From 8c509a5659d540dc41f6cc19ee6989fc249f519d Mon Sep 17 00:00:00 2001 From: Zachary Snow Date: Thu, 30 Dec 2021 00:01:30 -0700 Subject: [PATCH] sv: fix size cast clipping expression width --- CHANGELOG | 2 ++ frontends/ast/genrtlil.cc | 3 ++- tests/simple/lesser_size_cast.sv | 7 +++++++ 3 files changed, 11 insertions(+), 1 deletion(-) create mode 100644 tests/simple/lesser_size_cast.sv diff --git a/CHANGELOG b/CHANGELOG index ab1632a09..9402f9bbb 100644 --- a/CHANGELOG +++ b/CHANGELOG @@ -16,6 +16,8 @@ Yosys 0.11 .. Yosys 0.12 - Support parameters using struct as a wiretype - Fixed regression preventing the use array querying functions in case expressions and case item expressions + - Fixed static size casts inadvertently limiting the result width of binary + operations * New commands and options - Added "-genlib" option to "abc" pass diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc index 1fe74bb72..2788a850f 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; diff --git a/tests/simple/lesser_size_cast.sv b/tests/simple/lesser_size_cast.sv new file mode 100644 index 000000000..8c0bc9814 --- /dev/null +++ b/tests/simple/lesser_size_cast.sv @@ -0,0 +1,7 @@ +module top ( + input signed [1:0] a, + input signed [2:0] b, + output signed [4:0] c +); + assign c = 2'(a) * b; +endmodule -- 2.30.2