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Added iCE40 const folding support for SB_CARRY

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Clifford Wolf 2015-04-27 08:38:14 +02:00
parent 752851954b
commit 8d4a675f91
3 changed files with 134 additions and 2 deletions
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1
techlibs/ice40/Makefile.inc
View file

@ -1,6 +1,7 @@
OBJS += techlibs/ice40/synth_ice40.o OBJS += techlibs/ice40/synth_ice40.o
OBJS += techlibs/ice40/ice40_ffssr.o OBJS += techlibs/ice40/ice40_ffssr.o
OBJS += techlibs/ice40/ice40_opt.o
GENFILES += techlibs/ice40/brams_init1.vh GENFILES += techlibs/ice40/brams_init1.vh
GENFILES += techlibs/ice40/brams_init2.vh GENFILES += techlibs/ice40/brams_init2.vh

131
techlibs/ice40/ice40_opt.cc Normal file
View file

@ -0,0 +1,131 @@
/*
* 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/register.h"
#include "kernel/log.h"
#include <stdlib.h>
#include <stdio.h>
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
static void run_ice40_opts(Module *module)
{
for (auto cell : module->selected_cells())
{
if (cell->type == "\\SB_CARRY")
{
SigSpec non_const_inputs, replacement_output;
int count_zeros = 0, count_ones = 0;
SigBit inbit[3] = {cell->getPort("\\I0"), cell->getPort("\\I1"), cell->getPort("\\CI")};
for (int i = 0; i < 3; i++)
if (inbit[i].wire == nullptr) {
if (inbit[i] == State::S1)
count_ones++;
else
count_zeros++;
} else
non_const_inputs.append(inbit[i]);
if (count_zeros >= 2)
replacement_output = State::S0;
if (count_ones >= 2)
replacement_output = State::S1;
if (GetSize(non_const_inputs) == 1)
replacement_output = non_const_inputs;
if (GetSize(replacement_output)) {
module->connect(cell->getPort("\\CO"), replacement_output);
module->design->scratchpad_set_bool("opt.did_something", true);
log("Optimized away SB_CARRY cell %s.%s: CO=%s\n",
log_id(module), log_id(cell), log_signal(replacement_output));
module->remove(cell);
continue;
}
}
}
}
struct Ice40OptPass : public Pass {
Ice40OptPass() : Pass("ice40_opt", "iCE40: perform simple optimizations") { }
virtual void help()
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" ice40_opt [options] [selection]\n");
log("\n");
log("This command executes the following script:\n");
log("\n");
log(" do\n");
log(" <ice40 specific optimizations>\n");
log(" opt_const -mux_undef -undriven [-full]\n");
log(" opt_share\n");
log(" opt_rmdff\n");
log(" opt_clean\n");
log(" while <changed design>\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
string opt_const_args = "-mux_undef -undriven";
log_header("Executing ICE40_OPT pass (performing simple optimizations).\n");
log_push();
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
if (args[argidx] == "-full") {
opt_const_args += " -full";
continue;
}
break;
}
extra_args(args, argidx, design);
while (1)
{
design->scratchpad_unset("opt.did_something");
log_header("Running ICE40 specific optimizations.\n");
for (auto module : design->selected_modules())
run_ice40_opts(module);
Pass::call(design, "opt_const " + opt_const_args);
Pass::call(design, "opt_share");
Pass::call(design, "opt_rmdff");
Pass::call(design, "opt_clean");
if (design->scratchpad_get_bool("opt.did_something") == false)
break;
log_header("Rerunning OPT passes. (Removed registers in this run.)\n");
}
design->optimize();
design->sort();
design->check();
log_header("Finished OPT passes. (There is nothing left to do.)\n");
log_pop();
}
} Ice40OptPass;
PRIVATE_NAMESPACE_END

4
techlibs/ice40/synth_ice40.cc
View file

@ -198,7 +198,7 @@ struct SynthIce40Pass : public Pass {
Pass::call(design, "techmap -map +/techmap.v -map +/ice40/arith_map.v"); Pass::call(design, "techmap -map +/techmap.v -map +/ice40/arith_map.v");
if (retime) if (retime)
Pass::call(design, "abc -dff"); Pass::call(design, "abc -dff");
Pass::call(design, "opt -fast"); Pass::call(design, "ice40_opt");
} }
if (check_label(active, run_from, run_to, "map_ffs")) if (check_label(active, run_from, run_to, "map_ffs"))
@ -208,7 +208,7 @@ struct SynthIce40Pass : public Pass {
Pass::call(design, "opt_const -mux_undef"); Pass::call(design, "opt_const -mux_undef");
Pass::call(design, "simplemap"); Pass::call(design, "simplemap");
Pass::call(design, "ice40_ffssr"); Pass::call(design, "ice40_ffssr");
Pass::call(design, "clean"); Pass::call(design, "ice40_opt -full");
} }
if (check_label(active, run_from, run_to, "map_luts")) if (check_label(active, run_from, run_to, "map_luts"))