From 3121d19d95ae916b96baa000197f3ec2aa5c5ad7 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Fri, 14 Feb 2014 11:28:42 +0100
Subject: [PATCH] Added abc -keepff option
---
passes/abc/abc.cc | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/passes/abc/abc.cc b/passes/abc/abc.cc
index 4add6452d..bd0d983ac 100644
--- a/passes/abc/abc.cc
+++ b/passes/abc/abc.cc
@@ -109,7 +109,7 @@ static void mark_port(RTLIL::SigSpec sig)
}
}
-static void extract_cell(RTLIL::Cell *cell)
+static void extract_cell(RTLIL::Cell *cell, bool keepff)
{
if (cell->type == "$_DFF_N_" || cell->type == "$_DFF_P_")
{
@@ -121,6 +121,11 @@ static void extract_cell(RTLIL::Cell *cell)
RTLIL::SigSpec sig_d = cell->connections["\\D"];
RTLIL::SigSpec sig_q = cell->connections["\\Q"];
+ if (keepff)
+ for (auto &c : sig_q.chunks)
+ if (c.wire != NULL)
+ c.wire->attributes["\\keep"] = 1;
+
assign_map.apply(sig_d);
assign_map.apply(sig_q);
@@ -403,7 +408,7 @@ static std::string fold_abc_cmd(std::string str)
}
static void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::string script_file, std::string exe_file,
- std::string liberty_file, std::string constr_file, bool cleanup, int lut_mode, bool dff_mode, std::string clk_str)
+ std::string liberty_file, std::string constr_file, bool cleanup, int lut_mode, bool dff_mode, std::string clk_str, bool keepff)
{
module = current_module;
map_autoidx = RTLIL::autoidx++;
@@ -498,7 +503,7 @@ static void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std
if (design->selected(current_module, it.second))
cells.push_back(it.second);
for (auto c : cells)
- extract_cell(c);
+ extract_cell(c, keepff);
for (auto &wire_it : module->wires) {
if (wire_it.second->port_id > 0 || wire_it.second->get_bool_attribute("\\keep"))
@@ -940,6 +945,10 @@ struct AbcPass : public Pass {
log(" with -dff, then it falls back to the automatic dection of clock domain\n");
log(" if the specified clock is not found in a module.)\n");
log("\n");
+ log(" -keepff\n");
+ log(" set the \"keep\" attribute on flip-flop output wires. (and thus preserve\n");
+ log(" them, for example for equivialence checking.)\n");
+ log("\n");
log(" -nocleanup\n");
log(" when this option is used, the temporary files created by this pass\n");
log(" are not removed. this is useful for debugging.\n");
@@ -960,7 +969,7 @@ struct AbcPass : public Pass {
std::string exe_file = rewrite_yosys_exe("yosys-abc");
std::string script_file, liberty_file, constr_file, clk_str;
- bool dff_mode = false, cleanup = true;
+ bool dff_mode = false, keepff = false, cleanup = true;
int lut_mode = 0;
size_t argidx;
@@ -1001,6 +1010,10 @@ struct AbcPass : public Pass {
clk_str = args[++argidx];
continue;
}
+ if (arg == "-keepff") {
+ keepff = true;
+ continue;
+ }
if (arg == "-nocleanup") {
cleanup = false;
continue;
@@ -1020,7 +1033,7 @@ struct AbcPass : public Pass {
if (mod_it.second->processes.size() > 0)
log("Skipping module %s as it contains processes.\n", mod_it.second->name.c_str());
else
- abc_module(design, mod_it.second, script_file, exe_file, liberty_file, constr_file, cleanup, lut_mode, dff_mode, clk_str);
+ abc_module(design, mod_it.second, script_file, exe_file, liberty_file, constr_file, cleanup, lut_mode, dff_mode, clk_str, keepff);
}
assign_map.clear();