From 86efe9a616b70ffa64bb344d83aa42956e5fd470 Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddie@fpgeh.com>
Date: Wed, 12 Jun 2019 09:01:15 -0700
Subject: [PATCH] Revert "Merge remote-tracking branch 'origin/eddie/muxpack'
 into xc7mux"

This reverts commit 2223ca91b0cc559bb876e8e97372a8f77da1603e, reversing
changes made to eaee250a6e63e58dfef63fa30c4120db78223e24.
---
 passes/opt/muxpack.cc    | 24 ++++++++++--------------
 tests/various/muxpack.v  | 26 --------------------------
 tests/various/muxpack.ys | 15 ---------------
 3 files changed, 10 insertions(+), 55 deletions(-)

diff --git a/passes/opt/muxpack.cc b/passes/opt/muxpack.cc
index 8c4db4e4d..f9e5c8f09 100644
--- a/passes/opt/muxpack.cc
+++ b/passes/opt/muxpack.cc
@@ -94,27 +94,23 @@ struct MuxpackWorker
 		{
 			log_debug("Considering %s (%s)\n", log_id(cell), log_id(cell->type));
 
-			SigSpec a_sig = cell->getPort("\\A");
-			if (cell->type == "$mux") {
-				SigSpec b_sig = cell->getPort("\\B");
-				if (sig_chain_prev.count(a_sig) + sig_chain_prev.count(b_sig) != 1)
-					goto start_cell;
-
-				if (!sig_chain_prev.count(a_sig))
-					a_sig = b_sig;
-			}
-			else if (cell->type == "$pmux") {
-				if (!sig_chain_prev.count(a_sig))
+			SigSpec next_sig = cell->getPort("\\A");
+			if (sig_chain_prev.count(next_sig) == 0) {
+				if (cell->type == "$mux") {
+					next_sig = cell->getPort("\\B");
+					if (sig_chain_prev.count(next_sig) == 0)
+						goto start_cell;
+				}
+				else
 					goto start_cell;
 			}
-			else log_abort();
 
 			{
-				for (auto bit : a_sig.bits())
+				for (auto bit : next_sig.bits())
 					if (sigbit_with_non_chain_users.count(bit))
 						goto start_cell;
 
-				Cell *c1 = sig_chain_prev.at(a_sig);
+				Cell *c1 = sig_chain_prev.at(next_sig);
 				Cell *c2 = cell;
 
 				if (c1->getParam("\\WIDTH") != c2->getParam("\\WIDTH"))
diff --git a/tests/various/muxpack.v b/tests/various/muxpack.v
index f1bd5ea8e..7c189fff8 100644
--- a/tests/various/muxpack.v
+++ b/tests/various/muxpack.v
@@ -110,29 +110,3 @@ always @* begin
     endcase
 end
 endmodule
-
-module mux_if_bal_8_2 #(parameter N=8, parameter W=2) (input [N*W-1:0] i, input [$clog2(N)-1:0] s, output reg [W-1:0] o);
-always @*
-    if (s[0] == 1'b0)
-     if (s[1] == 1'b0)
-      if (s[2] == 1'b0)
-       o <= i[0*W+:W];
-      else
-       o <= i[1*W+:W];
-     else
-      if (s[2] == 1'b0)
-       o <= i[2*W+:W];
-      else
-       o <= i[3*W+:W];
-    else
-     if (s[1] == 1'b0)
-      if (s[2] == 1'b0)
-       o <= i[4*W+:W];
-      else
-       o <= i[5*W+:W];
-     else
-      if (s[2] == 1'b0)
-       o <= i[6*W+:W];
-      else
-       o <= i[7*W+:W];
-endmodule
diff --git a/tests/various/muxpack.ys b/tests/various/muxpack.ys
index 9ea743b9f..0c5b82818 100644
--- a/tests/various/muxpack.ys
+++ b/tests/various/muxpack.ys
@@ -133,18 +133,3 @@ design -import gold -as gold
 design -import gate -as gate
 miter -equiv -flatten -make_assert -make_outputs gold gate miter
 sat -verify -prove-asserts -show-ports miter
-
-design -load read
-hierarchy -top mux_if_bal_8_2
-prep
-design -save gold
-muxpack
-opt
-stat
-select -assert-count 7 t:$mux
-select -assert-count 0 t:$pmux
-design -stash gate
-design -import gold -as gold
-design -import gate -as gate
-miter -equiv -flatten -make_assert -make_outputs gold gate miter
-sat -verify -prove-asserts -show-ports miter
-- 
2.30.2