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Altera_Forum
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11 years ago

Adding two uint4

Hi, I'm struggling with adding int4 data. I want to be able to add two 96b numbers (what implies adding with carry) in my kernel and I came up with this code: uint4 Add(uint4 a, uint4 b){ u...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

In OpenCL C language you cannot dynamically index into vector types. That is a and b as used above is not allowed. You could do the following instead:

uint4 Add(uint4 a, uint4 b){

ulong4 c;

c.s0 = (ulong) a.s0 + (ulong) b.s0;

c.s1 = (ulong) a.s1 + (ulong) b.s1 + (c.s0 >> 32);

c.s2 = (ulong) a.s2 + (ulong) b.s2 + (c.s1 >> 32);

return (uint4)(c.s0, c.s1, c.s2, 0);

}