Re: Improving dot product for standard multidimensional D arrays
On Sunday, 1 March 2020 at 20:58:42 UTC, p.shkadzko wrote:
pragma(inline) static int toIdx(T)(Matrix!T m, in int i, in int
j)
{
return m.cols * i + j;
}
This is row-major order [1]. BTW: Why don't you make toIdx a
member of Matrix? It saves one parameter. You may also define
opIndex as
ref T opIndex(in int r, in int c)
Then the innermost summation becomes more readable:
m3[i, j] += m1[i, k] * m2[k, j];
How about performing an in-place transposition of m2 before
performing the dot product? Then you can then rewrite the
innermost loop:
m3[i, j] += m1[i, k] * m2[j, k]; // note: j and k swapped
This should avoid the costly jumping thru the memory. A good
starting point for a performance analysis would be looking over
the assember code of the innermost loop.
[1] https://en.wikipedia.org/wiki/Row_major
Re: Can't compile dlangui
On Friday, 7 February 2020 at 12:04:10 UTC, A.Perea wrote: Hi, I'm trying to compile dlangide, and it fails when compiling the dependency dlangui. Trying to compile dlangui independently gives the same error message (see below for full stack trace) [...] On Friday, 7 February 2020 at 12:04:10 UTC, A.Perea wrote: Here is reported issue: https://issues.dlang.org/show_bug.cgi?id=20623
Re: Improving dot product for standard multidimensional D arrays
On Tuesday, 3 March 2020 at 10:25:27 UTC, maarten van damme wrote: it is difficult to write an efficient matrix matrix multiplication in any language. If you want a fair comparison, implement your naive method in python and compare those timings. [snip] And of course there's going to be a big slowdown in using native python. Numpy basically calls blas in the background. A naive C implementation might be another comparison.
Re: Improving dot product for standard multidimensional D arrays
On Tuesday, 3 March 2020 at 10:25:27 UTC, maarten van damme wrote: it is difficult to write an efficient matrix matrix multiplication in any language. If you want a fair comparison, implement your naive method in python and compare those timings. Op di 3 mrt. 2020 om 04:20 schreef 9il via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com>: On Sunday, 1 March 2020 at 20:58:42 UTC, p.shkadzko wrote: > [...] Matrix multiplication is about cache-friendly blocking. https://www.cs.utexas.edu/users/pingali/CS378/2008sp/papers/gotoPaper.pdf `mir-blas` package can be used for matrix operations for ndslice. `cblas` - if you want to work with your own matrix type . Yeah, got it. After some reading, I understand that's not trivial once bigger matrices are involved.
Re: core.atomic.atomicStore and structs
On Tuesday, 3 March 2020 at 11:35:35 UTC, MoonlightSentinel wrote: On Tuesday, 3 March 2020 at 11:04:53 UTC, Saurabh Das wrote: PS: Any chance this will make it into DMD 2.091.0? Yes, this fix will be in the upcoming release. Excellent. Thank you so much! :) Saurabh
Re: core.atomic.atomicStore and structs
On Tuesday, 3 March 2020 at 11:04:53 UTC, Saurabh Das wrote: PS: Any chance this will make it into DMD 2.091.0? Yes, this fix will be in the upcoming release.
Re: core.atomic.atomicStore and structs
On Tuesday, 3 March 2020 at 10:57:36 UTC, MoonlightSentinel wrote: On Tuesday, 3 March 2020 at 09:12:40 UTC, Saurabh Das wrote: Is this supposed to not work anymore? Or is this a bug? That is a bug, see https://issues.dlang.org/show_bug.cgi?id=20629 Oh wow you fixed it already! Amazing! Thanks MoonlightSentinel. Saurabh PS: Any chance this will make it into DMD 2.091.0?
Re: core.atomic.atomicStore and structs
On Tuesday, 3 March 2020 at 09:12:40 UTC, Saurabh Das wrote: Is this supposed to not work anymore? Or is this a bug? That is a bug, see https://issues.dlang.org/show_bug.cgi?id=20629
Re: Improving dot product for standard multidimensional D arrays
it is difficult to write an efficient matrix matrix multiplication in any language. If you want a fair comparison, implement your naive method in python and compare those timings. Op di 3 mrt. 2020 om 04:20 schreef 9il via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com>: > On Sunday, 1 March 2020 at 20:58:42 UTC, p.shkadzko wrote: > > Hello again, > > > > Thanks to previous thread on multidimensional arrays, I managed > > to play around with pure D matrix representations and even > > benchmark a little against numpy: > > > > [...] > > Matrix multiplication is about cache-friendly blocking. > https://www.cs.utexas.edu/users/pingali/CS378/2008sp/papers/gotoPaper.pdf > > `mir-blas` package can be used for matrix operations for ndslice. > `cblas` - if you want to work with your own matrix type . >
core.atomic.atomicStore and structs
Hi,
Consider this code:
```
import core.atomic;
struct MyStruct
{
uint a, b;
}
static assert(MyStruct.sizeof == ulong.sizeof);
void main()
{
shared MyStruct ms1;
MyStruct ms2 = atomicLoad(ms1); // This is fine
MyStruct ms3;
cas(, ms2, ms3);// This is also fine
atomicStore(ms1, ms2); // This gives a compile
error
}
```
This used to work in DMD 2.088.1. It does not work in the latest
DMD 2.091.0-beta.2. It gives a compile error like this:
```
/home/ec2-user/dlang/dmd-2.091.0-beta.2/linux/bin64/../../src/druntime/import/core/internal/atomic.d(233):
Error: template core.internal.atomic.atomicExchange cannot deduce function
from argument types !(cast(MemoryOrder)5, false)(MyStruct*, MyStruct),
candidates are:
/home/ec2-user/dlang/dmd-2.091.0-beta.2/linux/bin64/../../src/druntime/import/core/internal/atomic.d(291):
atomicExchange(MemoryOrder order = MemoryOrder.seq, bool result = true,
T)(T* dest, T value)
with order = order,
result = false,
T = MyStruct
whose parameters have the following constraints:
> is(T : ulong)
or:
> is(T == class)
or:
> is(T == interface)
or:
> is(T U : U*)
Tip: not satisfied constraints are marked with >
/home/ec2-user/dlang/dmd-2.091.0-beta.2/linux/bin64/../../src/druntime/import/core/atomic.d(127):
Error: template instance core.internal.atomic.atomicStore!(cast(MemoryOrder)5,
MyStruct) error instantiating
/home/ec2-user/dlang/dmd-2.091.0-beta.2/linux/bin64/../../src/druntime/import/core/atomic.d(142):
instantiated from here: atomicStore!(cast(MemoryOrder)5, MyStruct,
MyStruct)
atomic_test.d(18):instantiated from here:
atomicStore!(cast(MemoryOrder)5, MyStruct, MyStruct)
```
Is this supposed to not work anymore? Or is this a bug?
Thanks,
Saurabh
