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-rw-r--r--README4
-rw-r--r--frontends/ast/ast.cc1
-rw-r--r--frontends/ast/ast.h1
-rw-r--r--frontends/ast/genrtlil.cc8
-rw-r--r--frontends/ast/simplify.cc12
-rw-r--r--frontends/verilog/parser.y22
6 files changed, 48 insertions, 0 deletions
diff --git a/README b/README
index f0c9bc74..ee5eb797 100644
--- a/README
+++ b/README
@@ -275,6 +275,10 @@ Verilog Attributes and non-standard features
always block: "assert(<expression>);". It is transformed to a $assert cell
that is supported by the "sat" and "write_btor" commands.
+- Sized constants (the syntax <size>'s?[bodh]<value>) support constant
+ expressions as <size>. If the expresion is not a simple identifier, it
+ must be put in parentheses. Examples: WIDTH'd42, (4+2)'b101010
+
Workarounds for known build problems
====================================
diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 40f7826f..96608ae3 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -82,6 +82,7 @@ std::string AST::type2str(AstNodeType type)
X(AST_PREFIX)
X(AST_ASSERT)
X(AST_FCALL)
+ X(AST_TO_BITS)
X(AST_TO_SIGNED)
X(AST_TO_UNSIGNED)
X(AST_CONCAT)
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index caae679a..01702c3c 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -61,6 +61,7 @@ namespace AST
AST_ASSERT,
AST_FCALL,
+ AST_TO_BITS,
AST_TO_SIGNED,
AST_TO_UNSIGNED,
AST_CONCAT,
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index 6001e278..99d8566d 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -664,6 +664,14 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint)
sign_hint = false;
break;
+ case AST_TO_BITS:
+ while (children[0]->simplify(true, false, false, 1, -1, false) == true) { }
+ if (children[0]->type != AST_CONSTANT)
+ log_error("Left operand of tobits expression is not constant at %s:%d!\n", filename.c_str(), linenum);
+ children[1]->detectSignWidthWorker(sub_width_hint, sign_hint);
+ width_hint = std::max(width_hint, children[0]->bitsAsConst().as_int());
+ break;
+
case AST_TO_SIGNED:
children.at(0)->detectSignWidthWorker(width_hint, sub_sign_hint);
break;
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 5a2d1ae6..f19befe2 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -258,6 +258,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
}
break;
+ case AST_TO_BITS:
case AST_TO_SIGNED:
case AST_TO_UNSIGNED:
case AST_CONCAT:
@@ -442,6 +443,17 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
goto apply_newNode;
}
+ // evaluate TO_BITS nodes
+ if (type == AST_TO_BITS) {
+ if (children[0]->type != AST_CONSTANT)
+ log_error("Left operand of to_bits expression is not constant at %s:%d!\n", filename.c_str(), linenum);
+ if (children[1]->type != AST_CONSTANT)
+ log_error("Right operand of to_bits expression is not constant at %s:%d!\n", filename.c_str(), linenum);
+ RTLIL::Const new_value = children[1]->bitsAsConst(children[0]->bitsAsConst().as_int(), children[1]->is_signed);
+ newNode = mkconst_bits(new_value.bits, children[1]->is_signed);
+ goto apply_newNode;
+ }
+
// annotate constant ranges
if (type == AST_RANGE) {
bool old_range_valid = range_valid;
diff --git a/frontends/verilog/parser.y b/frontends/verilog/parser.y
index b0c4db8a..5b6bf58c 100644
--- a/frontends/verilog/parser.y
+++ b/frontends/verilog/parser.y
@@ -1051,6 +1051,28 @@ basic_expr:
rvalue {
$$ = $1;
} |
+ '(' expr ')' TOK_CONST {
+ if ($4->substr(0, 1) != "'")
+ frontend_verilog_yyerror("Syntax error.");
+ AstNode *bits = $2;
+ AstNode *val = const2ast(*$4, case_type_stack.size() == 0 ? 0 : case_type_stack.back());
+ if (val == NULL)
+ log_error("Value conversion failed: `%s'\n", $4->c_str());
+ $$ = new AstNode(AST_TO_BITS, bits, val);
+ delete $4;
+ } |
+ hierarchical_id TOK_CONST {
+ if ($2->substr(0, 1) != "'")
+ frontend_verilog_yyerror("Syntax error.");
+ AstNode *bits = new AstNode(AST_IDENTIFIER);
+ bits->str = *$1;
+ AstNode *val = const2ast(*$2, case_type_stack.size() == 0 ? 0 : case_type_stack.back());
+ if (val == NULL)
+ log_error("Value conversion failed: `%s'\n", $2->c_str());
+ $$ = new AstNode(AST_TO_BITS, bits, val);
+ delete $1;
+ delete $2;
+ } |
TOK_CONST {
$$ = const2ast(*$1, case_type_stack.size() == 0 ? 0 : case_type_stack.back());
if ($$ == NULL)