From 7f3f25841e8aab9ebe06ddf096a520a66f6249fc Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Mon, 10 Jun 2013 21:04:04 +0200
Subject: [PATCH] More sign-extension related fixes

---
 techlibs/stdcells.v | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/techlibs/stdcells.v b/techlibs/stdcells.v
index 01cfb9d14..41e20214d 100644
--- a/techlibs/stdcells.v
+++ b/techlibs/stdcells.v
@@ -123,8 +123,8 @@ input [B_WIDTH-1:0] B;
 output [Y_WIDTH-1:0] Y;
 
 wire [Y_WIDTH-1:0] A_buf, B_buf;
-\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
-\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
 
 genvar i;
 generate
@@ -154,8 +154,8 @@ input [B_WIDTH-1:0] B;
 output [Y_WIDTH-1:0] Y;
 
 wire [Y_WIDTH-1:0] A_buf, B_buf;
-\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
-\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
 
 genvar i;
 generate
@@ -185,8 +185,8 @@ input [B_WIDTH-1:0] B;
 output [Y_WIDTH-1:0] Y;
 
 wire [Y_WIDTH-1:0] A_buf, B_buf;
-\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
-\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
 
 genvar i;
 generate
@@ -216,8 +216,8 @@ input [B_WIDTH-1:0] B;
 output [Y_WIDTH-1:0] Y;
 
 wire [Y_WIDTH-1:0] A_buf, B_buf;
-\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
-\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
 
 genvar i;
 generate
@@ -980,14 +980,15 @@ input [A_WIDTH-1:0] A;
 input [B_WIDTH-1:0] B;
 output [Y_WIDTH-1:0] Y;
 
-wire signed [Y_WIDTH:0] buffer_a = A_SIGNED ? $signed(A) : A;
-wire signed [Y_WIDTH:0] buffer_b = B_SIGNED ? $signed(B) : B;
+wire [Y_WIDTH-1:0] A_buf, B_buf;
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
+\$pos #(.A_SIGNED(A_SIGNED && B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
 
 \$arraymul #(
 	.WIDTH(Y_WIDTH)
 ) arraymul (
-	.A(buffer_a),
-	.B(buffer_b),
+	.A(A_buf),
+	.B(B_buf),
 	.Y(Y)
 );
 
-- 
2.30.2