yosys/kernel/mem.cc

1355 lines
46 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2020 Marcelina Kościelnicka <mwk@0x04.net>
*
* 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/mem.h"
#include "kernel/ff.h"
USING_YOSYS_NAMESPACE
void Mem::remove() {
if (cell) {
module->remove(cell);
cell = nullptr;
}
if (mem) {
module->memories.erase(mem->name);
delete mem;
mem = nullptr;
}
for (auto &port : rd_ports) {
if (port.cell) {
module->remove(port.cell);
port.cell = nullptr;
}
}
for (auto &port : wr_ports) {
if (port.cell) {
module->remove(port.cell);
port.cell = nullptr;
}
}
for (auto &init : inits) {
if (init.cell) {
module->remove(init.cell);
init.cell = nullptr;
}
}
}
void Mem::emit() {
check();
std::vector<int> rd_left;
for (int i = 0; i < GetSize(rd_ports); i++) {
auto &port = rd_ports[i];
if (port.removed) {
if (port.cell) {
module->remove(port.cell);
}
} else {
rd_left.push_back(i);
}
}
std::vector<int> wr_left;
for (int i = 0; i < GetSize(wr_ports); i++) {
auto &port = wr_ports[i];
if (port.removed) {
if (port.cell) {
module->remove(port.cell);
}
} else {
wr_left.push_back(i);
}
}
std::vector<int> init_left;
for (int i = 0; i < GetSize(inits); i++) {
auto &init = inits[i];
if (init.removed) {
if (init.cell) {
module->remove(init.cell);
}
} else {
init_left.push_back(i);
}
}
for (int i = 0; i < GetSize(rd_left); i++)
if (i != rd_left[i])
std::swap(rd_ports[i], rd_ports[rd_left[i]]);
rd_ports.resize(GetSize(rd_left));
for (int i = 0; i < GetSize(wr_left); i++)
if (i != wr_left[i])
std::swap(wr_ports[i], wr_ports[wr_left[i]]);
wr_ports.resize(GetSize(wr_left));
for (int i = 0; i < GetSize(init_left); i++)
if (i != init_left[i])
std::swap(inits[i], inits[init_left[i]]);
inits.resize(GetSize(init_left));
for (auto &port : rd_ports) {
for (int i = 0; i < GetSize(wr_left); i++) {
port.transparency_mask[i] = port.transparency_mask[wr_left[i]];
port.collision_x_mask[i] = port.collision_x_mask[wr_left[i]];
}
port.transparency_mask.resize(GetSize(wr_left));
port.collision_x_mask.resize(GetSize(wr_left));
}
for (auto &port : wr_ports) {
for (int i = 0; i < GetSize(wr_left); i++)
port.priority_mask[i] = port.priority_mask[wr_left[i]];
port.priority_mask.resize(GetSize(wr_left));
}
if (packed) {
if (mem) {
module->memories.erase(mem->name);
delete mem;
mem = nullptr;
}
if (!cell) {
if (memid.empty())
memid = NEW_ID;
cell = module->addCell(memid, ID($mem_v2));
}
cell->type = ID($mem_v2);
cell->attributes = attributes;
cell->parameters[ID::MEMID] = Const(memid.str());
cell->parameters[ID::WIDTH] = Const(width);
cell->parameters[ID::OFFSET] = Const(start_offset);
cell->parameters[ID::SIZE] = Const(size);
Const rd_wide_continuation, rd_clk_enable, rd_clk_polarity, rd_transparency_mask, rd_collision_x_mask;
Const wr_wide_continuation, wr_clk_enable, wr_clk_polarity, wr_priority_mask;
Const rd_ce_over_srst, rd_arst_value, rd_srst_value, rd_init_value;
SigSpec rd_clk, rd_en, rd_addr, rd_data;
SigSpec wr_clk, wr_en, wr_addr, wr_data;
SigSpec rd_arst, rd_srst;
int abits = 0;
for (auto &port : rd_ports)
abits = std::max(abits, GetSize(port.addr));
for (auto &port : wr_ports)
abits = std::max(abits, GetSize(port.addr));
cell->parameters[ID::ABITS] = Const(abits);
std::vector<int> wr_port_xlat;
for (int i = 0; i < GetSize(wr_ports); i++)
for (int j = 0; j < (1 << wr_ports[i].wide_log2); j++)
wr_port_xlat.push_back(i);
for (auto &port : rd_ports) {
if (port.cell) {
module->remove(port.cell);
port.cell = nullptr;
}
for (int sub = 0; sub < (1 << port.wide_log2); sub++)
{
rd_wide_continuation.bits.push_back(State(sub != 0));
rd_clk_enable.bits.push_back(State(port.clk_enable));
rd_clk_polarity.bits.push_back(State(port.clk_polarity));
rd_ce_over_srst.bits.push_back(State(port.ce_over_srst));
rd_clk.append(port.clk);
rd_arst.append(port.arst);
rd_srst.append(port.srst);
rd_en.append(port.en);
SigSpec addr = port.sub_addr(sub);
addr.extend_u0(abits, false);
rd_addr.append(addr);
log_assert(GetSize(addr) == abits);
for (auto idx : wr_port_xlat) {
rd_transparency_mask.bits.push_back(State(bool(port.transparency_mask[idx])));
rd_collision_x_mask.bits.push_back(State(bool(port.collision_x_mask[idx])));
}
}
rd_data.append(port.data);
for (auto &bit : port.arst_value)
rd_arst_value.bits.push_back(bit);
for (auto &bit : port.srst_value)
rd_srst_value.bits.push_back(bit);
for (auto &bit : port.init_value)
rd_init_value.bits.push_back(bit);
}
if (rd_ports.empty()) {
rd_wide_continuation = State::S0;
rd_clk_enable = State::S0;
rd_clk_polarity = State::S0;
rd_ce_over_srst = State::S0;
rd_arst_value = State::S0;
rd_srst_value = State::S0;
rd_init_value = State::S0;
}
if (rd_ports.empty() || wr_ports.empty()) {
rd_transparency_mask = State::S0;
rd_collision_x_mask = State::S0;
}
cell->parameters[ID::RD_PORTS] = Const(GetSize(rd_clk));
cell->parameters[ID::RD_CLK_ENABLE] = rd_clk_enable;
cell->parameters[ID::RD_CLK_POLARITY] = rd_clk_polarity;
cell->parameters[ID::RD_TRANSPARENCY_MASK] = rd_transparency_mask;
cell->parameters[ID::RD_COLLISION_X_MASK] = rd_collision_x_mask;
cell->parameters[ID::RD_WIDE_CONTINUATION] = rd_wide_continuation;
cell->parameters[ID::RD_CE_OVER_SRST] = rd_ce_over_srst;
cell->parameters[ID::RD_ARST_VALUE] = rd_arst_value;
cell->parameters[ID::RD_SRST_VALUE] = rd_srst_value;
