From 1ea6db3db82e933099ca285f5d483cb7fdb70f02 Mon Sep 17 00:00:00 2001 From: Clifford Wolf Date: Wed, 2 Dec 2015 22:02:20 +0100 Subject: Improved proc_mux performance for huge always blocks --- passes/proc/proc_mux.cc | 189 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 153 insertions(+), 36 deletions(-) (limited to 'passes/proc') diff --git a/passes/proc/proc_mux.cc b/passes/proc/proc_mux.cc index 904d92114..943e8c562 100644 --- a/passes/proc/proc_mux.cc +++ b/passes/proc/proc_mux.cc @@ -27,35 +27,121 @@ USING_YOSYS_NAMESPACE PRIVATE_NAMESPACE_BEGIN -RTLIL::SigSpec find_any_lvalue(const RTLIL::CaseRule *cs) +struct SigSnippets { - for (auto &action : cs->actions) { - if (action.first.size()) - return action.first; - } + idict sigidx; + dict bit2snippet; + pool snippets; - for (auto sw : cs->switches) - for (auto cs2 : sw->cases) { - RTLIL::SigSpec sig = find_any_lvalue(cs2); - if (sig.size()) - return sig; + void insert(SigSpec sig) + { + if (sig.empty()) + return; + + int key = sigidx(sig); + if (snippets.count(key)) + return; + + SigSpec new_sig; + + for (int i = 0; i < GetSize(sig); i++) + { + int other_key = bit2snippet.at(sig[i], -1); + + if (other_key < 0) { + new_sig.append(sig[i]); + continue; + } + + if (!new_sig.empty()) { + int new_key = sigidx(new_sig); + snippets.insert(new_key); + for (auto bit : new_sig) + bit2snippet[bit] = new_key; + new_sig = SigSpec(); + } + + SigSpec other_sig = sigidx[other_key]; + int k = 0, n = 1; + + while (other_sig[k] != sig[i]) { + k++; + log_assert(k < GetSize(other_sig)); + } + + while (i+n < GetSize(sig) && k+n < GetSize(other_sig) && sig[i+n] == other_sig[k+n]) + n++; + + SigSpec sig1 = other_sig.extract(0, k); + SigSpec sig2 = other_sig.extract(k, n); + SigSpec sig3 = other_sig.extract(k+n, GetSize(other_sig)-k-n); + + for (auto bit : other_sig) + bit2snippet.erase(bit); + snippets.erase(other_key); + + insert(sig1); + insert(sig2); + insert(sig3); + + i += n-1; + } + + if (!new_sig.empty()) { + int new_key = sigidx(new_sig); + snippets.insert(new_key); + for (auto bit : new_sig) + bit2snippet[bit] = new_key; + } } - return RTLIL::SigSpec(); -} + void insert(const RTLIL::CaseRule *cs) + { + for (auto &action : cs->actions) + insert(action.first); -void extract_core_signal(const RTLIL::CaseRule *cs, RTLIL::SigSpec &sig) + for (auto sw : cs->switches) + for (auto cs2 : sw->cases) + insert(cs2); + } +}; + +struct SnippetSwCache { - for (auto &action : cs->actions) { - RTLIL::SigSpec lvalue = action.first.extract(sig); - if (lvalue.size()) - sig = lvalue; + dict, hash_ptr_ops> cache; + const SigSnippets *snippets; + int current_snippet; + + bool check(RTLIL::SwitchRule *sw) + { + return cache[sw].count(current_snippet) != 0; } - for (auto sw : cs->switches) - for (auto cs2 : sw->cases) - extract_core_signal(cs2, sig); -} + void insert(const RTLIL::CaseRule *cs, vector &sw_stack) + { + for (auto &action : cs->actions) + for (auto bit : action.first) { + int sn = snippets->bit2snippet.at(bit, -1); + if (sn < 0) + continue; + for (auto sw : sw_stack) + cache[sw].insert(sn); + } + + for (auto sw : cs->switches) { + sw_stack.push_back(sw); + for (auto cs2 : sw->cases) + insert(cs2, sw_stack); + sw_stack.pop_back(); + } + } + + void insert(const RTLIL::CaseRule *cs) + { + vector sw_stack; + insert(cs, sw_stack); + } +}; RTLIL::SigSpec