[docs] update ops/matmul.jl

Adding basic docs for matmul functions.

Author: arhik

src/ops/matmul.jl

@@ -1,5 +1,10 @@
 export naive_matmul_kernel, matmul
 
+"""
+	matmul_heuristics(x, y)
+This function computes workgroup size and workgroup count heuristics for a given input.
+This is used by `naive_matmul_kernel`.
+"""
 function matmul_heuristics(x, y)
 	aSize = size(x)
 	bSize = size(y)
@@ -9,6 +14,12 @@ function matmul_heuristics(x, y)
 	return (outSize, outSize, (1, 1))
 end
 
+"""
+	naive_matmul_kernel(x::WgpuArray{T, N}, y::WgpuArray{T, N}, out::WgpuArray{T, N}) where {T, N}
+This is naive matrix multiplication implementation kernel. This is not supposed to be used as a regular
+julia function. This needs to be passed to @wgpukernel to under transformations to `WGSL` compatible
+shader code.
+"""
 function naive_matmul_kernel(x::WgpuArray{T, N}, y::WgpuArray{T, N}, out::WgpuArray{T, N}) where {T, N}
 	gIdx = globalId.x
 	gIdy = globalId.y
@@ -23,14 +34,24 @@ function naive_matmul_kernel(x::WgpuArray{T, N}, y::WgpuArray{T, N}, out::WgpuAr
 	out[gId] = sum
 end
 
+"""
+	matmul(x::WgpuArray{T, N}, y::WgpuArray{T, N}) where {T, N}
+This is wrapper function for end users which uses naive implementation of matrix multiplication 
+`naive_matmul_kernel` kernel for matrix computation. 
+"""
 function matmul(x::WgpuArray{T, N}, y::WgpuArray{T, N}) where {T, N}
 	(outSize, wgSize, wgCount) = matmul_heuristics(x, y)
 	out = WgpuArray{eltype(x), ndims(x)}(undef, outSize)
 	@wgpukernel launch=true workgroupSizes=wgSize workgroupCount=wgCount shmem=() naive_matmul_kernel(x, y, out)
 	return out
 end
 
-
+"""
+	tiled_matmul_kernel(x::WgpuArray{T, N}, y::WgpuArray{T, N}, out::WgpuArray{T, N}) where {T, N}
+This is compute kernel which carries out tiled matrix multiplication of input `WgpuArrays`. This is 
+not supposed to be used as a regular julia function. This instead needs to be passed to `@wgpukernel` macro
+inside a wrapper function.
+"""
 function tiled_matmul_kernel(x::WgpuArray{T, N}, y::WgpuArray{T, N}, out::WgpuArray{T, N}) where {T, N}
 	#set out matrix to zero
 	gId = xDims.x*globalId.y + globalId.x
@@ -61,18 +82,29 @@ function tiled_matmul_kernel(x::WgpuArray{T, N}, y::WgpuArray{T, N}, out::WgpuAr
 
 	out[gId] = sum
 end
-# For now valid only for square matrices of size powers of 2 and base size 16.
+
+"""
+	tiled_matmul_heuristics(x::WgpuArray{T, N}, y::WgpuArray{T, N}) where {T, N}
+This function computes workgroup size and workgroup count for a given input for
+`tiled_matmul_heuristics` kernel function.
+"""
 function tiled_matmul_heuristics(x::WgpuArray{T, N}, y::WgpuArray{T, N}) where {T, N}
 	aSize = size(x)
 	bSize = size(y)
 	@assert last(aSize) == first(bSize)
 	outSize = (first(aSize), last(bSize))
 	@assert eltype(x) == eltype(y)
+	# For now valid only for square matrices of size powers of 2 and base size 16.
 	wgSize = (16, 16) # This can be fixed for now
 	wgCount = div.((outSize[1], outSize[2]), 16, RoundUp)
 	return (outSize, wgSize, wgCount)
 end
 
+"""
+	tiled_matmul(x::WgpuArray{T, N}, y::WgpuArray{T, N}) where {T, N}
+This is user end matrix multiplication function which carries out tiled matrix multiplication of
+input `WgpuArray` arguments.
+"""
 function tiled_matmul(x::WgpuArray{T, N}, y::WgpuArray{T, N}) where {T, N}
 	(outSize, wgSize, wgCount) = tiled_matmul_heuristics(x, y)
 	out = WgpuArray{eltype(x), ndims(x)}(undef, outSize)