
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 15 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* (PI) (fma -2.0 u2 0.5)))))
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \mathsf{fma}\left(-2, u2, 0.5\right)\right)
\end{array}
Initial program 59.4%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3256.8
Applied rewrites56.8%
Taylor expanded in u2 around inf
Applied rewrites99.0%
Applied rewrites98.9%
Taylor expanded in u2 around 0
Applied rewrites99.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* (* 2.0 (PI)) u2))))
(if (<= (* (sqrt (- (log (- 1.0 u1)))) t_0) 0.20000000298023224)
(*
(sqrt (* (fma (fma (fma 0.25 u1 0.3333333333333333) u1 0.5) u1 1.0) u1))
t_0)
(*
(sqrt (log (/ 1.0 (- 1.0 u1))))
(fma (* -2.0 (* u2 u2)) (* (PI) (PI)) 1.0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;\sqrt{-\log \left(1 - u1\right)} \cdot t\_0 \leq 0.20000000298023224:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.25, u1, 0.3333333333333333\right), u1, 0.5\right), u1, 1\right) \cdot u1} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\log \left(\frac{1}{1 - u1}\right)} \cdot \mathsf{fma}\left(-2 \cdot \left(u2 \cdot u2\right), \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)\\
\end{array}
\end{array}
if (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) < 0.200000003Initial program 53.7%
Taylor expanded in u1 around 0
Applied rewrites98.4%
if 0.200000003 < (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) Initial program 97.7%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3297.7
Applied rewrites97.7%
Taylor expanded in u2 around 0
Applied rewrites92.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<=
(* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2)))
0.1379999965429306)
(*
(sqrt (* (fma (fma 0.3333333333333333 u1 0.5) u1 1.0) u1))
(fma (* -2.0 (* u2 u2)) (* (PI) (PI)) 1.0))
(sqrt (- (log1p (- u1))))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \leq 0.1379999965429306:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(0.3333333333333333, u1, 0.5\right), u1, 1\right) \cdot u1} \cdot \mathsf{fma}\left(-2 \cdot \left(u2 \cdot u2\right), \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\end{array}
\end{array}
if (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) < 0.137999997Initial program 52.4%
Taylor expanded in u1 around 0
Applied rewrites98.0%
Taylor expanded in u2 around 0
Applied rewrites86.2%
if 0.137999997 < (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) Initial program 96.9%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3296.9
Applied rewrites96.9%
Taylor expanded in u2 around 0
Applied rewrites85.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* (* 2.0 (PI)) u2))))
(if (<= t_0 0.9999997019767761)
(* (sqrt (* (fma (fma 0.3333333333333333 u1 0.5) u1 1.0) u1)) t_0)
(sqrt (- (log1p (- u1)))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq 0.9999997019767761:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(0.3333333333333333, u1, 0.5\right), u1, 1\right) \cdot u1} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) < 0.999999702Initial program 60.0%
Taylor expanded in u1 around 0
Applied rewrites91.1%
if 0.999999702 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 58.9%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3256.4
Applied rewrites56.4%
Taylor expanded in u2 around 0
Applied rewrites99.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* (* 2.0 (PI)) u2))))
(if (<= t_0 0.9999997019767761)
(* (sqrt (fma (* 0.5 u1) u1 u1)) t_0)
(sqrt (- (log1p (- u1)))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq 0.9999997019767761:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(0.5 \cdot u1, u1, u1\right)} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) < 0.999999702Initial program 60.0%
lift-log.f32N/A
lift--.f32N/A
flip--N/A
log-divN/A
lower--.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.0
Applied rewrites98.0%
Taylor expanded in u1 around 0
Applied rewrites87.5%
Applied rewrites87.7%
if 0.999999702 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 58.9%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3256.4
Applied rewrites56.4%
Taylor expanded in u2 around 0
