1 files changed, 143 insertions, 0 deletions
diff --git a/kernel/bitpattern.h b/kernel/bitpattern.h
new file mode 100644
index 000000000..aaefa50fc
--- /dev/null
+++ b/kernel/bitpattern.h
@@ -0,0 +1,143 @@
+/*
+ *  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.
+ *
+ */
+
+#ifndef BITPATTERN_H
+#define BITPATTERN_H
+
+#include "kernel/log.h"
+#include "kernel/rtlil.h"
+
+struct BitPatternPool
+{
+	int width;
+	typedef std::vector<RTLIL::State> bits_t;
+	std::set<bits_t> pool;
+
+	BitPatternPool(RTLIL::SigSpec sig)
+	{
+		width = sig.width;
+		if (width > 0) {
+			std::vector<RTLIL::State> pattern(width);
+			sig.optimize();
+			for (int i = 0; i < width; i++) {
+				RTLIL::SigSpec s = sig.extract(i, 1);
+				s.optimize();
+				assert(s.chunks.size() == 1);
+				if (s.chunks[0].wire == NULL && s.chunks[0].data.bits[0] <= RTLIL::State::S1)
+					pattern[i] = s.chunks[0].data.bits[0];
+				else
+					pattern[i] = RTLIL::State::Sa;
+			}
+			pool.insert(pattern);
+		}
+	}
+
+	BitPatternPool(int width)
+	{
+		this->width = width;
+		if (width > 0) {
+			std::vector<RTLIL::State> pattern(width);
+			for (int i = 0; i < width; i++)
+				pattern[i] = RTLIL::State::Sa;
+			pool.insert(pattern);
+		}
+	}
+
+	bits_t sig2bits(RTLIL::SigSpec sig)
+	{
+		sig.optimize();
+		assert(sig.is_fully_const());
+		assert(sig.chunks.size() == 1);
+		bits_t bits = sig.chunks[0].data.bits;
+		for (auto &b : bits)
+			if (b > RTLIL::State::S1)
+				b = RTLIL::State::Sa;
+		return bits;
+	}
+
+	bool match(bits_t a, bits_t b)
+	{
+		assert(int(a.size()) == width);
+		assert(int(b.size()) == width);
+		for (int i = 0; i < width; i++)
+			if (a[i] <= RTLIL::State::S1 && b[i] <= RTLIL::State::S1 && a[i] != b[i])
+				return false;
+		return true;
+	}
+
+	bool has_any(RTLIL::SigSpec sig)
+	{
+		bits_t bits = sig2bits(sig);
+		for (auto &it : pool)
+			if (match(it, bits))
+				return true;
+		return false;
+	}
+
+	bool has_all(RTLIL::SigSpec sig)
+	{
+		bits_t bits = sig2bits(sig);
+		for (auto &it : pool)
+			if (match(it, bits)) {
+				for (int i = 0; i < width; i++)
+					if (bits[i] > RTLIL::State::S1 && it[i] <= RTLIL::State::S1)
+						goto next_pool_entry;
+				return true;
+	next_pool_entry:;
+			}
+		return false;
+	}
+
+	bool take(RTLIL::SigSpec sig)
+	{
+		bool status = false;
+		bits_t bits = sig2bits(sig);
+		std::vector<bits_t> pattern_list;
+		for (auto &it : pool)
+			if (match(it, bits))
+				pattern_list.push_back(it);
+		for (auto pattern : pattern_list) {
+			pool.erase(pattern);
+			for (int i = 0; i < width; i++) {
+				if (pattern[i] != RTLIL::State::Sa || bits[i] == RTLIL::State::Sa)
+					continue;
+				bits_t new_pattern = pattern;
+				new_pattern[i] = bits[i] == RTLIL::State::S1 ? RTLIL::State::S0 : RTLIL::State::S1;
+				pool.insert(new_pattern);
+			}
+			status = true;
+		}
+		return status;
+	}
+
+	bool take_all()
+	{
+		if (pool.empty())
+			return false;
+		pool.clear();
+		return true;
+	}
+
+	bool empty()
+	{
+		return pool.empty();
+	}
+}; 
+
+#endif