LDC2 win64 calling convention

[realhet]

Thank You for the explanation!

But my tests has different results:

void* SSE_sobelRow(ubyte* src, ubyte* dst, size_t srcStride){ asm{
   push RDI;

   mov RAX, 0; mov RDX, 0; mov RCX, 0; //clear 'parameter' 
registers

   mov RAX, src;
   mov RDI, dst;

   //gen
   movups XMM0,[RAX];
   movaps XMM1,XMM0;
   pslldq XMM0,1;
   movaps XMM2,XMM1;
   psrldq XMM1,1;
   pavgb XMM1,XMM0;
   pavgb XMM1,XMM2;
   movups [RDI],XMM1;
   //gen end

   pop RDI;
}}

When I clear those volatile regs that are used for register 
calling, I'm still able to get good results.
However when I put "mov [RBP+8], 0" into the code it generates an 
access violation, so this is why I think parameters are on the 
stack.

What I'm really unsire is that the registers I HAVE TO save in my 
asm routine.
Currently I think I only able to trash the contents of RAX, RCX, 
RDX, XMM0..XMM5 based on the Microsoft calling model. But I'm not 
sure what's the actual case with LDC2 Win64.

If my code is surrounded by SSE the optimizations of the LDC2 
compiler, and I can't satisfy the requirements, I will have 
random errors in the future. I better avoid those.

On the 32bit target the rule is simpe: you could do with all the 
XMM regs and a,c,d what you want. Now at 64bit I'm quite unsure. 
:S