kernel input stream sub_domain access in CAL???

Discussion created by jean-claude on Dec 22, 2008
Latest reply on Dec 22, 2008 by jean-claude
guidance appreciated - Thanks


I just moved from Brook to CAL, and I find some difficulty dealing with
Stream sub-domain as input to a kernel.

Here it a short example, assume I have 3 CAL stream memory resources:

CALresource A_Res;     // 256*256 float4
CALresource B_Res;     // 16*16 float4
CALresource C_Res;     // 16*16 float4

// Resource allocation
calResAllocLocal2D(&A_Res, device, 256, 256, CAL_FORMAT_FLOAT4, 0);
calResAllocLocal2D(&B_Res, device,  16,  16, CAL_FORMAT_FLOAT4, 0);
calResAllocLocal2D(&C_Res, device,  16,  16, CAL_FORMAT_FLOAT4, 0);

// Memory binding
CALmem A_Mem;    calCtxGetmem(&A_Mem,ctx,A_Res);
CALmem B_Mem;    calCtxGetmem(&B_Mem,ctx,B_Res);
CALmem C_Mem;    calCtxGetmem(&C_Mem,ctx,C_Res);

Assume now, I have a kernel that computes the 16x16 C values by using
B and 16x16 subdomains of A (ie sliding 16x16 windows originated at
x,y coordinates) such as:

C = function of ( A.domain(x,y,x+16,y+16) ,  B )   with x and y variables

void kernel k_compute(output float4 c<>, float4 a<>, float4 b<> {



So ahead of kernel execution there is a memory binding

calCtxSetMem(ctx, i0, A_Mem);    // should I specify the input Stream domain here ????
calCtxSetMem(ctx, i1, B_Mem);
calCtxSetMem(ctx, o0, C_Mem);

domain = {0,0,16,16}; // this is the OUTPUT computation domain

calCtxRunProgram(&e, ctx, func, domain);



(1) How do I specify A stream sub_domain as an INPUT to my CAL kernel??

(2) Is this to be done when calCtxGetmem mapping the resource to mem? If yes how?


Thanks for guidance.