diff options
Diffstat (limited to 'ComputeShaders')
| -rw-r--r-- | ComputeShaders/mulMatByRowTiled.hlsl | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/ComputeShaders/mulMatByRowTiled.hlsl b/ComputeShaders/mulMatByRowTiled.hlsl index fea2fcb..11c7c18 100644 --- a/ComputeShaders/mulMatByRowTiled.hlsl +++ b/ComputeShaders/mulMatByRowTiled.hlsl @@ -39,7 +39,8 @@ void main( uint3 group: SV_GroupID, uint3 thread : SV_GroupThreadID, uint thread // Zero out the shared buffer for( i = thread.y; i < TILE_Y; i += THREADS_Y ) resTemp[ i ][ thread.x ] = 0.0; - GroupMemoryBarrierWithGroupSync(); + // Before the reduction at the end of this shader, each thread only loads/stores the [ thread.y + THREADS_Y * N ][ thread.x ] elements of the shared buffer, + // where N is an integer. That's why until the end, we don't need these thread sync instructions. // Count of rows to compute in this thread group const uint height = min( TILE_Y, arg0Size.y - group.x * TILE_Y ); @@ -70,7 +71,6 @@ void main( uint3 group: SV_GroupID, uint3 thread : SV_GroupThreadID, uint thread acc = mad( v0, v1, acc ); resTemp[ i ][ thread.x ] = acc; } - GroupMemoryBarrierWithGroupSync(); } const uint rem = arg0Size.x % THREADS_X; @@ -92,10 +92,11 @@ void main( uint3 group: SV_GroupID, uint3 thread : SV_GroupThreadID, uint thread acc = mad( v0, v1, acc ); resTemp[ i ][ thread.x ] = acc; } - GroupMemoryBarrierWithGroupSync(); } - // Now we need horizontal sums of these shared accumulators, i.e. reduce [height][THREADS_X] shared array into [height][1] column + // Now we need horizontal sum of these shared accumulators, reducing [height][THREADS_X] shared array into [height][1] column + GroupMemoryBarrierWithGroupSync(); + for( i = THREADS_X / 2; i > 0; i /= 2 ) { if( thread.x < i ) |