testsuite/synth: add testcase from #1023

2 files changed, 51 insertions, 0 deletions

diff --git a/testsuite/synth/issue1023/barrel_shifter.vhdl b/testsuite/synth/issue1023/barrel_shifter.vhdl
new file mode 100644
index 000000000..585c8afd7
--- /dev/null
+++ b/testsuite/synth/issue1023/barrel_shifter.vhdl
@@ -0,0 +1,42 @@
+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+use ieee.math_real.all;
+
+-------------------------------------------------------------------------------
+
+entity barrel_shifter is
+
+  generic (
+    NBITS : positive := 8);
+
+  port (
+    din, d : in  std_logic_vector(NBITS-1 downto 0);  -- data in, shift distance
+    dout   : out std_logic_vector(NBITS-1 downto 0));  -- data out
+
+end entity barrel_shifter;
+
+-------------------------------------------------------------------------------
+
+architecture dfl of barrel_shifter is
+  -- TODO: Calculate the number of required shift stages as a constant.
+  constant nshift : natural := natural(log2(real(NBITS)));
+
+  -- custom vector for the shift stages
+  type my_vec is array(0 to nshift) of std_logic_vector(NBITS-1 downto 0);
+  signal vector : my_vec;
+  -- vector of zeros
+  constant ZEROS : std_logic_vector(NBITS-1 downto 0) := (others => '0');
+
+begin  -- architecture dfl
+    vector(0) <= din;
+
+    gen: for i in 0 to nshift-1 generate
+        vector(i+1) <= (vector(i)(NBITS-1-2**i downto 0)
+                       & ZEROS(2**i-1 downto 0))
+                   when d(i) = '1'
+                   else vector(i);
+    end generate gen;
+    dout <= vector(nshift);
+
+end architecture dfl;
diff --git a/testsuite/synth/issue1023/testsuite.sh b/testsuite/synth/issue1023/testsuite.sh
new file mode 100755
index 000000000..f87fbd010
--- /dev/null
+++ b/testsuite/synth/issue1023/testsuite.sh
@@ -0,0 +1,9 @@
+#! /bin/sh
+
+. ../../testenv.sh
+
+synth barrel_shifter.vhdl -e $t > syn_barrel_shifter.vhdl
+analyze syn_barrel_shifter.vhdl
+clean
+
+echo "Test successful"