diff --git a/base/compiler/abstractinterpretation.jl b/base/compiler/abstractinterpretation.jl
index a6e0463e34b3d..daf87525e0228 100644
--- a/base/compiler/abstractinterpretation.jl
+++ b/base/compiler/abstractinterpretation.jl
@@ -2667,18 +2667,18 @@ struct BestguessInfo{Interp<:AbstractInterpreter}
     end
 end
 
-function widenreturn(@nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn(@nospecialize(rt), info::BestguessInfo)
     return widenreturn(typeinf_lattice(info.interp), rt, info)
 end
 
-function widenreturn(𝕃ᵢ::AbstractLattice, @nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn(𝕃ᵢ::AbstractLattice, @nospecialize(rt), info::BestguessInfo)
     return widenreturn(widenlattice(𝕃ᵢ), rt, info)
 end
-function widenreturn_noslotwrapper(𝕃ᵢ::AbstractLattice, @nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn_noslotwrapper(𝕃ᵢ::AbstractLattice, @nospecialize(rt), info::BestguessInfo)
     return widenreturn_noslotwrapper(widenlattice(𝕃ᵢ), rt, info)
 end
 
-function widenreturn(𝕃ᵢ::MustAliasesLattice, @nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn(𝕃ᵢ::MustAliasesLattice, @nospecialize(rt), info::BestguessInfo)
     if isa(rt, MustAlias)
         if 1 ≤ rt.slot ≤ info.nargs
             rt = InterMustAlias(rt)
@@ -2690,7 +2690,7 @@ function widenreturn(𝕃ᵢ::MustAliasesLattice, @nospecialize(rt), info::Bestg
     return widenreturn(widenlattice(𝕃ᵢ), rt, info)
 end
 
-function widenreturn(𝕃ᵢ::ConditionalsLattice, @nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn(𝕃ᵢ::ConditionalsLattice, @nospecialize(rt), info::BestguessInfo)
     ⊑ᵢ = ⊑(𝕃ᵢ)
     if !(⊑(ipo_lattice(info.interp), info.bestguess, Bool)) || info.bestguess === Bool
         # give up inter-procedural constraint back-propagation
@@ -2727,7 +2727,7 @@ function widenreturn(𝕃ᵢ::ConditionalsLattice, @nospecialize(rt), info::Best
     isa(rt, InterConditional) && return rt
     return widenreturn(widenlattice(𝕃ᵢ), rt, info)
 end
-function bool_rt_to_conditional(@nospecialize(rt), info::BestguessInfo)
+@noinfer function bool_rt_to_conditional(@nospecialize(rt), info::BestguessInfo)
     bestguess = info.bestguess
     if isa(bestguess, InterConditional)
         # if the bestguess so far is already `Conditional`, try to convert
@@ -2745,7 +2745,7 @@ function bool_rt_to_conditional(@nospecialize(rt), info::BestguessInfo)
     end
     return rt
 end
-function bool_rt_to_conditional(@nospecialize(rt), slot_id::Int, info::BestguessInfo)
+@noinfer function bool_rt_to_conditional(@nospecialize(rt), slot_id::Int, info::BestguessInfo)
     ⊑ᵢ = ⊑(typeinf_lattice(info.interp))
     old = info.slottypes[slot_id]
     new = widenslotwrapper(info.changes[slot_id].typ) # avoid nested conditional
@@ -2764,13 +2764,13 @@ function bool_rt_to_conditional(@nospecialize(rt), slot_id::Int, info::Bestguess
     return rt
 end
 
-function widenreturn(𝕃ᵢ::PartialsLattice, @nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn(𝕃ᵢ::PartialsLattice, @nospecialize(rt), info::BestguessInfo)
     return widenreturn_partials(𝕃ᵢ, rt, info)
 end
-function widenreturn_noslotwrapper(𝕃ᵢ::PartialsLattice, @nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn_noslotwrapper(𝕃ᵢ::PartialsLattice, @nospecialize(rt), info::BestguessInfo)
     return widenreturn_partials(𝕃ᵢ, rt, info)
 end
-function widenreturn_partials(𝕃ᵢ::PartialsLattice, @nospecialize(rt), info::BestguessInfo)
+@noinfer function widenreturn_partials(𝕃ᵢ::PartialsLattice, @nospecialize(rt), info::BestguessInfo)
     if isa(rt, PartialStruct)
         fields = copy(rt.fields)
         local anyrefine = false
@@ -2793,21 +2793,21 @@ function widenreturn_partials(𝕃ᵢ::PartialsLattice, @nospecialize(rt), info:
     return widenreturn(widenlattice(𝕃ᵢ), rt, info)
 end
 
