1 /*
2  *  yosys -- Yosys Open SYnthesis Suite
3  *
4  *  Copyright (C) 2012  Claire Xenia Wolf <claire@yosyshq.com>
5  *
6  *  Permission to use, copy, modify, and/or distribute this software for any
7  *  purpose with or without fee is hereby granted, provided that the above
8  *  copyright notice and this permission notice appear in all copies.
9  *
10  *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  *
18  */
19 
20 #ifndef MACC_H
21 #define MACC_H
22 
23 #include "kernel/yosys.h"
24 
25 YOSYS_NAMESPACE_BEGIN
26 
27 struct Macc
28 {
29 	struct port_t {
30 		RTLIL::SigSpec in_a, in_b;
31 		bool is_signed, do_subtract;
32 	};
33 
34 	std::vector<port_t> ports;
35 	RTLIL::SigSpec bit_ports;
36 
optimizeMacc37 	void optimize(int width)
38 	{
39 		std::vector<port_t> new_ports;
40 		RTLIL::SigSpec new_bit_ports;
41 		RTLIL::Const off(0, width);
42 
43 		for (auto &port : ports)
44 		{
45 			if (GetSize(port.in_a) == 0 && GetSize(port.in_b) == 0)
46 				continue;
47 
48 			if (GetSize(port.in_a) < GetSize(port.in_b))
49 				std::swap(port.in_a, port.in_b);
50 
51 			if (GetSize(port.in_a) == 1 && GetSize(port.in_b) == 0 && !port.is_signed && !port.do_subtract) {
52 				bit_ports.append(port.in_a);
53 				continue;
54 			}
55 
56 			if (port.in_a.is_fully_const() && port.in_b.is_fully_const()) {
57 				RTLIL::Const v = port.in_a.as_const();
58 				if (GetSize(port.in_b))
59 					v = const_mul(v, port.in_b.as_const(), port.is_signed, port.is_signed, width);
60 				if (port.do_subtract)
61 					off = const_sub(off, v, port.is_signed, port.is_signed, width);
62 				else
63 					off = const_add(off, v, port.is_signed, port.is_signed, width);
64 				continue;
65 			}
66 
67 			if (port.is_signed) {
68 				while (GetSize(port.in_a) > 1 && port.in_a[GetSize(port.in_a)-1] == port.in_a[GetSize(port.in_a)-2])
69 					port.in_a.remove(GetSize(port.in_a)-1);
70 				while (GetSize(port.in_b) > 1 && port.in_b[GetSize(port.in_b)-1] == port.in_b[GetSize(port.in_b)-2])
71 					port.in_b.remove(GetSize(port.in_b)-1);
72 			} else {
73 				while (GetSize(port.in_a) > 1 && port.in_a[GetSize(port.in_a)-1] == State::S0)
74 					port.in_a.remove(GetSize(port.in_a)-1);
75 				while (GetSize(port.in_b) > 1 && port.in_b[GetSize(port.in_b)-1] == State::S0)
76 					port.in_b.remove(GetSize(port.in_b)-1);
77 			}
78 
79 			new_ports.push_back(port);
80 		}
81 
82 		for (auto &bit : bit_ports)
83 			if (bit == State::S1)
84 				off = const_add(off, RTLIL::Const(1, width), false, false, width);
85 			else if (bit != State::S0)
86 				new_bit_ports.append(bit);
87 
88 		if (off.as_bool()) {
89 			port_t port;
90 			port.in_a = off;
91 			port.is_signed = false;
92 			port.do_subtract = false;
93 			new_ports.push_back(port);
94 		}
95 
96 		new_ports.swap(ports);
97 		bit_ports = new_bit_ports;
98 	}
99 
from_cellMacc100 	void from_cell(RTLIL::Cell *cell)
101 	{
102 		RTLIL::SigSpec port_a = cell->getPort(ID::A);
103 
104 		ports.clear();
105 		bit_ports = cell->getPort(ID::B);
106 
107 		std::vector<RTLIL::State> config_bits = cell->getParam(ID::CONFIG).bits;
108 		int config_cursor = 0;
109 
110 		int config_width = cell->getParam(ID::CONFIG_WIDTH).as_int();
111 		log_assert(GetSize(config_bits) >= config_width);
112 
113 		int num_bits = 0;
114 		if (config_bits[config_cursor++] == State::S1) num_bits |= 1;
115 		if (config_bits[config_cursor++] == State::S1) num_bits |= 2;
116 		if (config_bits[config_cursor++] == State::S1) num_bits |= 4;
117 		if (config_bits[config_cursor++] == State::S1) num_bits |= 8;
118 
119 		int port_a_cursor = 0;
120 		while (port_a_cursor < GetSize(port_a))
121 		{
122 			log_assert(config_cursor + 2 + 2*num_bits <= config_width);
