libparse: support space ANDs

passes/techmap/dfflibmap.cc

@@ -92,9 +92,6 @@ static bool parse_next_state(const LibertyAst *cell, const LibertyAst *attr, std
 	auto expr = attr->value;
 	auto cell_name = cell->args[0];
 
-	for (size_t pos = expr.find_first_of("\" \t"); pos != std::string::npos; pos = expr.find_first_of("\" \t"))
-		expr.erase(pos, 1);
-
 	// if this isn't an enable flop, the next_state variable is usually just the input pin name.
 	if (expr[expr.size()-1] == '\'') {
 		data_name = expr.substr(0, expr.size()-1);
@@ -117,7 +114,7 @@ static bool parse_next_state(const LibertyAst *cell, const LibertyAst *attr, std
 	// the next_state variable isn't just a pin name; perhaps this is an enable?
 	auto helper = LibertyExpression::Lexer(expr);
 	auto tree = LibertyExpression::parse(helper);
-	log_debug("liberty expression:\n%s\n", tree.str().c_str());
+	// log_debug("liberty expression:\n%s\n", tree.str().c_str());
 
 	if (tree.kind == LibertyExpression::Kind::EMPTY) {
 		if (!warned_cells.count(cell_name)) {

passes/techmap/libparse.cc

@@ -163,6 +163,12 @@ void LibertyAst::dump(FILE *f, sieve &blacklist, sieve &whitelist, std::string i
 }
 
 #ifndef FILTERLIB
+
+// binary operators excluding ' '
+bool LibertyExpression::is_nice_binop(char c) {
+	return c == '*' || c == '&' || c == '^' || c == '+' || c == '|';
+}
+
 // https://matklad.github.io/2020/04/13/simple-but-powerful-pratt-parsing.html
 LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 	if (s.empty())
@@ -204,13 +210,6 @@ LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 
 		c = s.peek();
 
-		while (isspace(c)) {
-			if (s.empty())
-				return lhs;
-			s.next();
-			c = s.peek();
-		}
-
 		if (c == '\'') { // postfix NOT
 			if (min_prio > 7)
 				break;
@@ -235,11 +234,27 @@ LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 			lhs = std::move(n);
 
 			continue;
-		} else if (c == '&' || c == '*') { // infix AND
+		} else if (c == '&' || c == '*' || isspace(c)) { // infix AND
-			// technically space should be considered infix AND. it seems rare in practice.
 			if (min_prio > 3)
 				break;
-			s.next();
+
+			if (isspace(c)) {
+				// Rewind past this space and any further spaces
+				while (isspace(c) && !s.empty()) {
+					if (s.empty())
+						return lhs;
+					s.next();
+					c = s.peek();
+				}
+				if (is_nice_binop(c)) {
+					// We found a real binop, so this space wasn't an AND
+					// and we just discard it as meaningless whitespace
+					continue;
+				}
+			} else {
+				// Rewind past this op
+				s.next();
+			}
 
 			auto rhs = parse(s, 4);
 			auto n = LibertyExpression{};
@@ -310,7 +325,6 @@ bool LibertyExpression::eval(dict<std::string, bool>& values) {
 std::string LibertyExpression::str(int indent)
 {
 	std::string prefix;
-	prefix = std::string(indent, ' ');
 	switch (kind) {
 		case AND:
 			prefix += "(and ";
@@ -337,10 +351,9 @@ std::string LibertyExpression::str(int indent)
 	bool first = true;
 	for (auto child : children) {
 		if (!first) {
-			prefix += "\n" + child.str(indent + add_indent);
+			prefix += "\n" + std::string(indent + add_indent, ' ');
-		} else {
-			prefix += child.str(0);
 		}
+		prefix += child.str(indent + add_indent);
 		first = false;
 	}
 	prefix += ")";

passes/techmap/libparse.h

@@ -93,6 +93,9 @@ namespace Yosys
 		static LibertyExpression parse(Lexer &s, int min_prio = 0);
 		void get_pin_names(pool<std::string>& names);
 		bool eval(dict<std::string, bool>& values);
+		std::string str(int indent = 0);
+	private:
+		static bool is_nice_binop(char c);
 	};
 
 	class LibertyInputStream {