Add $cover cell type and SVA cover() support

7 files changed, 16 insertions, 5 deletions

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 2d58c682f..38a19a36f 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -84,6 +84,7 @@ std::string AST::type2str(AstNodeType type)
 	X(AST_PREFIX)
 	X(AST_ASSERT)
 	X(AST_ASSUME)
+	X(AST_COVER)
 	X(AST_FCALL)
 	X(AST_TO_BITS)
 	X(AST_TO_SIGNED)
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index cd6e264e6..0b9116d39 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -65,6 +65,7 @@ namespace AST
 		AST_PREFIX,
 		AST_ASSERT,
 		AST_ASSUME,
+		AST_COVER,
 
 		AST_FCALL,
 		AST_TO_BITS,
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index db8d7409f..bdac4de00 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -1336,9 +1336,11 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 	// generate $assert cells
 	case AST_ASSERT:
 	case AST_ASSUME:
+	case AST_COVER:
 		{
 			const char *celltype = "$assert";
 			if (type == AST_ASSUME) celltype = "$assume";
+			if (type == AST_COVER) celltype = "$cover";
 
 			log_assert(children.size() == 2);
 
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index c1e77c6ec..eecc04132 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1400,7 +1400,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 	}
 skip_dynamic_range_lvalue_expansion:;
 
-	if (stage > 1 && (type == AST_ASSERT || type == AST_ASSUME) && current_block != NULL)
+	if (stage > 1 && (type == AST_ASSERT || type == AST_ASSUME || type == AST_COVER) && current_block != NULL)
 	{
 		std::stringstream sstr;
 		sstr << "$formal$" << filename << ":" << linenum << "$" << (autoidx++);
@@ -1462,7 +1462,7 @@ skip_dynamic_range_lvalue_expansion:;
 		goto apply_newNode;
 	}
 
-	if (stage > 1 && (type == AST_ASSERT || type == AST_ASSUME) && children.size() == 1)
+	if (stage > 1 && (type == AST_ASSERT || type == AST_ASSUME || type == AST_COVER) && children.size() == 1)
 	{
 		children.push_back(mkconst_int(1, false, 1));
 		did_something = true;
diff --git a/frontends/verific/verific.cc b/frontends/verific/verific.cc
index 9bf5a6c6c..f5efdea7e 100644
--- a/frontends/verific/verific.cc
+++ b/frontends/verific/verific.cc
@@ -752,8 +752,8 @@ struct VerificImporter
 			}
 
 			if (inst->Type() == PRIM_SVA_IMMEDIATE_COVER || inst->Type() == PRIM_SVA_COVER) {
-				// Net *in = inst->GetInput();
-				// module->addCover(NEW_ID, net_map.at(in), State::S1);
+				Net *in = inst->GetInput();
+				module->addCover(NEW_ID, net_map.at(in), State::S1);
 				continue;
 			}
 
diff --git a/frontends/verilog/verilog_lexer.l b/frontends/verilog/verilog_lexer.l
index c22fdf39c..4d040e3d1 100644
--- a/frontends/verilog/verilog_lexer.l
+++ b/frontends/verilog/verilog_lexer.l
@@ -177,6 +177,7 @@ YOSYS_NAMESPACE_END
 
 "assert"   { if (formal_mode) return TOK_ASSERT; SV_KEYWORD(TOK_ASSERT); }
 "assume"   { if (formal_mode) return TOK_ASSUME; SV_KEYWORD(TOK_ASSUME); }
+"cover"    { if (formal_mode) return TOK_COVER; SV_KEYWORD(TOK_COVER); }
 "restrict" { if (formal_mode) return TOK_RESTRICT; SV_KEYWORD(TOK_RESTRICT); }
 "property" { if (formal_mode) return TOK_PROPERTY; SV_KEYWORD(TOK_PROPERTY); }
 "logic"    { SV_KEYWORD(TOK_REG); }
diff --git a/frontends/verilog/verilog_parser.y b/frontends/verilog/verilog_parser.y
index ba47bf2d3..0f823a082 100644
--- a/frontends/verilog/verilog_parser.y
+++ b/frontends/verilog/verilog_parser.y
@@ -114,7 +114,7 @@ static void free_attr(std::map<std::string, AstNode*> *al)
 %token TOK_SYNOPSYS_FULL_CASE TOK_SYNOPSYS_PARALLEL_CASE
 %token TOK_SUPPLY0 TOK_SUPPLY1 TOK_TO_SIGNED TOK_TO_UNSIGNED
 %token TOK_POS_INDEXED TOK_NEG_INDEXED TOK_ASSERT TOK_ASSUME
-%token TOK_RESTRICT TOK_PROPERTY TOK_ENUM TOK_TYPEDEF
+%token TOK_RESTRICT TOK_COVER TOK_PROPERTY TOK_ENUM TOK_TYPEDEF
 
 %type <ast> range range_or_multirange  non_opt_range non_opt_multirange range_or_signed_int
 %type <ast> wire_type expr basic_expr concat_list rvalue lvalue lvalue_concat_list
@@ -1000,6 +1000,9 @@ assert:
 	TOK_ASSUME '(' expr ')' ';' {
 		ast_stack.back()->children.push_back(new AstNode(AST_ASSUME, $3));
 	} |
+	TOK_COVER '(' expr ')' ';' {
+		ast_stack.back()->children.push_back(new AstNode(AST_COVER, $3));
+	} |
 	TOK_RESTRICT '(' expr ')' ';' {
 		if (norestrict_mode)
 			delete $3;
@@ -1014,6 +1017,9 @@ assert_property:
 	TOK_ASSUME TOK_PROPERTY '(' expr ')' ';' {
 		ast_stack.back()->children.push_back(new AstNode(AST_ASSUME, $4));
 	} |
+	TOK_COVER TOK_PROPERTY '(' expr ')' ';' {
+		ast_stack.back()->children.push_back(new AstNode(AST_COVER, $4));
+	} |
 	TOK_RESTRICT TOK_PROPERTY '(' expr ')' ';' {
 		if (norestrict_mode)
 			delete $4;