From 161565be104fd0c7b7c4224bd23e9502625e041a Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Sun, 31 Mar 2013 11:19:11 +0200
Subject: [PATCH] Added AST_INITIAL (before verilog "initial" was mapped to
 AST_ALWAYS)

---
 frontends/ast/ast.cc       | 9 +++++++++
 frontends/ast/ast.h        | 1 +
 frontends/ast/genrtlil.cc  | 4 +++-
 frontends/ast/simplify.cc  | 2 +-
 frontends/verilog/parser.y | 2 +-
 5 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 091b196ef..391e0a444 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -122,6 +122,7 @@ std::string AST::type2str(AstNodeType type)
 	X(AST_CELL)
 	X(AST_PRIMITIVE)
 	X(AST_ALWAYS)
+	X(AST_INITIAL)
 	X(AST_BLOCK)
 	X(AST_ASSIGN_EQ)
 	X(AST_ASSIGN_LE)
@@ -417,6 +418,14 @@ void AstNode::dumpVlog(FILE *f, std::string indent)
 		}
 		break;
 
+	case AST_INITIAL:
+		fprintf(f, "%s" "initial\n", indent.c_str());
+		for (auto child : children) {
+			if (child->type != AST_POSEDGE && child->type != AST_NEGEDGE && child->type != AST_EDGE)
+				child->dumpVlog(f, indent + "  ");
+		}
+		break;
+
 	case AST_POSEDGE:
 	case AST_NEGEDGE:
 	case AST_EDGE:
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index 05b9a95cf..918f12c1a 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -103,6 +103,7 @@ namespace AST
 		AST_CELL,
 		AST_PRIMITIVE,
 		AST_ALWAYS,
+		AST_INITIAL,
 		AST_BLOCK,
 		AST_ASSIGN_EQ,
 		AST_ASSIGN_LE,
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index 47ca37bd0..2f5370fe8 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -310,6 +310,7 @@ struct AST_INTERNAL::ProcessGenerator
 
 		case AST_COND:
 		case AST_ALWAYS:
+		case AST_INITIAL:
 			for (auto child : ast->children)
 				if (child->type == AST_BLOCK)
 					collect_lvalues(reg, child, type_eq, type_le, false);
@@ -1013,7 +1014,8 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint)
 		break;
 
 	// use ProcessGenerator for always blocks
-	case AST_ALWAYS: {
+	case AST_ALWAYS:
+	case AST_INITIAL: {
 			AstNode *always = this->clone();
 			ProcessGenerator generator(always);
 			delete always;
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index a03cd0bed..fbbe66ed3 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -196,7 +196,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage)
 				current_block = this;
 				current_block_child = children[i];
 			}
-			if (type == AST_ALWAYS && children[i]->type == AST_BLOCK)
+			if ((type == AST_ALWAYS || type == AST_INITIAL) && children[i]->type == AST_BLOCK)
 				current_top_block = children[i];
 			did_something_here = children[i]->simplify(const_fold_here, at_zero, in_lvalue_here, stage);
 			if (did_something_here)
diff --git a/frontends/verilog/parser.y b/frontends/verilog/parser.y
index 9caa236f8..22af178e8 100644
--- a/frontends/verilog/parser.y
+++ b/frontends/verilog/parser.y
@@ -607,7 +607,7 @@ always_stmt:
 		ast_stack.pop_back();
 	} |
 	attr TOK_INITIAL {
-		AstNode *node = new AstNode(AST_ALWAYS);
+		AstNode *node = new AstNode(AST_INITIAL);
 		append_attr(node, $1);
 		ast_stack.back()->children.push_back(node);
 		ast_stack.push_back(node);
-- 
2.30.2