diff options
Diffstat (limited to 'frontends/ast/genrtlil.cc')
| -rw-r--r-- | frontends/ast/genrtlil.cc | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc index ed709aa33..d81c53dfb 100644 --- a/frontends/ast/genrtlil.cc +++ b/frontends/ast/genrtlil.cc @@ -877,7 +877,7 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun this_width = id_ast->children[0]->range_left - id_ast->children[0]->range_right + 1; if (children.size() > 1) range = children[1]; - } else if (id_ast->type == AST_STRUCT_ITEM) { + } else if (id_ast->type == AST_STRUCT_ITEM || id_ast->type == AST_STRUCT) { AstNode *tmp_range = make_struct_member_range(this, id_ast); this_width = tmp_range->range_left - tmp_range->range_right + 1; delete tmp_range; @@ -932,7 +932,8 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun if (children.at(0)->type != AST_CONSTANT) log_file_error(filename, location.first_line, "Static cast with non constant expression!\n"); children.at(1)->detectSignWidthWorker(width_hint, sign_hint); - width_hint = children.at(0)->bitsAsConst().as_int(); + this_width = children.at(0)->bitsAsConst().as_int(); + width_hint = max(width_hint, this_width); if (width_hint <= 0) log_file_error(filename, location.first_line, "Static cast with zero or negative size!\n"); break; @@ -1083,15 +1084,20 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun sub_sign_hint = true; children.at(0)->detectSignWidthWorker(sub_width_hint, sub_sign_hint); width_hint = max(width_hint, sub_width_hint); - sign_hint = false; + sign_hint &= sub_sign_hint; } break; } + if (str == "\\$size" || str == "\\$bits" || str == "\\$high" || str == "\\$low" || str == "\\$left" || str == "\\$right") { + width_hint = max(width_hint, 32); + break; + } if (current_scope.count(str)) { // This width detection is needed for function calls which are - // unelaborated, which currently only applies to calls to recursive - // functions reached by unevaluated ternary branches. + // unelaborated, which currently applies to calls to functions + // reached via unevaluated ternary branches or used in case or case + // item expressions. const AstNode *func = current_scope.at(str); if (func->type != AST_FUNCTION) log_file_error(filename, location.first_line, "Function call to %s resolved to something that isn't a function!\n", RTLIL::unescape_id(str).c_str()); @@ -1102,8 +1108,8 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun break; } log_assert(wire && wire->type == AST_WIRE); - sign_hint = wire->is_signed; - width_hint = 1; + sign_hint &= wire->is_signed; + int result_width = 1; if (!wire->children.empty()) { log_assert(wire->children.size() == 1); @@ -1116,10 +1122,11 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun if (left->type != AST_CONSTANT || right->type != AST_CONSTANT) log_file_error(filename, location.first_line, "Function %s has non-constant width!", RTLIL::unescape_id(str).c_str()); - width_hint = abs(int(left->asInt(true) - right->asInt(true))); + result_width = abs(int(left->asInt(true) - right->asInt(true))); delete left; delete right; } + width_hint = max(width_hint, result_width); break; } YS_FALLTHROUGH @@ -1525,13 +1532,20 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint) // changing the size of signal can be done directly using RTLIL::SigSpec case AST_CAST_SIZE: { RTLIL::SigSpec size = children[0]->genRTLIL(); - RTLIL::SigSpec sig = children[1]->genRTLIL(); if (!size.is_fully_const()) log_file_error(filename, location.first_line, "Static cast with non constant expression!\n"); int width = size.as_int(); if (width <= 0) log_file_error(filename, location.first_line, "Static cast with zero or negative size!\n"); - sig.extend_u0(width, sign_hint); + // determine the *signedness* of the expression + int sub_width_hint = -1; + bool sub_sign_hint = true; + children[1]->detectSignWidth(sub_width_hint, sub_sign_hint); + // generate the signal given the *cast's* size and the + // *expression's* signedness + RTLIL::SigSpec sig = children[1]->genWidthRTLIL(width, sub_sign_hint); + // context may effect this node's signedness, but not that of the + // casted expression is_signed = sign_hint; return sig; } |