wip: domination analysis

src/EscapeAnalysis.jl

@@ -145,6 +145,11 @@ end
 # analysis
 # ========
 
+const FieldDef   = Pair{Int,Any}
+const FieldInfo  = IdSet{FieldDef}
+const FieldsInfo = Vector{FieldInfo}
+struct UnintializedField end
+
 """
     x::EscapeLattice
 
@@ -186,7 +191,7 @@ struct EscapeLattice
     ReturnEscape::Bool
     ThrownEscape::Bool
     EscapeSites::BitSet
-    FieldSets::Union{Vector{IdSet{Any}},Bool}
+    FieldSets::Union{FieldsInfo,Bool}
     # TODO: ArgEscape::Int
 
     function EscapeLattice(Analyzed::Bool,
@@ -297,7 +302,7 @@ x::EscapeLattice ⊑ y::EscapeLattice = begin
         if isa(yf, Bool)
             yf === false && return false
         else
-            xf, yf = xf::Vector{IdSet{Any}}, yf::Vector{IdSet{Any}}
+            xf, yf = xf::FieldsInfo, yf::FieldsInfo
             xn, yn = length(xf), length(yf)
             xn > yn && return false
             for i in 1:xn
@@ -331,10 +336,10 @@ x::EscapeLattice ⊔ y::EscapeLattice = begin
     elseif yf === false
         FieldSets = xf
     else
-        xf, yf = xf::Vector{IdSet{Any}}, yf::Vector{IdSet{Any}}
+        xf, yf = xf::FieldsInfo, yf::FieldsInfo
         xn, yn = length(xf), length(yf)
         nmax, nmin = max(xn, yn), min(xn, yn)
-        FieldSets = Vector{IdSet{Any}}(undef, nmax)
+        FieldSets = FieldsInfo(undef, nmax)
         for i in 1:nmax
             if i > nmax
                 FieldSets[i] = (xn > yn ? xf : yf)[i]
@@ -752,7 +757,7 @@ function escape_new!(ir::IRCode, pc::Int, args::Vector{Any},
     if info == NotAnalyzed()
         info = NoEscape()
     end
-    newinfo = add_fieldsets(info, ir.stmts[pc][:type], args)
+    newinfo = add_fieldsets(info, ir.stmts[pc][:type], pc, args)
     add_escape_change!(SSAValue(pc), ir, newinfo, changes)
 
     # propagate the escape information of this object to all its fields as well
@@ -762,22 +767,23 @@ function escape_new!(ir::IRCode, pc::Int, args::Vector{Any},
     end
 end
 
-function add_fieldsets(info::EscapeLattice, @nospecialize(typ), args::Vector{Any})
+function add_fieldsets(info::EscapeLattice, @nospecialize(typ), pc::Int, args::Vector{Any})
     FieldSets = info.FieldSets
     nfields = fieldcount_noerror(typ)
     if isa(FieldSets, Bool) && !FieldSets
         if nfields === nothing
             # abstract type, can't propagate
             FieldSets = true
         else
-            FieldSets = IdSet{Any}[IdSet{Any}() for _ in 1:nfields]
+            FieldSets = FieldInfo[FieldInfo() for _ in 1:nfields]
         end
     end
     if !isa(FieldSets, Bool)
         @assert nfields == length(FieldSets)
-        for i in 2:length(args)
-            i-1 > nfields::Int && break # see https://github.com/JuliaLang/julia/issues/43146
-            push!(FieldSets[i-1], args[i])
+        nargs = length(args)
+        for i in 1:nfields
+            val = nargs < i+1 ? UnintializedField() : args[i+1]
+            push!(FieldSets[i], FieldDef(pc, val))
         end
     end
     return EscapeLattice(info, FieldSets)
@@ -837,16 +843,7 @@ function escape_builtin!(::typeof(typeassert), ir::IRCode, pc::Int, args::Vector
 end
 
 function escape_builtin!(::typeof(tuple), ir::IRCode, pc::Int, args::Vector{Any}, state::EscapeState, changes::Changes)
-    info = state.ssavalues[pc]
-    if info == NotAnalyzed()
-        info = NoEscape()
-    end
-    tupleinfo = add_fieldsets(info, ir.stmts[pc][:type], args)
-    add_escape_change!(SSAValue(pc), ir, tupleinfo, changes)
-    # propagate the escape information of this object to all its fields as well,
-    for i in 2:length(args)
-        add_escape_change!(args[i], ir, ignore_fieldsets(info), changes)
-    end
+    escape_new!(ir, pc, args, state, changes)
 end
 
 function escape_builtin!(::typeof(getfield), ir::IRCode, pc::Int, args::Vector{Any}, state::EscapeState, changes::Changes)
@@ -881,14 +878,14 @@ function escape_builtin!(::typeof(getfield), ir::IRCode, pc::Int, args::Vector{A
             fidx = nothing
         end
         if fidx !== nothing
-            for x in FieldSets[fidx]
+            for (_, x) in FieldSets[fidx]
                 add_escape_change!(x, ir, info, changes)
                 add_alias_change!(x, SSAValue(pc), ir, changes)
             end
         else
             # when the field can't be known precisely,
             # propagate this escape information to all the fields conservatively
-            for FieldSet in FieldSets, x in FieldSet
+            for FieldSet in FieldSets, (_, x) in FieldSet
                 add_escape_change!(x, ir, info, changes)
                 add_alias_change!(x, SSAValue(pc), ir, changes)
             end
@@ -939,7 +936,7 @@ function escape_builtin!(::typeof(setfield!), ir::IRCode, pc::Int, args::Vector{
         else
             nfields = fieldcount_noerror(typ)
             if nfields !== nothing
-                FieldSets = IdSet{Any}[IdSet{Any}() for _ in 1:nfields]
+                FieldSets = FieldInfo[FieldInfo() for _ in 1:nfields]
                 @goto add_field
             else
                 # fields aren't known precisely
@@ -955,12 +952,12 @@ function escape_builtin!(::typeof(setfield!), ir::IRCode, pc::Int, args::Vector{
             fidx = nothing
         end
         if fidx !== nothing
-            push!(FieldSets[fidx], val)
+            push!(FieldSets[fidx], FieldDef(pc, val))
         else
             # when the field can't be known precisely,
             # add this alias information to all the field sets conservatively
             for FieldSet in FieldSets
-                push!(FieldSet, val)
+                push!(FieldSet, FieldDef(pc, val))
             end
         end
         # update `obj`'s escape information with the new field sets