Add testcase for issue50.

1 files changed, 64 insertions, 0 deletions

diff --git a/testsuite/gna/issue50/idct.d/sub_159.vhd b/testsuite/gna/issue50/idct.d/sub_159.vhd
new file mode 100644
index 000000000..fb69c2984
--- /dev/null
+++ b/testsuite/gna/issue50/idct.d/sub_159.vhd
@@ -0,0 +1,64 @@
+library ieee;
+use ieee.std_logic_1164.all;
+
+library ieee;
+use ieee.numeric_std.all;
+
+entity sub_159 is
+	port (
+		gt : out std_logic;
+		result : out std_logic_vector(31 downto 0);
+		in_a : in  std_logic_vector(31 downto 0);
+		in_b : in  std_logic_vector(31 downto 0);
+		sign : in  std_logic
+	);
+end sub_159;
+
+architecture augh of sub_159 is
+
+	signal carry_inA : std_logic_vector(33 downto 0);
+	signal carry_inB : std_logic_vector(33 downto 0);
+	signal carry_res : std_logic_vector(33 downto 0);
+
+	-- Signals to generate the comparison outputs
+	signal msb_abr  : std_logic_vector(2 downto 0);
+	signal tmp_sign : std_logic;
+	signal tmp_eq   : std_logic;
+	signal tmp_le   : std_logic;
+	signal tmp_ge   : std_logic;
+
+begin
+
+	-- To handle the CI input, the operation is '0' - CI
+	-- If CI is not present, the operation is '0' - '0'
+	carry_inA <= '0' & in_a & '0';
+	carry_inB <= '0' & in_b & '0';
+	-- Compute the result
+	carry_res <= std_logic_vector(unsigned(carry_inA) - unsigned(carry_inB));
+
+	-- Set the outputs
+	result <= carry_res(32 downto 1);
+
+	-- Other comparison outputs
+
+	-- Temporary signals
+	msb_abr <= carry_inA(32) & carry_inB(32) & carry_res(32);
+	tmp_sign <= sign;
+	tmp_eq  <= '1' when in_a = in_b else '0';
+
+	tmp_le <=
+		tmp_eq when msb_abr = "000" or msb_abr = "110" else
+		'1' when msb_abr = "001" or msb_abr = "111" else
+		'1' when tmp_sign = '0' and (msb_abr = "010" or msb_abr = "011") else
+		'1' when tmp_sign = '1' and (msb_abr = "100" or msb_abr = "101") else
+		'0';
+
+	tmp_ge <=
+		'1' when msb_abr = "000" or msb_abr = "110" else
+		'1' when tmp_sign = '0' and (msb_abr = "100" or msb_abr = "101") else
+		'1' when tmp_sign = '1' and (msb_abr = "010" or msb_abr = "011") else
+		'0';
+
+	gt <= not(tmp_le);
+
+end architecture;