Applied rewrites99.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (cos (* -2.0 (* (PI) u2)))))
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \cos \left(-2 \cdot \left(\mathsf{PI}\left(\right) \cdot u2\right)\right)
\end{array}
Initial program 59.4%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3256.8
Applied rewrites56.8%
Taylor expanded in u2 around inf
Applied rewrites99.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u2 0.00013000000035390258)
(sqrt (- (log1p (- u1))))
(*
(sqrt (* (fma (fma (fma 0.25 u1 0.3333333333333333) u1 0.5) u1 1.0) u1))
(cos (* (* 2.0 (PI)) u2)))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.00013000000035390258:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.25, u1, 0.3333333333333333\right), u1, 0.5\right), u1, 1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 1.3e-4Initial program 59.2%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3256.6
Applied rewrites56.6%
Taylor expanded in u2 around 0
Applied rewrites99.3%
if 1.3e-4 < u2 Initial program 59.6%
Taylor expanded in u1 around 0
Applied rewrites92.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u2 0.00013000000035390258) (sqrt (- (log1p (- u1)))) (* (sqrt (* (fma 0.5 u1 1.0) u1)) (cos (* (* 2.0 (PI)) u2)))))
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.00013000000035390258:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 1.3e-4Initial program 59.2%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3256.6
Applied rewrites56.6%
Taylor expanded in u2 around 0
Applied rewrites99.3%
if 1.3e-4 < u2 Initial program 59.6%
Taylor expanded in u1 around 0
Applied rewrites87.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u2 0.0007999999797903001) (sqrt (- (log1p (- u1)))) (* (sqrt u1) (cos (* (* 2.0 (PI)) u2)))))
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.0007999999797903001:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 7.9999998e-4Initial program 59.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3256.4
Applied rewrites56.4%
Taylor expanded in u2 around 0
Applied rewrites97.4%
if 7.9999998e-4 < u2 Initial program 60.0%
Taylor expanded in u1 around 0
Applied rewrites74.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (* (fma (fma 0.3333333333333333 u1 0.5) u1 1.0) u1)) (fma (* -2.0 (* u2 u2)) (* (PI) (PI)) 1.0)))
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(0.3333333333333333, u1, 0.5\right), u1, 1\right) \cdot u1} \cdot \mathsf{fma}\left(-2 \cdot \left(u2 \cdot u2\right), \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)
\end{array}
Initial program 59.4%
Taylor expanded in u1 around 0
Applied rewrites91.9%
Taylor expanded in u2 around 0
Applied rewrites81.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= u2 0.0001900000061141327) (sqrt (* (fma (fma (fma 0.25 u1 0.3333333333333333) u1 0.5) u1 1.0) u1)) (* (sqrt u1) (fma (* -2.0 (* u2 u2)) (* (PI) (PI)) 1.0))))
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.0001900000061141327:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.25, u1, 0.3333333333333333\right), u1, 0.5\right), u1, 1\right) \cdot u1}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \mathsf{fma}\left(-2 \cdot \left(u2 \cdot u2\right), \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)\\
\end{array}
\end{array}
if u2 < 1.90000006e-4Initial program 59.5%
lift-log.f32N/A
lift--.f32N/A
flip--N/A
log-divN/A
lower--.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3299.3
Applied rewrites99.3%
Taylor expanded in u2 around 0
Applied rewrites98.6%
Taylor expanded in u1 around 0
Applied rewrites93.6%
if 1.90000006e-4 < u2 Initial program 59.2%
Taylor expanded in u1 around 0
Applied rewrites75.5%
Taylor expanded in u2 around 0
Applied rewrites55.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* (fma (fma (fma 0.25 u1 0.3333333333333333) u1 0.5) u1 1.0) u1)))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((fmaf(fmaf(fmaf(0.25f, u1, 0.3333333333333333f), u1, 0.5f), u1, 1.0f) * u1));
}
function code(cosTheta_i, u1, u2) return sqrt(Float32(fma(fma(fma(Float32(0.25), u1, Float32(0.3333333333333333)), u1, Float32(0.5)), u1, Float32(1.0)) * u1)) end
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.25, u1, 0.3333333333333333\right), u1, 0.5\right), u1, 1\right) \cdot u1}
