# This file is a part of Julia. License is MIT: https://julialang.org/license
function is_argtype_match(@nospecialize(given_argtype),
@nospecialize(cache_argtype),
overridden_by_const::Bool)
if isa(given_argtype, Const) || isa(given_argtype, PartialStruct) || isa(given_argtype, PartialOpaque)
return is_lattice_equal(given_argtype, cache_argtype)
end
return !overridden_by_const
end
# In theory, there could be a `cache` containing a matching `InferenceResult`
# for the provided `linfo` and `given_argtypes`. The purpose of this function is
# to return a valid value for `cache_lookup(linfo, argtypes, cache).argtypes`,
# so that we can construct cache-correct `InferenceResult`s in the first place.
function matching_cache_argtypes(linfo::MethodInstance, given_argtypes::Vector, va_override::Bool)
@assert isa(linfo.def, Method) # ensure the next line works
nargs::Int = linfo.def.nargs
given_argtypes = anymap(widenconditional, given_argtypes)
isva = va_override || linfo.def.isva
if isva || isvarargtype(given_argtypes[end])
isva_given_argtypes = Vector{Any}(undef, nargs)
for i = 1:(nargs - isva)
isva_given_argtypes[i] = argtype_by_index(given_argtypes, i)
end
if isva
if length(given_argtypes) < nargs && isvarargtype(given_argtypes[end])
last = length(given_argtypes)
else
last = nargs
end
isva_given_argtypes[nargs] = tuple_tfunc(given_argtypes[last:end])
end
given_argtypes = isva_given_argtypes
end
@assert length(given_argtypes) == nargs
cache_argtypes, overridden_by_const = matching_cache_argtypes(linfo, nothing, va_override)
for i in 1:nargs
given_argtype = given_argtypes[i]
cache_argtype = cache_argtypes[i]
if !is_argtype_match(given_argtype, cache_argtype, overridden_by_const[i])
# prefer the argtype we were given over the one computed from `linfo`
cache_argtypes[i] = given_argtype
overridden_by_const[i] = true
end
end
return cache_argtypes, overridden_by_const
end
function most_general_argtypes(method::Union{Method, Nothing}, @nospecialize(specTypes),
isva::Bool, withfirst::Bool = true)
toplevel = method === nothing
linfo_argtypes = Any[unwrap_unionall(specTypes).parameters...]
nargs::Int = toplevel ? 0 : method.nargs
if !withfirst
# For opaque closure, the closure environment is processed elsewhere
nargs -= 1
end
cache_argtypes = Vector{Any}(undef, nargs)
# First, if we're dealing with a varargs method, then we set the last element of `args`
# to the appropriate `Tuple` type or `PartialStruct` instance.
if !toplevel && isva
if specTypes == Tuple
if nargs > 1
linfo_argtypes = svec(Any[Any for i = 1:(nargs - 1)]..., Tuple.parameters[1])
end
vargtype = Tuple
else
linfo_argtypes_length = length(linfo_argtypes)
if nargs > linfo_argtypes_length
va = linfo_argtypes[linfo_argtypes_length]
if isvarargtype(va)
new_va = rewrap_unionall(unconstrain_vararg_length(va), specTypes)
vargtype = Tuple{new_va}
else
vargtype = Tuple{}
end
else
vargtype_elements = Any[]
for p in linfo_argtypes[nargs:linfo_argtypes_length]
p = isvarargtype(p) ? unconstrain_vararg_length(p) : p
push!(vargtype_elements, rewrap(p, specTypes))
end
for i in 1:length(vargtype_elements)
atyp = vargtype_elements[i]
if isa(atyp, DataType) && isdefined(atyp, :instance)
# replace singleton types with their equivalent Const object
vargtype_elements[i] = Const(atyp.instance)
elseif isconstType(atyp)
vargtype_elements[i] = Const(atyp.parameters[1])
end
end
vargtype = tuple_tfunc(vargtype_elements)
end
end
cache_argtypes[nargs] = vargtype
nargs -= 1
end
# Now, we propagate type info from `linfo_argtypes` into `cache_argtypes`, improving some
# type info as we go (where possible). Note that if we're dealing with a varargs method,
# we already handled the last element of `cache_argtypes` (and decremented `nargs` so that
# we don't overwrite the result of that work here).
linfo_argtypes_length = length(linfo_argtypes)
if linfo_argtypes_length > 0
n = linfo_argtypes_length > nargs ? nargs : linfo_argtypes_length
tail_index = n
local lastatype
for i = 1:n
atyp = linfo_argtypes[i]
if i == n && isvarargtype(atyp)
atyp = unwrapva(atyp)
tail_index -= 1
end
while isa(atyp, TypeVar)
atyp = atyp.ub
end
if isa(atyp, DataType) && isdefined(atyp, :instance)
# replace singleton types with their equivalent Const object
atyp = Const(atyp.instance)
elseif isconstType(atyp)
atyp = Const(atyp.parameters[1])
else
atyp = rewrap(atyp, specTypes)
end
i == n && (lastatype = atyp)
cache_argtypes[i] = atyp
end
for i = (tail_index + 1):nargs
cache_argtypes[i] = lastatype
end
else
@assert nargs == 0 "invalid specialization of method" # wrong number of arguments
end
cache_argtypes
end
function matching_cache_argtypes(linfo::MethodInstance, ::Nothing, va_override::Bool)
mthd = isa(linfo.def, Method) ? linfo.def::Method : nothing
cache_argtypes = most_general_argtypes(mthd, linfo.specTypes,
va_override || (isa(mthd, Method) ? mthd.isva : false))
return cache_argtypes, falses(length(cache_argtypes))
end
function cache_lookup(linfo::MethodInstance, given_argtypes::Vector{Any}, cache::Vector{InferenceResult})
method = linfo.def::Method
nargs::Int = method.nargs
method.isva && (nargs -= 1)
length(given_argtypes) >= nargs || return nothing
for cached_result in cache
cached_result.linfo === linfo || continue
cache_match = true
cache_argtypes = cached_result.argtypes
cache_overridden_by_const = cached_result.overridden_by_const
for i in 1:nargs
if !is_argtype_match(given_argtypes[i],
cache_argtypes[i],
cache_overridden_by_const[i])
cache_match = false
break
end
end
if method.isva && cache_match
cache_match = is_argtype_match(tuple_tfunc(given_argtypes[(nargs + 1):end]),
cache_argtypes[end],
cache_overridden_by_const[end])
end
cache_match || continue
return cached_result
end
return nothing
end