xmm tutorials

I don't know about tutorial information, but you can download the opcode descriptions from Intel and AMD. Also Intel and AMD has optimization manuals that cover some SSE (xmm).

A few notes:
- Make sure data is 16 byte aligned.
- Usually 64 bytes / iteration is the sweet spot for unrolling SSE loops that load and/or store data from/to memory
- Optimize the algorithm first, then attempt to make it parallel then implement it using the SSE instructions.

Here's a simple StringLength function using XMM registers.

Code:

strlen: 
;;string len with aligned and padded buffer
;;[esp+4] string pointer
      mov     eax,[esp+4]
 push    ebx
 test    eax,eax
     jz      .fail
       pxor    xmm0,xmm0
   mov     ebx,eax
.len:
;;load 32 bytes of the string
       movdqa  xmm2,[eax+16]
       movdqa  xmm1,[eax]
;;search for a null character
 pcmpeqb xmm2,xmm0
   pcmpeqb xmm1,xmm0
;;move results to 32bit registers
      pmovmskb edx,xmm2
   pmovmskb ecx,xmm1
;;combine the bit flagged results and increment the loop
       shl     edx,16
      add     eax,32
      or      ecx,edx
     jz      .len
;;calculate the length (end-start + byte_offset - 32)
       sub     eax,ebx
     bsf     ecx,ecx
     lea     eax,[eax+ecx-32]
    pop     ebx
 ret     4
.fail:
     xor     eax,eax
     pop     ebx
 ret     4