\end{array}
Initial program 59.4%
lift-log.f32N/A
lift--.f32N/A
flip--N/A
log-divN/A
lower--.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.8
Applied rewrites98.8%
Taylor expanded in u2 around 0
Applied rewrites79.5%
Taylor expanded in u1 around 0
Applied rewrites76.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* (fma (fma 0.3333333333333333 u1 0.5) u1 1.0) u1)))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((fmaf(fmaf(0.3333333333333333f, u1, 0.5f), u1, 1.0f) * u1));
}
function code(cosTheta_i, u1, u2) return sqrt(Float32(fma(fma(Float32(0.3333333333333333), u1, Float32(0.5)), u1, Float32(1.0)) * u1)) end
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(0.3333333333333333, u1, 0.5\right), u1, 1\right) \cdot u1}
\end{array}
Initial program 59.4%
lift-log.f32N/A
lift--.f32N/A
flip--N/A
log-divN/A
lower--.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.8
Applied rewrites98.8%
Taylor expanded in u2 around 0
Applied rewrites79.5%
Taylor expanded in u1 around 0
Applied rewrites74.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* (fma 0.5 u1 1.0) u1)))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((fmaf(0.5f, u1, 1.0f) * u1));
}
function code(cosTheta_i, u1, u2) return sqrt(Float32(fma(Float32(0.5), u1, Float32(1.0)) * u1)) end
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1}
\end{array}
Initial program 59.4%
lift-log.f32N/A
lift--.f32N/A
flip--N/A
log-divN/A
lower--.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.8
Applied rewrites98.8%
Taylor expanded in u2 around 0
Applied rewrites79.5%
Taylor expanded in u1 around 0
Applied rewrites72.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt u1))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1);
}
module fmin_fmax_functions
implicit none
private
public fmax
public fmin
interface fmax
module procedure fmax88
module procedure fmax44
module procedure fmax84
module procedure fmax48
end interface
interface fmin
module procedure fmin88
module procedure fmin44
module procedure fmin84
module procedure fmin48
end interface
contains
real(8) function fmax88(x, y) result (res)
real(8), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(x, max(x, y), y /= y), x /= x)
end function
real(4) function fmax44(x, y) result (res)
real(4), intent (in) :: x
real(4), intent (in) :: y
res = merge(y, merge(x, max(x, y), y /= y), x /= x)
end function
real(8) function fmax84(x, y) result(res)
real(8), intent (in) :: x
real(4), intent (in) :: y
res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
end function
real(8) function fmax48(x, y) result(res)
real(4), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
end function
real(8) function fmin88(x, y) result (res)
real(8), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(x, min(x, y), y /= y), x /= x)
end function
real(4) function fmin44(x, y) result (res)
real(4), intent (in) :: x
real(4), intent (in) :: y
res = merge(y, merge(x, min(x, y), y /= y), x /= x)
end function
real(8) function fmin84(x, y) result(res)
real(8), intent (in) :: x
real(4), intent (in) :: y
res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
end function
real(8) function fmin48(x, y) result(res)
real(4), intent (in) :: x
real(8), intent (in) :: y
res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
end function
end module
real(4) function code(costheta_i, u1, u2)
use fmin_fmax_functions
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = sqrt(u1)
end function
function code(cosTheta_i, u1, u2) return sqrt(u1) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1); end
\begin{array}{l}
\\
\sqrt{u1}
\end{array}
Initial program 59.4%
lift-log.f32N/A
lift--.f32N/A
flip--N/A
log-divN/A
lower--.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.8
Applied rewrites98.8%
Taylor expanded in u2 around 0
Applied rewrites79.5%
Taylor expanded in u1 around 0
Applied rewrites64.0%
herbie shell --seed 2025021
(FPCore (cosTheta_i u1 u2)
:name "Beckmann Sample, near normal, slope_x"
:precision binary32
:pre (and (and (and (> cosTheta_i 0.9999) (<= cosTheta_i 1.0)) (and (<= 2.328306437e-10 u1) (<= u1 1.0))) (and (<= 2.328306437e-10 u2) (<= u2 1.0)))
(* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2))))