-function widenreturn(::ConstsLattice, @nospecialize(rt), ::BestguessInfo)
+@noinfer function widenreturn(::ConstsLattice, @nospecialize(rt), ::BestguessInfo)
     return widenreturn_consts(rt)
 end
-function widenreturn_noslotwrapper(::ConstsLattice, @nospecialize(rt), ::BestguessInfo)
+@noinfer function widenreturn_noslotwrapper(::ConstsLattice, @nospecialize(rt), ::BestguessInfo)
     return widenreturn_consts(rt)
 end
-function widenreturn_consts(@nospecialize(rt))
+@noinfer function widenreturn_consts(@nospecialize(rt))
     isa(rt, Const) && return rt
     return widenconst(rt)
 end
 
-function widenreturn(::JLTypeLattice, @nospecialize(rt), ::BestguessInfo)
+@noinfer function widenreturn(::JLTypeLattice, @nospecialize(rt), ::BestguessInfo)
     return widenconst(rt)
 end
-function widenreturn_noslotwrapper(::JLTypeLattice, @nospecialize(rt), ::BestguessInfo)
+@noinfer function widenreturn_noslotwrapper(::JLTypeLattice, @nospecialize(rt), ::BestguessInfo)
     return widenconst(rt)
 end
 
diff --git a/base/compiler/abstractlattice.jl b/base/compiler/abstractlattice.jl
index a84050816cb21..d9aa802074ede 100644
--- a/base/compiler/abstractlattice.jl
+++ b/base/compiler/abstractlattice.jl
@@ -161,7 +161,7 @@ If `𝕃` is `JLTypeLattice`, this is equivalent to subtyping.
 """
 function ⊑ end
 
-⊑(::JLTypeLattice, @nospecialize(a::Type), @nospecialize(b::Type)) = a <: b
+@noinfer ⊑(::JLTypeLattice, @nospecialize(a::Type), @nospecialize(b::Type)) = a <: b
 
 """
     ⊏(𝕃::AbstractLattice, a, b) -> Bool
@@ -169,7 +169,7 @@ function ⊑ end
 The strict partial order over the type inference lattice.
 This is defined as the irreflexive kernel of `⊑`.
 """
-⊏(𝕃::AbstractLattice, @nospecialize(a), @nospecialize(b)) = ⊑(𝕃, a, b) && !⊑(𝕃, b, a)
+@noinfer ⊏(𝕃::AbstractLattice, @nospecialize(a), @nospecialize(b)) = ⊑(𝕃, a, b) && !⊑(𝕃, b, a)
 
 """
     ⋤(𝕃::AbstractLattice, a, b) -> Bool
@@ -177,7 +177,7 @@ This is defined as the irreflexive kernel of `⊑`.
 This order could be used as a slightly more efficient version of the strict order `⊏`,
 where we can safely assume `a ⊑ b` holds.
 """
-⋤(𝕃::AbstractLattice, @nospecialize(a), @nospecialize(b)) = !⊑(𝕃, b, a)
+@noinfer ⋤(𝕃::AbstractLattice, @nospecialize(a), @nospecialize(b)) = !⊑(𝕃, b, a)
 
 """
     is_lattice_equal(𝕃::AbstractLattice, a, b) -> Bool
@@ -186,7 +186,7 @@ Check if two lattice elements are partial order equivalent.
 This is basically `a ⊑ b && b ⊑ a` in the lattice of `𝕃`
 but (optionally) with extra performance optimizations.
 """
-function is_lattice_equal(𝕃::AbstractLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function is_lattice_equal(𝕃::AbstractLattice, @nospecialize(a), @nospecialize(b))
     a === b && return true
     return ⊑(𝕃, a, b) && ⊑(𝕃, b, a)
 end
@@ -197,14 +197,14 @@ end
 Determines whether the given lattice element `t` of `𝕃` has non-trivial extended lattice
 information that would not be available from the type itself.
 """
-has_nontrivial_extended_info(𝕃::AbstractLattice, @nospecialize t) =
+@noinfer has_nontrivial_extended_info(𝕃::AbstractLattice, @nospecialize t) =
     has_nontrivial_extended_info(widenlattice(𝕃), t)
-function has_nontrivial_extended_info(𝕃::PartialsLattice, @nospecialize t)
+@noinfer function has_nontrivial_extended_info(𝕃::PartialsLattice, @nospecialize t)
     isa(t, PartialStruct) && return true
     isa(t, PartialOpaque) && return true
     return has_nontrivial_extended_info(widenlattice(𝕃), t)
 end
-function has_nontrivial_extended_info(𝕃::ConstsLattice, @nospecialize t)
+@noinfer function has_nontrivial_extended_info(𝕃::ConstsLattice, @nospecialize t)
     isa(t, PartialTypeVar) && return true
     if isa(t, Const)
         val = t.val
@@ -212,7 +212,7 @@ function has_nontrivial_extended_info(𝕃::ConstsLattice, @nospecialize t)
     end
     return has_nontrivial_extended_info(widenlattice(𝕃), t)
 end
-has_nontrivial_extended_info(::JLTypeLattice, @nospecialize(t)) = false
+@noinfer has_nontrivial_extended_info(::JLTypeLattice, @nospecialize(t)) = false
 
