From a3c4ba6e822f2c4c7a11d64b8370435137df1119 Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Wed, 15 Apr 2009 13:21:39 +0000
Subject: [PATCH] - minor improvements for load/store shifter Committed on the
 Free edition of March Hare Software CVSNT Server. Upgrade to CVS Suite for
 more features and support: http://march-hare.com/cvsnt/

git-svn-id: http://moon:8086/svn/vhdl/trunk@430 cc03376c-175c-47c8-b038-4cd826a8556b
---
 lib/CPUs/MIPS/src/core/mips_types.vhd | 154 +++++++++++++-------------
 1 file changed, 75 insertions(+), 79 deletions(-)

diff --git a/lib/CPUs/MIPS/src/core/mips_types.vhd b/lib/CPUs/MIPS/src/core/mips_types.vhd
index fd83491..915a46e 100644
--- a/lib/CPUs/MIPS/src/core/mips_types.vhd
+++ b/lib/CPUs/MIPS/src/core/mips_types.vhd
@@ -264,7 +264,7 @@ package mips_types is
 	end record;
 
 	type cop0_ctrl_out_t is record
-		RE				: STD_LOGIC;
+		EB				: STD_LOGIC;
 		exc_inject		: STD_LOGIC;
 		exc_commit		: STD_LOGIC;
 		exc_pending		: STD_LOGIC;
@@ -454,56 +454,53 @@ package body mips_types is
 	function store_be(va : unsigned(1 downto 0); be_src, word2_en, word4_en, align_left, bypass : std_logic) return unsigned is
 	variable result : unsigned(3 downto 0);
 	begin
-		if bypass = '1' then
-			result := (3 downto 0 => be_src);
-		elsif word2_en = '1' then
-			case va is
-				when "00" | "01" =>
-					result := "00" & be_src & be_src;
-				when "10" | "11" =>
-					result := be_src & be_src & "00";
-				when others =>
-					result := "0000";
-			end case;
-		elsif word4_en = '1' then
-			case va is
-				when "00" =>
-					result := "000" & be_src;
-				when "01" =>
-					result := "00" & be_src & '0';
-				when "10" =>
-					result := '0' & be_src & "00";
-				when "11" =>
-					result := be_src & "000";
-				when others =>
-					result := "0000";
-			end case;
-		elsif align_left = '1' then
-			case va is
-				when "00" =>
-					result := be_src & be_src & be_src & be_src;
-				when "01" =>
-					result := be_src & be_src & be_src & '0';
-				when "10" =>
-					result := be_src & be_src & "00";
-				when "11" =>
-					result := be_src & "000";
-				when others =>
-					result := "0000";
-			end case;
-		else
-			case va is
-				when "00" =>
-					result := "000" & be_src;
-				when "01" =>
-					result := "00" & be_src & be_src;
-				when "10" =>
-					result := '0' & be_src & be_src & be_src;
-				when "11" =>
-					result := be_src & be_src & be_src & be_src;
-				when others =>
-					result := "0000";
-			end case;
+		result := (3 downto 0 => be_src);
+		if bypass = '0' then
+			if word2_en = '1' then
+				case va is
+					when "00" =>
+						result := "00" & be_src & be_src;
+					when "10" =>
+						result := be_src & be_src & "00";
+					when others => null;
+				end case;
+			elsif word4_en = '1' then
+				case va is
+					when "00" =>
+						result := "000" & be_src;
+					when "01" =>
+						result := "00" & be_src & '0';
+					when "10" =>
+						result := '0' & be_src & "00";
+					when "11" =>
+						result := be_src & "000";
+					when others => null;
+				end case;
+			elsif align_left = '1' then
+				case va is
+					when "00" =>
+						result := be_src & be_src & be_src & be_src;
+					when "01" =>
+						result := be_src & be_src & be_src & '0';
+					when "10" =>
+						result := be_src & be_src & "00";
+					when "11" =>
+						result := be_src & "000";
+					when others => null;
+				end case;
+			else
+				case va is
+					when "00" =>
+						result := "000" & be_src;
+					when "01" =>
+						result := "00" & be_src & be_src;
+					when "10" =>
+						result := '0' & be_src & be_src & be_src;
+					when "11" =>
+						result := be_src & be_src & be_src & be_src;
+					when others => null;
+				end case;
+			end if;
 		end if;
 		
 		return result;
@@ -539,34 +536,33 @@ package body mips_types is
 	function load_be(va : unsigned(1 downto 0); align_left, bypass : std_logic) return unsigned is
 	variable result : unsigned(3 downto 0);
 	begin
-		if bypass = '1' then
-			result := (3 downto 0 => '1');
-		elsif align_left = '1' then
-			case va is
-				when "00" =>
-					result := "1000";
-				when "01" =>
-					result := "1100";
-				when "10" =>
-					result := "1110";
-				when "11" =>
-					result := "1111";
-				when others =>
-					result := "0000";
-			end case;
-		else
-			case va is
-				when "00" =>
-					result := "1111";
-				when "01" =>
-					result := "0111";
-				when "10" =>
-					result := "0011";
-				when "11" =>
-					result := "0001";
-				when others =>
-					result := "0000";
-			end case;
+		result := (3 downto 0 => '1');
+		if bypass = '0' then
+			if align_left = '1' then
+				case va is
+					when "00" =>
+						result := "1000";
+					when "01" =>
+						result := "1100";
+					when "10" =>
+						result := "1110";
+					when "11" =>
+						result := "1111";
+					when others => null;
+				end case;
+			else
+				case va is
+					when "00" =>
+						result := "1111";
+					when "01" =>
+						result := "0111";
+					when "10" =>
+						result := "0011";
+					when "11" =>
+						result := "0001";
+					when others => null;
+				end case;
+			end if;
 		end if;
 		
 		return result;