From affae35847c45e708436b9142cfa7d7eb6b5aec6 Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddie@fpgeh.com>
Date: Fri, 7 Feb 2020 11:02:48 -0800
Subject: [PATCH] techmap: fix shiftx2mux decomposition
---
techlibs/common/techmap.v | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/techlibs/common/techmap.v b/techlibs/common/techmap.v
index be6530eb4..ecf4d5dc5 100644
--- a/techlibs/common/techmap.v
+++ b/techlibs/common/techmap.v
@@ -149,16 +149,14 @@ module _90_shift_shiftx (A, B, Y);
_TECHMAP_CONSTVAL_B_[CLOG2_Y_WIDTH-1:0] == {CLOG2_Y_WIDTH{1'b0}}) begin
// Halve the size of $shift/$shiftx by $mux-ing A according to
// the LSB of B, after discarding the zeroed bits
- localparam len = 2**(B_WIDTH-1);
localparam Y_WIDTH2 = 2**CLOG2_Y_WIDTH;
- wire [len-1:0] T, F, AA;
- wire [(A_WIDTH+Y_WIDTH2*2):0] Apad = {{Y_WIDTH2*2{extbit}}, A};
+ localparam entries = (A_WIDTH+Y_WIDTH-1)/Y_WIDTH2;
+ localparam len = Y_WIDTH2 * ((entries+1)/2);
+ wire [len-1:0] AA;
+ wire [(A_WIDTH+Y_WIDTH2+Y_WIDTH-1)-1:0] Apad = {{(Y_WIDTH2+Y_WIDTH-1){extbit}}, A};
genvar i;
- for (i = 0; i < A_WIDTH; i=i+Y_WIDTH2*2) begin
- assign F[i/2 +: Y_WIDTH2] = A[i +: Y_WIDTH2];
- assign T[i/2 +: Y_WIDTH2] = Apad[i+Y_WIDTH2 +: Y_WIDTH2];
- assign AA[i/2 +: Y_WIDTH2] = B[CLOG2_Y_WIDTH] ? T[i/2 +: Y_WIDTH2] : F[i/2 +: Y_WIDTH2];
- end
+ for (i = 0; i < A_WIDTH; i=i+Y_WIDTH2*2)
+ assign AA[i/2 +: Y_WIDTH2] = B[CLOG2_Y_WIDTH] ? Apad[i+Y_WIDTH2 +: Y_WIDTH2] : Apad[i +: Y_WIDTH2];
wire [B_WIDTH-2:0] BB = {B[B_WIDTH-1:CLOG2_Y_WIDTH+1], {CLOG2_Y_WIDTH{1'b0}}};
if (_TECHMAP_CELLTYPE_ == "$shift")
$shift #(.A_SIGNED(A_SIGNED), .B_SIGNED(B_SIGNED), .A_WIDTH(len), .B_WIDTH(B_WIDTH-1), .Y_WIDTH(Y_WIDTH)) _TECHMAP_REPLACE_ (.A(AA), .B(BB), .Y(Y));