Merge pull request #27228 from JuliaLang/kf/pinodearg

Handle PiNodes of arguments in type lifting

base/compiler/ssair/passes.jl

@@ -833,7 +833,10 @@ function type_lift_pass!(ir::IRCode)
  # node (or an UpsilonNode() argument to a PhiC node),
  # so lift all these nodes that have maybe undef values
  processed = IdDict{Int, Union{SSAValue, Bool}}()
- if !isa(val, SSAValue)
+ while isa(val, SSAValue) && isa(ir.stmts[val.id], PiNode)
+ val = ir.stmts[val.id].val
+ end
+ if !isa(val, SSAValue) || (!isa(ir.stmts[val.id], PhiNode) && !isa(ir.stmts[val.id], PhiCNode))
  (isa(val, GlobalRef) || isexpr(val, :static_parameter)) && continue
  if stmt.head === :undefcheck
  ir.stmts[idx] = nothing
@@ -843,19 +846,8 @@ function type_lift_pass!(ir::IRCode)
  continue
  end
  stmt_id = val.id
- while isa(ir.stmts[stmt_id], PiNode)
- stmt_id = ir.stmts[stmt_id].val.id
- end
  worklist = Tuple{Int, Int, SSAValue, Int}[(stmt_id, 0, SSAValue(0), 0)]
  def = ir.stmts[stmt_id]
- if !isa(def, PhiNode) && !isa(def, PhiCNode)
- if stmt.head === :isdefined
- ir.stmts[idx] = true
- else
- ir.stmts[idx] = nothing
- end
- continue
- end
  if !haskey(lifted_undef, stmt_id)
  first = true
  while !isempty(worklist)

test/core.jl

@@ -6127,3 +6127,14 @@ end
 foo27204(x) = f27204(x)()
 @test foo27204(true) == 1
 @test foo27204(false) == 2
+
+# Issue 27209
+@noinline function f27209(x::Union{Float64, Nothing})
+ if x === nothing
+ y = x; return @isdefined(y)
+ else
+ return @isdefined(y)
+ end
+end
+g27209(x) = f27209(x ? nothing : 1.0)
+@test g27209(true) == true