From e511f07d76d738533a6bc4dcf495dca15afc8b13 Mon Sep 17 00:00:00 2001
From: gingerBill <gingerBill@users.noreply.github.com>
Date: Mon, 29 Sep 2025 10:45:24 +0100
Subject: [PATCH] Short circuit for `Union{}`

---
 src/llvm_backend_const.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/llvm_backend_const.cpp b/src/llvm_backend_const.cpp
index 782c75cd2..87e7962d4 100644
--- a/src/llvm_backend_const.cpp
+++ b/src/llvm_backend_const.cpp
@@ -603,6 +603,17 @@ gb_internal lbValue lb_const_value(lbModule *m, Type *type, ExactValue value, lb
 				return res;
 			}
 		} else {
+			if (value_type == nullptr) {
+				if (value.kind == ExactValue_Compound) {
+					ast_node(cl, CompoundLit, value.value_compound);
+					if (cl->elems.count == 0) {
+						return lb_const_nil(m, original_type);
+					}
+				} else if (value.kind == ExactValue_Invalid) {
+					return lb_const_nil(m, original_type);
+				}
+			}
+
 			GB_ASSERT_MSG(value_type != nullptr, "%s :: %s", type_to_string(original_type), exact_value_to_string(value));
 
 			i64 block_size = bt->Union.variant_block_size;