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Import initial pmux2shiftx from eddieh

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Signed-off-by: Clifford Wolf <clifford@clifford.at>
This commit is contained in:
Clifford Wolf 2019-04-19 14:03:05 +02:00
parent eafc4bd49f
commit 1bf8c2b823
2 changed files with 82 additions and 0 deletions
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1
passes/opt/Makefile.inc
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@ -13,5 +13,6 @@ OBJS += passes/opt/wreduce.o
OBJS += passes/opt/opt_demorgan.o
OBJS += passes/opt/rmports.o
OBJS += passes/opt/opt_lut.o
OBJS += passes/opt/pmux2shiftx.o
endif

81
passes/opt/pmux2shiftx.cc Normal file
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@ -0,0 +1,81 @@
/*
* 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
struct Pmux2ShiftxPass : public Pass {
Pmux2ShiftxPass() : Pass("pmux2shiftx", "transform $pmux cells to $shiftx cells") { }
void help() YS_OVERRIDE
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" pmux2shiftx [selection]\n");
log("\n");
log("This pass transforms $pmux cells to $shiftx cells.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
log_header(design, "Executing PMUX2SHIFTX pass.\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
break;
}
extra_args(args, argidx, design);
for (auto module : design->selected_modules())
for (auto cell : module->selected_cells())
{
if (cell->type != "$pmux")
continue;
// Create a new encoder, out of a $pmux, that takes
// the existing pmux's 'S' input and transforms it
// back into a binary value
RTLIL::SigSpec shiftx_a;
RTLIL::SigSpec pmux_s;
int s_width = cell->getParam("\\S_WIDTH").as_int();
if (!cell->getPort("\\A").is_fully_undef()) {
++s_width;
shiftx_a.append(cell->getPort("\\A"));
pmux_s.append(module->Not(NEW_ID, module->ReduceOr(NEW_ID, cell->getPort("\\S"))));
}
const int clog2width = ceil(log2(s_width));
RTLIL::SigSpec pmux_b;
for (int i = s_width-1; i >= 0; i--)
pmux_b.append(RTLIL::Const(i, clog2width));
shiftx_a.append(cell->getPort("\\B"));
pmux_s.append(cell->getPort("\\S"));
RTLIL::SigSpec pmux_y = module->addWire(NEW_ID, clog2width);
module->addPmux(NEW_ID, RTLIL::Const(RTLIL::Sx, clog2width), pmux_b, pmux_s, pmux_y);
module->addShiftx(NEW_ID, shiftx_a, pmux_y, cell->getPort("\\Y"));
module->remove(cell);
}
}
} Pmux2ShiftxPass;
PRIVATE_NAMESPACE_END