Fast path constants in update_julia_type only if correct type (#47480)

* Fast path constants in update_julia_type only if correct type Fixes #47247 Co-authored-by: Jameson Nash <[email protected]>
JuliaLang · Nov 8, 2022 · dad08f2 · dad08f2
1 parent 92cf557
commit dad08f2
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/src/codegen.cpp b/src/codegen.cpp
@@ -1726,8 +1726,10 @@ static inline jl_cgval_t mark_julia_type(jl_codectx_t &ctx, Value *v, bool isbox
 // see if it might be profitable (and cheap) to change the type of v to typ
 static inline jl_cgval_t update_julia_type(jl_codectx_t &ctx, const jl_cgval_t &v, jl_value_t *typ)
 {
-    if (v.typ == jl_bottom_type || v.constant || typ == (jl_value_t*)jl_any_type || jl_egal(v.typ, typ))
+    if (v.typ == jl_bottom_type || typ == (jl_value_t*)jl_any_type || jl_egal(v.typ, typ))
         return v; // fast-path
+    if (v.constant)
+        return jl_isa(v.constant, typ) ? v : jl_cgval_t();
     if (jl_is_concrete_type(v.typ) && !jl_is_kind(v.typ)) {
         if (jl_is_concrete_type(typ) && !jl_is_kind(typ)) {
             // type mismatch: changing from one leaftype to another

diff --git a/test/compiler/codegen.jl b/test/compiler/codegen.jl
@@ -781,3 +781,7 @@ f_isdefined_nospecialize(@nospecialize(x)) = isdefined(x, 1)
 # Test codegen for isa(::Any, Type)
 f_isa_type(@nospecialize(x)) = isa(x, Type)
 @test !occursin("jl_isa", get_llvm(f_isa_type, Tuple{Any}, true, false, false))
+
+# Issue #47247
+f47247(a::Ref{Int}, b::Nothing) = setfield!(a, :x, b)
+@test_throws TypeError f47247(Ref(5), nothing)