From 8206546c45d8fe74ac291a548fa372d1bd98f966 Mon Sep 17 00:00:00 2001
From: Zachary Snow <zach@zachjs.com>
Date: Sat, 5 Dec 2020 18:56:18 -0700
Subject: Fix constants bound to single bit arguments (fixes #2383)
---
frontends/ast/simplify.cc | 8 ++++++++
tests/various/const_arg_loop.v | 10 ++++++++++
2 files changed, 18 insertions(+)
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index fb6623f02..8cd459913 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -3337,6 +3337,14 @@ skip_dynamic_range_lvalue_expansion:;
wire->type = AST_LOCALPARAM;
wire->attributes.erase(ID::nosync);
wire->children.insert(wire->children.begin(), arg->clone());
+ // args without a range implicitly have width 1
+ if (wire->children.back()->type != AST_RANGE) {
+ AstNode* range = new AstNode();
+ range->type = AST_RANGE;
+ wire->children.push_back(range);
+ range->children.push_back(mkconst_int(0, true));
+ range->children.push_back(mkconst_int(0, true));
+ }
continue;
}
AstNode *wire_id = new AstNode(AST_IDENTIFIER);
diff --git a/tests/various/const_arg_loop.v b/tests/various/const_arg_loop.v
index 3bfff4acd..567bccc25 100644
--- a/tests/various/const_arg_loop.v
+++ b/tests/various/const_arg_loop.v
@@ -39,6 +39,12 @@ module top;
end
endfunction
+ function automatic [16:0] operation4;
+ input [15:0] a;
+ input b;
+ operation4 = {a, b};
+ endfunction
+
wire [31:0] a;
assign a = 2;
@@ -53,6 +59,9 @@ module top;
wire [31:0] x3;
assign x3 = operation3(A, a);
+ wire [16:0] x4;
+ assign x4 = operation4(a[15:0], 0);
+
// `define VERIFY
`ifdef VERIFY
assert property (a == 2);
@@ -60,5 +69,6 @@ module top;
assert property (x1 == 16);
assert property (x2 == 4);
assert property (x3 == 16);
+ assert property (x4 == a << 1);
`endif
endmodule
--
cgit v1.2.3