On Friday, 23 March 2012 at 10:48:55 UTC, Dmitry Olshansky wrote:
On 23.03.2012 9:57, Comrad wrote:
On Thursday, 22 March 2012 at 10:43:35 UTC, Trass3r wrote:
What is the status at the moment? What compiler and with
which
compiler flags I should use to achieve maximum performance?
In general gdc or ldc. Not sure how good vectorization is
though, esp.
auto-vectorization.
On the other hand the so called vector operations like a[] =
b[] +
c[]; are lowered to hand-written SSE assembly even in dmd.
I had such a snippet to test:
1 import std.stdio;
2 void main()
3 {
4 double[2] a=[1.,0.];
5 double[2] a1=[1.,0.];
6 double[2] a2=[1.,0.];
7 double[2] a3=[0.,0.];
Here is a culprit, the array ops [] are tuned for arbitrary
long(!) arrays, they are not plain 1 simd SEE op. They are
handcrafted loops(!) on SSE ops, cool and fast for arrays in
general, not fixed pairs/trios/etc. I believe it might change
in future, if compiler is able to deduce that size is fixed,
and use more optimal code for small sizes.
So currently there is no such an optimization exists for any d
compiler?
