Improved support for constant functions

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 2ae3cae0843133d6c0ae6df1b997ac560255fe4f..5e37911d3e0de1a3ee1daf06239a26c60e050545 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1167,9 +1167,11 @@ skip_dynamic_range_lvalue_expansion:;
                if (in_param)
                {
                        bool all_args_const = true;
-                       for (auto child : children)
+                       for (auto child : children) {
+                               while (child->simplify(true, false, false, 1, -1, false, true)) { }
                                if (child->type != AST_CONSTANT)
                                        all_args_const = false;
+                       }
 
                        if (all_args_const) {
                                AstNode *func_workspace = current_scope[str]->clone();
@@ -1931,6 +1933,53 @@ AstNode *AstNode::eval_const_function(AstNode *fcall)
                        continue;
                }
 
+               if (stmt->type == AST_CASE)
+               {
+                       AstNode *expr = stmt->children.at(0)->clone();
+                       expr->replace_variables(variables, fcall);
+                       while (expr->simplify(true, false, false, 1, -1, false, true)) { }
+
+                       AstNode *sel_case = NULL;
+                       for (size_t i = 1; i < stmt->children.size(); i++)
+                       {
+                               bool found_match = false;
+                               log_assert(stmt->children.at(i)->type == AST_COND);
+
+                               if (stmt->children.at(i)->children.front()->type == AST_DEFAULT) {
+                                       sel_case = stmt->children.at(i)->children.back();
+                                       continue;
+                               }
+
+                               for (size_t j = 0; j+1 < stmt->children.at(i)->children.size() && !found_match; j++)
+                               {
+                                       AstNode *cond = stmt->children.at(i)->children.at(j)->clone();
+                                       cond->replace_variables(variables, fcall);
+
+                                       cond = new AstNode(AST_EQ, expr->clone(), cond);
+                                       while (cond->simplify(true, false, false, 1, -1, false, true)) { }
+
+                                       if (cond->type != AST_CONSTANT)
+                                               log_error("Non-constant expression in constant function at %s:%d (called from %s:%d).\n",
+                                                               stmt->filename.c_str(), stmt->linenum, fcall->filename.c_str(), fcall->linenum);
+
+                                       found_match = cond->asBool();
+                                       delete cond;
+                               }
+
+                               if (found_match) {
+                                       sel_case = stmt->children.at(i)->children.back();
+                                       break;
+                               }
+                       }
+
+                       block->children.erase(block->children.begin());
+                       if (sel_case)
+                               block->children.insert(block->children.begin(), sel_case->clone());
+                       delete stmt;
+                       delete expr;
+                       continue;
+               }
+
                if (stmt->type == AST_BLOCK)
                {
                        block->children.erase(block->children.begin());