Merge branch 'master' of github.com:cliffordwolf/yosys

16 files changed, 162 insertions, 22 deletions

diff --git a/backends/smt2/smt2.cc b/backends/smt2/smt2.cc
index 02d6f3fb6..584a1df1a 100644
--- a/backends/smt2/smt2.cc
+++ b/backends/smt2/smt2.cc
@@ -49,6 +49,7 @@ struct Smt2Worker
 			regsmode(regsmode), wiresmode(wiresmode), verbose(verbose), idcounter(0)
 	{
 		decls.push_back(stringf("(declare-sort |%s_s| 0)\n", log_id(module)));
+		decls.push_back(stringf("(declare-fun |%s_is| (|%s_s|) Bool)\n", log_id(module), log_id(module)));
 
 		for (auto cell : module->cells())
 		for (auto &conn : cell->connections()) {
@@ -324,6 +325,16 @@ struct Smt2Worker
 		exported_cells.insert(cell);
 		recursive_cells.insert(cell);
 
+		if (cell->type == "$initstate")
+		{
+			SigBit bit = sigmap(cell->getPort("\\Y").as_bit());
+			decls.push_back(stringf("(define-fun |%s#%d| ((state |%s_s|)) Bool (|%s_is| state)) ; %s\n",
+					log_id(module), idcounter, log_id(module), log_id(module), log_signal(bit)));
+			register_bool(bit, idcounter++);
+			recursive_cells.erase(cell);
+			return;
+		}
+
 		if (cell->type == "$_DFF_P_" || cell->type == "$_DFF_N_")
 		{
 			registers.insert(cell);
@@ -755,7 +766,9 @@ struct Smt2Backend : public Backend {
 		log("the assumptions in the module.\n");
 		log("\n");
 		log("The '<mod>_i' function evaluates to 'true' when the given state conforms\n");
-		log("to the initial state.\n");
+		log("to the initial state. Furthermore the '<mod>_is' function should be asserted\n");
+		log("to be true for initial states in addition to '<mod>_i', and should be\n");
+		log("asserted to be false for non-initial states.\n");
 		log("\n");
 		log("For hierarchical designs, the '<mod>_h' function must be asserted for each\n");
 		log("state to establish the design hierarchy. The '<mod>_h <cellname>' function\n");
diff --git a/backends/smt2/smtbmc.py b/backends/smt2/smtbmc.py
index f74908f87..0e94a1675 100644
--- a/backends/smt2/smtbmc.py
+++ b/backends/smt2/smtbmc.py
@@ -130,6 +130,7 @@ if tempind:
         smt.write("(declare-fun s%d () %s_s)" % (step, topmod))
         smt.write("(assert (%s_u s%d))" % (topmod, step))
         smt.write("(assert (%s_h s%d))" % (topmod, step))
+        smt.write("(assert (not (%s_is s%d)))" % (topmod, step))
 
         if step == num_steps:
             smt.write("(assert (not (%s_a s%d)))" % (topmod, step))
@@ -172,9 +173,11 @@ else: # not tempind
 
         if step == 0:
             smt.write("(assert (%s_i s0))" % (topmod))
+            smt.write("(assert (%s_is s0))" % (topmod))
 
         else:
             smt.write("(assert (%s_t s%d s%d))" % (topmod, step-1, step))
+            smt.write("(assert (not (%s_is s%d)))" % (topmod, step))
 
         if step < skip_steps:
             if assume_skipped is not None and step >= assume_skipped:
diff --git a/examples/smtbmc/demo1.v b/examples/smtbmc/demo1.v
index 2e628b7da..b1e505bdd 100644
--- a/examples/smtbmc/demo1.v
+++ b/examples/smtbmc/demo1.v
@@ -1,5 +1,5 @@
 module demo1(input clk, input addtwo, output iseven);
-	reg [3:0] cnt = 0;
+	reg [3:0] cnt;
 	wire [3:0] next_cnt;
 
 	inc inc_inst (addtwo, iseven, cnt, next_cnt);
@@ -8,6 +8,7 @@ module demo1(input clk, input addtwo, output iseven);
 		cnt = (iseven ? cnt == 10 : cnt == 11) ? 0 : next_cnt;
 	
 	assert property (cnt != 15);
+	initial assume (!cnt[3] && !cnt[0]);
 	// initial predict ((iseven && addtwo) || cnt == 9);
 endmodule
 
diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 82b4edef1..29795590c 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -44,7 +44,8 @@ namespace AST {
 
