AppleAccelerate.jl
This provides a Julia interface to some of OS X's Accelerate framework. At the moment, the package consists mostly of an interface to the array-oriented functions, which provide a vectorised form of many common mathematical functions, however the package does provide access to several other vectorized operations and more are being added on a regular basis. In general, the performance is significantly better than using standard libm functions, though there does appear to be some reduced accuracy.
OS Requirements
MacOS 12 is required in order to run AppleAccelerate.jl. On older MacOS versions, your mileage may vary.
Supported Functions
The following functions are supported:
- Rounding:
ceil
,floor
,trunc
,round
- Logarithmic:
exp
,exp2
,expm1
,log
,log1p
,log2
,log10
- Trigonometric:
sin
,sinpi
,cos
,cospi
,tan
,tanpi
,asin
,acos
,atan
,atan2
,cis
- Hyperbolic:
sinh
,cosh
,tanh
,asinh
,acosh
,atanh
- Convolution:
conv
,xcorr
- Other:
sqrt
,copysign
,exponent
,abs
,rem
Note there are some slight differences from behaviour in Base:
- No
DomainError
s are raised, insteadNaN
values are returned. round
breaks ties (values with a fractional part of 0.5) by choosing the nearest even value.exponent
returns a floating point value of the same type (instead of anInt
).
Some additional functions that are also available:
rec(x)
: reciprocal (1.0 ./ x
)rsqrt(x)
: reciprocal square-root (1.0 ./ sqrt(x)
)pow(x,y)
: power (x .^ y
in Base)fdiv(x,y)
: divide (x ./ y
in Base)sincos(x)
: returns(sin(x), cos(x))
Example
To avoid naming conflicts with Base, methods are not exported and so need to be accessed via the namespace:
using AppleAccelerate
using BenchmarkTools
X = randn(1_000_000);
@btime exp.($X); # standard libm function
@btime AppleAccelerate.exp($X); # Accelerate array-oriented function
The @replaceBase
macro replaces the relevant Base methods directly
@btime sin.($X); # standard libm function
AppleAccelerate.@replaceBase sin cos tan
@btime sin($X); # will use AppleAccelerate methods for vectorised operations
X = randn(1_000_000);
Y = fill(3.0, 1_000_000);
@btime $X .^ $Y;
AppleAccelerate.@replaceBase(^, /) # use parenthesised form for infix ops
@btime $X ^ $Y;
Output arrays can be specified as first arguments of the functions suffixed
with !
:
out = zeros(Float64, 1_000_000)
@btime AppleAccelerate.exp!($out, $X)
Warning: no dimension checks are performed on the !
functions, so ensure
your input and output arrays are of the same length.
Operations can be performed in-place by specifying the output array as the
input array (e.g. AppleAccelerate.exp!(X,X)
). This is not mentioned in the
Accelerate docs, but this comment by one of the authors indicates that it is safe.