cell->parameters[ID::RD_INIT_VALUE] = rd_init_value;
cell->parameters.erase(ID::RD_TRANSPARENT);
cell->setPort(ID::RD_CLK, rd_clk);
cell->setPort(ID::RD_EN, rd_en);
cell->setPort(ID::RD_ARST, rd_arst);
cell->setPort(ID::RD_SRST, rd_srst);
cell->setPort(ID::RD_ADDR, rd_addr);
cell->setPort(ID::RD_DATA, rd_data);
for (auto &port : wr_ports) {
if (port.cell) {
module->remove(port.cell);
port.cell = nullptr;
}
for (int sub = 0; sub < (1 << port.wide_log2); sub++)
{
wr_wide_continuation.bits.push_back(State(sub != 0));
wr_clk_enable.bits.push_back(State(port.clk_enable));
wr_clk_polarity.bits.push_back(State(port.clk_polarity));
wr_clk.append(port.clk);
for (auto idx : wr_port_xlat)
wr_priority_mask.bits.push_back(State(bool(port.priority_mask[idx])));
SigSpec addr = port.sub_addr(sub);
addr.extend_u0(abits, false);
wr_addr.append(addr);
log_assert(GetSize(addr) == abits);
}
wr_en.append(port.en);
wr_data.append(port.data);
}
if (wr_ports.empty()) {
wr_wide_continuation = State::S0;
wr_clk_enable = State::S0;
wr_clk_polarity = State::S0;
wr_priority_mask = State::S0;
}
cell->parameters[ID::WR_PORTS] = Const(GetSize(wr_clk));
cell->parameters[ID::WR_CLK_ENABLE] = wr_clk_enable;
cell->parameters[ID::WR_CLK_POLARITY] = wr_clk_polarity;
cell->parameters[ID::WR_PRIORITY_MASK] = wr_priority_mask;
cell->parameters[ID::WR_WIDE_CONTINUATION] = wr_wide_continuation;
cell->setPort(ID::WR_CLK, wr_clk);
cell->setPort(ID::WR_EN, wr_en);
cell->setPort(ID::WR_ADDR, wr_addr);
cell->setPort(ID::WR_DATA, wr_data);
for (auto &init : inits) {
if (init.cell) {
module->remove(init.cell);
init.cell = nullptr;
}
}
cell->parameters[ID::INIT] = get_init_data();
} else {
if (cell) {
module->remove(cell);
cell = nullptr;
}
if (!mem) {
if (memid.empty())
memid = NEW_ID;
mem = new RTLIL::Memory;
mem->name = memid;
module->memories[memid] = mem;
}
mem->width = width;
mem->start_offset = start_offset;
mem->size = size;
mem->attributes = attributes;
for (auto &port : rd_ports) {
if (!port.cell)
port.cell = module->addCell(NEW_ID, ID($memrd_v2));
port.cell->type = ID($memrd_v2);
port.cell->attributes = port.attributes;
port.cell->parameters[ID::MEMID] = memid.str();
port.cell->parameters[ID::ABITS] = GetSize(port.addr);
port.cell->parameters[ID::WIDTH] = width << port.wide_log2;
port.cell->parameters[ID::CLK_ENABLE] = port.clk_enable;
port.cell->parameters[ID::CLK_POLARITY] = port.clk_polarity;
port.cell->parameters[ID::CE_OVER_SRST] = port.ce_over_srst;
port.cell->parameters[ID::ARST_VALUE] = port.arst_value;
port.cell->parameters[ID::SRST_VALUE] = port.srst_value;
port.cell->parameters[ID::INIT_VALUE] = port.init_value;
port.cell->parameters[ID::TRANSPARENCY_MASK] = port.transparency_mask;
port.cell->parameters[ID::COLLISION_X_MASK] = port.collision_x_mask;
port.cell->parameters.erase(ID::TRANSPARENT);
port.cell->setPort(ID::CLK, port.clk);
port.cell->setPort(ID::EN, port.en);
port.cell->setPort(ID::ARST, port.arst);
port.cell->setPort(ID::SRST, port.srst);
port.cell->setPort(ID::ADDR, port.addr);
port.cell->setPort(ID::DATA, port.data);
}
int idx = 0;
for (auto &port : wr_ports) {
if (!port.cell)
port.cell = module->addCell(NEW_ID, ID($memwr_v2));
port.cell->type = ID($memwr_v2);
port.cell->attributes = port.attributes;
if (port.cell->parameters.count(ID::PRIORITY))
port.cell->parameters.erase(ID::PRIORITY);
port.cell->parameters[ID::MEMID] = memid.str();
port.cell->parameters[ID::ABITS] = GetSize(port.addr);
port.cell->parameters[ID::WIDTH] = width << port.wide_log2;
port.cell->parameters[ID::CLK_ENABLE] = port.clk_enable;
port.cell->parameters[ID::CLK_POLARITY] = port.clk_polarity;
port.cell->parameters[ID::PORTID] = idx++;
port.cell->parameters[ID::PRIORITY_MASK] = port.priority_mask;
port.cell->setPort(ID::CLK, port.clk);
port.cell->setPort(ID::EN, port.en);
port.cell->setPort(ID::ADDR, port.addr);
port.cell->setPort(ID::DATA, port.data);
}
idx = 0;
for (auto &init : inits) {
bool v2 = !init.en.is_fully_ones();
if (!init.cell)
init.cell = module->addCell(NEW_ID, v2 ? ID($meminit_v2) : ID($meminit));
else
init.cell->type = v2 ? ID($meminit_v2) : ID($meminit);
init.cell->attributes = init.attributes;
init.cell->parameters[ID::MEMID] = memid.str();
init.cell->parameters[ID::ABITS] = GetSize(init.addr);
init.cell->parameters[ID::WIDTH] = width;
init.cell->parameters[ID::WORDS] = GetSize(init.data) / width;
init.cell->parameters[ID::PRIORITY] = idx++;
init.cell->setPort(ID::ADDR, init.addr);
init.cell->setPort(ID::DATA, init.data);
if (v2)
init.cell->setPort(ID::EN, init.en);
else
init.cell->unsetPort(ID::EN);
}
}
}
void Mem::clear_inits() {
for (auto &init : inits)
init.removed = true;
}
void Mem::coalesce_inits() {
// start address -> end address
std::map<int, int> chunks;
// Figure out chunk boundaries.
for (auto &init : inits) {
if (init.removed)
continue;
bool valid = false;
for (auto bit : init.en)
if (bit == State::S1)
valid = true;
if (!valid) {
init.removed = true;
continue;
}
int addr = init.addr.as_int();
int addr_e = addr + GetSize(init.data) / width;
auto it_e = chunks.upper_bound(addr_e);
auto it = it_e;
while (it != chunks.begin()) {
--it;
if (it->second < addr) {
++it;
break;
}
}
if (it == it_e) {
// No overlapping inits — add this one to index.
