From adc6efb58468a7e2f85f756d4a9d4686ad0a8c45 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Thu, 11 Apr 2019 12:34:51 -0700 Subject: Recognise default entry in case even if all cases covered (#931) --- passes/proc/proc_rmdead.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'passes/proc') diff --git a/passes/proc/proc_rmdead.cc b/passes/proc/proc_rmdead.cc index 7c334e661..d2f8d9ead 100644 --- a/passes/proc/proc_rmdead.cc +++ b/passes/proc/proc_rmdead.cc @@ -34,7 +34,7 @@ void proc_rmdead(RTLIL::SwitchRule *sw, int &counter) for (size_t i = 0; i < sw->cases.size(); i++) { - bool is_default = GetSize(sw->cases[i]->compare) == 0 && (!pool.empty() || GetSize(sw->signal) == 0); + bool is_default = GetSize(sw->cases[i]->compare) == 0 || GetSize(sw->signal) == 0; for (size_t j = 0; j < sw->cases[i]->compare.size(); j++) { RTLIL::SigSpec sig = sw->cases[i]->compare[j]; -- cgit v1.2.3 From b3378745fd993f48b8114fb08e5019b34374ee72 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Mon, 15 Apr 2019 17:52:45 -0700 Subject: Revert "Recognise default entry in case even if all cases covered (fix for #931)" --- passes/proc/proc_rmdead.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'passes/proc') diff --git a/passes/proc/proc_rmdead.cc b/passes/proc/proc_rmdead.cc index d2f8d9ead..7c334e661 100644 --- a/passes/proc/proc_rmdead.cc +++ b/passes/proc/proc_rmdead.cc @@ -34,7 +34,7 @@ void proc_rmdead(RTLIL::SwitchRule *sw, int &counter) for (size_t i = 0; i < sw->cases.size(); i++) { - bool is_default = GetSize(sw->cases[i]->compare) == 0 || GetSize(sw->signal) == 0; + bool is_default = GetSize(sw->cases[i]->compare) == 0 && (!pool.empty() || GetSize(sw->signal) == 0); for (size_t j = 0; j < sw->cases[i]->compare.size(); j++) { RTLIL::SigSpec sig = sw->cases[i]->compare[j]; -- cgit v1.2.3 From 4da4a6da2f65d04dbdb50b84310fd91e23348986 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Tue, 16 Apr 2019 11:07:51 -0700 Subject: Revert #895 --- passes/proc/proc_mux.cc | 28 ---------------------------- 1 file changed, 28 deletions(-) (limited to 'passes/proc') diff --git a/passes/proc/proc_mux.cc b/passes/proc/proc_mux.cc index bac2dc2cd..1329c1fef 100644 --- a/passes/proc/proc_mux.cc +++ b/passes/proc/proc_mux.cc @@ -340,7 +340,6 @@ RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, SnippetSwCache &swcache, d // evaluate in reverse order to give the first entry the top priority RTLIL::SigSpec initial_val = result; RTLIL::Cell *last_mux_cell = NULL; - bool shiftx = initial_val.is_fully_undef(); for (size_t i = 0; i < sw->cases.size(); i++) { int case_idx = sw->cases.size() - i - 1; RTLIL::CaseRule *cs2 = sw->cases[case_idx]; @@ -349,33 +348,6 @@ RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, SnippetSwCache &swcache, d append_pmux(mod, sw->signal, cs2->compare, value, last_mux_cell, sw, ifxmode); else result = gen_mux(mod, sw->signal, cs2->compare, value, result, last_mux_cell, sw, ifxmode); - - // Ignore output values which are entirely don't care - if (shiftx && !value.is_fully_undef()) { - // Keep checking if case condition is the same as the current case index - if (cs2->compare.size() == 1 && cs2->compare.front().is_fully_const()) - shiftx = (cs2->compare.front().as_int() == case_idx); - else - shiftx = false; - } - } - - // Transform into a $shiftx where possible - if (shiftx && last_mux_cell && last_mux_cell->type == "$pmux") { - // Create bit-blasted $shiftx-es that shifts by the address line used in the case statement - auto pmux_b_port = last_mux_cell->getPort("\\B"); - auto pmux_y_port = last_mux_cell->getPort("\\Y"); - int width = last_mux_cell->getParam("\\WIDTH").as_int(); - for (int i = 0; i < width; ++i) { - RTLIL::SigSpec a_port; - // Because we went in reverse order above, un-reverse $pmux's B port here - for (int j = pmux_b_port.size()/width-1; j >= 0; --j) - a_port.append(pmux_b_port.extract(j*width+i, 1)); - // Create a $shiftx that shifts by the address line used in the case statement - mod->addShiftx(NEW_ID, a_port, sw->signal, pmux_y_port.extract(i, 1)); - } - // Disconnect $pmux by replacing its