 """
     is_const_prop_profitable_arg(𝕃::AbstractLattice, t) -> Bool
@@ -220,9 +220,9 @@ has_nontrivial_extended_info(::JLTypeLattice, @nospecialize(t)) = false
 Determines whether the given lattice element `t` of `𝕃` has new extended lattice information
 that should be forwarded along with constant propagation.
 """
-is_const_prop_profitable_arg(𝕃::AbstractLattice, @nospecialize t) =
+@noinfer is_const_prop_profitable_arg(𝕃::AbstractLattice, @nospecialize t) =
     is_const_prop_profitable_arg(widenlattice(𝕃), t)
-function is_const_prop_profitable_arg(𝕃::PartialsLattice, @nospecialize t)
+@noinfer function is_const_prop_profitable_arg(𝕃::PartialsLattice, @nospecialize t)
     if isa(t, PartialStruct)
         return true # might be a bit aggressive, may want to enable some check like follows:
         # for i = 1:length(t.fields)
@@ -236,7 +236,7 @@ function is_const_prop_profitable_arg(𝕃::PartialsLattice, @nospecialize t)
     isa(t, PartialOpaque) && return true
     return is_const_prop_profitable_arg(widenlattice(𝕃), t)
 end
-function is_const_prop_profitable_arg(𝕃::ConstsLattice, @nospecialize t)
+@noinfer function is_const_prop_profitable_arg(𝕃::ConstsLattice, @nospecialize t)
     if isa(t, Const)
         # don't consider mutable values useful constants
         val = t.val
@@ -245,24 +245,24 @@ function is_const_prop_profitable_arg(𝕃::ConstsLattice, @nospecialize t)
     isa(t, PartialTypeVar) && return false # this isn't forwardable
     return is_const_prop_profitable_arg(widenlattice(𝕃), t)
 end
-is_const_prop_profitable_arg(::JLTypeLattice, @nospecialize t) = false
+@noinfer is_const_prop_profitable_arg(::JLTypeLattice, @nospecialize t) = false
 
-is_forwardable_argtype(𝕃::AbstractLattice, @nospecialize(x)) =
+@noinfer is_forwardable_argtype(𝕃::AbstractLattice, @nospecialize(x)) =
     is_forwardable_argtype(widenlattice(𝕃), x)
-function is_forwardable_argtype(𝕃::ConditionalsLattice, @nospecialize x)
+@noinfer function is_forwardable_argtype(𝕃::ConditionalsLattice, @nospecialize x)
     isa(x, Conditional) && return true
     return is_forwardable_argtype(widenlattice(𝕃), x)
 end
-function is_forwardable_argtype(𝕃::PartialsLattice, @nospecialize x)
+@noinfer function is_forwardable_argtype(𝕃::PartialsLattice, @nospecialize x)
     isa(x, PartialStruct) && return true
     isa(x, PartialOpaque) && return true
     return is_forwardable_argtype(widenlattice(𝕃), x)
 end
-function is_forwardable_argtype(𝕃::ConstsLattice, @nospecialize x)
+@noinfer function is_forwardable_argtype(𝕃::ConstsLattice, @nospecialize x)
     isa(x, Const) && return true
     return is_forwardable_argtype(widenlattice(𝕃), x)
 end
-function is_forwardable_argtype(::JLTypeLattice, @nospecialize x)
+@noinfer function is_forwardable_argtype(::JLTypeLattice, @nospecialize x)
     return false
 end
 
@@ -281,9 +281,9 @@ External lattice `𝕃ᵢ::ExternalLattice` may overload:
 """
 function widenreturn end, function widenreturn_noslotwrapper end
 
-is_valid_lattice(𝕃::AbstractLattice, @nospecialize(elem)) =
+@noinfer is_valid_lattice(𝕃::AbstractLattice, @nospecialize(elem)) =
     is_valid_lattice_norec(𝕃, elem) && is_valid_lattice(widenlattice(𝕃), elem)
-is_valid_lattice(𝕃::JLTypeLattice, @nospecialize(elem)) = is_valid_lattice_norec(𝕃, elem)
+@noinfer is_valid_lattice(𝕃::JLTypeLattice, @nospecialize(elem)) = is_valid_lattice_norec(𝕃, elem)
 
 has_conditional(𝕃::AbstractLattice) = has_conditional(widenlattice(𝕃))
 has_conditional(::AnyConditionalsLattice) = true
@@ -306,12 +306,12 @@ has_extended_unionsplit(::JLTypeLattice) = false
 const fallback_lattice = InferenceLattice(BaseInferenceLattice.instance)
 const fallback_ipo_lattice = InferenceLattice(IPOResultLattice.instance)
 
