I'm trying to understand how to use the `core.simd` functionality, and I'm having trouble initializing a float4 vector.

Here's my example code:

```
import std.stdio;
import core.simd;

void main()
{
  float[4] values = [1.0f, 2.0f, 3.0f, 4.0f];
  float delta = 15.0f;

  writeln(doSimd(values, delta));

}

float[4] doSimd(float[4] values, float delta)
{
  float4 v_delta = delta;
  float4 v_values = values;

  // ... do SIMD ...

  return [v_delta[0], v_delta[0],v_delta[0],v_delta[0]];
}
```

Compilation is failing with the following error:

```
source/app.d(16,21): Error: cannot implicitly convert expression values of type float[4] to __vector(float[4])
dmd failed with exit code 1.
```
How do you initialize a float4 with some useful data?

Here's a cleaned up version:

```
import std.stdio;
import core.simd;

void main()
{
  float[4] values = [1.0f, 2.0f, 3.0f, 4.0f];
  float delta = 15.0f;

  writeln(doSimd(values, delta));

}

float[4] doSimd(float[4] values, float delta)
{
  float4 v_delta = delta;
  float4 v_values = values;

  v_values = __simd(XMM.ADDPS, v_values, v_delta);

  return [v_values[0], v_values[1],v_values[2],v_values[3]];
}
```

The problem is with initializing v_values.

Well, this seems to be working:

> float[4] doSimd(float[4] values, float delta)
> {
>   float4 v_delta = delta;
> 
>   float4 v_values = __simd(XMM.ADDPS,
>                            __simd(XMM.LODAPS, values[0]),
>                            v_delta);
> 
>   return [v_values[0], v_values[1],v_values[2],v_values[3]];
> }

Not sure if it's correct though.

On Saturday, 21 September 2019 at 13:42:09 UTC, Bogdan wrote:
> Well, this seems to be working:
>
>> float[4] doSimd(float[4] values, float delta)
>> {
>>   float4 v_delta = delta;
>> 
>>   float4 v_values = __simd(XMM.ADDPS,
>>                            __simd(XMM.LODAPS, values[0]),
>>                            v_delta);
>> 
>>   return [v_values[0], v_values[1],v_values[2],v_values[3]];
>> }
>
> Not sure if it's correct though.

float4 x;
float x1, x2, x3, x4;
x[0] = x1;
x[1] = x2;
x[2] = x3;
x[3] = x4;

On Saturday, 21 September 2019 at 14:31:15 UTC, Stefan Koch wrote:
> On Saturday, 21 September 2019 at 13:42:09 UTC, Bogdan wrote:
>> Well, this seems to be working:
>>
>>> float[4] doSimd(float[4] values, float delta)
>>> {
>>>   float4 v_delta = delta;
>>> 
>>>   float4 v_values = __simd(XMM.ADDPS,
>>>                            __simd(XMM.LODAPS, values[0]),
>>>                            v_delta);
>>> 
>>>   return [v_values[0], v_values[1],v_values[2],v_values[3]];
>>> }
>>
>> Not sure if it's correct though.
>
> float4 x;
> float x1, x2, x3, x4;
> x[0] = x1;
> x[1] = x2;
> x[2] = x3;
> x[3] = x4;

Thank you! That also seems to be working.
Turns out that using this method for drawing a rectangle is about twice as slow than a naive implementation, so I'm almost certainly doing something silly/wrong. :)

On Saturday, 21 September 2019 at 12:50:46 UTC, Bogdan wrote:
> I'm trying to understand how to use the `core.simd` functionality, and I'm having trouble initializing a float4 vector.
>
> Here's my example code:
>
> ```
> import std.stdio;
> import core.simd;
>
> void main()
> {
>   float[4] values = [1.0f, 2.0f, 3.0f, 4.0f];
>   float delta = 15.0f;
>
>   writeln(doSimd(values, delta));
>
> }
>
> float[4] doSimd(float[4] values, float delta)
> {
>   float4 v_delta = delta;
>   float4 v_values = values;
>
>   // ... do SIMD ...
>
>   return [v_delta[0], v_delta[0],v_delta[0],v_delta[0]];
> }
> ```
>
> Compilation is failing with the following error:
>
> ```
> source/app.d(16,21): Error: cannot implicitly convert expression values of type float[4] to __vector(float[4])
> dmd failed with exit code 1.
> ```
> How do you initialize a float4 with some useful data?

You should probably have a look at this...

https://github.com/AuburnSounds/intel-intrinsics

On Sunday, 6 October 2019 at 11:53:29 UTC, NaN wrote:
>
> You should probably have a look at this...
>
> https://github.com/AuburnSounds/intel-intrinsics

Thanks, that looks quite useful.
Also, it seems that I need to use either LDC or GDC instead of DMD. :)