3 files changed, 86 insertions, 0 deletions
diff --git a/testsuite/synth/issue2286/tb_test_addsub.vhdl b/testsuite/synth/issue2286/tb_test_addsub.vhdl
new file mode 100644
index 000000000..da2150ebe
--- /dev/null
+++ b/testsuite/synth/issue2286/tb_test_addsub.vhdl
@@ -0,0 +1,51 @@
+entity tb_test_addsub is
+end tb_test_addsub;
+
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+
+architecture behav of tb_test_addsub is
+  signal s_slv        : std_logic_vector(3 downto 0);
+  signal s_nat        : natural range 0 to 15;
+  signal s_add_slvslv : std_logic_vector(3 downto 0);
+  signal s_add_slvnat : std_logic_vector(3 downto 0);
+  signal s_add_natslv : std_logic_vector(3 downto 0);
+  signal s_sub_slvslv : std_logic_vector(3 downto 0);
+  signal s_sub_slvnat : std_logic_vector(3 downto 0);
+  signal s_sub_natslv : std_logic_vector(3 downto 0);
+begin
+  dut: entity work.test_addsub
+    port map (s_slv,
+              s_nat,
+              s_add_slvslv,
+              s_add_slvnat,
+              s_add_natslv,
+              s_sub_slvslv,
+              s_sub_slvnat,
+              s_sub_natslv);
+  process
+  begin
+    s_slv <= x"6";
+    s_nat <= 6;
+    wait for 1 ns;
+    assert s_add_slvslv = x"C" severity failure;
+    assert s_add_slvnat = x"C" severity failure;
+    assert s_add_natslv = x"C" severity failure;
+    assert s_sub_slvslv = x"0" severity failure;
+    assert s_sub_slvnat = x"0" severity failure;
+    assert s_sub_natslv = x"0" severity failure;
+
+    s_slv <= x"6";
+    s_nat <= 10;
+    wait for 1 ns;
+    assert s_add_slvslv = x"C" severity failure;
+    assert s_add_slvnat = x"0" severity failure;
+    assert s_add_natslv = x"0" severity failure;
+    assert s_sub_slvslv = x"0" severity failure;
+    assert s_sub_slvnat = x"C" severity failure;
+    assert s_sub_natslv = x"4" severity failure;
+
+    wait;
+  end process;
+end behav;
diff --git a/testsuite/synth/issue2286/test_addsub.vhdl b/testsuite/synth/issue2286/test_addsub.vhdl
new file mode 100644
index 000000000..00e6aed21
--- /dev/null
+++ b/testsuite/synth/issue2286/test_addsub.vhdl
@@ -0,0 +1,26 @@
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std_unsigned.all;
+
+entity test_addsub is
+  port (
+    slv : in  std_logic_vector(3 downto 0);
+    nat : in  natural range 0 to 15;
+    add_slvslv : out std_logic_vector(3 downto 0);
+    add_slvnat : out std_logic_vector(3 downto 0);
+    add_natslv : out std_logic_vector(3 downto 0);
+    sub_slvslv : out std_logic_vector(3 downto 0);
+    sub_slvnat : out std_logic_vector(3 downto 0);
+    sub_natslv : out std_logic_vector(3 downto 0)
+  );
+end;
+
+architecture rtl of test_addsub is
+begin
+  add_slvslv <= slv + slv;
+  add_slvnat <= slv + nat;
+  add_natslv <= nat + slv;
+  sub_slvslv <= slv - slv;
+  sub_slvnat <= slv - nat;
+  sub_natslv <= nat - slv;
+end;
diff --git a/testsuite/synth/issue2286/testsuite.sh b/testsuite/synth/issue2286/testsuite.sh
new file mode 100755
index 000000000..e4f4b7ded
--- /dev/null
+++ b/testsuite/synth/issue2286/testsuite.sh
@@ -0,0 +1,9 @@
+#! /bin/sh
+
+. ../../testenv.sh
+
+export GHDL_STD_FLAGS=--std=08
+
+synth_tb test_addsub
+
+echo "Test successful"