Fix typo in codegen for isdefinedglobal (#57889)

Fixes #57872

Author: Keno

Compiler/test/codegen.jl

@@ -1027,3 +1027,8 @@ module TurnedIntoExplicit
 
     @test !occursin("jl_apply_generic", get_llvm(f, Tuple{UInt}))
 end
+
+# Test codegen for `isdefinedglobal` of constant (#57872)
+const x57872 = "Hello"
+f57872() = (Core.isdefinedglobal(@__MODULE__, Base.compilerbarrier(:const, :x57872)), x57872) # Extra globalref here to force world age bounds
+@test f57872() == (true, "Hello")

src/codegen.cpp

@@ -3817,30 +3817,29 @@ static bool emit_f_opfield(jl_codectx_t &ctx, jl_cgval_t *ret, jl_value_t *f,
 
 static jl_cgval_t emit_isdefinedglobal(jl_codectx_t &ctx, jl_module_t *modu, jl_sym_t *name, int allow_import, enum jl_memory_order order)
 {
-    Value *isnull = NULL;
     jl_binding_t *bnd = allow_import ? jl_get_binding(modu, name) : jl_get_module_binding(modu, name, 0);
     struct restriction_kind_pair rkp = { NULL, NULL, PARTITION_KIND_GUARD, 0 };
     if (allow_import && jl_get_binding_leaf_partitions_restriction_kind(bnd, &rkp, ctx.min_world, ctx.max_world)) {
-        if (jl_bkind_is_some_constant(rkp.kind))
-            return mark_julia_const(ctx, rkp.restriction);
+        if (jl_bkind_is_some_constant(rkp.kind) && rkp.restriction)
+            return mark_julia_const(ctx, jl_true);
         if (rkp.kind == PARTITION_KIND_GLOBAL) {
             Value *bp = julia_binding_gv(ctx, rkp.binding_if_global);
             bp = julia_binding_pvalue(ctx, bp);
             LoadInst *v = ctx.builder.CreateAlignedLoad(ctx.types().T_prjlvalue, bp, Align(sizeof(void*)));
             jl_aliasinfo_t ai = jl_aliasinfo_t::fromTBAA(ctx, ctx.tbaa().tbaa_binding);
             ai.decorateInst(v);
             v->setOrdering(get_llvm_atomic_order(order));
-            isnull = ctx.builder.CreateICmpNE(v, Constant::getNullValue(ctx.types().T_prjlvalue));
+            Value *isnull = ctx.builder.CreateICmpNE(v, Constant::getNullValue(ctx.types().T_prjlvalue));
             return mark_julia_type(ctx, isnull, false, jl_bool_type);
         }
     }
-    Value *v = ctx.builder.CreateCall(prepare_call(jlboundp_func), {
+    Value *isdef = ctx.builder.CreateCall(prepare_call(jlboundp_func), {
             literal_pointer_val(ctx, (jl_value_t*)modu),
             literal_pointer_val(ctx, (jl_value_t*)name),
             ConstantInt::get(getInt32Ty(ctx.builder.getContext()), allow_import)
         });
-    isnull = ctx.builder.CreateICmpNE(v, ConstantInt::get(getInt32Ty(ctx.builder.getContext()), 0));
-    return mark_julia_type(ctx, isnull, false, jl_bool_type);
+    isdef = ctx.builder.CreateTrunc(isdef, getInt1Ty(ctx.builder.getContext()));
+    return mark_julia_type(ctx, isdef, false, jl_bool_type);
 }
 
 static bool emit_f_opmemory(jl_codectx_t &ctx, jl_cgval_t *ret, jl_value_t *f,