From 4cec21b93e62e9c43a0ab9618c0111ee65e520c1 Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddie@fpgeh.com>
Date: Wed, 15 Apr 2020 16:29:11 -0700
Subject: [PATCH] abc9_ops: -prep_dff_map to error if async flop found

---
 passes/techmap/abc9_ops.cc  | 12 +++++++-----
 techlibs/xilinx/cells_sim.v |  4 ----
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/passes/techmap/abc9_ops.cc b/passes/techmap/abc9_ops.cc
index ee25866c3..62007c61e 100644
--- a/passes/techmap/abc9_ops.cc
+++ b/passes/techmap/abc9_ops.cc
@@ -181,7 +181,7 @@ void prep_dff_map(RTLIL::Design *design)
 		for (auto cell : module->cells())
 			if (cell->type.in(ID($_DFF_N_), ID($_DFF_P_))) {
 				if (dff_cell)
-					log_error("More than one $_DFF_[NP]_ cell found in module '%s' marked (* abc9_flop *)\n", log_id(module));
+					log_error("Module '%s' with (* abc9_flop *) contains more than one $_DFF_[NP]_ cell.\n", log_id(module));
 				dff_cell = cell;
 
 				// Block sequential synthesis on cells with (* init *) != 1'b0
@@ -207,10 +207,15 @@ void prep_dff_map(RTLIL::Design *design)
 					goto continue_outer_loop;
 				}
 			}
+			else if (cell->type.in(ID($_DFF_NN0_), ID($_DFF_NN1_), ID($_DFF_NP0_), ID($_DFF_NP1_),
+						ID($_DFF_PN0_), ID($_DFF_PN1_), ID($_DFF_PP0_), ID($_DFF_PP1_),
+						ID($__DFFE_NN0), ID($__DFFE_NN1), ID($__DFFE_NP0), ID($__DFFE_NP1),
+						ID($__DFFE_PN0), ID($__DFFE_PN1), ID($__DFFE_PP0), ID($__DFFE_PP1)))
+				log_error("Module '%s' with (* abc9_flop *) contains an asynchronous $_DFFE?_[NP][NP][01]_? cell, which is not supported for sequential synthesis.\n", log_id(module));
 			else if (cell->type.in(ID($specify2), ID($specify3), ID($specrule)))
 				specify_cells.emplace_back(cell);
 		if (!dff_cell)
-			log_error("$_DFF_[NP]_ cell not found in module '%s' marked (* abc9_flop *)\n", log_id(module));
+			log_error("Module '%s' with (* abc9_flop *) does not any contain $_DFF_[NP]_ cells.\n", log_id(module));
 
 		D = dff_cell->getPort(ID::D);
 
@@ -229,9 +234,6 @@ void prep_dff_map(RTLIL::Design *design)
 			D = w;
 		}
 
-		if (GetSize(specify_cells) == 0)
-			log_error("Module '%s' marked (* abc9_flop *) contains no specify timing information.\n", log_id(module));
-
 		// Rewrite $specify cells that end with $_DFF_[NP]_.Q
 		//   to $_DFF_[NP]_.D since it will be moved into
 		//   the submodule
diff --git a/techlibs/xilinx/cells_sim.v b/techlibs/xilinx/cells_sim.v
index 5143f87da..25df3a865 100644
--- a/techlibs/xilinx/cells_sim.v
+++ b/techlibs/xilinx/cells_sim.v
@@ -656,7 +656,6 @@ module FDRSE (
       Q <= d;
 endmodule
 
-(* lib_whitebox *)
 module FDCE (
   output reg Q,
   (* clkbuf_sink *)
@@ -699,7 +698,6 @@ module FDCE (
   endspecify
 endmodule
 
-(* lib_whitebox *)
 module FDCE_1 (
   output reg Q,
   (* clkbuf_sink *)
@@ -724,7 +722,6 @@ module FDCE_1 (
   endspecify
 endmodule
 
-(* lib_whitebox *)
 module FDPE (
   output reg Q,
   (* clkbuf_sink *)
@@ -766,7 +763,6 @@ module FDPE (
   endspecify
 endmodule
 
-(* lib_whitebox *)
 module FDPE_1 (
   output reg Q,
   (* clkbuf_sink *)
-- 
2.30.2