inlining: avoid Union computations in the inliner call analysis (#4…

…4095)

base/compiler/ssair/inlining.jl

@@ -1168,7 +1168,6 @@ function analyze_single_call!(
  sig::Signature, state::InliningState, todo::Vector{Pair{Int, Any}})
  argtypes = sig.argtypes
  cases = InliningCase[]
- local signature_union = Bottom
  local only_method = nothing # keep track of whether there is one matching method
  local meth::MethodLookupResult
  local fully_covered = true
@@ -1180,6 +1179,7 @@ function analyze_single_call!(
  return nothing
  elseif length(meth) == 0
  # No applicable methods; try next union split
+ fully_covered = false
  continue
  else
  if length(meth) == 1 && only_method !== false
@@ -1193,8 +1193,8 @@ function analyze_single_call!(
  end
  end
  for match in meth
- signature_union = Union{signature_union, match.spec_types}
  fully_covered &= handle_match!(match, argtypes, flag, state, cases)
+ fully_covered &= match.fully_covers
  end
  end
 
@@ -1214,8 +1214,6 @@ function analyze_single_call!(
  item === nothing && return nothing
  push!(cases, InliningCase(match.spec_types, item))
  fully_covered = match.fully_covers
- else
- fully_covered &= atype <: signature_union
  end
 
  handle_cases!(ir, idx, stmt, atype, cases, fully_covered, todo, state.params)
@@ -1230,7 +1228,6 @@ function handle_const_call!(
  infos = isa(call, MethodMatchInfo) ? MethodMatchInfo[call] : call.matches
  cases = InliningCase[]
  local fully_covered = true
- local signature_union = Bottom
  local j = 0
  for i in 1:length(infos)
  meth = infos[i].results
@@ -1240,24 +1237,22 @@ function handle_const_call!(
  return nothing
  elseif length(meth) == 0
  # No applicable methods; try next union split
+ fully_covered = false
  continue
  end
  for match in meth
  j += 1
  result = results[j]
  if isa(result, ConstResult)
  case = const_result_item(result, state)
- signature_union = Union{signature_union, result.mi.specTypes}
  push!(cases, InliningCase(result.mi.specTypes, case))
- continue
  elseif isa(result, InferenceResult)
- signature_union = Union{signature_union, result.linfo.specTypes}
  fully_covered &= handle_inf_result!(result, argtypes, flag, state, cases)
  else
  @assert result === nothing
- signature_union = Union{signature_union, match.spec_types}
  fully_covered &= handle_match!(match, argtypes, flag, state, cases)
  end
+ fully_covered &= match.fully_covers
  end
  end
 
@@ -1271,8 +1266,6 @@ function handle_const_call!(
  item === nothing && return nothing
  push!(cases, InliningCase(mi.specTypes, item))
  fully_covered = atype <: mi.specTypes
- else
- fully_covered &= atype <: signature_union
  end
 
  handle_cases!(ir, idx, stmt, atype, cases, fully_covered, todo, state.params)