-⊑(@nospecialize(a), @nospecialize(b)) = ⊑(fallback_lattice, a, b)
-tmeet(@nospecialize(a), @nospecialize(b)) = tmeet(fallback_lattice, a, b)
-tmerge(@nospecialize(a), @nospecialize(b)) = tmerge(fallback_lattice, a, b)
-⊏(@nospecialize(a), @nospecialize(b)) = ⊏(fallback_lattice, a, b)
-⋤(@nospecialize(a), @nospecialize(b)) = ⋤(fallback_lattice, a, b)
-is_lattice_equal(@nospecialize(a), @nospecialize(b)) = is_lattice_equal(fallback_lattice, a, b)
+@noinfer @nospecialize(a) ⊑ @nospecialize(b) = ⊑(fallback_lattice, a, b)
+@noinfer @nospecialize(a) ⊏ @nospecialize(b) = ⊏(fallback_lattice, a, b)
+@noinfer @nospecialize(a) ⋤ @nospecialize(b) = ⋤(fallback_lattice, a, b)
+@noinfer tmeet(@nospecialize(a), @nospecialize(b)) = tmeet(fallback_lattice, a, b)
+@noinfer tmerge(@nospecialize(a), @nospecialize(b)) = tmerge(fallback_lattice, a, b)
+@noinfer is_lattice_equal(@nospecialize(a), @nospecialize(b)) = is_lattice_equal(fallback_lattice, a, b)
 
 # Widenlattice with argument
 widenlattice(::JLTypeLattice, @nospecialize(t)) = widenconst(t)
diff --git a/base/compiler/typelattice.jl b/base/compiler/typelattice.jl
index 700a6d333cbc4..7126ca95025bd 100644
--- a/base/compiler/typelattice.jl
+++ b/base/compiler/typelattice.jl
@@ -244,7 +244,7 @@ const CompilerTypes = Union{MaybeUndef, Const, Conditional, MustAlias, NotFound,
 # slot wrappers
 # =============
 
-function assert_nested_slotwrapper(@nospecialize t)
+@noinfer function assert_nested_slotwrapper(@nospecialize t)
     @assert !(t isa Conditional)      "found nested Conditional"
     @assert !(t isa InterConditional) "found nested InterConditional"
     @assert !(t isa MustAlias)        "found nested MustAlias"
@@ -252,7 +252,7 @@ function assert_nested_slotwrapper(@nospecialize t)
     return t
 end
 
-function widenslotwrapper(@nospecialize typ)
+@noinfer function widenslotwrapper(@nospecialize typ)
     if isa(typ, AnyConditional)
         return widenconditional(typ)
     elseif isa(typ, AnyMustAlias)
@@ -261,7 +261,7 @@ function widenslotwrapper(@nospecialize typ)
     return typ
 end
 
-function widenwrappedslotwrapper(@nospecialize typ)
+@noinfer function widenwrappedslotwrapper(@nospecialize typ)
     if isa(typ, LimitedAccuracy)
         return LimitedAccuracy(widenslotwrapper(typ.typ), typ.causes)
     end
@@ -271,7 +271,7 @@ end
 # Conditional
 # ===========
 
-function widenconditional(@nospecialize typ)
+@noinfer function widenconditional(@nospecialize typ)
     if isa(typ, AnyConditional)
         if typ.thentype === Union{}
             return Const(false)
@@ -285,7 +285,7 @@ function widenconditional(@nospecialize typ)
     end
     return typ
 end
-function widenwrappedconditional(@nospecialize typ)
+@noinfer function widenwrappedconditional(@nospecialize typ)
     if isa(typ, LimitedAccuracy)
         return LimitedAccuracy(widenconditional(typ.typ), typ.causes)
     end
@@ -294,7 +294,7 @@ end
 
