optimizations in sites_to_orbs

src/slices.jl

@@ -339,53 +339,47 @@ sites_to_orbs(c::CellSites, g) = sites_to_orbs(c, blockstructure(g))
 
 function sites_to_orbs(cs::CellSites, os::OrbitalBlockStructure)
     sites = siteindices(cs)
-    orbinds, groups = orbinds_and_groups(sites, os)
-    return CellIndices(cell(cs), orbinds, OrbitalLikeGrouped(dictionary(groups)))
+    groups = _groups(sites, os) # sites, orbranges
+    orbinds = _orbinds(sites, groups, os)
+    return CellIndices(cell(cs), orbinds, OrbitalLikeGrouped(Dictionary(groups...)))
 end
 
 function sites_to_orbs_flat(cs::CellSites, os::OrbitalBlockStructure)
     sites = siteindices(cs)
-    orbinds = orbinds_only(sites, os)
+    orbinds = _orbinds(sites, os)
     return CellIndices(cell(cs), orbinds, OrbitalLike())
 end
 
-function orbinds_and_groups(sites, os)
-    orbinds = Int[]
-    groups = Pair{Int,UnitRange{Int}}[]
-    for i in sites
-        rng = flatrange(os, i)
-        append!(orbinds, rng)
-        push!(groups, i => rng) # site index => orb range
+_groups(i::Integer, os) = [i], [flatrange(os, i)]
+_groups(::Colon, os) = _groups(siterange(os), os)
+
+function _groups(sites, os)
+    siteinds = Int[]
+    orbranges = UnitRange{Int}[]
+    sizehint!(siteinds, length(sites))
+    sizehint!(orbranges, length(sites))
+    for site in sites
+        rng = flatrange(os, site)
+        push!(siteinds, site)
+        push!(orbranges, rng)
     end
-    return orbinds, groups
-end
-
-function orbinds_and_groups(i::Integer, os)
-    orbinds = flatrange(os, i)  # a UnitRange
-    groups = (i => orbinds,)
-    return orbinds, groups
+    return siteinds, orbranges
 end
 
-function orbinds_and_groups(::Colon, os)
-    orbinds = flatrange(os, :)  # a UnitRange
-    groups = Pair{Int,UnitRange{Int}}[]
-    for i in siterange(os)
-        push!(groups, i => flatrange(os, i))
-    end
-    return orbinds, groups
-end
+_orbinds(sites::Union{Integer,Colon,AbstractUnitRange}, _, os) = flatrange(os, sites)
 
-function orbinds_and_groups(sites::AbstractUnitRange, os)
-    orbinds = flatrange(os, sites)  # a UnitRange
-    groups = Pair{Int,UnitRange{Int}}[]
-    for i in sites
-        push!(groups, i => flatrange(os, i))
+function _orbinds(_, (sites, orbrngs), os)  # reuse precomputed groups
+    orbinds = Int[]
+    sizehint!(orbinds, length(sites))
+    for rng in orbrngs
+        append!(orbinds, rng)
     end
-    return orbinds, groups
+    return orbinds
 end
 
-function orbinds_only(sites, os)
+function _orbinds(sites, os)
     orbinds = Int[]
+    sizehint!(orbinds, length(sites))
     for i in sites
         rng = flatrange(os, i)
         append!(orbinds, rng)

src/solvers/green/schur.jl

@@ -54,7 +54,7 @@ function SchurFactorsSolver(h::Hamiltonian{T,<:Any,1}, shift = one(Complex{T}))
     iG, (p, pd) = store_diagonal_ptrs(fh0)
     ptrs = (p, pd, pd[sinds])
     workspace = SchurWorkspace{Complex{T}}(size(L), length(linds), length(rinds))
-    return SchurFactorsSolver(shift, hm, h0, hp, l_leq_r, iG, ptrs, linds, rinds, sinds, L, R, R´L´, workspace)
+    return SchurFactorsSolver(T(shift), hm, h0, hp, l_leq_r, iG, ptrs, linds, rinds, sinds, L, R, R´L´, workspace)
 end
 
 function SchurWorkspace{C}((n, d), l, r) where {C}
@@ -341,9 +341,9 @@ end
 
 #region ## apply ##
 
-function apply(s::GS.Schur, h::AbstractHamiltonian1D{T}, contacts::Contacts) where {T}
+function apply(s::GS.Schur, h::AbstractHamiltonian1D, contacts::Contacts)
     h´ = hamiltonian(h)
-    fsolver = SchurFactorsSolver(h´, T(s.shift))
+    fsolver = SchurFactorsSolver(h´, s.shift)
     h0 = unitcell_hamiltonian(h)
     boundary = round(only(s.boundary))
     rsites = stored_cols(h[unflat(1)])