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Added lut2mux pass

This commit is contained in:
Clifford Wolf 2015-09-18 21:55:48 +02:00
parent d212d4d0c1
commit c851f51656
2 changed files with 94 additions and 0 deletions
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1
passes/techmap/Makefile.inc
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@ -20,6 +20,7 @@ OBJS += passes/techmap/pmuxtree.o
OBJS += passes/techmap/muxcover.o
OBJS += passes/techmap/aigmap.o
OBJS += passes/techmap/tribuf.o
OBJS += passes/techmap/lut2mux.o
endif
GENFILES += passes/techmap/techmap.inc

93
passes/techmap/lut2mux.cc Normal file
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@ -0,0 +1,93 @@
/*
* 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/yosys.h"
#include "kernel/sigtools.h"
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
int lut2mux(Cell *cell)
{
SigSpec sig_a = cell->getPort("\\A");
SigSpec sig_y = cell->getPort("\\Y");
Const lut = cell->getParam("\\LUT");
int count = 1;
if (GetSize(sig_a) == 1)
{
cell->module->addMuxGate(NEW_ID, lut[0], lut[1], sig_a, sig_y);
}
else
{
SigSpec sig_a_hi = sig_a[GetSize(sig_a)-1];
SigSpec sig_a_lo = sig_a.extract(0, GetSize(sig_a)-1);
SigSpec sig_y1 = cell->module->addWire(NEW_ID);
SigSpec sig_y2 = cell->module->addWire(NEW_ID);
Const lut1 = lut.extract(0, GetSize(lut)/2);
Const lut2 = lut.extract(GetSize(lut)/2, GetSize(lut)/2);
count += lut2mux(cell->module->addLut(NEW_ID, sig_a_lo, sig_y1, lut1));
count += lut2mux(cell->module->addLut(NEW_ID, sig_a_lo, sig_y2, lut2));
cell->module->addMuxGate(NEW_ID, sig_y1, sig_y2, sig_a_hi, sig_y);
}
cell->module->remove(cell);
return count;
}
struct Lut2muxPass : public Pass {
Lut2muxPass() : Pass("lut2mux", "convert $lut to $_MUX_") { }
virtual void help()
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" lut2mux [options] [selection]\n");
log("\n");
log("This pass converts $lut cells to $_MUX_ gates.\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
log_header("Executing LUT2MUX pass (mapping to constant drivers).\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
// if (args[argidx] == "-v") {
// continue;
// }
break;
}
extra_args(args, argidx, design);
for (auto module : design->selected_modules())
for (auto cell : module->selected_cells()) {
if (cell->type == "$lut") {
IdString cell_name = cell->name;
int count = lut2mux(cell);
log("Converted %s.%s to %d MUX cells.\n", log_id(module), log_id(cell_name), count);
}
}
}
} Lut2muxPass;
PRIVATE_NAMESPACE_END