From 3c220e0b3271af2505f45c9828d878a492831174 Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Wed, 4 Dec 2013 21:19:54 +0100 Subject: [PATCH] Added support for $clog2 system function --- frontends/ast/simplify.cc | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc index ae2f0caae..94b588f25 100644 --- a/frontends/ast/simplify.cc +++ b/frontends/ast/simplify.cc @@ -1052,11 +1052,27 @@ skip_dynamic_range_lvalue_expansion:; // replace function and task calls with the code from the function or task if ((type == AST_FCALL || type == AST_TCALL) && !str.empty()) { - if (type == AST_FCALL) { - if (current_scope.count(str) == 0 || current_scope[str]->type != AST_FUNCTION) { - current_ast_mod->dumpAst(stderr, "> "); - log_error("Can't resolve function name `%s' at %s:%d.\n", str.c_str(), filename.c_str(), linenum); + if (type == AST_FCALL) + { + if (str == "\\$clog2") + { + AstNode *buf = children[0]->clone(); + while (buf->simplify(true, false, false, stage, width_hint, sign_hint)) { } + if (!buf->type == AST_CONSTANT) + log_error("Failed to evaluate system function `%s' with non-constant value at %s:%d.\n", str.c_str(), filename.c_str(), linenum); + + RTLIL::Const arg_value = buf->bitsAsConst(); + uint32_t result = 0; + for (size_t i = 0; i < arg_value.bits.size(); i++) + if (arg_value.bits.at(i) == RTLIL::State::S1) + result = i; + + newNode = mkconst_int(result, false); + goto apply_newNode; } + + if (current_scope.count(str) == 0 || current_scope[str]->type != AST_FUNCTION) + log_error("Can't resolve function name `%s' at %s:%d.\n", str.c_str(), filename.c_str(), linenum); } if (type == AST_TCALL) { if (current_scope.count(str) == 0 || current_scope[str]->type != AST_TASK) -- 2.30.2