 # `Conditional` and `InterConditional` are valid in opposite contexts
 # (i.e. local inference and inter-procedural call), as such they will never be compared
-function issubconditional(lattice::AbstractLattice, a::C, b::C) where {C<:AnyConditional}
+@noinfer function issubconditional(lattice::AbstractLattice, a::C, b::C) where {C<:AnyConditional}
     if is_same_conditionals(a, b)
         if ⊑(lattice, a.thentype, b.thentype)
             if ⊑(lattice, a.elsetype, b.elsetype)
@@ -307,7 +307,7 @@ end
 
 is_same_conditionals(a::C, b::C) where C<:AnyConditional = a.slot == b.slot
 
-is_lattice_bool(lattice::AbstractLattice, @nospecialize(typ)) = typ !== Bottom && ⊑(lattice, typ, Bool)
+@noinfer is_lattice_bool(lattice::AbstractLattice, @nospecialize(typ)) = typ !== Bottom && ⊑(lattice, typ, Bool)
 
 maybe_extract_const_bool(c::Const) = (val = c.val; isa(val, Bool)) ? val : nothing
 function maybe_extract_const_bool(c::AnyConditional)
@@ -315,12 +315,12 @@ function maybe_extract_const_bool(c::AnyConditional)
     (c.elsetype === Bottom && !(c.thentype === Bottom)) && return true
     nothing
 end
-maybe_extract_const_bool(@nospecialize c) = nothing
+@noinfer maybe_extract_const_bool(@nospecialize c) = nothing
 
 # MustAlias
 # =========
 
-function widenmustalias(@nospecialize typ)
+@noinfer function widenmustalias(@nospecialize typ)
     if isa(typ, AnyMustAlias)
         return typ.fldtyp
     elseif isa(typ, LimitedAccuracy)
@@ -329,13 +329,13 @@ function widenmustalias(@nospecialize typ)
     return typ
 end
 
-function isalreadyconst(@nospecialize t)
+@noinfer function isalreadyconst(@nospecialize t)
     isa(t, Const) && return true
     isa(t, DataType) && isdefined(t, :instance) && return true
     return isconstType(t)
 end
 
-function maybe_const_fldidx(@nospecialize(objtyp), @nospecialize(fldval))
+@noinfer function maybe_const_fldidx(@nospecialize(objtyp), @nospecialize(fldval))
     t = widenconst(objtyp)
     if isa(fldval, Int)
         fldidx = fldval
@@ -352,7 +352,7 @@ function maybe_const_fldidx(@nospecialize(objtyp), @nospecialize(fldval))
     return fldidx
 end
 
-function form_mustalias_conditional(alias::MustAlias, @nospecialize(thentype), @nospecialize(elsetype))
+@noinfer function form_mustalias_conditional(alias::MustAlias, @nospecialize(thentype), @nospecialize(elsetype))
     (; slot, vartyp, fldidx) = alias
     if isa(vartyp, PartialStruct)
         fields = vartyp.fields
@@ -401,7 +401,7 @@ ignorelimited(typ::LimitedAccuracy) = typ.typ
 # lattice order
 # =============
 
-function ⊑(lattice::InferenceLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function ⊑(lattice::InferenceLattice, @nospecialize(a), @nospecialize(b))
     r = ⊑(widenlattice(lattice), ignorelimited(a), ignorelimited(b))
     r || return false
     isa(b, LimitedAccuracy) || return true
@@ -420,7 +420,7 @@ function ⊑(lattice::InferenceLattice, @nospecialize(a), @nospecialize(b))
     return b.causes ⊆ a.causes
 end
 
-function ⊑(lattice::OptimizerLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function ⊑(lattice::OptimizerLattice, @nospecialize(a), @nospecialize(b))
     if isa(a, MaybeUndef)
         isa(b, MaybeUndef) || return false
         a, b = a.typ, b.typ
@@ -430,7 +430,7 @@ function ⊑(lattice::OptimizerLattice, @nospecialize(a), @nospecialize(b))
     return ⊑(widenlattice(lattice), a, b)
 end
 
-function ⊑(lattice::AnyConditionalsLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function ⊑(lattice::AnyConditionalsLattice, @nospecialize(a), @nospecialize(b))
     # Fast paths for common cases
     b === Any && return true
     a === Any && return false
@@ -450,7 +450,7 @@ function ⊑(lattice::AnyConditionalsLattice, @nospecialize(a), @nospecialize(b)
     return ⊑(widenlattice(lattice), a, b)
 end
 
-function ⊑(𝕃::AnyMustAliasesLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function ⊑(𝕃::AnyMustAliasesLattice, @nospecialize(a), @nospecialize(b))
     MustAliasT = isa(𝕃, MustAliasesLattice) ? MustAlias : InterMustAlias
     if isa(a, MustAliasT)
         if isa(b, MustAliasT)
@@ -463,7 +463,7 @@ function ⊑(𝕃::AnyMustAliasesLattice, @nospecialize(a), @nospecialize(b))
     return ⊑(widenlattice(𝕃), a, b)
 end
 
-function ⊑(lattice::PartialsLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function ⊑(lattice::PartialsLattice, @nospecialize(a), @nospecialize(b))
     if isa(a, PartialStruct)
         if isa(b, PartialStruct)
             if !(length(a.fields) == length(b.fields) && a.typ <: b.typ)
@@ -526,7 +526,7 @@ function ⊑(lattice::PartialsLattice, @nospecialize(a), @nospecialize(b))
     return ⊑(widenlattice(lattice), a, b)
 end
 
