improved ast simplify of const functions

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index a20aacff53d4af4e2db219761c10996149ecdabc..5f40b60a88d93c8d14ccd1992dbfd67800d05e34 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -140,7 +140,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
        if (type == AST_FUNCTION || type == AST_TASK)
                return false;
 
-       // deactivate all calls non-synthesis system taks
+       // deactivate all calls to non-synthesis system taks
        if ((type == AST_FCALL || type == AST_TCALL) && (str == "$display" || str == "$stop" || str == "$finish")) {
                delete_children();
                str = std::string();
@@ -245,9 +245,9 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
        case AST_ASSIGN_EQ:
        case AST_ASSIGN_LE:
        case AST_ASSIGN:
-               while (!children[0]->basic_prep && children[0]->simplify(false, false, true, stage, -1, false, false) == true)
+               while (!children[0]->basic_prep && children[0]->simplify(false, false, true, stage, -1, false, in_param) == true)
                        did_something = true;
-               while (!children[1]->basic_prep && children[1]->simplify(false, false, false, stage, -1, false, false) == true)
+               while (!children[1]->basic_prep && children[1]->simplify(false, false, false, stage, -1, false, in_param) == true)
                        did_something = true;
                children[0]->detectSignWidth(backup_width_hint, backup_sign_hint);
                children[1]->detectSignWidth(width_hint, sign_hint);
@@ -1825,12 +1825,16 @@ void AstNode::replace_variables(std::map<std::string, AstNode::varinfo_t> &varia
        if (type == AST_IDENTIFIER && variables.count(str)) {
                int offset = variables.at(str).offset, width = variables.at(str).val.bits.size();
                if (!children.empty()) {
+                       if (children.size() != 1 || children.at(0)->type != AST_RANGE)
+                               log_error("Memory access in constant function is not supported in %s:%d (called from %s:%d).\n",
+                                               filename.c_str(), linenum, fcall->filename.c_str(), fcall->linenum);
+                       children.at(0)->replace_variables(variables, fcall);
                        while (simplify(true, false, false, 1, -1, false, true)) { }
-                       if (!range_valid)
+                       if (!children.at(0)->range_valid)
                                log_error("Non-constant range in %s:%d (called from %s:%d).\n",
                                                filename.c_str(), linenum, fcall->filename.c_str(), fcall->linenum);
-                       offset = std::min(range_left, range_right);
-                       width = std::min(std::abs(range_left - range_right) + 1, width);
+                       offset = std::min(children.at(0)->range_left, children.at(0)->range_right);
+                       width = std::min(std::abs(children.at(0)->range_left - children.at(0)->range_right) + 1, width);
                }
                offset -= variables.at(str).offset;
                std::vector<RTLIL::State> &var_bits = variables.at(str).val.bits;
@@ -1850,6 +1854,7 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
 {
        std::map<std::string, AstNode*> backup_scope;
        std::map<std::string, AstNode::varinfo_t> variables;
+       bool delete_temp_block = false;
        AstNode *block = NULL;
 
        size_t argidx = 0;
@@ -1878,6 +1883,16 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
                        continue;
                }
 
+               if (child->type == AST_ASSIGN_EQ)
+               {
+                       log_assert(block == NULL);
+                       delete_temp_block = true;
+                       block = new AstNode(AST_BLOCK);
+                       block->children.push_back(child->clone());
+                       continue;
+               }
+
+               child->dumpAst(NULL, "unexpected> ");
                log_abort();
        }
 
@@ -1900,8 +1915,11 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
                        stmt->children.at(1)->replace_variables(variables, fcall);
                        while (stmt->simplify(true, false, false, 1, -1, false, true)) { }
 
+                       if (stmt->type != AST_ASSIGN_EQ)
+                               continue;
+
                        if (stmt->children.at(1)->type != AST_CONSTANT)
-                               log_error("Non-constant expression in constant function at %s:%d (called from %s:%d).\n",
+                               log_error("Non-constant expression in constant function at %s:%d (called from %s:%d). X\n",
                                                stmt->filename.c_str(), stmt->linenum, fcall->filename.c_str(), fcall->linenum);
 
                        if (stmt->children.at(0)->type != AST_IDENTIFIER || !stmt->children.at(0)->children.empty())
@@ -2011,6 +2029,9 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
                log_abort();
        }
 
+       if (delete_temp_block)
+               delete block;
+
        for (auto &it : backup_scope)
                if (it.second == NULL)
                        current_scope.erase(it.first);