123 
124 			port_t this_port;
125 			this_port.is_signed = config_bits[config_cursor++] == State::S1;
126 			this_port.do_subtract = config_bits[config_cursor++] == State::S1;
127 
128 			int size_a = 0;
129 			for (int i = 0; i < num_bits; i++)
130 				if (config_bits[config_cursor++] == State::S1)
131 					size_a |= 1 << i;
132 
133 			this_port.in_a = port_a.extract(port_a_cursor, size_a);
134 			port_a_cursor += size_a;
135 
136 			int size_b = 0;
137 			for (int i = 0; i < num_bits; i++)
138 				if (config_bits[config_cursor++] == State::S1)
139 					size_b |= 1 << i;
140 
141 			this_port.in_b = port_a.extract(port_a_cursor, size_b);
142 			port_a_cursor += size_b;
143 
144 			if (size_a || size_b)
145 				ports.push_back(this_port);
146 		}
147 
148 		log_assert(config_cursor == config_width);
149 		log_assert(port_a_cursor == GetSize(port_a));
150 	}
151 
to_cellMacc152 	void to_cell(RTLIL::Cell *cell) const
153 	{
154 		RTLIL::SigSpec port_a;
155 		std::vector<RTLIL::State> config_bits;
156 		int max_size = 0, num_bits = 0;
157 
158 		for (auto &port : ports) {
159 			max_size = max(max_size, GetSize(port.in_a));
160 			max_size = max(max_size, GetSize(port.in_b));
161 		}
162 
163 		while (max_size)
164 			num_bits++, max_size /= 2;
165 
166 		log_assert(num_bits < 16);
167 		config_bits.push_back(num_bits & 1 ? State::S1 : State::S0);
168 		config_bits.push_back(num_bits & 2 ? State::S1 : State::S0);
169 		config_bits.push_back(num_bits & 4 ? State::S1 : State::S0);
170 		config_bits.push_back(num_bits & 8 ? State::S1 : State::S0);
171 
172 		for (auto &port : ports)
173 		{
174 			if (GetSize(port.in_a) == 0)
175 				continue;
176 
177 			config_bits.push_back(port.is_signed ? State::S1 : State::S0);
178 			config_bits.push_back(port.do_subtract ? State::S1 : State::S0);
179 
180 			int size_a = GetSize(port.in_a);
181 			for (int i = 0; i < num_bits; i++)
182 				config_bits.push_back(size_a & (1 << i) ? State::S1 : State::S0);
183 
184 			int size_b = GetSize(port.in_b);
185 			for (int i = 0; i < num_bits; i++)
186 				config_bits.push_back(size_b & (1 << i) ? State::S1 : State::S0);
187 
188 			port_a.append(port.in_a);
189 			port_a.append(port.in_b);
190 		}
191 
192 		cell->setPort(ID::A, port_a);
193 		cell->setPort(ID::B, bit_ports);
194 		cell->setParam(ID::CONFIG, config_bits);
195 		cell->setParam(ID::CONFIG_WIDTH, GetSize(config_bits));
196 		cell->setParam(ID::A_WIDTH, GetSize(port_a));
197 		cell->setParam(ID::B_WIDTH, GetSize(bit_ports));
198 	}
199 
evalMacc200 	bool eval(RTLIL::Const &result) const
201 	{
202 		for (auto &bit : result.bits)
203 			bit = State::S0;
204 
205 		for (auto &port : ports)
206 		{
207 			if (!port.in_a.is_fully_const() || !port.in_b.is_fully_const())
208 				return false;
209 
210 			RTLIL::Const summand;
211 			if (GetSize(port.in_b) == 0)
212 				summand = const_pos(port.in_a.as_const(), port.in_b.as_const(), port.is_signed, port.is_signed, GetSize(result));
213 			else
214 				summand = const_mul(port.in_a.as_const(), port.in_b.as_const(), port.is_signed, port.is_signed, GetSize(result));
215 
216 			if (port.do_subtract)
217 				result = const_sub(result, summand, port.is_signed, port.is_signed, GetSize(result));
218 			else
219 				result = const_add(result, summand, port.is_signed, port.is_signed, GetSize(result));
220 		}
221 
222 		for (auto bit : bit_ports) {
223 			if (bit.wire)
224 				return false;
225 			result = const_add(result, bit.data, false, false, GetSize(result));
226 		}
227 
228 		return true;
229 	}
230 
231 	Macc(RTLIL::Cell *cell = nullptr)
232 	{
233 		if (cell != nullptr)
234 			from_cell(cell);
235 	}
236 };
237 
238 YOSYS_NAMESPACE_END
239 
240 #endif
241