Avoid creation of bogus initial blocks for assert/assume in always @*

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index fea7c1814b109e031502ceec8439cd745197506f..fd27240090bd448a72c06903359cc69b11a16ca3 100644 (file)
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -52,6 +52,7 @@ namespace AST_INTERNAL {
        RTLIL::SigSpec ignoreThisSignalsInInitial;
        AstNode *current_always, *current_top_block, *current_block, *current_block_child;
        AstModule *current_module;
+       bool current_always_clocked;
 }
 
 // convert node types to string

diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index c9fe58a3d8565b40fe9e21edef941aee98b0d106..cd6e264e67b82c4cfafc59a8c3778494f20c3fd9 100644 (file)
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -310,6 +310,7 @@ namespace AST_INTERNAL
        extern RTLIL::SigSpec ignoreThisSignalsInInitial;
        extern AST::AstNode *current_always, *current_top_block, *current_block, *current_block_child;
        extern AST::AstModule *current_module;
+       extern bool current_always_clocked;
        struct ProcessGenerator;
 }
 

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index aa2afa4ce9ac5477ce082e7308e9aeeea5e054fc..8387c11c6711ae106b486a46acf3c525ab1567e7 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -397,9 +397,18 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
        auto backup_current_block_child = current_block_child;
        auto backup_current_top_block = current_top_block;
        auto backup_current_always = current_always;
+       auto backup_current_always_clocked = current_always_clocked;
 
        if (type == AST_ALWAYS || type == AST_INITIAL)
+       {
                current_always = this;
+               current_always_clocked = false;
+
+               if (type == AST_ALWAYS)
+                       for (auto child : children)
+                               if (child->type == AST_POSEDGE || child->type == AST_NEGEDGE)
+                                       current_always_clocked = true;
+       }
 
        int backup_width_hint = width_hint;
        bool backup_sign_hint = sign_hint;
@@ -652,6 +661,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
        current_block_child = backup_current_block_child;
        current_top_block = backup_current_top_block;
        current_always = backup_current_always;
+       current_always_clocked = backup_current_always_clocked;
 
        for (auto it = backup_scope.begin(); it != backup_scope.end(); it++) {
                if (it->second == NULL)
@@ -1367,7 +1377,7 @@ skip_dynamic_range_lvalue_expansion:;
                AstNode *wire_en = new AstNode(AST_WIRE);
                wire_en->str = id_en;
                current_ast_mod->children.push_back(wire_en);
-               if (current_always == nullptr || current_always->type != AST_INITIAL) {
+               if (current_always_clocked) {
                        current_ast_mod->children.push_back(new AstNode(AST_INITIAL, new AstNode(AST_BLOCK, new AstNode(AST_ASSIGN_LE, new AstNode(AST_IDENTIFIER), AstNode::mkconst_int(0, false, 1)))));
                        current_ast_mod->children.back()->children[0]->children[0]->children[0]->str = id_en;
                }