chunks[addr] = addr_e;
} else {
// We have an overlap — all chunks in the [it, it_e)
// range will be merged with this init.
if (it->first < addr)
addr = it->first;
auto it_last = it_e;
it_last--;
if (it_last->second > addr_e)
addr_e = it_last->second;
chunks.erase(it, it_e);
chunks[addr] = addr_e;
}
}
// Group inits by the chunk they belong to.
dict<int, std::vector<int>> inits_by_chunk;
for (int i = 0; i < GetSize(inits); i++) {
auto &init = inits[i];
if (init.removed)
continue;
auto it = chunks.upper_bound(init.addr.as_int());
--it;
inits_by_chunk[it->first].push_back(i);
int addr = init.addr.as_int();
int addr_e = addr + GetSize(init.data) / width;
log_assert(addr >= it->first && addr_e <= it->second);
}
// Process each chunk.
for (auto &it : inits_by_chunk) {
int caddr = it.first;
int caddr_e = chunks[caddr];
auto &chunk_inits = it.second;
if (GetSize(chunk_inits) == 1) {
auto &init = inits[chunk_inits[0]];
if (!init.en.is_fully_ones()) {
for (int i = 0; i < GetSize(init.data); i++)
if (init.en[i % width] != State::S1)
init.data[i] = State::Sx;
init.en = Const(State::S1, width);
}
continue;
}
Const cdata(State::Sx, (caddr_e - caddr) * width);
for (int idx : chunk_inits) {
auto &init = inits[idx];
int offset = (init.addr.as_int() - caddr) * width;
log_assert(offset >= 0);
log_assert(offset + GetSize(init.data) <= GetSize(cdata));
for (int i = 0; i < GetSize(init.data); i++)
if (init.en[i % width] == State::S1)
cdata.bits[i+offset] = init.data.bits[i];
init.removed = true;
}
MemInit new_init;
new_init.addr = caddr;
new_init.data = cdata;
new_init.en = Const(State::S1, width);
inits.push_back(new_init);
}
}
Const Mem::get_init_data() const {
Const init_data(State::Sx, width * size);
for (auto &init : inits) {
if (init.removed)
continue;
int offset = (init.addr.as_int() - start_offset) * width;
for (int i = 0; i < GetSize(init.data); i++)
if (0 <= i+offset && i+offset < GetSize(init_data) && init.en[i % width] == State::S1)
init_data.bits[i+offset] = init.data.bits[i];
}
return init_data;
}
void Mem::check() {
int max_wide_log2 = 0;
for (auto &port : rd_ports) {
if (port.removed)
continue;
log_assert(GetSize(port.clk) == 1);
log_assert(GetSize(port.en) == 1);
log_assert(GetSize(port.arst) == 1);
log_assert(GetSize(port.srst) == 1);
log_assert(GetSize(port.data) == (width << port.wide_log2));
log_assert(GetSize(port.init_value) == (width << port.wide_log2));
log_assert(GetSize(port.arst_value) == (width << port.wide_log2));
log_assert(GetSize(port.srst_value) == (width << port.wide_log2));
if (!port.clk_enable) {
log_assert(port.en == State::S1);
log_assert(port.arst == State::S0);
log_assert(port.srst == State::S0);
}
for (int j = 0; j < port.wide_log2; j++) {
log_assert(port.addr[j] == State::S0);
}
max_wide_log2 = std::max(max_wide_log2, port.wide_log2);
log_assert(GetSize(port.transparency_mask) == GetSize(wr_ports));
log_assert(GetSize(port.collision_x_mask) == GetSize(wr_ports));
for (int j = 0; j < GetSize(wr_ports); j++) {
auto &wport = wr_ports[j];
if ((port.transparency_mask[j] || port.collision_x_mask[j]) && !wport.removed) {
log_assert(port.clk_enable);
log_assert(wport.clk_enable);
log_assert(port.clk == wport.clk);
log_assert(port.clk_polarity == wport.clk_polarity);
}
log_assert(!port.transparency_mask[j] || !port.collision_x_mask[j]);
}
}
for (int i = 0; i < GetSize(wr_ports); i++) {
auto &port = wr_ports[i];
if (port.removed)
continue;
log_assert(GetSize(port.clk) == 1);
log_assert(GetSize(port.en) == (width << port.wide_log2));
log_assert(GetSize(port.data) == (width << port.wide_log2));
for (int j = 0; j < port.wide_log2; j++) {
log_assert(port.addr[j] == State::S0);
}
max_wide_log2 = std::max(max_wide_log2, port.wide_log2);
log_assert(GetSize(port.priority_mask) == GetSize(wr_ports));
for (int j = 0; j < GetSize(wr_ports); j++) {
auto &wport = wr_ports[j];
if (port.priority_mask[j] && !wport.removed) {
log_assert(j < i);
log_assert(port.clk_enable == wport.clk_enable);
if (port.clk_enable) {
log_assert(port.clk == wport.clk);
log_assert(port.clk_polarity == wport.clk_polarity);
}
}
}
}
int mask = (1 << max_wide_log2) - 1;
log_assert(!(start_offset & mask));
log_assert(!(size & mask));
}
namespace {
struct MemIndex {
dict<IdString, pool<Cell *>> rd_ports;
dict<IdString, pool<Cell *>> wr_ports;
dict<IdString, pool<Cell *>> inits;
MemIndex (Module *module) {
for (auto cell: module->cells()) {
if (cell->type.in(ID($memwr), ID($memwr_v2)))
wr_ports[cell->parameters.at(ID::MEMID).decode_string()].insert(cell);
else if (cell->type.in(ID($memrd), ID($memrd_v2)))
rd_ports[cell->parameters.at(ID::MEMID).decode_string()].insert(cell);
else if (cell->type.in(ID($meminit), ID($meminit_v2)))
inits[cell->parameters.at(ID::MEMID).decode_string()].insert(cell);
}
}
};
Mem mem_from_memory(Module *module, RTLIL::Memory *mem, const MemIndex &index) {
Mem res(module, mem->name, mem->width, mem->start_offset, mem->size);
res.packed = false;
res.mem = mem;
res.attributes = mem->attributes;
std::vector<bool> rd_transparent;
std::vector<int> wr_portid;
if (index.rd_ports.count(mem->name)) {
for (auto cell : index.rd_ports.at(mem->name)) {
MemRd mrd;
bool is_compat = cell->type == ID($memrd);
mrd.cell = cell;
mrd.attributes = cell->attributes;
mrd.clk_enable = cell->parameters.at(ID::CLK_ENABLE).as_bool();
mrd.clk_polarity = cell->parameters.at(ID::CLK_POLARITY).as_bool();
mrd.clk = cell->getPort(ID::CLK);
mrd.en = cell->getPort(ID::EN);
mrd.addr = cell->getPort(ID::ADDR);
mrd.data = cell->getPort(ID::DATA);
mrd.wide_log2 = ceil_log2(GetSize(mrd.data) / mem->width);
bool transparent = false;
if (is_compat) {
transparent = cell->parameters.at(ID::TRANSPARENT).as_bool();
mrd.ce_over_srst = false;
mrd.arst_value = Const(State::Sx, mem->width << mrd.wide_log2);
mrd.srst_value = Const(State::Sx, mem->width << mrd.wide_log2);
mrd.init_value = Const(State::Sx, mem->width << mrd.wide_log2);
mrd.srst = State::S0;
mrd.arst = State::S0;
if (!mrd.clk_enable) {
// Fix some patterns that we'll allow for backwards compatibility,
// but don't want to see moving forwards: async transparent
// ports (inherently meaningless) and async ports without
// const 1 tied to EN bit (which may mean a latch in the future).
