1 files changed, 15 insertions, 3 deletions

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index c56ac7d5f..e00087280 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -540,6 +540,18 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 		}
 	}
 
+	if (type == AST_CONDX && children.size() > 0 && children.at(0)->type == AST_CONSTANT) {
+		for (auto &bit : children.at(0)->bits)
+			if (bit == State::Sz || bit == State::Sx)
+				bit = State::Sa;
+	}
+
+	if (type == AST_CONDZ && children.size() > 0 && children.at(0)->type == AST_CONSTANT) {
+		for (auto &bit : children.at(0)->bits)
+			if (bit == State::Sz)
+				bit = State::Sa;
+	}
+
 	if (const_fold && type == AST_CASE)
 	{
 		while (children[0]->simplify(const_fold, at_zero, in_lvalue, stage, width_hint, sign_hint, in_param)) { }
@@ -548,7 +560,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			new_children.push_back(children[0]);
 			for (int i = 1; i < GetSize(children); i++) {
 				AstNode *child = children[i];
-				log_assert(child->type == AST_COND);
+				log_assert(child->type == AST_COND || child->type == AST_CONDX || child->type == AST_CONDZ);
 				for (auto v : child->children) {
 					if (v->type == AST_DEFAULT)
 						goto keep_const_cond;
@@ -1125,7 +1137,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 		AstNode *selected_case = NULL;
 		for (size_t i = 1; i < children.size(); i++)
 		{
-			log_assert(children.at(i)->type == AST_COND);
+			log_assert(children.at(i)->type == AST_COND || children.at(i)->type == AST_CONDX || children.at(i)->type == AST_CONDZ);
 
 			AstNode *this_genblock = NULL;
 			for (auto child : children.at(i)->children) {
@@ -2984,7 +2996,7 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
 			for (size_t i = 1; i < stmt->children.size(); i++)
 			{
 				bool found_match = false;
-				log_assert(stmt->children.at(i)->type == AST_COND);
+				log_assert(stmt->children.at(i)->type == AST_COND || stmt->children.at(i)->type == AST_CONDX || stmt->children.at(i)->type == AST_CONDZ);
 
 				if (stmt->children.at(i)->children.front()->type == AST_DEFAULT) {
 					sel_case = stmt->children.at(i)->children.back();