
(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 (+ (* (/ 1.0 (sqrt (/ 1.0 (+ 1.0 x)))) (sqrt (- x 1.0))) x)))
float code(float x) {
return logf((((1.0f / sqrtf((1.0f / (1.0f + x)))) * sqrtf((x - 1.0f))) + x));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log((((1.0e0 / sqrt((1.0e0 / (1.0e0 + x)))) * sqrt((x - 1.0e0))) + x))
end function
function code(x) return log(Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) / Float32(Float32(1.0) + x)))) * sqrt(Float32(x - Float32(1.0)))) + x)) end
function tmp = code(x) tmp = log((((single(1.0) / sqrt((single(1.0) / (single(1.0) + x)))) * sqrt((x - single(1.0)))) + x)); end
\begin{array}{l}
\\
\log \left(\frac{1}{\sqrt{\frac{1}{1 + x}}} \cdot \sqrt{x - 1} + x\right)
\end{array}
Initial program 54.2%
lift-sqrt.f32N/A
pow1/2N/A
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
*-commutativeN/A
unpow-prod-downN/A
lower-*.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
lower--.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
+-commutativeN/A
lower-+.f3299.2
Applied rewrites99.2%
lift-sqrt.f32N/A
lift-+.f32N/A
flip-+N/A
clear-numN/A
sqrt-divN/A
metadata-evalN/A
lower-/.f32N/A
lower-sqrt.f32N/A
lower-/.f32N/A
lower--.f32N/A
metadata-evalN/A
lift-*.f32N/A
lower--.f3254.3
Applied rewrites54.3%
lift-/.f32N/A
clear-numN/A
lift--.f32N/A
metadata-evalN/A
lift-*.f32N/A
lift--.f32N/A
flip-+N/A
lift-+.f32N/A
lower-/.f3299.2
Applied rewrites99.2%
Final simplification99.2%
(FPCore (x) :precision binary32 (log (+ (* (sqrt (+ 1.0 x)) (sqrt (- x 1.0))) x)))
float code(float x) {
return logf(((sqrtf((1.0f + x)) * sqrtf((x - 1.0f))) + x));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log(((sqrt((1.0e0 + x)) * sqrt((x - 1.0e0))) + x))
end function
function code(x) return log(Float32(Float32(sqrt(Float32(Float32(1.0) + x)) * sqrt(Float32(x - Float32(1.0)))) + x)) end
function tmp = code(x) tmp = log(((sqrt((single(1.0) + x)) * sqrt((x - single(1.0)))) + x)); end
\begin{array}{l}
\\
\log \left(\sqrt{1 + x} \cdot \sqrt{x - 1} + x\right)
\end{array}
Initial program 54.2%
lift-sqrt.f32N/A
pow1/2N/A
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
*-commutativeN/A
unpow-prod-downN/A
lower-*.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
lower--.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
+-commutativeN/A
lower-+.f3299.2
Applied rewrites99.2%
Final simplification99.2%
(FPCore (x) :precision binary32 (log (* (- 2.0 (/ 0.5 (* x x))) x)))
float code(float x) {
return logf(((2.0f - (0.5f / (x * x))) * x));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log(((2.0e0 - (0.5e0 / (x * x))) * x))
end function
function code(x) return log(Float32(Float32(Float32(2.0) - Float32(Float32(0.5) / Float32(x * x))) * x)) end
function tmp = code(x) tmp = log(((single(2.0) - (single(0.5) / (x * x))) * x)); end
\begin{array}{l}
\\
\log \left(\left(2 - \frac{0.5}{x \cdot x}\right) \cdot x\right)
\end{array}
Initial program 54.2%
lift-sqrt.f32N/A
pow1/2N/A
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
*-commutativeN/A
unpow-prod-downN/A
lower-*.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
lower--.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
+-commutativeN/A
lower-+.f3299.2
Applied rewrites99.2%
Taylor expanded in x around inf
*-commutativeN/A
sub-negN/A
+-commutativeN/A
metadata-evalN/A
metadata-evalN/A
rem-square-sqrtN/A
unpow2N/A
distribute-neg-inN/A
associate--l+N/A
lower-*.f32N/A
Applied rewrites98.0%
(FPCore (x) :precision binary32 (log (+ (- x (/ 0.5 x)) x)))
float code(float x) {
return logf(((x - (0.5f / x)) + x));
}
real(4) function code(x)
real(4), intent (in) :: x
code = log(((x - (0.5e0 / x)) + x))
end function
function code(x) return log(Float32(Float32(x - Float32(Float32(0.5) / x)) + x)) end
function tmp = code(x) tmp = log(((x - (single(0.5) / x)) + x)); end
\begin{array}{l}
\\
\log \left(\left(x - \frac{0.5}{x}\right) + x\right)
\end{array}
Initial program 54.2%
Taylor expanded in x around inf
sub-negN/A
distribute-lft-inN/A
*-rgt-identityN/A
distribute-rgt-neg-outN/A
unsub-negN/A
remove-double-negN/A
distribute-rgt-neg-outN/A
distribute-lft-neg-outN/A
mul-1-negN/A
*-commutativeN/A
lower--.f32N/A
*-commutativeN/A
mul-1-negN/A
distribute-lft-neg-outN/A
*-commutativeN/A
distribute-rgt-neg-inN/A
metadata-evalN/A
associate-*r*N/A
Applied rewrites98.0%
Final simplification98.0%
(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 54.2%
lift-sqrt.f32N/A
pow1/2N/A
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
*-commutativeN/A
unpow-prod-downN/A
lower-*.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
lower--.f32N/A
pow1/2N/A
lower-sqrt.f32N/A
+-commutativeN/A
lower-+.f3299.2
Applied rewrites99.2%
Taylor expanded in x around -inf
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
neg-mul-1N/A
mul-1-negN/A
remove-double-neg96.5
Applied rewrites96.5%
Final simplification96.5%
(FPCore (x) :precision binary32 (log 0.0))
float code(float x) {
return logf(0.0f);
}
real(4) function code(x)
real(4), intent (in) :: x
code = log(0.0e0)
end function
function code(x) return log(Float32(0.0)) end
function tmp = code(x) tmp = log(single(0.0)); end
\begin{array}{l}
\\
\log 0
\end{array}
Initial program 54.2%
lift--.f32N/A
sub-negN/A
+-commutativeN/A
flip-+N/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
pow2N/A
lift-*.f32N/A
pow-prod-downN/A
pow-prod-upN/A
lower-pow.f32N/A
metadata-evalN/A
lower--.f32N/A
metadata-eval30.3
Applied rewrites30.3%
Taylor expanded in x around inf
+-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
metadata-evalN/A
mul0-rgt1.3
Applied rewrites1.3%
(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 2024277
(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)))))