 // instanciate global variables (private API)
 namespace AST_INTERNAL {
-	bool flag_dump_ast1, flag_dump_ast2, flag_dump_vlog, flag_nolatches, flag_nomeminit, flag_nomem2reg, flag_mem2reg, flag_lib, flag_noopt, flag_icells, flag_autowire;
+	bool flag_dump_ast1, flag_dump_ast2, flag_dump_vlog, flag_dump_rtlil, flag_nolatches, flag_nomeminit;
+	bool flag_nomem2reg, flag_mem2reg, flag_lib, flag_noopt, flag_icells, flag_autowire;
 	AstNode *current_ast, *current_ast_mod;
 	std::map<std::string, AstNode*> current_scope;
 	const dict<RTLIL::SigBit, RTLIL::SigBit> *genRTLIL_subst_ptr = NULL;
@@ -175,7 +176,7 @@ bool AstNode::get_bool_attribute(RTLIL::IdString id)
 
 // create new node (AstNode constructor)
 // (the optional child arguments make it easier to create AST trees)
-AstNode::AstNode(AstNodeType type, AstNode *child1, AstNode *child2)
+AstNode::AstNode(AstNodeType type, AstNode *child1, AstNode *child2, AstNode *child3)
 {
 	static unsigned int hashidx_count = 123456789;
 	hashidx_count = mkhash_xorshift(hashidx_count);
@@ -203,6 +204,8 @@ AstNode::AstNode(AstNodeType type, AstNode *child1, AstNode *child2)
 		children.push_back(child1);
 	if (child2)
 		children.push_back(child2);
+	if (child3)
+		children.push_back(child3);
 }
 
 // create a (deep recursive) copy of a node
@@ -969,16 +972,25 @@ static AstModule* process_module(AstNode *ast, bool defer)
 	current_module->icells = flag_icells;
 	current_module->autowire = flag_autowire;
 	current_module->fixup_ports();
+
+	if (flag_dump_rtlil) {
+		log("Dumping generated RTLIL:\n");
+		log_module(current_module);
+		log("--- END OF RTLIL DUMP ---\n");
+	}
+
 	return current_module;
 }
 
 // create AstModule instances for all modules in the AST tree and add them to 'design'
-void AST::process(RTLIL::Design *design, AstNode *ast, bool dump_ast1, bool dump_ast2, bool dump_vlog, bool nolatches, bool nomeminit, bool nomem2reg, bool mem2reg, bool lib, bool noopt, bool icells, bool ignore_redef, bool defer, bool autowire)
+void AST::process(RTLIL::Design *design, AstNode *ast, bool dump_ast1, bool dump_ast2, bool dump_vlog, bool dump_rtlil,
+		bool nolatches, bool nomeminit, bool nomem2reg, bool mem2reg, bool lib, bool noopt, bool icells, bool ignore_redef, bool defer, bool autowire)
 {
 	current_ast = ast;
 	flag_dump_ast1 = dump_ast1;
 	flag_dump_ast2 = dump_ast2;
 	flag_dump_vlog = dump_vlog;
+	flag_dump_rtlil = dump_rtlil;
 	flag_nolatches = nolatches;
 	flag_nomeminit = nomeminit;
 	flag_nomem2reg = nomem2reg;
@@ -1023,9 +1035,8 @@ void AST::process(RTLIL::Design *design, AstNode *ast, bool dump_ast1, bool dump
 
 			design->add(process_module(*it, defer));
 		}
-		else if ((*it)->type == AST_PACKAGE){
+		else if ((*it)->type == AST_PACKAGE)
 			design->verilog_packages.push_back((*it)->clone());
-		}
 		else
 			global_decls.push_back(*it);
 	}
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index 5310bcadb..530c11ba5 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -187,7 +187,7 @@ namespace AST
 		int linenum;
 
 		// creating and deleting nodes
-		AstNode(AstNodeType type = AST_NONE, AstNode *child1 = NULL, AstNode *child2 = NULL);
+		AstNode(AstNodeType type = AST_NONE, AstNode *child1 = NULL, AstNode *child2 = NULL, AstNode *child3 = NULL);
 		AstNode *clone();
 		void cloneInto(AstNode *other);
 		void delete_children();
@@ -272,7 +272,8 @@ namespace AST
 	};
 
