From f7913285067ed30bf5087f265db7e0bd523af2b6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marcelina=20Ko=C5=9Bcielnicka?= Date: Fri, 13 Aug 2021 00:43:15 +0200 Subject: Add opt_mem_widen pass. If all of us are wide, then none of us are! --- passes/opt/Makefile.inc | 1 + passes/opt/opt_mem_widen.cc | 107 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 108 insertions(+) create mode 100644 passes/opt/opt_mem_widen.cc (limited to 'passes/opt') diff --git a/passes/opt/Makefile.inc b/passes/opt/Makefile.inc index d8eb2f0b9..4e52ad8da 100644 --- a/passes/opt/Makefile.inc +++ b/passes/opt/Makefile.inc @@ -4,6 +4,7 @@ OBJS += passes/opt/opt_merge.o OBJS += passes/opt/opt_mem.o OBJS += passes/opt/opt_mem_feedback.o OBJS += passes/opt/opt_mem_priority.o +OBJS += passes/opt/opt_mem_widen.o OBJS += passes/opt/opt_muxtree.o OBJS += passes/opt/opt_reduce.o OBJS += passes/opt/opt_dff.o diff --git a/passes/opt/opt_mem_widen.cc b/passes/opt/opt_mem_widen.cc new file mode 100644 index 000000000..95e01088c --- /dev/null +++ b/passes/opt/opt_mem_widen.cc @@ -0,0 +1,107 @@ +/* + * yosys -- Yosys Open SYnthesis Suite + * + * Copyright (C) 2021 Marcelina Kościelnicka + * + * 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/mem.h" + +USING_YOSYS_NAMESPACE +PRIVATE_NAMESPACE_BEGIN + +struct OptMemWidenPass : public Pass { + OptMemWidenPass() : Pass("opt_mem_widen", "optimize memories where all ports are wide") { } + void help() override + { + // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| + log("\n"); + log(" opt_mem_widen [options] [selection]\n"); + log("\n"); + log("This pass looks for memories where all ports are wide and adjusts the base\n"); + log("memory width up until that stops being the case.\n"); + log("\n"); + } + void execute(std::vector args, RTLIL::Design *design) override + { + log_header(design, "Executing OPT_MEM_WIDEN pass (optimize memories where all ports are wide).\n"); + + size_t argidx; + for (argidx = 1; argidx < args.size(); argidx++) { + // if (args[argidx] == "-nomux") { + // mode_nomux = true; + // continue; + // } + break; + } + extra_args(args, argidx, design); + + int total_count = 0; + for (auto module : design->selected_modules()) { + for (auto &mem : Mem::get_selected_memories(module)) { + // If the memory has no read ports, opt_clean will remove it + // instead. + if (mem.rd_ports.empty()) + continue; + int factor_log2 = mem.rd_ports[0].wide_log2; + for (auto &port : mem.rd_ports) + if (port.wide_log2 < factor_log2) + factor_log2 = port.wide_log2; + for (auto &port : mem.wr_ports) + if (port.wide_log2 < factor_log2) + factor_log2 = port.wide_log2; + if (factor_log2 == 0) + continue; + log("Widening base width of memory %s in module %s by factor %d.\n", log_id(mem.memid), log_id(module->name), 1 << factor_log2); + total_count++; + // The inits are too messy to expand one-by-one, for they may + // collide with one another after expansion. Just hit it with + // a hammer. + bool has_init = !mem.inits.empty(); + Const init_data; + if (has_init) { + init_data = mem.get_init_data(); + mem.clear_inits(); + } + mem.width <<= factor_log2; + mem.size >>= factor_log2; + mem.start_offset >>= factor_log2; + if (has_init) { + MemInit new_init; + new_init.addr = mem.start_offset; + new_init.data = init_data; + new_init.en = Const(State::S1, mem.width); + mem.inits.push_back(new_init); + } + for (auto &port : mem.rd_ports) { + port.wide_log2 -= factor_log2; + port.addr = port.addr.extract_end(factor_log2); + } + for (auto &port : mem.wr_ports) { + port.wide_log2 -= factor_log2; + port.addr = port.addr.extract_end(factor_log2); + } + mem.emit(); + } + } + + if (total_count) + design->scratchpad_set_bool("opt.did_something", true); + log("Performed a total of %d transformations.\n", total_count); + } +} OptMemWidenPass; + +PRIVATE_NAMESPACE_END -- cgit v1.2.3