transparent = false;
if (mrd.en == State::Sx)
mrd.en = State::S1;
}
} else {
mrd.ce_over_srst = cell->parameters.at(ID::CE_OVER_SRST).as_bool();
mrd.arst_value = cell->parameters.at(ID::ARST_VALUE);
mrd.srst_value = cell->parameters.at(ID::SRST_VALUE);
mrd.init_value = cell->parameters.at(ID::INIT_VALUE);
mrd.arst = cell->getPort(ID::ARST);
mrd.srst = cell->getPort(ID::SRST);
}
res.rd_ports.push_back(mrd);
rd_transparent.push_back(transparent);
}
}
if (index.wr_ports.count(mem->name)) {
std::vector<std::pair<int, MemWr>> ports;
for (auto cell : index.wr_ports.at(mem->name)) {
MemWr mwr;
bool is_compat = cell->type == ID($memwr);
mwr.cell = cell;
mwr.attributes = cell->attributes;
mwr.clk_enable = cell->parameters.at(ID::CLK_ENABLE).as_bool();
mwr.clk_polarity = cell->parameters.at(ID::CLK_POLARITY).as_bool();
mwr.clk = cell->getPort(ID::CLK);
mwr.en = cell->getPort(ID::EN);
mwr.addr = cell->getPort(ID::ADDR);
mwr.data = cell->getPort(ID::DATA);
mwr.wide_log2 = ceil_log2(GetSize(mwr.data) / mem->width);
ports.push_back(std::make_pair(cell->parameters.at(is_compat ? ID::PRIORITY : ID::PORTID).as_int(), mwr));
}
std::sort(ports.begin(), ports.end(), [](const std::pair<int, MemWr> &a, const std::pair<int, MemWr> &b) { return a.first < b.first; });
for (auto &it : ports) {
res.wr_ports.push_back(it.second);
wr_portid.push_back(it.first);
}
for (int i = 0; i < GetSize(res.wr_ports); i++) {
auto &port = res.wr_ports[i];
bool is_compat = port.cell->type == ID($memwr);
if (is_compat) {
port.priority_mask.resize(GetSize(res.wr_ports));
for (int j = 0; j < i; j++) {
auto &oport = res.wr_ports[j];
if (port.clk_enable != oport.clk_enable)
continue;
if (port.clk_enable && port.clk != oport.clk)
continue;
if (port.clk_enable && port.clk_polarity != oport.clk_polarity)
continue;
port.priority_mask[j] = true;
}
} else {
Const orig_prio_mask = port.cell->parameters.at(ID::PRIORITY_MASK);
for (int orig_portid : wr_portid) {
bool has_prio = orig_portid < GetSize(orig_prio_mask) && orig_prio_mask[orig_portid] == State::S1;
port.priority_mask.push_back(has_prio);
}
}
}
}
if (index.inits.count(mem->name)) {
std::vector<std::pair<int, MemInit>> inits;
for (auto cell : index.inits.at(mem->name)) {
MemInit init;
init.cell = cell;
init.attributes = cell->attributes;
auto addr = cell->getPort(ID::ADDR);
auto data = cell->getPort(ID::DATA);
if (!addr.is_fully_const())
log_error("Non-constant address %s in memory initialization %s.\n", log_signal(addr), log_id(cell));
if (!data.is_fully_const())
log_error("Non-constant data %s in memory initialization %s.\n", log_signal(data), log_id(cell));
init.addr = addr.as_const();
init.data = data.as_const();
if (cell->type == ID($meminit_v2)) {
auto en = cell->getPort(ID::EN);
if (!en.is_fully_const())
log_error("Non-constant enable %s in memory initialization %s.\n", log_signal(en), log_id(cell));
init.en = en.as_const();
} else {
init.en = RTLIL::Const(State::S1, mem->width);
}
inits.push_back(std::make_pair(cell->parameters.at(ID::PRIORITY).as_int(), init));
}
std::sort(inits.begin(), inits.end(), [](const std::pair<int, MemInit> &a, const std::pair<int, MemInit> &b) { return a.first < b.first; });
for (auto &it : inits)
res.inits.push_back(it.second);
}
for (int i = 0; i < GetSize(res.rd_ports); i++) {
auto &port = res.rd_ports[i];
bool is_compat = port.cell->type == ID($memrd);
if (is_compat) {
port.transparency_mask.resize(GetSize(res.wr_ports));
port.collision_x_mask.resize(GetSize(res.wr_ports));
if (!rd_transparent[i])
continue;
if (!port.clk_enable)
continue;
for (int j = 0; j < GetSize(res.wr_ports); j++) {
auto &wport = res.wr_ports[j];
if (!wport.clk_enable)
continue;
if (port.clk != wport.clk)
continue;
if (port.clk_polarity != wport.clk_polarity)
continue;
port.transparency_mask[j] = true;
}
} else {
Const orig_trans_mask = port.cell->parameters.at(ID::TRANSPARENCY_MASK);
Const orig_cx_mask = port.cell->parameters.at(ID::COLLISION_X_MASK);
for (int orig_portid : wr_portid) {
port.transparency_mask.push_back(orig_portid < GetSize(orig_trans_mask) && orig_trans_mask[orig_portid] == State::S1);
port.collision_x_mask.push_back(orig_portid < GetSize(orig_cx_mask) && orig_cx_mask[orig_portid] == State::S1);
}
}
}
res.check();
return res;
}
Mem mem_from_cell(Cell *cell) {
Mem res(cell->module, cell->parameters.at(ID::MEMID).decode_string(),
cell->parameters.at(ID::WIDTH).as_int(),
cell->parameters.at(ID::OFFSET).as_int(),
cell->parameters.at(ID::SIZE).as_int()
);
bool is_compat = cell->type == ID($mem);
int abits = cell->parameters.at(ID::ABITS).as_int();
res.packed = true;
res.cell = cell;
res.attributes = cell->attributes;
Const &init = cell->parameters.at(ID::INIT);
if (!init.is_fully_undef()) {
int pos = 0;
while (pos < res.size) {
Const word = init.extract(pos * res.width, res.width, State::Sx);
if (word.is_fully_undef()) {
pos++;
} else {
int epos;
for (epos = pos; epos < res.size; epos++) {
Const eword = init.extract(epos * res.width, res.width, State::Sx);
if (eword.is_fully_undef())
break;
}
MemInit minit;
minit.addr = res.start_offset + pos;
minit.data = init.extract(pos * res.width, (epos - pos) * res.width, State::Sx);
minit.en = RTLIL::Const(State::S1, res.width);
res.inits.push_back(minit);
pos = epos;
}
}
}
int n_rd_ports = cell->parameters.at(ID::RD_PORTS).as_int();
int n_wr_ports = cell->parameters.at(ID::WR_PORTS).as_int();
Const rd_wide_continuation = is_compat ? Const(State::S0, n_rd_ports) : cell->parameters.at(ID::RD_WIDE_CONTINUATION);
