From 09471846c553855c43224ce32d855c46f4df5140 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Thu, 21 Nov 2013 13:49:00 +0100
Subject: Major improvements in mem2reg and added "init" sync rules

---
 passes/proc/proc_init.cc | 114 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 passes/proc/proc_init.cc

(limited to 'passes/proc/proc_init.cc')

diff --git a/passes/proc/proc_init.cc b/passes/proc/proc_init.cc
new file mode 100644
index 00000000..fca20fda
--- /dev/null
+++ b/passes/proc/proc_init.cc
@@ -0,0 +1,114 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *  
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *  
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "kernel/register.h"
+#include "kernel/sigtools.h"
+#include "kernel/log.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+static void proc_get_const(RTLIL::SigSpec &sig, RTLIL::CaseRule &rule)
+{
+	assert(rule.compare.size() == 0);
+
+	while (1) {
+		sig.optimize();
+		RTLIL::SigSpec tmp = sig;
+		for (auto &it : rule.actions)
+			tmp.replace(it.first, it.second);
+		if (tmp == sig)
+			break;
+		sig = tmp;
+	}
+}
+
+static void proc_init(RTLIL::Module *mod, RTLIL::Process *proc)
+{
+	bool found_init = false;
+
+	for (auto &sync : proc->syncs)
+		if (sync->type == RTLIL::SyncType::STi)
+		{
+			found_init = true;
+			log("Found init rule in `%s.%s'.\n", mod->name.c_str(), proc->name.c_str());
+
+			for (auto &action : sync->actions)
+			{
+				RTLIL::SigSpec lhs = action.first;
+				RTLIL::SigSpec rhs = action.second;
+
+				lhs.optimize();
+				proc_get_const(rhs, proc->root_case);
+
+				if (!rhs.is_fully_const())
+					log_cmd_error("Failed to get a constant init value for %s: %s\n", log_signal(lhs), log_signal(rhs));
+
+				int offset = 0;
+				for (size_t i = 0; i < lhs.chunks.size(); i++) {
+					if (lhs.chunks[i].wire == NULL)
+						continue;
+					RTLIL::Wire *wire = lhs.chunks[i].wire;
+					RTLIL::SigSpec value = rhs.extract(offset, lhs.chunks[i].width);
+					if (value.width != wire->width)
+						log_cmd_error("Init value is not for the entire wire: %s = %s\n", log_signal(lhs.chunks[i]), log_signal(value));
+					log("  Setting init value: %s = %s\n", log_signal(wire), log_signal(value));
+					wire->attributes["\\init"] = value.as_const();
+					offset += wire->width;
+				}
+			}
+		}
+
+	if (found_init) {
+		std::vector<RTLIL::SyncRule*> new_syncs;
+		for (auto &sync : proc->syncs)
+			if (sync->type == RTLIL::SyncType::STi)
+				delete sync;
+			else
+				new_syncs.push_back(sync);
+		proc->syncs.swap(new_syncs);
+	}
+}
+
+struct ProcInitPass : public Pass {
+	ProcInitPass() : Pass("proc_init", "convert initial block to init attributes") { }
+	virtual void help()
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    proc_init [selection]\n");
+		log("\n");
+		log("This pass extracts the 'init' actions from processes (generated from verilog\n");
+		log("'initial' blocks) and sets the initial value to the 'init' attribute on the\n");
+		log("respective wire.\n");
+		log("\n");
+	}
+	virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+	{
+		log_header("Executing PROC_INIT pass (extract init attributes).\n");
+
+		extra_args(args, 1, design);
+
+		for (auto &mod_it : design->modules)
+			if (design->selected(mod_it.second))
+				for (auto &proc_it : mod_it.second->processes)
+					if (design->selected(mod_it.second, proc_it.second))
+						proc_init(mod_it.second, proc_it.second);
+	}
+} ProcInitPass;
+ 
-- 
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