Bugfix in recursive AST simplification

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 55ed28b0122e51f05a893dc931311306a0cafc71..72d90e4aef9dd796a2831dd998022ca4a9018eb6 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -219,7 +219,8 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
                for (size_t i = 0; i < children.size(); i++) {
                        AstNode *node = children[i];
                        if (node->type == AST_PARAMETER || node->type == AST_LOCALPARAM || node->type == AST_WIRE || node->type == AST_AUTOWIRE)
-                               while (node->simplify(true, false, false, 1, -1, false, node->type == AST_PARAMETER || node->type == AST_LOCALPARAM)) { }
+                               while (node->simplify(true, false, false, 1, -1, false, node->type == AST_PARAMETER || node->type == AST_LOCALPARAM))
+                                       did_something = true;
                }
        }
 
@@ -241,8 +242,10 @@ 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[1]->basic_prep && children[1]->simplify(false, false, false, stage, -1, false, false) == true) { }
+               while (!children[0]->basic_prep && children[0]->simplify(false, false, true, stage, -1, false, false) == true)
+                       did_something = true;
+               while (!children[1]->basic_prep && children[1]->simplify(false, false, false, stage, -1, false, false) == true)
+                       did_something = true;
                children[0]->detectSignWidth(backup_width_hint, backup_sign_hint);
                children[1]->detectSignWidth(width_hint, sign_hint);
                width_hint = std::max(width_hint, backup_width_hint);
@@ -251,11 +254,13 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 
        case AST_PARAMETER:
        case AST_LOCALPARAM:
-               while (!children[0]->basic_prep && children[0]->simplify(false, false, false, stage, -1, false, true) == true) { }
+               while (!children[0]->basic_prep && children[0]->simplify(false, false, false, stage, -1, false, true) == true)
+                       did_something = true;
                children[0]->detectSignWidth(width_hint, sign_hint);
                if (children.size() > 1) {
                        assert(children[1]->type == AST_RANGE);
-                       while (!children[1]->basic_prep && children[1]->simplify(false, false, false, stage, -1, false, true) == true) { }
+                       while (!children[1]->basic_prep && children[1]->simplify(false, false, false, stage, -1, false, true) == true)
+                               did_something = true;
                        if (!children[1]->range_valid)
                                log_error("Non-constant width range on parameter decl at %s:%d.\n", filename.c_str(), linenum);
                        width_hint = std::max(width_hint, children[1]->range_left - children[1]->range_right + 1);
@@ -311,7 +316,8 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
                width_hint = -1;
                sign_hint = true;
                for (auto child : children) {
-                       while (!child->basic_prep && child->simplify(false, false, in_lvalue, stage, -1, false, in_param) == true) { }
+                       while (!child->basic_prep && child->simplify(false, false, in_lvalue, stage, -1, false, in_param) == true)
+                               did_something = true;
                        child->detectSignWidthWorker(width_hint, sign_hint);
                }
                reset_width_after_children = true;
@@ -341,9 +347,11 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 
        if (detect_width_simple && width_hint < 0) {
                for (auto child : children)
-                       while (!child->basic_prep && child->simplify(false, false, in_lvalue, stage, -1, false, in_param) == true) { }
+                       while (!child->basic_prep && child->simplify(false, false, in_lvalue, stage, -1, false, in_param) == true)
+                               did_something = true;
                if (type == AST_REPLICATE)
-                       while (children[0]->simplify(true, false, in_lvalue, stage, -1, false, in_param) == true) { }
+                       while (children[0]->simplify(true, false, in_lvalue, stage, -1, false, in_param) == true)
+                               did_something = true;
                detectSignWidth(width_hint, sign_hint);
        }
 
@@ -389,7 +397,8 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
                }
        }
        for (auto &attr : attributes) {
-               while (attr.second->simplify(true, false, false, stage, -1, false, true)) { }
+               while (attr.second->simplify(true, false, false, stage, -1, false, true))
+                       did_something = true;
        }
 
        if (reset_width_after_children) {
@@ -539,7 +548,10 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
                        current_scope[str] = auto_wire;
                        did_something = true;
                }
-               id2ast = current_scope[str];
+               if (id2ast != current_scope[str]) {
+                       id2ast = current_scope[str];
+                       did_something = true;
+               }
        }
 
        // split memory access with bit select to individual statements