I'm a bit new to the inline assembler, I'm trying to use the `movdqu` operation to move a 128 bit double quadword from a pointer location into another location like this:

align(16) union __m128i { ubyte[16] data };

void store(__m128i* src, __m128i* dst) {
	asm { movdqu [dst], src; }
}


The compiler complains about a "bad type/size of operands 'movdqu'", but these two data segments are 16 byte align so they should be in an XMM# register? Is there something I'm missing here?

On Thursday, 9 October 2014 at 12:37:20 UTC, Etienne wrote:
> I'm a bit new to the inline assembler, I'm trying to use the `movdqu` operation to move a 128 bit double quadword from a pointer location into another location like this:
>
> align(16) union __m128i { ubyte[16] data };
>
> void store(__m128i* src, __m128i* dst) {
> 	asm { movdqu [dst], src; }
> }
>
>
> The compiler complains about a "bad type/size of operands 'movdqu'", but these two data segments are 16 byte align so they should be in an XMM# register? Is there something I'm missing here?

I know virtually nothing about SSE, but you can't move directly
from memory to memory, can you? You need go through a register,
no?

This compiles:

align(16) union __m128i { ubyte[16] data; } /* note the position
of the semicolon */

void store(__m128i* src, __m128i* dst) {
     asm
     {
         movdqu XMM0, [src]; /* note: [src] */
         movdqu [dst], XMM0;
     }
}

On 2014-10-09 8:54 AM, anonymous wrote:
> This compiles:
>
> align(16) union __m128i { ubyte[16] data; } /* note the position
> of the semicolon */
>
> void store(__m128i* src, __m128i* dst) {
>       asm
>       {
>           movdqu XMM0, [src]; /* note: [src] */
>           movdqu [dst], XMM0;
>       }
> }

Yes, this does compile, but the value from src never ends up stored in dst.

void main() {
	__m128i src;
	src.data[0] = 255;
	__m128i dst;
	writeln(src.data); // shows 255 at offset 0
	store(&src, &dst);
	writeln(dst.data); // remains set as the initial array
}

http://x86.renejeschke.de/html/file_module_x86_id_184.html

Is this how it's meant to be used?

Maybe someone can help with the more specific problem. I'm translating a crypto engine here:

https://github.com/etcimon/botan/blob/master/source/botan/block/aes_ni/aes_ni.d

But I need this to work on DMD, LDC and GDC. I decided to write the assembler code directly for the functions in this module:

https://github.com/etcimon/botan/blob/master/source/botan/utils/simd/xmmintrin.d

If there's anything someone can tell me about this, I'd be thankful. I'm very experienced in every aspect of programming, but still at my first baby steps in assembler.

On Thursday, 9 October 2014 at 13:29:27 UTC, Etienne wrote:
> On 2014-10-09 8:54 AM, anonymous wrote:
>> This compiles:
>>
>> align(16) union __m128i { ubyte[16] data; } /* note the position
>> of the semicolon */
>>
>> void store(__m128i* src, __m128i* dst) {
>>      asm
>>      {
>>          movdqu XMM0, [src]; /* note: [src] */
>>          movdqu [dst], XMM0;
>>      }
>> }
>
> Yes, this does compile, but the value from src never ends up stored in dst.
>
> void main() {
> 	__m128i src;
> 	src.data[0] = 255;
> 	__m128i dst;
> 	writeln(src.data); // shows 255 at offset 0
> 	store(&src, &dst);
> 	writeln(dst.data); // remains set as the initial array
> }
>
> http://x86.renejeschke.de/html/file_module_x86_id_184.html
>
> Is this how it's meant to be used?

I'm out of my knowledge zone here, but it seems to work when you
move the pointers to registers first:

void store(__m128i* src, __m128i* dst) {
     asm
     {
         mov RAX, src;
         mov RBX, dst;
         movdqu XMM0, [RAX];
         movdqu [RBX], XMM0;
     }
}

On 2014-10-09 9:46 AM, anonymous wrote:
> I'm out of my knowledge zone here, but it seems to work when you
> move the pointers to registers first:
>
> void store(__m128i* src, __m128i* dst) {
>       asm
>       {
>           mov RAX, src;
>           mov RBX, dst;
>           movdqu XMM0, [RAX];
>           movdqu [RBX], XMM0;
>       }
> }

Absolutely incredible! My first useful working assembler code. You save the day. Now I can probably write a whole SIMD library ;)