-function ⊑(lattice::ConstsLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function ⊑(lattice::ConstsLattice, @nospecialize(a), @nospecialize(b))
     if isa(a, Const)
         if isa(b, Const)
             return a.val === b.val
@@ -548,7 +548,7 @@ function ⊑(lattice::ConstsLattice, @nospecialize(a), @nospecialize(b))
     return ⊑(widenlattice(lattice), a, b)
 end
 
-function is_lattice_equal(lattice::InferenceLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function is_lattice_equal(lattice::InferenceLattice, @nospecialize(a), @nospecialize(b))
     if isa(a, LimitedAccuracy)
         isa(b, LimitedAccuracy) || return false
         a.causes == b.causes || return false
@@ -560,7 +560,7 @@ function is_lattice_equal(lattice::InferenceLattice, @nospecialize(a), @nospecia
     return is_lattice_equal(widenlattice(lattice), a, b)
 end
 
-function is_lattice_equal(lattice::OptimizerLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function is_lattice_equal(lattice::OptimizerLattice, @nospecialize(a), @nospecialize(b))
     if isa(a, MaybeUndef) || isa(b, MaybeUndef)
         # TODO: Unwrap these and recurse to is_lattice_equal
         return ⊑(lattice, a, b) && ⊑(lattice, b, a)
@@ -568,7 +568,7 @@ function is_lattice_equal(lattice::OptimizerLattice, @nospecialize(a), @nospecia
     return is_lattice_equal(widenlattice(lattice), a, b)
 end
 
-function is_lattice_equal(lattice::AnyConditionalsLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function is_lattice_equal(lattice::AnyConditionalsLattice, @nospecialize(a), @nospecialize(b))
     ConditionalT = isa(lattice, ConditionalsLattice) ? Conditional : InterConditional
     if isa(a, ConditionalT) || isa(b, ConditionalT)
         # TODO: Unwrap these and recurse to is_lattice_equal
@@ -577,7 +577,7 @@ function is_lattice_equal(lattice::AnyConditionalsLattice, @nospecialize(a), @no
     return is_lattice_equal(widenlattice(lattice), a, b)
 end
 
-function is_lattice_equal(lattice::PartialsLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function is_lattice_equal(lattice::PartialsLattice, @nospecialize(a), @nospecialize(b))
     if isa(a, PartialStruct)
         isa(b, PartialStruct) || return false
         length(a.fields) == length(b.fields) || return false
@@ -600,7 +600,7 @@ function is_lattice_equal(lattice::PartialsLattice, @nospecialize(a), @nospecial
     return is_lattice_equal(widenlattice(lattice), a, b)
 end
 
-function is_lattice_equal(lattice::ConstsLattice, @nospecialize(a), @nospecialize(b))
+@noinfer function is_lattice_equal(lattice::ConstsLattice, @nospecialize(a), @nospecialize(b))
     a === b && return true
     if a isa Const
         if issingletontype(b)
@@ -625,7 +625,7 @@ end
 # lattice operations
 # ==================
 
-function tmeet(lattice::PartialsLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(lattice::PartialsLattice, @nospecialize(v), @nospecialize(t::Type))
     if isa(v, PartialStruct)
         has_free_typevars(t) && return v
         widev = widenconst(v)
@@ -663,7 +663,7 @@ function tmeet(lattice::PartialsLattice, @nospecialize(v), @nospecialize(t::Type
     return tmeet(widenlattice(lattice), v, t)
 end
 
-function tmeet(lattice::ConstsLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(lattice::ConstsLattice, @nospecialize(v), @nospecialize(t::Type))
     if isa(v, Const)
         if !has_free_typevars(t) && !isa(v.val, t)
             return Bottom
@@ -673,7 +673,7 @@ function tmeet(lattice::ConstsLattice, @nospecialize(v), @nospecialize(t::Type))
     tmeet(widenlattice(lattice), widenconst(v), t)
 end
 
-function tmeet(lattice::ConditionalsLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(lattice::ConditionalsLattice, @nospecialize(v), @nospecialize(t::Type))
     if isa(v, Conditional)
         if !(Bool <: t)
             return Bottom
@@ -683,33 +683,33 @@ function tmeet(lattice::ConditionalsLattice, @nospecialize(v), @nospecialize(t::
     tmeet(widenlattice(lattice), v, t)
 end
 
-function tmeet(𝕃::MustAliasesLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(𝕃::MustAliasesLattice, @nospecialize(v), @nospecialize(t::Type))
     if isa(v, MustAlias)
         v = widenmustalias(v)
     end
     return tmeet(widenlattice(𝕃), v, t)
 end
 
