Merge branch 'isa_shift_improve' into 'devel'

Improving timing and resource consuming in SHIFT and MUX.

See merge request ndk/ndk-fpga!364

Author: jakubcabal

comp/axis_tools/flow/switch/comp/switch_fabric/comp/islip/comp/priority_enc/priority_enc.vhd

@@ -32,9 +32,10 @@ architecture FULL of PRIORITY_ENC is
 
 begin
 
-    barrel_bit_rotator_right_i : entity work.BARREL_BIT_SHIFTER(barrel_bit_shifter_arch)
+    barrel_bit_rotator_right_i : entity work.BARREL_SHIFTER_GEN
     generic map (
-        DATA_WIDTH => DATA_WIDTH,
+        BLOCKS     => DATA_WIDTH,
+        BLOCK_SIZE => 1,
         SHIFT_LEFT => false
     )
     port map (
@@ -52,9 +53,10 @@ begin
         DO => s_priority_r
     );
 
-    barrel_bit_rotator_left_i : entity work.BARREL_BIT_SHIFTER(barrel_bit_shifter_arch)
+    barrel_bit_rotator_left_i : entity work.BARREL_SHIFTER_GEN
     generic map (
-        DATA_WIDTH => DATA_WIDTH,
+        BLOCKS     => DATA_WIDTH,
+        BLOCK_SIZE => 1,
         SHIFT_LEFT => true
     )
     port map (

comp/base/logic/barrel_shifter/Modules.tcl

@@ -10,9 +10,6 @@
 set PKG_BASE         "$OFM_PATH/comp/base/pkg"
 set MUX_BASE         "$OFM_PATH/comp/base/logic/mux"
 
-# barrel_bit_shifter entity:
-set MOD "$MOD $ENTITY_BASE/barrel_bit_shifter_ent.vhd"
-
 if { $ARCHGRP == "FULL" } {
 
    set COMPONENTS [list \
@@ -21,24 +18,12 @@ if { $ARCHGRP == "FULL" } {
       [list "PKG_TYPE"    $PKG_BASE   "TYPE"]   \
    ]
 
-   set MOD "$MOD $ENTITY_BASE/barrel_bit_rotator.vhd"
-   set MOD "$MOD $ENTITY_BASE/barrel_shifter.vhd"
    set MOD "$MOD $ENTITY_BASE/barrel_shifter_gen.vhd"
+   set MOD "$MOD $ENTITY_BASE/barrel_shifter.vhd"
    set MOD "$MOD $ENTITY_BASE/barrel_shifter_gen_piped.vhd"
 
 }
 
-if { $ARCHGRP == "SHIFTER" } {
-
-   set COMPONENTS [list \
-      [list "PKG_MATH"    $PKG_BASE   "MATH"]   \
-      [list "GENMUX"      $MUX_BASE   "FULL"]   \
-   ]
-
-   set MOD "$MOD $ENTITY_BASE/barrel_bit_shifter.vhd"
-
-}
-
 # -----------------------------------------------------------------------------
 
 if { $ARCHGRP == "EMPTY" } {

comp/base/logic/barrel_shifter/barrel_bit_rotator.vhd

@@ -1,26 +1,20 @@
---
 -- barrel_shifter.vhd Barrel shifter with generic data width
--- Copyright (C) 2009 CESNET
--- Author(s): Vaclav Bartos <washek@liberouter.org>
+-- Copyright (C) 2026 CESNET
+-- Author(s): Radek Iša <isa@cesnet.cz>
 --
 -- SPDX-License-Identifier: BSD-3-Clause
 --
--- $Id$
---
--- TODO:
---
 
 library IEEE;
 use IEEE.std_logic_1164.all;
-use IEEE.std_logic_arith.all;
-use IEEE.std_logic_unsigned.all;
+use IEEE.numeric_std.all;
 
 use work.math_pack.all;
 
 -- ----------------------------------------------------------------------------
 --                  ENTITY DECLARATION -- Barrel shifter                     --
 -- ----------------------------------------------------------------------------
-
+-- Note: please prefr BARREL_SHIFTER_GEN instead
 entity BARREL_SHIFTER is
     generic (
         DATA_WIDTH  : integer := 64;
@@ -36,33 +30,26 @@ entity BARREL_SHIFTER is
     );
 end entity;
 
--- ----------------------------------------------------------------------------
---                       ARCHITECTURE DECLARATION                            --
--- ----------------------------------------------------------------------------
 
 architecture BARREL_SHIFTER_ARCH of BARREL_SHIFTER is
     constant BLOCK_WIDTH : natural := DATA_WIDTH / BLOCKS;
 begin
 
-    assert DATA_WIDTH mod BLOCKS = 0
-        report "DATA_WIDTH is not multiple of BLOCKS"
-        severity Failure;
-
-    multiplexors: for i in 0 to BLOCKS-1 generate
-        process (DATA_IN, SEL)
-            variable sel_aux : integer;
-            variable sel_blk : integer;
-        begin
-            if (SHIFT_LEFT) then
-                sel_aux := conv_integer('0'&SEL);
-            else
-                sel_aux := conv_integer('0'&(0-SEL));
-            end if;
-
-            sel_blk := ((BLOCKS-sel_aux+i) mod BLOCKS);
+    assert (DATA_WIDTH mod BLOCKS = 0)
+        report "DATA_WIDTH must be divisible by BLOCK"
+        severity failure;
+
+    shifter_inst : entity work.BARREL_SHIFTER_GEN
+    generic map (
+        BLOCKS     => BLOCKS,
+        BLOCK_SIZE => BLOCK_WIDTH,
+        SHIFT_LEFT => SHIFT_LEFT
+    )
+    port map (
+        DATA_IN  => DATA_IN,
+        DATA_OUT => DATA_OUT,
+        SEL      => SEL
+    );
+end architecture;
 
-            DATA_OUT((i+1)*BLOCK_WIDTH-1 downto i*BLOCK_WIDTH) <= DATA_IN((sel_blk+1)*BLOCK_WIDTH-1 downto sel_blk*BLOCK_WIDTH);
-        end process;
-    end generate;
 
-end architecture;