GPGPU Programming for Games and Science

158 GPGPU Programming for Games and Science

should be unrolled by the compiler.. Modify the compute shader as shown

next:

[ unroll ]

for ( int r=0; r< 3; ++r)

{

[ unroll ]

for ( int c=0; c< 3; ++c)

{

result += weight[r ][c] ∗ input [t + offset [ r ][ c ]];

}

}

which tells the compiler to unroll both loops, if possible. In this case, the

number of loop iterations is known at compile time, and we expect to obtain

nine occurrences of the inner-loop body, say,

re su lt += 0.0625 f ∗ input [ int2 (t .x − 1, t.y − 1)];

re su lt += 0.1250 f ∗ input [ int2 (t .x , t .y − 1)];

re su lt += 0.0625 f ∗ input [ int2 (t .x + 1, t .y − 1)];

re su lt += 0.1250 f ∗ input [ int2 ...