-function tmeet(lattice::InferenceLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(lattice::InferenceLattice, @nospecialize(v), @nospecialize(t::Type))
     # TODO: This can probably happen and should be handled
     @assert !isa(v, LimitedAccuracy)
     tmeet(widenlattice(lattice), v, t)
 end
 
-function tmeet(lattice::InterConditionalsLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(lattice::InterConditionalsLattice, @nospecialize(v), @nospecialize(t::Type))
     # TODO: This can probably happen and should be handled
     @assert !isa(v, AnyConditional)
     tmeet(widenlattice(lattice), v, t)
 end
 
-function tmeet(𝕃::InterMustAliasesLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(𝕃::InterMustAliasesLattice, @nospecialize(v), @nospecialize(t::Type))
     if isa(v, InterMustAlias)
         v = widenmustalias(v)
     end
     return tmeet(widenlattice(𝕃), v, t)
 end
 
-function tmeet(lattice::OptimizerLattice, @nospecialize(v), @nospecialize(t::Type))
+@noinfer function tmeet(lattice::OptimizerLattice, @nospecialize(v), @nospecialize(t::Type))
     # TODO: This can probably happen and should be handled
     @assert !isa(v, MaybeUndef)
     tmeet(widenlattice(lattice), v, t)
@@ -727,7 +727,7 @@ widenconst(m::MaybeUndef) = widenconst(m.typ)
 widenconst(::PartialTypeVar) = TypeVar
 widenconst(t::PartialStruct) = t.typ
 widenconst(t::PartialOpaque) = t.typ
-widenconst(t::Type) = t
+@noinfer widenconst(@nospecialize t::Type) = t
 widenconst(::TypeVar) = error("unhandled TypeVar")
 widenconst(::TypeofVararg) = error("unhandled Vararg")
 widenconst(::LimitedAccuracy) = error("unhandled LimitedAccuracy")
@@ -743,7 +743,7 @@ function smerge(lattice::AbstractLattice, sa::Union{NotFound,VarState}, sb::Unio
     return VarState(tmerge(lattice, sa.typ, sb.typ), sa.undef | sb.undef)
 end
 
-@inline schanged(lattice::AbstractLattice, @nospecialize(n), @nospecialize(o)) =
+@noinfer @inline schanged(lattice::AbstractLattice, @nospecialize(n), @nospecialize(o)) =
     (n !== o) && (o === NOT_FOUND || (n !== NOT_FOUND && !(n.undef <= o.undef && ⊑(lattice, n.typ, o.typ))))
 
 # remove any lattice elements that wrap the reassigned slot object from the vartable
diff --git a/base/compiler/typelimits.jl b/base/compiler/typelimits.jl
index b5bbcde63e699..b998816dda9da 100644
--- a/base/compiler/typelimits.jl
+++ b/base/compiler/typelimits.jl
@@ -303,7 +303,7 @@ end
 
 # A simplified type_more_complex query over the extended lattice
 # (assumes typeb ⊑ typea)
-function issimplertype(𝕃::AbstractLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function issimplertype(𝕃::AbstractLattice, @nospecialize(typea), @nospecialize(typeb))
     typea isa MaybeUndef && (typea = typea.typ) # n.b. does not appear in inference
     typeb isa MaybeUndef && (typeb = typeb.typ) # n.b. does not appear in inference
     @assert !isa(typea, LimitedAccuracy) && !isa(typeb, LimitedAccuracy) "LimitedAccuracy not supported by simplertype lattice" # n.b. the caller was supposed to handle these
@@ -413,7 +413,7 @@ function merge_causes(causesa::IdSet{InferenceState}, causesb::IdSet{InferenceSt
     end
 end
 
-@noinline function tmerge_limited(lattice::InferenceLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer @noinline function tmerge_limited(lattice::InferenceLattice, @nospecialize(typea), @nospecialize(typeb))
     typea === Union{} && return typeb
     typeb === Union{} && return typea
 
@@ -464,7 +464,7 @@ end
     return LimitedAccuracy(tmerge(widenlattice(lattice), typea, typeb), causes)
 end
 
-function tmerge(lattice::InferenceLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function tmerge(lattice::InferenceLattice, @nospecialize(typea), @nospecialize(typeb))
     if isa(typea, LimitedAccuracy) || isa(typeb, LimitedAccuracy)
         return tmerge_limited(lattice, typea, typeb)
     end
@@ -474,7 +474,7 @@ function tmerge(lattice::InferenceLattice, @nospecialize(typea), @nospecialize(t
     return tmerge(widenlattice(lattice), typea, typeb)
 end
 
