1 files changed, 6 insertions, 19 deletions

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index e947125bf..54b9efaad 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -2319,7 +2319,7 @@ skip_dynamic_range_lvalue_expansion:;
 				if (attr.first.str().rfind("\\via_celltype_defparam_", 0) == 0)
 				{
 					AstNode *cell_arg = new AstNode(AST_PARASET, attr.second->clone());
-					cell_arg->str = RTLIL::escape_id(attr.first.str().substr(strlen("\\via_celltype_defparam_")));
+					cell_arg->str = RTLIL::escape_id(attr.first.substr(strlen("\\via_celltype_defparam_")));
 					cell->children.push_back(cell_arg);
 				}
 
@@ -2793,13 +2793,13 @@ AstNode *AstNode::readmem(bool is_readmemh, std::string mem_filename, AstNode *m
 		std::getline(f, line);
 
 		for (int i = 0; i < GetSize(line); i++) {
-			if (in_comment && line.substr(i, 2) == "*/") {
+			if (in_comment && line.compare(i, 2, "*/") == 0) {
 				line[i] = ' ';
 				line[i+1] = ' ';
 				in_comment = false;
 				continue;
 			}
-			if (!in_comment && line.substr(i, 2) == "/*")
+			if (!in_comment && line.compare(i, 2, "/*") == 0)
 				in_comment = true;
 			if (in_comment)
 				line[i] = ' ';
@@ -2808,7 +2808,7 @@ AstNode *AstNode::readmem(bool is_readmemh, std::string mem_filename, AstNode *m
 		while (1)
 		{
 			token = next_token(line, " \t\r\n");
-			if (token.empty() || token.substr(0, 2) == "//")
+			if (token.empty() || token.compare(0, 2, "//") == 0)
 				break;
 
 			if (token[0] == '@') {
@@ -3439,19 +3439,11 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
 {
 	std::map<std::string, AstNode*> backup_scope;
 	std::map<std::string, AstNode::varinfo_t> variables;
-	bool delete_temp_block = false;
-	AstNode *block = NULL;
+	AstNode *block = new AstNode(AST_BLOCK);
 
 	size_t argidx = 0;
 	for (auto child : children)
 	{
-		if (child->type == AST_BLOCK)
-		{
-			log_assert(block == NULL);
-			block = child;
-			continue;
-		}
-
 		if (child->type == AST_WIRE)
 		{
 			while (child->simplify(true, false, false, 1, -1, false, true)) { }
@@ -3468,13 +3460,9 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
 			continue;
 		}
 
-		log_assert(block == NULL);
-		delete_temp_block = true;
-		block = new AstNode(AST_BLOCK);
 		block->children.push_back(child->clone());
 	}
 
-	log_assert(block != NULL);
 	log_assert(variables.count(str) != 0);
 
 	while (!block->children.empty())
@@ -3642,8 +3630,7 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
 		log_abort();
 	}
 
-	if (delete_temp_block)
-		delete block;
+	delete block;
 
 	for (auto &it : backup_scope)
 		if (it.second == NULL)