Add $live and $fair cell types, add support for s_eventually keyword

6 files changed, 40 insertions, 4 deletions

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 06660102b..482acd364 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -84,6 +84,8 @@ std::string AST::type2str(AstNodeType type)
 	X(AST_PREFIX)
 	X(AST_ASSERT)
 	X(AST_ASSUME)
+	X(AST_LIVE)
+	X(AST_FAIR)
 	X(AST_COVER)
 	X(AST_FCALL)
 	X(AST_TO_BITS)
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index 0b9116d39..bddda9667 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -65,6 +65,8 @@ namespace AST
 		AST_PREFIX,
 		AST_ASSERT,
 		AST_ASSUME,
+		AST_LIVE,
+		AST_FAIR,
 		AST_COVER,
 
 		AST_FCALL,
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index bdac4de00..78e83e038 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -1336,10 +1336,15 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 	// generate $assert cells
 	case AST_ASSERT:
 	case AST_ASSUME:
+	case AST_LIVE:
+	case AST_FAIR:
 	case AST_COVER:
 		{
-			const char *celltype = "$assert";
+			const char *celltype = nullptr;
+			if (type == AST_ASSERT) celltype = "$assert";
 			if (type == AST_ASSUME) celltype = "$assume";
+			if (type == AST_LIVE) celltype = "$live";
+			if (type == AST_FAIR) celltype = "$fair";
 			if (type == AST_COVER) celltype = "$cover";
 
 			log_assert(children.size() == 2);
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index f7fcbc479..28c9945ab 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 || type == AST_COVER) && current_block != NULL)
+	if (stage > 1 && (type == AST_ASSERT || type == AST_ASSUME || type == AST_LIVE || type == AST_FAIR || 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 || type == AST_COVER) && children.size() == 1)
+	if (stage > 1 && (type == AST_ASSERT || type == AST_ASSUME || type == AST_LIVE || type == AST_FAIR || type == AST_COVER) && children.size() == 1)
 	{
 		children.push_back(mkconst_int(1, false, 1));
 		did_something = true;
diff --git a/frontends/verilog/verilog_lexer.l b/frontends/verilog/verilog_lexer.l
index 091c1a029..885332b76 100644
--- a/frontends/verilog/verilog_lexer.l
+++ b/frontends/verilog/verilog_lexer.l
@@ -191,6 +191,9 @@ YOSYS_NAMESPACE_END
 "logic"      { SV_KEYWORD(TOK_REG); }
 "bit"        { SV_KEYWORD(TOK_REG); }
 
+"eventually"   { if (formal_mode) return TOK_EVENTUALLY; SV_KEYWORD(TOK_EVENTUALLY); }
+"s_eventually" { if (formal_mode) return TOK_EVENTUALLY; SV_KEYWORD(TOK_EVENTUALLY); }
+
 "input"   { return TOK_INPUT; }
 "output"  { return TOK_OUTPUT; }
 "inout"   { return TOK_INOUT; }
diff --git a/frontends/verilog/verilog_parser.y b/frontends/verilog/verilog_parser.y
index 9b2498694..60b1ecffd 100644
--- a/frontends/verilog/verilog_parser.y
+++ b/frontends/verilog/verilog_parser.y
@@ -116,7 +116,7 @@ static void free_attr(std::map<std::string, AstNode*> *al)
 %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_COVER TOK_PROPERTY TOK_ENUM TOK_TYPEDEF
-%token TOK_RAND TOK_CONST TOK_CHECKER TOK_ENDCHECKER
+%token TOK_RAND TOK_CONST TOK_CHECKER TOK_ENDCHECKER TOK_EVENTUALLY
 %token TOK_INCREMENT TOK_DECREMENT TOK_UNIQUE TOK_PRIORITY
 
 %type <ast> range range_or_multirange  non_opt_range non_opt_multirange range_or_signed_int
@@ -1030,6 +1030,12 @@ assert:
 	TOK_ASSUME '(' expr ')' ';' {
 		ast_stack.back()->children.push_back(new AstNode(AST_ASSUME, $3));
 	} |
+	TOK_ASSERT '(' TOK_EVENTUALLY expr ')' ';' {
+		ast_stack.back()->children.push_back(new AstNode(assume_asserts_mode ? AST_FAIR : AST_LIVE, $4));
+	} |
+	TOK_ASSUME '(' TOK_EVENTUALLY expr ')' ';' {
+		ast_stack.back()->children.push_back(new AstNode(AST_FAIR, $4));
+	} |
 	TOK_COVER '(' expr ')' ';' {
 		ast_stack.back()->children.push_back(new AstNode(AST_COVER, $3));
 	} |
@@ -1044,6 +1050,12 @@ assert:
 			delete $3;
 		else
 			ast_stack.back()->children.push_back(new AstNode(AST_ASSUME, $3));
+	} |
+	TOK_RESTRICT '(' TOK_EVENTUALLY expr ')' ';' {
+		if (norestrict_mode)
+			delete $4;
+		else
+			ast_stack.back()->children.push_back(new AstNode(AST_FAIR, $4));
 	};
 
 assert_property:
@@ -1053,6 +1065,12 @@ assert_property:
 	TOK_ASSUME TOK_PROPERTY '(' expr ')' ';' {
 		ast_stack.back()->children.push_back(new AstNode(AST_ASSUME, $4));
 	} |
+	TOK_ASSERT TOK_PROPERTY '(' TOK_EVENTUALLY expr ')' ';' {
+		ast_stack.back()->children.push_back(new AstNode(assume_asserts_mode ? AST_FAIR : AST_LIVE, $5));
+	} |
+	TOK_ASSUME TOK_PROPERTY '(' TOK_EVENTUALLY expr ')' ';' {
+		ast_stack.back()->children.push_back(new AstNode(AST_FAIR, $5));
+	} |
 	TOK_COVER TOK_PROPERTY '(' expr ')' ';' {
 		ast_stack.back()->children.push_back(new AstNode(AST_COVER, $4));
 	} |
@@ -1061,6 +1079,12 @@ assert_property:
 			delete $4;
 		else
 			ast_stack.back()->children.push_back(new AstNode(AST_ASSUME, $4));
+	} |
+	TOK_RESTRICT TOK_PROPERTY '(' TOK_EVENTUALLY expr ')' ';' {
+		if (norestrict_mode)
+			delete $5;
+		else
+			ast_stack.back()->children.push_back(new AstNode(AST_FAIR, $5));
 	};
 
 simple_behavioral_stmt: