From 9d0b69edaafa98c4bb67974415f354a344a5821d Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Sun, 2 Feb 2014 22:11:08 +0100 Subject: [PATCH] Added opt_const -mux_bool --- passes/opt/opt.cc | 22 ++++++++++++++++++---- passes/opt/opt_const.cc | 32 +++++++++++++++++++++++++++++--- 2 files changed, 47 insertions(+), 7 deletions(-) diff --git a/passes/opt/opt.cc b/passes/opt/opt.cc index 467baf235..53c27e0f5 100644 --- a/passes/opt/opt.cc +++ b/passes/opt/opt.cc @@ -31,7 +31,7 @@ struct OptPass : public Pass { { // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| log("\n"); - log(" opt [selection]\n"); + log(" opt [-mux_undef] [-mux_bool] [selection]\n"); log("\n"); log("This pass calls all the other opt_* passes in a useful order. This performs\n"); log("a series of trivial optimizations and cleanups. This pass executes the other\n"); @@ -46,16 +46,30 @@ struct OptPass : public Pass { log(" opt_share\n"); log(" opt_rmdff\n"); log(" opt_clean\n"); - log(" opt_const\n"); + log(" opt_const [-mux_undef] [-mux_bool]\n"); log(" while [changed design]\n"); log("\n"); } virtual void execute(std::vector args, RTLIL::Design *design) { + std::string opt_const_args; + log_header("Executing OPT pass (performing simple optimizations).\n"); log_push(); - extra_args(args, 1, design); + size_t argidx; + for (argidx = 1; argidx < args.size(); argidx++) { + if (args[argidx] == "-mux_undef") { + opt_const_args += " -mux_undef"; + continue; + } + if (args[argidx] == "-mux_bool") { + opt_const_args += " -mux_bool"; + continue; + } + break; + } + extra_args(args, argidx, design); log_header("Optimizing in-memory representation of design.\n"); design->optimize(); @@ -69,7 +83,7 @@ struct OptPass : public Pass { Pass::call(design, "opt_share"); Pass::call(design, "opt_rmdff"); Pass::call(design, "opt_clean"); - Pass::call(design, "opt_const"); + Pass::call(design, "opt_const" + opt_const_args); if (OPT_DID_SOMETHING == false) break; log_header("Rerunning OPT passes. (Maybe there is more to do..)\n"); diff --git a/passes/opt/opt_const.cc b/passes/opt/opt_const.cc index 2b2c83a51..535dd02fc 100644 --- a/passes/opt/opt_const.cc +++ b/passes/opt/opt_const.cc @@ -42,7 +42,7 @@ void replace_cell(RTLIL::Module *module, RTLIL::Cell *cell, std::string info, st did_something = true; } -void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool consume_x, bool mux_undef) +void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool consume_x, bool mux_undef, bool mux_bool) { if (!design->selected(module)) return; @@ -244,6 +244,24 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons } } + if (mux_bool && cell->type == "$mux" && cell->connections["\\A"] == RTLIL::SigSpec(0, 1) && cell->connections["\\B"] == RTLIL::SigSpec(1, 1)) { + replace_cell(module, cell, "mux_bool", "\\Y", cell->connections["\\S"]); + goto next_cell; + } + + if (mux_bool && cell->type == "$mux" && cell->connections["\\A"] == RTLIL::SigSpec(1, 1) && cell->connections["\\B"] == RTLIL::SigSpec(0, 1)) { + cell->connections["\\A"] = cell->connections["\\S"]; + cell->connections.erase("\\B"); + cell->connections.erase("\\S"); + cell->parameters["\\A_WIDTH"] = cell->parameters["\\WIDTH"]; + cell->parameters["\\Y_WIDTH"] = cell->parameters["\\WIDTH"]; + cell->parameters["\\A_SIGNED"] = 0; + cell->parameters.erase("\\WIDTH"); + cell->type = "$not"; + did_something = true; + goto next_cell; + } + if (mux_undef && (cell->type == "$mux" || cell->type == "$pmux")) { RTLIL::SigSpec new_a, new_b, new_s; int width = cell->connections.at("\\A").width; @@ -392,10 +410,14 @@ struct OptConstPass : public Pass { log(" -mux_undef\n"); log(" remove 'undef' inputs from $mux, $pmux and $_MUX_ cells\n"); log("\n"); + log(" -mux_bool\n"); + log(" replace $mux cells with inverters or buffers when possible\n"); + log("\n"); } virtual void execute(std::vector args, RTLIL::Design *design) { bool mux_undef = false; + bool mux_bool = false; log_header("Executing OPT_CONST pass (perform const folding).\n"); log_push(); @@ -406,6 +428,10 @@ struct OptConstPass : public Pass { mux_undef = true; continue; } + if (args[argidx] == "-mux_bool") { + mux_bool = true; + continue; + } break; } extra_args(args, argidx, design); @@ -414,9 +440,9 @@ struct OptConstPass : public Pass { do { do { did_something = false; - replace_const_cells(design, mod_it.second, false, mux_undef); + replace_const_cells(design, mod_it.second, false, mux_undef, mux_bool); } while (did_something); - replace_const_cells(design, mod_it.second, true, mux_undef); + replace_const_cells(design, mod_it.second, true, mux_undef, mux_bool); } while (did_something); log_pop(); -- 2.30.2