Const wr_wide_continuation = is_compat ? Const(State::S0, n_wr_ports) : cell->parameters.at(ID::WR_WIDE_CONTINUATION);
for (int i = 0, ni; i < n_rd_ports; i = ni) {
ni = i + 1;
while (ni < n_rd_ports && rd_wide_continuation[ni] == State::S1)
ni++;
MemRd mrd;
mrd.wide_log2 = ceil_log2(ni - i);
log_assert(ni - i == (1 << mrd.wide_log2));
mrd.clk_enable = cell->parameters.at(ID::RD_CLK_ENABLE).extract(i, 1).as_bool();
mrd.clk_polarity = cell->parameters.at(ID::RD_CLK_POLARITY).extract(i, 1).as_bool();
mrd.clk = cell->getPort(ID::RD_CLK).extract(i, 1);
mrd.en = cell->getPort(ID::RD_EN).extract(i, 1);
mrd.addr = cell->getPort(ID::RD_ADDR).extract(i * abits, abits);
mrd.data = cell->getPort(ID::RD_DATA).extract(i * res.width, (ni - i) * res.width);
if (is_compat) {
mrd.ce_over_srst = false;
mrd.arst_value = Const(State::Sx, res.width << mrd.wide_log2);
mrd.srst_value = Const(State::Sx, res.width << mrd.wide_log2);
mrd.init_value = Const(State::Sx, res.width << mrd.wide_log2);
mrd.arst = State::S0;
mrd.srst = State::S0;
} else {
mrd.ce_over_srst = cell->parameters.at(ID::RD_CE_OVER_SRST).extract(i, 1).as_bool();
mrd.arst_value = cell->parameters.at(ID::RD_ARST_VALUE).extract(i * res.width, (ni - i) * res.width);
mrd.srst_value = cell->parameters.at(ID::RD_SRST_VALUE).extract(i * res.width, (ni - i) * res.width);
mrd.init_value = cell->parameters.at(ID::RD_INIT_VALUE).extract(i * res.width, (ni - i) * res.width);
mrd.arst = cell->getPort(ID::RD_ARST).extract(i, 1);
mrd.srst = cell->getPort(ID::RD_SRST).extract(i, 1);
}
if (!is_compat) {
Const transparency_mask = cell->parameters.at(ID::RD_TRANSPARENCY_MASK).extract(i * n_wr_ports, n_wr_ports);
Const collision_x_mask = cell->parameters.at(ID::RD_COLLISION_X_MASK).extract(i * n_wr_ports, n_wr_ports);
for (int j = 0; j < n_wr_ports; j++)
if (wr_wide_continuation[j] != State::S1) {
mrd.transparency_mask.push_back(transparency_mask[j] == State::S1);
mrd.collision_x_mask.push_back(collision_x_mask[j] == State::S1);
}
}
res.rd_ports.push_back(mrd);
}
for (int i = 0, ni; i < n_wr_ports; i = ni) {
ni = i + 1;
while (ni < n_wr_ports && wr_wide_continuation[ni] == State::S1)
ni++;
MemWr mwr;
mwr.wide_log2 = ceil_log2(ni - i);
log_assert(ni - i == (1 << mwr.wide_log2));
mwr.clk_enable = cell->parameters.at(ID::WR_CLK_ENABLE).extract(i, 1).as_bool();
mwr.clk_polarity = cell->parameters.at(ID::WR_CLK_POLARITY).extract(i, 1).as_bool();
mwr.clk = cell->getPort(ID::WR_CLK).extract(i, 1);
mwr.en = cell->getPort(ID::WR_EN).extract(i * res.width, (ni - i) * res.width);
mwr.addr = cell->getPort(ID::WR_ADDR).extract(i * abits, abits);
mwr.data = cell->getPort(ID::WR_DATA).extract(i * res.width, (ni - i) * res.width);
if (!is_compat) {
Const priority_mask = cell->parameters.at(ID::WR_PRIORITY_MASK).extract(i * n_wr_ports, n_wr_ports);
for (int j = 0; j < n_wr_ports; j++)
if (wr_wide_continuation[j] != State::S1)
mwr.priority_mask.push_back(priority_mask[j] == State::S1);
}
res.wr_ports.push_back(mwr);
}
if (is_compat) {
for (int i = 0; i < GetSize(res.wr_ports); i++) {
auto &port = res.wr_ports[i];
port.priority_mask.resize(GetSize(res.wr_ports));
for (int j = 0; j < i; j++) {
auto &oport = res.wr_ports[j];
if (port.clk_enable != oport.clk_enable)
continue;
if (port.clk_enable && port.clk != oport.clk)
continue;
if (port.clk_enable && port.clk_polarity != oport.clk_polarity)
continue;
port.priority_mask[j] = true;
}
}
for (int i = 0; i < GetSize(res.rd_ports); i++) {
auto &port = res.rd_ports[i];
port.transparency_mask.resize(GetSize(res.wr_ports));
port.collision_x_mask.resize(GetSize(res.wr_ports));
if (!cell->parameters.at(ID::RD_TRANSPARENT).extract(i, 1).as_bool())
continue;
if (!port.clk_enable)
continue;
for (int j = 0; j < GetSize(res.wr_ports); j++) {
auto &wport = res.wr_ports[j];
if (!wport.clk_enable)
continue;
if (port.clk != wport.clk)
continue;
if (port.clk_polarity != wport.clk_polarity)
continue;
port.transparency_mask[j] = true;
}
}
}
res.check();
return res;
}
}
std::vector<Mem> Mem::get_all_memories(Module *module) {
std::vector<Mem> res;
MemIndex index(module);
for (auto it: module->memories) {
res.push_back(mem_from_memory(module, it.second, index));
}
for (auto cell: module->cells()) {
if (cell->type.in(ID($mem), ID($mem_v2)))
res.push_back(mem_from_cell(cell));
}
return res;
}
std::vector<Mem> Mem::get_selected_memories(Module *module) {
std::vector<Mem> res;
MemIndex index(module);
for (auto it: module->memories) {
if (module->design->selected(module, it.second))
res.push_back(mem_from_memory(module, it.second, index));
}
for (auto cell: module->selected_cells()) {
if (cell->type.in(ID($mem), ID($mem_v2)))
res.push_back(mem_from_cell(cell));
}
return res;
}
Cell *Mem::extract_rdff(int idx, FfInitVals *initvals) {
MemRd &port = rd_ports[idx];
if (!port.clk_enable)
return nullptr;
Cell *c;
// There are two ways to handle rdff extraction when transparency is involved:
//
// - if all of the following conditions are true, put the FF on address input:
//
// - the port has no clock enable, no reset, and no initial value
// - the port is transparent wrt all write ports (implying they also share
// the clock domain)
//
// - otherwise, put the FF on the data output, and make bypass paths for
// all write ports wrt which this port is transparent
bool trans_use_addr = true;
for (int i = 0; i < GetSize(wr_ports); i++)
if (!port.transparency_mask[i] && !wr_ports[i].removed)
trans_use_addr = false;
// If there are no write ports at all, we could possibly use either way; do data
// FF in this case.
