diff options
Diffstat (limited to 'frontends/ast/genrtlil.cc')
| -rw-r--r-- | frontends/ast/genrtlil.cc | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc index ed709aa33..4c25287ad 100644 --- a/frontends/ast/genrtlil.cc +++ b/frontends/ast/genrtlil.cc @@ -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; @@ -1087,6 +1088,11 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun } break; } + if (str == "\\$size" || str == "\\$bits" || str == "\\$high" || str == "\\$low" || str == "\\$left" || str == "\\$right") { + width_hint = 32; + sign_hint = true; + break; + } if (current_scope.count(str)) { // This width detection is needed for function calls which are @@ -1525,13 +1531,20 @@ 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; } |