gen_cmp(RTLIL::Module *mod, const RTLIL::SigSpec &signal, const std::vector &compare, RTLIL::SwitchRule *sw) { @@ -179,7 +265,8 @@ 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(); } -RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, RTLIL::CaseRule *cs, const RTLIL::SigSpec &sig, const RTLIL::SigSpec &defval) +RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, SnippetSwCache &swcache, dict &swpara, + RTLIL::CaseRule *cs, const RTLIL::SigSpec &sig, const RTLIL::SigSpec &defval) { RTLIL::SigSpec result = defval; @@ -190,9 +277,37 @@ RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, RTLIL::CaseRule *cs, const for (auto sw : cs->switches) { + if (!swcache.check(sw)) + continue; + // detect groups of parallel cases std::vector pgroups(sw->cases.size()); + bool is_simple_parallel_case = true; + if (!sw->get_bool_attribute("\\parallel_case")) { + if (!swpara.count(sw)) { + pool case_values; + for (size_t i = 0; i < sw->cases.size(); i++) { + RTLIL::CaseRule *cs2 = sw->cases[i]; + for (auto pat : cs2->compare) { + if (!pat.is_fully_def()) + goto not_simple_parallel_case; + Const cpat = pat.as_const(); + if (case_values.count(cpat)) + goto not_simple_parallel_case; + case_values.insert(cpat); + } + } + if (0) + not_simple_parallel_case: + is_simple_parallel_case = false; + swpara[sw] = is_simple_parallel_case; + } else { + is_simple_parallel_case = swpara.at(sw); + } + } + + if (!is_simple_parallel_case) { BitPatternPool pool(sw->signal.size()); bool extra_group_for_next_case = false; for (size_t i = 0; i < sw->cases.size(); i++) { @@ -225,7 +340,7 @@ RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, RTLIL::CaseRule *cs, const 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]; - RTLIL::SigSpec value = signal_to_mux_tree(mod, cs2, sig, initial_val); + RTLIL::SigSpec value = signal_to_mux_tree(mod, swcache, swpara, cs2, sig, initial_val); if (last_mux_cell && pgroups[case_idx] == pgroups[case_idx+1]) append_pmux(mod, sw->signal, cs2->compare, value, last_mux_cell, sw); else @@ -238,24 +353,26 @@ RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, RTLIL::CaseRule *cs, const void proc_mux(RTLIL::Module *mod, RTLIL::Process *proc) { - bool first = true; - while (1) - { - RTLIL::SigSpec sig = find_any_lvalue(&proc->root_case); + log("Creating decoders for process `%s.%s'.\n", mod->name.c_str(), proc->name.c_str()); - if (sig.size() == 0) - break; + SigSnippets sigsnip; + sigsnip.insert(&proc->root_case); - if (first) { - log("Creating decoders for process `%s.%s'.\n", mod->name.c_str(), proc->name.c_str()); - first = false; - } + SnippetSwCache swcache; + swcache.snippets = &sigsnip; + swcache.insert(&proc->root_case); + + dict swpara; - extract_core_signal(&proc->root_case, sig); + int cnt = 0; + for (int idx : sigsnip.snippets) + { + swcache.current_snippet = idx; + RTLIL::SigSpec sig = sigsnip.sigidx[idx]; - log(" creating decoder for signal `%s'.\n", log_signal(sig)); + log("%6d/%d: %s\n", ++cnt, GetSize(sigsnip.snippets), log_signal(sig)); - RTLIL::SigSpec value = signal_to_mux_tree(mod, &proc->root_case, sig, RTLIL::SigSpec(RTLIL::State::Sx, sig.size())); + RTLIL::SigSpec value = signal_to_mux_tree(mod, swcache, swpara, &proc->root_case, sig, RTLIL::SigSpec(RTLIL::State::Sx, sig.size())); mod->connect(RTLIL::SigSig(sig, value)); } } -- cgit v1.2.3