if (GetSize(wr_ports) == 0)
trans_use_addr = false;
if (port.en != State::S1 || port.srst != State::S0 || port.arst != State::S0 || !port.init_value.is_fully_undef())
trans_use_addr = false;
if (trans_use_addr)
{
// Do not put a register in front of constant address bits — this is both
// unnecessary and will break wide ports.
int width = 0;
for (int i = 0; i < GetSize(port.addr); i++)
if (port.addr[i].wire)
width++;
if (width)
{
SigSpec sig_q = module->addWire(stringf("$%s$rdreg[%d]$q", memid.c_str(), idx), width);
SigSpec sig_d;
int pos = 0;
for (int i = 0; i < GetSize(port.addr); i++)
if (port.addr[i].wire) {
sig_d.append(port.addr[i]);
port.addr[i] = sig_q[pos++];
}
c = module->addDff(stringf("$%s$rdreg[%d]", memid.c_str(), idx), port.clk, sig_d, sig_q, port.clk_polarity);
} else {
c = nullptr;
}
}
else
{
log_assert(port.arst == State::S0 || port.srst == State::S0);
SigSpec async_d = module->addWire(stringf("$%s$rdreg[%d]$d", memid.c_str(), idx), GetSize(port.data));
SigSpec sig_d = async_d;
for (int i = 0; i < GetSize(wr_ports); i++) {
auto &wport = wr_ports[i];
if (wport.removed)
continue;
if (port.transparency_mask[i] || port.collision_x_mask[i]) {
log_assert(wport.clk_enable);
log_assert(wport.clk == port.clk);
log_assert(wport.clk_enable == port.clk_enable);
int min_wide_log2 = std::min(port.wide_log2, wport.wide_log2);
int max_wide_log2 = std::max(port.wide_log2, wport.wide_log2);
bool wide_write = wport.wide_log2 > port.wide_log2;
for (int sub = 0; sub < (1 << max_wide_log2); sub += (1 << min_wide_log2)) {
SigSpec raddr = port.addr;
SigSpec waddr = wport.addr;
if (wide_write)
waddr = wport.sub_addr(sub);
else
raddr = port.sub_addr(sub);
SigSpec addr_eq;
if (raddr != waddr)
addr_eq = module->Eq(stringf("$%s$rdtransen[%d][%d][%d]$d", memid.c_str(), idx, i, sub), raddr, waddr);
int pos = 0;
int ewidth = width << min_wide_log2;
int wsub = wide_write ? sub : 0;
int rsub = wide_write ? 0 : sub;
while (pos < ewidth) {
int epos = pos;
while (epos < ewidth && wport.en[epos + wsub * width] == wport.en[pos + wsub * width])
epos++;
SigSpec cur = sig_d.extract(pos + rsub * width, epos-pos);
SigSpec other = port.transparency_mask[i] ? wport.data.extract(pos + wsub * width, epos-pos) : Const(State::Sx, epos-pos);
SigSpec cond;
if (raddr != waddr)
cond = module->And(stringf("$%s$rdtransgate[%d][%d][%d][%d]$d", memid.c_str(), idx, i, sub, pos), wport.en[pos + wsub * width], addr_eq);
else
cond = wport.en[pos + wsub * width];
SigSpec merged = module->Mux(stringf("$%s$rdtransmux[%d][%d][%d][%d]$d", memid.c_str(), idx, i, sub, pos), cur, other, cond);
sig_d.replace(pos + rsub * width, merged);
pos = epos;
}
}
}
}
IdString name = stringf("$%s$rdreg[%d]", memid.c_str(), idx);
FfData ff(initvals);
ff.width = GetSize(port.data);
ff.has_clk = true;
ff.sig_clk = port.clk;
ff.pol_clk = port.clk_polarity;
if (port.en != State::S1) {
ff.has_en = true;
ff.pol_en = true;
ff.sig_en = port.en;
}
if (port.arst != State::S0) {
ff.has_arst = true;
ff.pol_arst = true;
ff.sig_arst = port.arst;
ff.val_arst = port.arst_value;
}
if (port.srst != State::S0) {
ff.has_srst = true;
ff.pol_srst = true;
ff.sig_srst = port.srst;
ff.val_srst = port.srst_value;
ff.ce_over_srst = ff.has_en && port.ce_over_srst;
}
ff.sig_d = sig_d;
ff.sig_q = port.data;
ff.val_init = port.init_value;
port.data = async_d;
c = ff.emit(module, name);
}
log("Extracted %s FF from read port %d of %s.%s: %s\n", trans_use_addr ? "addr" : "data",
idx, log_id(module), log_id(memid), log_id(c));
port.en = State::S1;
port.clk = State::S0;
port.arst = State::S0;
port.srst = State::S0;
port.clk_enable = false;
port.clk_polarity = true;
port.ce_over_srst = false;
port.arst_value = Const(State::Sx, GetSize(port.data));
port.srst_value = Const(State::Sx, GetSize(port.data));
port.init_value = Const(State::Sx, GetSize(port.data));
for (int i = 0; i < GetSize(wr_ports); i++) {
port.transparency_mask[i] = false;
port.collision_x_mask[i] = false;
}
return c;
}
void Mem::narrow() {
// NOTE: several passes depend on this function not modifying
// the design at all until (and unless) emit() is called.