output port with a floating wire - last_mux_cell->setPort("\\Y", mod->addWire(NEW_ID, width)); } } -- cgit v1.2.3 From 88be1cbfa50238d77d9489218a8cca7275731da9 Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Thu, 18 Apr 2019 15:07:43 +0200 Subject: Improve proc full_case detection and handling, fixes #931 Signed-off-by: Clifford Wolf --- passes/proc/proc_mux.cc | 50 ++++++++++++++++++++++++++++++++++++++++++++++ passes/proc/proc_rmdead.cc | 18 ++++++++++++----- 2 files changed, 63 insertions(+), 5 deletions(-) (limited to 'passes/proc') diff --git a/passes/proc/proc_mux.cc b/passes/proc/proc_mux.cc index 1329c1fef..aac0b121c 100644 --- a/passes/proc/proc_mux.cc +++ b/passes/proc/proc_mux.cc @@ -108,6 +108,7 @@ struct SigSnippets struct SnippetSwCache { + dict, hash_ptr_ops> full_case_bits_cache; dict, hash_ptr_ops> cache; const SigSnippets *snippets; int current_snippet; @@ -268,6 +269,49 @@ void append_pmux(RTLIL::Module *mod, const RTLIL::SigSpec &signal, const std::ve last_mux_cell->parameters["\\S_WIDTH"] = last_mux_cell->getPort("\\S").size(); } +const pool &get_full_case_bits(SnippetSwCache &swcache, RTLIL::SwitchRule *sw) +{ + if (!swcache.full_case_bits_cache.count(sw)) + { + pool bits; + + if (sw->get_bool_attribute("\\full_case")) + { + bool first_case = true; + + for (auto cs : sw->cases) + { + pool case_bits; + + for (auto it : cs->actions) { + for (auto bit : it.first) + case_bits.insert(bit); + } + + for (auto it : cs->switches) { + for (auto bit : get_full_case_bits(swcache, it)) + case_bits.insert(bit); + } + + if (first_case) { + first_case = false; + bits = case_bits; + } else { + pool new_bits; + for (auto bit : bits) + if (case_bits.count(bit)) + new_bits.insert(bit); + bits.swap(new_bits); + } + } + } + + bits.swap(swcache.full_case_bits_cache[sw]); + } + + return swcache.full_case_bits_cache.at(sw); +} + RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, SnippetSwCache &swcache, dict &swpara, RTLIL::CaseRule *cs, const RTLIL::SigSpec &sig, const RTLIL::SigSpec &defval, bool ifxmode) { @@ -337,6 +381,12 @@ RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, SnippetSwCache &swcache, d } } + // mask default bits that are irrelevant because the output is driven by a full case + const pool &full_case_bits = get_full_case_bits(swcache, sw); + for (int i = 0; i < GetSize(sig); i++) + if (full_case_bits.count(sig[i])) + result[i] = State::Sx; + // evaluate in reverse order to give the first entry the top priority RTLIL::SigSpec initial_val = result; RTLIL::Cell *last_mux_cell = NULL; diff --git a/passes/proc/proc_rmdead.cc b/passes/proc/proc_rmdead.cc index 7c334e661..4f40be446 100644 --- a/passes/proc/proc_rmdead.cc +++ b/passes/proc/proc_rmdead.cc @@ -28,7 +28,7 @@ USING_YOSYS_NAMESPACE PRIVATE_NAMESPACE_BEGIN -void proc_rmdead(RTLIL::SwitchRule *sw, int &counter) +void proc_rmdead(RTLIL::SwitchRule *sw, int &counter, int &full_case_counter) { BitPatternPool pool(sw->signal); @@ -56,11 +56,16 @@ void proc_rmdead(RTLIL::SwitchRule *sw, int &counter) } for (auto switch_it : sw->cases[i]->switches) - proc_rmdead(switch_it, counter); + proc_rmdead(switch_it, counter, full_case_counter); if (is_default) pool.take_all(); } + + if (pool.empty() && !sw->get_bool_attribute("\\full_case")) { + sw->set_bool_attribute("\\full_case"); + full_case_counter++; + } } struct ProcRmdeadPass : public Pass { @@ -87,12 +92,15 @@ struct ProcRmdeadPass : public Pass { for (auto &proc_it : mod->processes) { if (!design->selected(mod, proc_it.second)) continue; - int counter = 0; + int counter = 0, full_case_counter = 0; for (auto switch_it : proc_it.second->root_case.switches) - proc_rmdead(switch_it, counter); + proc_rmdead(switch_it, counter, full_case_counter); if (counter > 0) log("Removed %d dead cases from process %s in module %s.\n", counter, - proc_it.first.c_str(), log_id(mod)); + log_id(proc_it.first), log_id(mod)); + if (full_case_counter > 0) + log("Marked %d switch rules as full_case in process %s in module %s.\n", + full_case_counter, log_id(proc_it.first), log_id(mod)); total_counter += counter; } } -- cgit v1.2.3