 	// process an AST tree (ast must point to an AST_DESIGN node) and generate RTLIL code
-	void process(RTLIL::Design *design, AstNode *ast, bool dump_ast1, bool dump_ast2, bool dump_vlog, bool nolatches, bool nomeminit, bool nomem2reg, bool mem2reg, bool lib, bool noopt, bool icells, bool ignore_redef, bool defer, bool autowire);
+	void process(RTLIL::Design *design, AstNode *ast, bool dump_ast1, bool dump_ast2, bool dump_vlog, bool dump_rtlil, bool nolatches, bool nomeminit,
+			bool nomem2reg, bool mem2reg, bool lib, bool noopt, bool icells, bool ignore_redef, bool defer, bool autowire);
 
 	// parametric modules are supported directly by the AST library
 	// therefore we need our own derivate of RTLIL::Module with overloaded virtual functions
@@ -302,7 +303,8 @@ namespace AST
 namespace AST_INTERNAL
 {
 	// internal state variables
-	extern bool flag_dump_ast1, flag_dump_ast2, flag_nolatches, flag_nomeminit, flag_nomem2reg, flag_mem2reg, flag_lib, flag_noopt, flag_icells, flag_autowire;
+	extern bool flag_dump_ast1, flag_dump_ast2, flag_dump_rtlil, flag_nolatches, flag_nomeminit;
+	extern bool flag_nomem2reg, flag_mem2reg, flag_lib, flag_noopt, flag_icells, flag_autowire;
 	extern AST::AstNode *current_ast, *current_ast_mod;
 	extern std::map<std::string, AST::AstNode*> current_scope;
 	extern const dict<RTLIL::SigBit, RTLIL::SigBit> *genRTLIL_subst_ptr;
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index 2fb95ff5a..04cdb9416 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -750,6 +750,19 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun
 		width_hint = max(width_hint, this_width);
 		break;
 
+	case AST_FCALL:
+		if (str == "\\$anyconst" || str == "\\$aconst") {
+			if (GetSize(children) == 1) {
+				while (children[0]->simplify(true, false, false, 1, -1, false, true) == true) { }
+				if (children[0]->type != AST_CONSTANT)
+					log_error("System function %s called with non-const argument at %s:%d!\n",
+							RTLIL::unescape_id(str).c_str(), filename.c_str(), linenum);
+				width_hint = max(width_hint, int(children[0]->asInt(true)));
+			}
+			break;
+		}
+		/* fall through */
+
 	// everything should have been handled above -> print error if not.
 	default:
 		for (auto f : log_files)
@@ -1427,6 +1440,38 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 			delete always;
 		} break;
 
+	case AST_FCALL: {
+			if (str == "\\$anyconst" || str == "\\$aconst")
+			{
+				string myid = stringf("%s$%d", RTLIL::unescape_id(str).c_str(), autoidx++);
+				int width = width_hint;
+
+				if (GetSize(children) > 1)
+					log_error("System function %s got %d arguments, expected 1 or 0 at %s:%d.\n",
+							RTLIL::unescape_id(str).c_str(), GetSize(children), filename.c_str(), linenum);
+
+				if (GetSize(children) == 1) {
+					if (children[0]->type != AST_CONSTANT)
+						log_error("System function %s called with non-const argument at %s:%d!\n",
+								RTLIL::unescape_id(str).c_str(), filename.c_str(), linenum);
+					width = children[0]->asInt(true);
+				}
+
+				if (width <= 0)
+					log_error("Failed to detect width of %s at %s:%d!\n",
+							RTLIL::unescape_id(str).c_str(), filename.c_str(), linenum);
+
+				Cell *cell = current_module->addCell(myid, str.substr(1));
+				cell->parameters["\\WIDTH"] = width;
+
+				Wire *wire = current_module->addWire(myid + "_wire", width);
+				cell->setPort("\\Y", wire);
+
+				is_signed = sign_hint;
+				return SigSpec(wire);
+			}
+		} /* fall through */
+
 	// everything should have been handled above -> print error if not.
 	default:
 		for (auto f : log_files)
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 9f88cddc2..79dc3b7c8 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1655,6 +1655,10 @@ skip_dynamic_range_lvalue_expansion:;
 				goto apply_newNode;
 			}
 