// Be careful to preserve this.
std::vector<MemRd> new_rd_ports;
std::vector<MemWr> new_wr_ports;
std::vector<std::pair<int, int>> new_rd_map;
std::vector<std::pair<int, int>> new_wr_map;
for (int i = 0; i < GetSize(rd_ports); i++) {
auto &port = rd_ports[i];
for (int sub = 0; sub < (1 << port.wide_log2); sub++) {
new_rd_map.push_back(std::make_pair(i, sub));
}
}
for (int i = 0; i < GetSize(wr_ports); i++) {
auto &port = wr_ports[i];
for (int sub = 0; sub < (1 << port.wide_log2); sub++) {
new_wr_map.push_back(std::make_pair(i, sub));
}
}
for (auto &it : new_rd_map) {
MemRd &orig = rd_ports[it.first];
MemRd port = orig;
if (it.second != 0)
port.cell = nullptr;
if (port.wide_log2) {
port.data = port.data.extract(it.second * width, width);
port.init_value = port.init_value.extract(it.second * width, width);
port.arst_value = port.arst_value.extract(it.second * width, width);
port.srst_value = port.srst_value.extract(it.second * width, width);
port.addr = port.sub_addr(it.second);
port.wide_log2 = 0;
}
port.transparency_mask.clear();
port.collision_x_mask.clear();
for (auto &it2 : new_wr_map)
port.transparency_mask.push_back(orig.transparency_mask[it2.first]);
for (auto &it2 : new_wr_map)
port.collision_x_mask.push_back(orig.collision_x_mask[it2.first]);
new_rd_ports.push_back(port);
}
for (auto &it : new_wr_map) {
MemWr &orig = wr_ports[it.first];
MemWr port = orig;
if (it.second != 0)
port.cell = nullptr;
if (port.wide_log2) {
port.data = port.data.extract(it.second * width, width);
port.en = port.en.extract(it.second * width, width);
port.addr = port.sub_addr(it.second);
port.wide_log2 = 0;
}
port.priority_mask.clear();
for (auto &it2 : new_wr_map)
port.priority_mask.push_back(orig.priority_mask[it2.first]);
new_wr_ports.push_back(port);
}
std::swap(rd_ports, new_rd_ports);
std::swap(wr_ports, new_wr_ports);
}
void Mem::emulate_priority(int idx1, int idx2, FfInitVals *initvals)
{
auto &port1 = wr_ports[idx1];
auto &port2 = wr_ports[idx2];
if (!port2.priority_mask[idx1])
return;
for (int i = 0; i < GetSize(rd_ports); i++) {
auto &rport = rd_ports[i];
if (rport.removed)
continue;
if (rport.transparency_mask[idx1] && !(rport.transparency_mask[idx2] || rport.collision_x_mask[idx2]))
emulate_transparency(idx1, i, initvals);
}
int min_wide_log2 = std::min(port1.wide_log2, port2.wide_log2);
int max_wide_log2 = std::max(port1.wide_log2, port2.wide_log2);
bool wide1 = port1.wide_log2 > port2.wide_log2;
for (int sub = 0; sub < (1 << max_wide_log2); sub += (1 << min_wide_log2)) {
SigSpec addr1 = port1.addr;
SigSpec addr2 = port2.addr;
if (wide1)
addr1 = port1.sub_addr(sub);
else
addr2 = port2.sub_addr(sub);
SigSpec addr_eq = module->Eq(NEW_ID, addr1, addr2);
int ewidth = width << min_wide_log2;
int sub1 = wide1 ? sub : 0;
int sub2 = wide1 ? 0 : sub;
dict<std::pair<SigBit, SigBit>, SigBit> cache;
for (int pos = 0; pos < ewidth; pos++) {
SigBit &en1 = port1.en[pos + sub1 * width];
SigBit &en2 = port2.en[pos + sub2 * width];
std::pair<SigBit, SigBit> key(en1, en2);
if (cache.count(key)) {
en1 = cache[key];
} else {
SigBit active2 = module->And(NEW_ID, addr_eq, en2);
SigBit nactive2 = module->Not(NEW_ID, active2);
en1 = cache[key] = module->And(NEW_ID, en1, nactive2);
}
}
}
port2.priority_mask[idx1] = false;
}
void Mem::emulate_transparency(int widx, int ridx, FfInitVals *initvals) {
auto &wport = wr_ports[widx];
auto &rport = rd_ports[ridx];
log_assert(rport.transparency_mask[widx]);
// If other write ports have priority over this one, emulate their transparency too.
for (int i = GetSize(wr_ports) - 1; i > widx; i--) {
if (wr_ports[i].removed)
continue;
if (rport.transparency_mask[i] && wr_ports[i].priority_mask[widx])
emulate_transparency(i, ridx, initvals);
}
int min_wide_log2 = std::min(rport.wide_log2, wport.wide_log2);
int max_wide_log2 = std::max(rport.wide_log2, wport.wide_log2);
bool wide_write = wport.wide_log2 > rport.wide_log2;
// The write data FF doesn't need full reset/init behavior, as it'll be masked by
// the mux whenever this would be relevant. It does, however, need to have the same
// clock enable signal as the read port.
SigSpec wdata_q = module->addWire(NEW_ID, GetSize(wport.data));
module->addDffe(NEW_ID, rport.clk, rport.en, wport.data, wdata_q, rport.clk_polarity, true);
for (int sub = 0; sub < (1 << max_wide_log2); sub += (1 << min_wide_log2)) {
SigSpec raddr = rport.addr;
SigSpec waddr = wport.addr;
for (int j = min_wide_log2; j < max_wide_log2; j++)
if (wide_write)
waddr = wport.sub_addr(sub);
else
raddr = rport.sub_addr(sub);
SigSpec addr_eq;
if (raddr != waddr)
addr_eq = module->Eq(NEW_ID, raddr, waddr);
int pos = 0;
int ewidth = width << min_wide_log2;
int wsub = wide_write ? sub : 0;
int rsub = wide_write ? 0 : sub;
SigSpec rdata_a = module->addWire(NEW_ID, ewidth);
while (pos < ewidth) {
int epos = pos;
while (epos < ewidth && wport.en[epos + wsub * width] == wport.en[pos + wsub * width])
epos++;
SigSpec cond;
if (raddr != waddr)
cond = module->And(NEW_ID, wport.en[pos + wsub * width], addr_eq);
else
cond = wport.en[pos + wsub * width];
SigSpec cond_q = module->addWire(NEW_ID);
// The FF for storing the bypass enable signal must be carefully
// constructed to preserve the overall init/reset/enable behavior
// of the whole port.
