From 2cbcd6224c0293a3abdf00f51c515fc556d9d3e1 Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddie@fpgeh.com>
Date: Wed, 12 Jun 2019 09:05:02 -0700
Subject: [PATCH] Revert "Merge remote-tracking branch
 'origin/eddie/shregmap_improve' into xc7mux"

This reverts commit a138381ac3f2c820d187f08531ffd823d6cbcfd5, reversing
changes made to b77c5da76919f7f99f171a0a2775896fbc8debc2.
---
 passes/techmap/shregmap.cc |  9 +++------
 tests/various/shregmap.v   | 22 ----------------------
 tests/various/shregmap.ys  | 31 -------------------------------
 3 files changed, 3 insertions(+), 59 deletions(-)
 delete mode 100644 tests/various/shregmap.v
 delete mode 100644 tests/various/shregmap.ys

diff --git a/passes/techmap/shregmap.cc b/passes/techmap/shregmap.cc
index 46f6a79fb..21dfe9619 100644
--- a/passes/techmap/shregmap.cc
+++ b/passes/techmap/shregmap.cc
@@ -293,13 +293,10 @@ struct ShregmapWorker
 
 				if (opts.init || sigbit_init.count(q_bit) == 0)
 				{
-					auto r = sigbit_chain_next.insert(std::make_pair(d_bit, cell));
-					if (!r.second) {
+					if (sigbit_chain_next.count(d_bit)) {
 						sigbit_with_non_chain_users.insert(d_bit);
-						Wire *wire = module->addWire(NEW_ID);
-						module->connect(wire, d_bit);
-						sigbit_chain_next.insert(std::make_pair(wire, cell));
-					}
+					} else
+						sigbit_chain_next[d_bit] = cell;
 
 					sigbit_chain_prev[q_bit] = cell;
 					continue;
diff --git a/tests/various/shregmap.v b/tests/various/shregmap.v
deleted file mode 100644
index 56e05c2c0..000000000
--- a/tests/various/shregmap.v
+++ /dev/null
@@ -1,22 +0,0 @@
-module shregmap_test(input i, clk, output [1:0] q);
-reg head = 1'b0;
-reg [3:0] shift1 = 4'b0000;
-reg [3:0] shift2 = 4'b0000;
-
-always @(posedge clk) begin
-    head <= i;
-    shift1 <= {shift1[2:0], head};
-    shift2 <= {shift2[2:0], head};
-end
-
-assign q = {shift2[3], shift1[3]};
-endmodule
-
-module $__SHREG_DFF_P_(input C, D, output Q);
-parameter DEPTH = 1;
-parameter [DEPTH-1:0] INIT = {DEPTH{1'b0}};
-reg [DEPTH-1:0] r = INIT;
-always @(posedge C) 
-    r <= { r[DEPTH-2:0], D };
-assign Q = r[DEPTH-1];
-endmodule
diff --git a/tests/various/shregmap.ys b/tests/various/shregmap.ys
deleted file mode 100644
index ca7f47015..000000000
--- a/tests/various/shregmap.ys
+++ /dev/null
@@ -1,31 +0,0 @@
-read_verilog shregmap.v
-design -copy-to model $__SHREG_DFF_P_
-hierarchy -top shregmap_test
-prep
-design -save gold
-
-techmap
-shregmap -init
-
-opt
-
-stat
-# show -width
-select -assert-count 1 t:$_DFF_P_
-select -assert-count 2 t:$__SHREG_DFF_P_
-
-design -stash gate
-
-design -import gold -as gold
-design -import gate -as gate
-design -copy-from model -as $__SHREG_DFF_P_ \$__SHREG_DFF_P_
-prep
-
-miter -equiv -flatten -make_assert -make_outputs gold gate miter
-sat -verify -prove-asserts -show-ports -seq 5 miter
-
-design -load gold
-stat
-
-design -load gate
-stat
-- 
2.30.2