+			// $anyconst and $aconst are mapped in AstNode::genRTLIL()
+			if (str == "\\$anyconst" || str == "\\$aconst")
+				return false;
+
 			if (str == "\\$clog2")
 			{
 				if (children.size() != 1)
diff --git a/frontends/verilog/verilog_frontend.cc b/frontends/verilog/verilog_frontend.cc
index 87ea8c6ae..8ec347e89 100644
--- a/frontends/verilog/verilog_frontend.cc
+++ b/frontends/verilog/verilog_frontend.cc
@@ -75,6 +75,9 @@ struct VerilogFrontend : public Frontend {
 		log("    -dump_vlog\n");
 		log("        dump ast as Verilog code (after simplification)\n");
 		log("\n");
+		log("    -dump_rtlil\n");
+		log("        dump generated RTLIL netlist\n");
+		log("\n");
 		log("    -yydebug\n");
 		log("        enable parser debug output\n");
 		log("\n");
@@ -168,6 +171,7 @@ struct VerilogFrontend : public Frontend {
 		bool flag_dump_ast1 = false;
 		bool flag_dump_ast2 = false;
 		bool flag_dump_vlog = false;
+		bool flag_dump_rtlil = false;
 		bool flag_nolatches = false;
 		bool flag_nomeminit = false;
 		bool flag_nomem2reg = false;
@@ -216,6 +220,10 @@ struct VerilogFrontend : public Frontend {
 				flag_dump_vlog = true;
 				continue;
 			}
+			if (arg == "-dump_rtlil") {
+				flag_dump_rtlil = true;
+				continue;
+			}
 			if (arg == "-yydebug") {
 				frontend_verilog_yydebug = true;
 				continue;
@@ -342,7 +350,7 @@ struct VerilogFrontend : public Frontend {
 		if (flag_nodpi)
 			error_on_dpi_function(current_ast);
 
-		AST::process(design, current_ast, flag_dump_ast1, flag_dump_ast2, flag_dump_vlog, flag_nolatches, flag_nomeminit, flag_nomem2reg, flag_mem2reg, lib_mode, flag_noopt, flag_icells, flag_ignore_redef, flag_defer, default_nettype_wire);
+		AST::process(design, current_ast, flag_dump_ast1, flag_dump_ast2, flag_dump_vlog, flag_dump_rtlil, flag_nolatches, flag_nomeminit, flag_nomem2reg, flag_mem2reg, lib_mode, flag_noopt, flag_icells, flag_ignore_redef, flag_defer, default_nettype_wire);
 
 		if (!flag_nopp)
 			delete lexin;
diff --git a/frontends/verilog/verilog_parser.y b/frontends/verilog/verilog_parser.y
index 4cb65a088..c2327011f 100644
--- a/frontends/verilog/verilog_parser.y
+++ b/frontends/verilog/verilog_parser.y
@@ -1219,7 +1219,7 @@ rvalue:
 		$$ = new AstNode(AST_IDENTIFIER, $2);
 		$$->str = *$1;
 		delete $1;
-		if ($2 == nullptr && $$->str == "\\$initstate")
+		if ($2 == nullptr && formal_mode && ($$->str == "\\$initstate" || $$->str == "\\$anyconst" || $$->str == "\\$aconst"))
 			$$->type = AST_FCALL;
 	} |
 	hierarchical_id non_opt_multirange {
diff --git a/kernel/celltypes.h b/kernel/celltypes.h
index 1eea0530c..9eb1523e9 100644
--- a/kernel/celltypes.h
+++ b/kernel/celltypes.h
@@ -118,6 +118,8 @@ struct CellTypes
 		setup_type("$assume", {A, EN}, pool<RTLIL::IdString>(), true);
 		setup_type("$predict", {A, EN}, pool<RTLIL::IdString>(), true);
 		setup_type("$initstate", pool<RTLIL::IdString>(), {Y}, true);
+		setup_type("$anyconst", pool<RTLIL::IdString>(), {Y}, true);
+		setup_type("$aconst", pool<RTLIL::IdString>(), {Y}, true);
 		setup_type("$equiv", {A, B}, {Y}, true);
 	}
 
diff --git a/kernel/log.cc b/kernel/log.cc
index fe84184a5..12dc453dc 100644
--- a/kernel/log.cc
+++ b/kernel/log.cc
@@ -427,6 +427,13 @@ const char *log_id(RTLIL::IdString str)
 	return p+1;
 }
 
+void log_module(RTLIL::Module *module, std::string indent)
+{
+	std::stringstream buf;
+	ILANG_BACKEND::dump_module(buf, indent, module, module->design, false);
+	log("%s", buf.str().c_str());
+}
+
 void log_cell(RTLIL::Cell *cell, std::string indent)
 {
 	std::stringstream buf;
diff --git a/kernel/log.h b/kernel/log.h
index 33e624dcb..f830655c1 100644
--- a/kernel/log.h
+++ b/kernel/log.h
@@ -85,6 +85,7 @@ template<typename T> static inline const char *log_id(T *obj) {
 	return log_id(obj->name);
 }
 
+void log_module(RTLIL::Module *module, std::string indent = "");
 void log_cell(RTLIL::Cell *cell, std::string indent = "");
 