FfData ff(initvals);
ff.width = 1;
ff.sig_q = cond_q;
ff.has_d = true;
ff.sig_d = cond;
ff.has_clk = true;
ff.sig_clk = rport.clk;
ff.pol_clk = rport.clk_polarity;
if (rport.en != State::S1) {
ff.has_en = true;
ff.sig_en = rport.en;
ff.pol_en = true;
}
if (rport.arst != State::S0) {
ff.has_arst = true;
ff.sig_arst = rport.arst;
ff.pol_arst = true;
ff.val_arst = State::S0;
}
if (rport.srst != State::S0) {
ff.has_srst = true;
ff.sig_srst = rport.srst;
ff.pol_srst = true;
ff.val_srst = State::S0;
ff.ce_over_srst = rport.ce_over_srst;
}
if (!rport.init_value.is_fully_undef())
ff.val_init = State::S0;
else
ff.val_init = State::Sx;
ff.emit(module, NEW_ID);
// And the final bypass mux.
SigSpec cur = rdata_a.extract(pos, epos-pos);
SigSpec other = wdata_q.extract(pos + wsub * width, epos-pos);
SigSpec dest = rport.data.extract(pos + rsub * width, epos-pos);
module->addMux(NEW_ID, cur, other, cond_q, dest);
pos = epos;
}
rport.data.replace(rsub * width, rdata_a);
}
rport.transparency_mask[widx] = false;
rport.collision_x_mask[widx] = true;
}
void Mem::prepare_wr_merge(int idx1, int idx2, FfInitVals *initvals) {
log_assert(idx1 < idx2);
auto &port1 = wr_ports[idx1];
auto &port2 = wr_ports[idx2];
// If port 2 has priority over a port before port 1, make port 1 have priority too.
for (int i = 0; i < idx1; i++)
if (port2.priority_mask[i])
port1.priority_mask[i] = true;
// If port 2 has priority over a port after port 1, emulate it.
for (int i = idx1 + 1; i < idx2; i++)
if (port2.priority_mask[i] && !wr_ports[i].removed)
emulate_priority(i, idx2, initvals);
// If some port had priority over port 2, make it have priority over the merged port too.
for (int i = idx2 + 1; i < GetSize(wr_ports); i++) {
auto &oport = wr_ports[i];
if (oport.priority_mask[idx2])
oport.priority_mask[idx1] = true;
}
// Make sure all read ports have identical collision/transparency behavior wrt both
// ports.
for (int i = 0; i < GetSize(rd_ports); i++) {
auto &rport = rd_ports[i];
if (rport.removed)
continue;
// If collision already undefined with both ports, it's fine.
if (rport.collision_x_mask[idx1] && rport.collision_x_mask[idx2])
continue;
// If one port has undefined collision, change it to the behavior
// of the other port.
if (rport.collision_x_mask[idx1]) {
rport.collision_x_mask[idx1] = false;
rport.transparency_mask[idx1] = rport.transparency_mask[idx2];
continue;
}
if (rport.collision_x_mask[idx2]) {
rport.collision_x_mask[idx2] = false;
rport.transparency_mask[idx2] = rport.transparency_mask[idx1];
continue;
}
// If transparent with both ports, also fine.
if (rport.transparency_mask[idx1] && rport.transparency_mask[idx2])
continue;
// If transparent with only one, emulate it, and remove the collision-X
// flag that emulate_transparency will set (to align with the other port).
if (rport.transparency_mask[idx1]) {
emulate_transparency(i, idx1, initvals);
rport.collision_x_mask[idx1] = false;
continue;
}
if (rport.transparency_mask[idx2]) {
emulate_transparency(i, idx2, initvals);
rport.collision_x_mask[idx2] = false;
continue;
}
// If we got here, it's transparent with neither port, which is fine.
}
}
void Mem::prepare_rd_merge(int idx1, int idx2, FfInitVals *initvals) {
auto &port1 = rd_ports[idx1];
auto &port2 = rd_ports[idx2];
// Note that going through write ports in order is important, since
// emulating transparency of a write port can change transparency
// mask for higher-numbered ports (due to transitive transparency
// emulation needed because of write port priority).
for (int i = 0; i < GetSize(wr_ports); i++) {
if (wr_ports[i].removed)
continue;
// Both ports undefined, OK.
if (port1.collision_x_mask[i] && port2.collision_x_mask[i])
continue;
// Only one port undefined — change its behavior
// to align with the other port.
if (port1.collision_x_mask[i]) {
port1.collision_x_mask[i] = false;
port1.transparency_mask[i] = port2.transparency_mask[i];
continue;
}
if (port2.collision_x_mask[i]) {
port2.collision_x_mask[i] = false;
port2.transparency_mask[i] = port1.transparency_mask[i];
continue;
}
// Both ports transparent, OK.
if (port1.transparency_mask[i] && port2.transparency_mask[i])
continue;
// Only one port transparent — emulate transparency
// on the other.
if (port1.transparency_mask[i]) {
emulate_transparency(i, idx1, initvals);
port1.collision_x_mask[i] = false;
continue;
}
if (port2.transparency_mask[i]) {
emulate_transparency(i, idx2, initvals);
port2.collision_x_mask[i] = false;
continue;
}
// No ports transparent, OK.
}
}
void Mem::widen_prep(int wide_log2) {
// Make sure start_offset and size are aligned to the port width,
// adjust if necessary.
int mask = ((1 << wide_log2) - 1);
int delta = start_offset & mask;
start_offset -= delta;
size += delta;
if (size & mask) {
size |= mask;
size++;
}
}
void Mem::widen_wr_port(int idx, int wide_log2) {
widen_prep(wide_log2);
auto &port = wr_ports[idx];
log_assert(port.wide_log2 <= wide_log2);
if (port.wide_log2 < wide_log2) {
SigSpec new_data, new_en;
SigSpec addr_lo = port.addr.extract(0, wide_log2);
for (int sub = 0; sub < (1 << wide_log2); sub += (1 << port.wide_log2))
{
Const cur_addr_lo(sub, wide_log2);
if (addr_lo == cur_addr_lo) {
// Always writes to this subword.
new_data.append(port.data);
new_en.append(port.en);
} else if (addr_lo.is_fully_const()) {
// Never writes to this subword.
new_data.append(Const(State::Sx, GetSize(port.data)));
new_en.append(Const(State::S0, GetSize(port.data)));
} else {
// May or may not write to this subword.
new_data.append(port.data);
SigSpec addr_eq = module->Eq(NEW_ID, addr_lo, cur_addr_lo);
SigSpec en = module->Mux(NEW_ID, Const(State::S0, GetSize(port.data)), port.en, addr_eq);
new_en.append(en);
}
}
port.addr.replace(port.wide_log2, Const(State::S0, wide_log2 - port.wide_log2));
port.data = new_data;
port.en = new_en;
port.wide_log2 = wide_log2;
}
}