loop.slang
//TEST:SIMPLE:-use-ir -dump-ir -profile cs_5_0 -entry main
#define GROUP_THREAD_COUNT 64
StructuredBuffer<float4> input;
RWStructuredBuffer<float4> output;
groupshared float4 s[GROUP_THREAD_COUNT];
[numthreads(GROUP_THREAD_COUNT, 1, 1)]
void main(
uint dispatchThreadID : SV_DispatchThreadID,
uint groupThreadID : SV_GroupThreadID,
uint groupID : SV_GroupIndex )
{
// the actual algorithm being done here is bogus
// load shared memory
s[groupThreadID] = input[dispatchThreadID];
// do some sum passes
for(uint stride = 1; stride < GROUP_THREAD_COUNT; stride <<= 1)
{
GroupMemoryBarrierWithGroupSync();
s[groupThreadID] += s[groupThreadID - stride];
}
GroupMemoryBarrierWithGroupSync();
output[dispatchThreadID] = s[0];
}