verilog: instead of modifying localparam size, extend init constant expr

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 8855d9954bcf20a97bd69cc8ee0ebbf08884ee6e..36ae831b8cd78930c9031f556ffc76504a5cba23 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1200,17 +1200,23 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
                if (varbuf->type != AST_CONSTANT)
                        log_file_error(filename, linenum, "Right hand side of 1st expression of generate for-loop is not constant!\n");
 
-               varbuf = new AstNode(AST_LOCALPARAM, varbuf);
-               varbuf->str = init_ast->children[0]->str;
-
                auto resolved = current_scope.at(init_ast->children[0]->str);
                if (resolved->range_valid) {
-                       varbuf->range_left = resolved->range_left;
-                       varbuf->range_right = resolved->range_right;
-                       varbuf->range_swapped = resolved->range_swapped;
-                       varbuf->range_valid = resolved->range_valid;
+                       int const_size = varbuf->range_left - varbuf->range_right;
+                       int resolved_size = resolved->range_left - resolved->range_right;
+                       if (const_size < resolved_size) {
+                               for (int i = const_size; i < resolved_size; i++)
+                                       varbuf->bits.push_back(resolved->is_signed ? varbuf->bits.back() : State::S0);
+                               varbuf->range_left = resolved->range_left;
+                               varbuf->range_right = resolved->range_right;
+                               varbuf->range_swapped = resolved->range_swapped;
+                               varbuf->range_valid = resolved->range_valid;
+                       }
                }
 
+               varbuf = new AstNode(AST_LOCALPARAM, varbuf);
+               varbuf->str = init_ast->children[0]->str;
+
                AstNode *backup_scope_varbuf = current_scope[varbuf->str];
                current_scope[varbuf->str] = varbuf;
 
@@ -3022,14 +3028,6 @@ void AstNode::expand_genblock(std::string index_var, std::string prefix, std::ma
                        current_ast_mod->children.push_back(p);
                        str = p->str;
                        id2ast = p;
-
-                       auto resolved = current_scope.at(index_var);
-                       if (resolved->range_valid) {
-                               p->range_left = resolved->range_left;
-                               p->range_right = resolved->range_right;
-                               p->range_swapped = resolved->range_swapped;
-                               p->range_valid = resolved->range_valid;
-                       }
                }
        }