mirror of
https://igit.ific.uv.es/alramos/latticegpu.jl.git
synced 2025-05-14 19:23:42 +02:00
78 lines
1.8 KiB
Julia
78 lines
1.8 KiB
Julia
###
|
|
### "THE BEER-WARE LICENSE":
|
|
### Alberto Ramos wrote this file. As long as you retain this
|
|
### notice you can do whatever you want with this stuff. If we meet some
|
|
### day, and you think this stuff is worth it, you can buy me a beer in
|
|
### return. <alberto.ramos@cern.ch>
|
|
###
|
|
### file: CG.jl
|
|
### created: Tue Nov 30 11:10:57 2021
|
|
###
|
|
|
|
function krnl_dot!(sum,fone,ftwo)
|
|
b=Int64(CUDA.threadIdx().x)
|
|
r=Int64(CUDA.blockIdx().x)
|
|
|
|
sum[b,r] = dot(fone[b,r],ftwo[b,r])
|
|
|
|
return nothing
|
|
end
|
|
|
|
function field_dot(fone::AbstractArray,ftwo::AbstractArray,sumf,lp)
|
|
|
|
CUDA.@sync begin
|
|
CUDA.@cuda threads=lp.bsz blocks=lp.rsz krnl_dot!(sumf,fone,ftwo)
|
|
end
|
|
|
|
return sum(sumf)
|
|
end
|
|
|
|
|
|
"""
|
|
function CG!(si, U, A, dpar::DiracParam, lp::SpaceParm, dws::DiracWorkspace{T}, maxiter::Int64 = 10, tol=1.0)
|
|
|
|
Solves the linear equation `Ax = si`
|
|
"""
|
|
function CG!(si, U, A, dpar::DiracParam, lp::SpaceParm, dws::DiracWorkspace{T}, maxiter::Int64 = 10, tol=1.0) where {T}
|
|
|
|
dws.sr .= si
|
|
dws.sp .= si
|
|
norm = CUDA.mapreduce(x -> norm2(x), +, si)
|
|
fill!(si,zero(eltype(si)))
|
|
err = 0.0
|
|
|
|
tol = tol * norm
|
|
|
|
iterations = 0
|
|
sumf = scalar_field(Complex{T}, lp)
|
|
|
|
niter = 0
|
|
for i in 1:maxiter
|
|
A(dws.sAp, U, dws.sp, dpar, dws, lp)
|
|
|
|
prod = field_dot(dws.sp,dws.sAp,sumf,lp)
|
|
|
|
alpha = norm/prod
|
|
|
|
si .= si .+ alpha .* dws.sp
|
|
dws.sr .= dws.sr .- alpha .* dws.sAp
|
|
|
|
err = CUDA.mapreduce(x -> norm2(x), +, dws.sr)
|
|
|
|
if err < tol
|
|
niter = i
|
|
break
|
|
end
|
|
|
|
beta = err/norm
|
|
dws.sp .= dws.sr .+ beta .* dws.sp
|
|
|
|
norm = err;
|
|
end
|
|
|
|
if err > tol
|
|
error("CG! not converged after $maxiter iterations (Residuals: $err)")
|
|
end
|
|
|
|
return niter
|
|
end
|