 #ifndef NDEBUG
diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index 2e5157e85..ad90965fb 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -1030,6 +1030,12 @@ namespace {
 				return;
 			}
 
+			if (cell->type.in("$aconst", "$anyconst")) {
+				port("\\Y", param("\\WIDTH"));
+				check_expected();
+				return;
+			}
+
 			if (cell->type == "$equiv") {
 				port("\\A", 1);
 				port("\\B", 1);
diff --git a/kernel/satgen.h b/kernel/satgen.h
index 31b7a3e5a..0a65b490c 100644
--- a/kernel/satgen.h
+++ b/kernel/satgen.h
@@ -69,7 +69,6 @@ struct SatGen
 	SigPool initial_state;
 	std::map<std::string, RTLIL::SigSpec> asserts_a, asserts_en;
 	std::map<std::string, RTLIL::SigSpec> assumes_a, assumes_en;
-	std::map<std::string, RTLIL::SigSpec> predict_a, predict_en;
 	std::map<std::string, std::map<RTLIL::SigBit, int>> imported_signals;
 	std::map<std::pair<std::string, int>, bool> initstates;
 	bool ignore_div_by_zero;
@@ -1320,6 +1319,28 @@ struct SatGen
 			return true;
 		}
 
+		if (cell->type == "$anyconst")
+		{
+			if (timestep < 2)
+				return true;
+
+			std::vector<int> d = importDefSigSpec(cell->getPort("\\Y"), timestep-1);
+			std::vector<int> q = importDefSigSpec(cell->getPort("\\Y"), timestep);
+
+			std::vector<int> qq = model_undef ? ez->vec_var(q.size()) : q;
+			ez->assume(ez->vec_eq(d, qq));
+
+			if (model_undef)
+			{
+				std::vector<int> undef_d = importUndefSigSpec(cell->getPort("\\D"), timestep-1);
+				std::vector<int> undef_q = importUndefSigSpec(cell->getPort("\\Q"), timestep);
+
+				ez->assume(ez->vec_eq(undef_d, undef_q));
+				undefGating(q, qq, undef_q);
+			}
+			return true;
+		}
+
 		if (cell->type == "$_BUF_" || cell->type == "$equiv")
 		{
 			std::vector<int> a = importDefSigSpec(cell->getPort("\\A"), timestep);
@@ -1374,14 +1395,6 @@ struct SatGen
 			return true;
 		}
 
-		if (cell->type == "$predict")
-		{
-			std::string pf = prefix + (timestep == -1 ? "" : stringf("@%d:", timestep));
-			predict_a[pf].append((*sigmap)(cell->getPort("\\A")));
-			predict_en[pf].append((*sigmap)(cell->getPort("\\EN")));
-			return true;
-		}
-
 		// Unsupported internal cell types: $pow $lut
 		// .. and all sequential cells except $dff and $_DFF_[NP]_
 		return false;
diff --git a/manual/CHAPTER_CellLib.tex b/manual/CHAPTER_CellLib.tex
index 0f1136346..bff01d06c 100644
--- a/manual/CHAPTER_CellLib.tex
+++ b/manual/CHAPTER_CellLib.tex
@@ -421,7 +421,7 @@ pass. The combinatorial logic cells can be mapped to physical cells from a Liber
 using the {\tt abc} pass.
 
 \begin{fixme}
-Add information about {\tt \$assert}, {\tt \$assume}, {\tt \$predict}, {\tt \$equiv}, and {\tt \$initstate} cells.
+Add information about {\tt \$assert}, {\tt \$assume}, {\tt \$predict}, {\tt \$equiv}, {\tt \$initstate}, {\tt \$aconst}, and {\tt \$anyconst} cells.
 \end{fixme}
 
 \begin{fixme}
diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v
index 8ab124034..ac4269c90 100644
--- a/techlibs/common/simlib.v
+++ b/techlibs/common/simlib.v
@@ -1330,6 +1330,30 @@ endmodule
 
 // --------------------------------------------------------
 
+module \$aconst (Y);
+
+parameter WIDTH = 0;
+
+output [WIDTH-1:0] Y;
+
+assign Y = 'bx;
+
+endmodule
+
+// --------------------------------------------------------
+
+module \$anyconst (Y);
+
+parameter WIDTH = 0;
+
+output [WIDTH-1:0] Y;
+
+assign Y = 'bx;
+
+endmodule
+
+// --------------------------------------------------------
+
 module \$equiv (A, B, Y);
 
 input A, B;