-function tmerge(lattice::ConditionalsLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function tmerge(lattice::ConditionalsLattice, @nospecialize(typea), @nospecialize(typeb))
     # type-lattice for Conditional wrapper (NOTE never be merged with InterConditional)
     if isa(typea, Conditional) && isa(typeb, Const)
         if typeb.val === true
@@ -509,7 +509,7 @@ function tmerge(lattice::ConditionalsLattice, @nospecialize(typea), @nospecializ
     return tmerge(widenlattice(lattice), typea, typeb)
 end
 
-function tmerge(lattice::InterConditionalsLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function tmerge(lattice::InterConditionalsLattice, @nospecialize(typea), @nospecialize(typeb))
     # type-lattice for InterConditional wrapper (NOTE never be merged with Conditional)
     if isa(typea, InterConditional) && isa(typeb, Const)
         if typeb.val === true
@@ -544,7 +544,7 @@ function tmerge(lattice::InterConditionalsLattice, @nospecialize(typea), @nospec
     return tmerge(widenlattice(lattice), typea, typeb)
 end
 
-function tmerge(𝕃::AnyMustAliasesLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function tmerge(𝕃::AnyMustAliasesLattice, @nospecialize(typea), @nospecialize(typeb))
     typea = widenmustalias(typea)
     typeb = widenmustalias(typeb)
     return tmerge(widenlattice(𝕃), typea, typeb)
@@ -552,7 +552,7 @@ end
 
 # N.B. This can also be called with both typea::Const and typeb::Const to
 # to recover PartialStruct from `Const`s with overlapping fields.
-function tmerge_partial_struct(lattice::PartialsLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function tmerge_partial_struct(lattice::PartialsLattice, @nospecialize(typea), @nospecialize(typeb))
     aty = widenconst(typea)
     bty = widenconst(typeb)
     if aty === bty
@@ -610,7 +610,7 @@ function tmerge_partial_struct(lattice::PartialsLattice, @nospecialize(typea), @
     return nothing
 end
 
-function tmerge(lattice::PartialsLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function tmerge(lattice::PartialsLattice, @nospecialize(typea), @nospecialize(typeb))
     # type-lattice for Const and PartialStruct wrappers
     aps = isa(typea, PartialStruct)
     bps = isa(typeb, PartialStruct)
@@ -653,8 +653,7 @@ function tmerge(lattice::PartialsLattice, @nospecialize(typea), @nospecialize(ty
     return tmerge(wl, typea, typeb)
 end
 
-
-function tmerge(lattice::ConstsLattice, @nospecialize(typea), @nospecialize(typeb))
+@noinfer function tmerge(lattice::ConstsLattice, @nospecialize(typea), @nospecialize(typeb))
     acp = isa(typea, Const) || isa(typea, PartialTypeVar)
     bcp = isa(typeb, Const) || isa(typeb, PartialTypeVar)
     if acp && bcp
@@ -666,7 +665,7 @@ function tmerge(lattice::ConstsLattice, @nospecialize(typea), @nospecialize(type
     return tmerge(wl, typea, typeb)
 end
 
-function tmerge(::JLTypeLattice, @nospecialize(typea::Type), @nospecialize(typeb::Type))
+@noinfer function tmerge(::JLTypeLattice, @nospecialize(typea::Type), @nospecialize(typeb::Type))
     # it's always ok to form a Union of two concrete types
     act = isconcretetype(typea)
     bct = isconcretetype(typeb)
@@ -682,7 +681,7 @@ function tmerge(::JLTypeLattice, @nospecialize(typea::Type), @nospecialize(typeb
     return tmerge_types_slow(typea, typeb)
 end
 
-@noinline function tmerge_types_slow(@nospecialize(typea::Type), @nospecialize(typeb::Type))
+@noinfer @noinline function tmerge_types_slow(@nospecialize(typea::Type), @nospecialize(typeb::Type))
     # collect the list of types from past tmerge calls returning Union
     # and then reduce over that list
     types = Any[]
diff --git a/base/compiler/utilities.jl b/base/compiler/utilities.jl
index 0d81008125ddc..57d42f109851b 100644
--- a/base/compiler/utilities.jl
+++ b/base/compiler/utilities.jl
@@ -346,7 +346,7 @@ end
 # types #
 #########
 
-function singleton_type(@nospecialize(ft))
+@noinfer function singleton_type(@nospecialize(ft))
     ft = widenslotwrapper(ft)
     if isa(ft, Const)
         return ft.val
@@ -358,7 +358,7 @@ function singleton_type(@nospecialize(ft))
     return nothing
 end
 
-function maybe_singleton_const(@nospecialize(t))
+@noinfer function maybe_singleton_const(@nospecialize(t))
     if isa(t, DataType)
         if issingletontype(t)
             return Const(t.instance)