
metadata-eval57.2%
Simplified57.2%
fma-undefine57.2%
difference-of-sqr--157.2%
sub-neg57.2%
metadata-eval57.2%
Applied egg-rr57.2%
Taylor expanded in x around 0 -0.0%
Simplified11.1%
Taylor expanded in x around inf 11.1%
associate-*r/11.1%
metadata-eval11.1%
Simplified11.1%
Taylor expanded in x around inf 11.8%
(FPCore (x) :precision binary32 -6.0)
float code(float x) {
return -6.0f;
}
real(4) function code(x)
real(4), intent (in) :: x
code = -6.0e0
end function
function code(x) return Float32(-6.0) end
function tmp = code(x) tmp = single(-6.0); end
\begin{array}{l}
\\
-6
\end{array}
Initial program 57.2%
fma-neg57.2%
metadata-eval57.2%
Simplified57.2%
fma-undefine57.2%
difference-of-sqr--157.2%
sub-neg57.2%
metadata-eval57.2%
Applied egg-rr57.2%
Taylor expanded in x around 0 -0.0%
Simplified11.1%
Taylor expanded in x around 0 3.0%
(FPCore (x) :precision binary32 (log (+ x (* (sqrt (- x 1.0)) (sqrt (+ x 1.0))))))
float code(float x) {
return logf((x + (sqrtf((x - 1.0f)) * sqrtf((x + 1.0f)))));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log((x + (sqrt((x - 1.0e0)) * sqrt((x + 1.0e0)))))
end function
function code(x) return log(Float32(x + Float32(sqrt(Float32(x - Float32(1.0))) * sqrt(Float32(x + Float32(1.0)))))) end
function tmp = code(x) tmp = log((x + (sqrt((x - single(1.0))) * sqrt((x + single(1.0)))))); end
\begin{array}{l}
\\
\log \left(x + \sqrt{x - 1} \cdot \sqrt{x + 1}\right)
\end{array}
herbie shell --seed 2024136
(FPCore (x)
:name "Rust f32::acosh"
:precision binary32
:pre (>= x 1.0)
:alt
(! :herbie-platform default (log (+ x (* (sqrt (- x 1)) (sqrt (+ x 1))))))
(log (+ x (sqrt (- (* x x) 1.0)))))