// license:BSD-3-Clause // copyright-holders:Aaron Giles /*************************************************************************** drcbeut.c Utility functions for dynamic recompiling backends. ***************************************************************************/ #include "emu.h" #include "drcbeut.h" using namespace uml; //************************************************************************** // DEBUGGING //************************************************************************** #define LOG_RECOVER (0) //************************************************************************** // DRC HASH TABLE //************************************************************************** //------------------------------------------------- // drc_hash_table - constructor //------------------------------------------------- drc_hash_table::drc_hash_table(drc_cache &cache, uint32_t modes, uint8_t addrbits, uint8_t ignorebits) : m_cache(cache), m_modes(modes), m_nocodeptr(nullptr), m_l1bits((addrbits - ignorebits) / 2), m_l2bits((addrbits - ignorebits) - m_l1bits), m_l1shift(ignorebits + m_l2bits), m_l2shift(ignorebits), m_l1mask((1 << m_l1bits) - 1), m_l2mask((1 << m_l2bits) - 1), m_base(reinterpret_cast(cache.alloc(modes * sizeof(**m_base)))), m_emptyl1(nullptr), m_emptyl2(nullptr) { reset(); } //------------------------------------------------- // reset - flush existing hash tables and create // new ones //------------------------------------------------- bool drc_hash_table::reset() { // allocate an empty l2 hash table m_emptyl2 = (drccodeptr *)m_cache.alloc_temporary(sizeof(drccodeptr) << m_l2bits); if (m_emptyl2 == nullptr) return false; // populate it with pointers to the recompile_exit code for (int entry = 0; entry < (1 << m_l2bits); entry++) m_emptyl2[entry] = m_nocodeptr; // allocate an empty l1 hash table m_emptyl1 = (drccodeptr **)m_cache.alloc_temporary(sizeof(drccodeptr *) << m_l1bits); if (m_emptyl1 == nullptr) return false; // populate it with pointers to the empty l2 table for (int entry = 0; entry < (1 << m_l1bits); entry++) m_emptyl1[entry] = m_emptyl2; // reset the hash tables for (int modenum = 0; modenum < m_modes; modenum++) m_base[modenum] = m_emptyl1; return true; } //------------------------------------------------- // block_begin - note the beginning of a block //------------------------------------------------- void drc_hash_table::block_begin(drcuml_block &block, const uml::instruction *instlist, uint32_t numinst) { // before generating code, pre-allocate any hash entries; we do this by setting dummy hash values for (int inum = 0; inum < numinst; inum++) { const uml::instruction &inst = instlist[inum]; // if the opcode is a hash, verify that it makes sense and then set a nullptr entry if (inst.opcode() == OP_HASH) { assert(inst.numparams() == 2); // if we fail to allocate, we must abort the block if (!set_codeptr(inst.param(0).immediate(), inst.param(1).immediate(), nullptr)) block.abort(); } // if the opcode is a hashjmp to a fixed location, make sure we preallocate the tables if (inst.opcode() == OP_HASHJMP && inst.param(0).is_immediate() && inst.param(1).is_immediate()) { // if we fail to allocate, we must abort the block drccodeptr code = get_codeptr(inst.param(0).immediate(), inst.param(1).immediate()); if (!set_codeptr(inst.param(0).immediate(), inst.param(1).immediate(), code)) block.abort(); } } } //------------------------------------------------- // block_end - note the end of a block //------------------------------------------------- void drc_hash_table::block_end(drcuml_block &block) { // nothing to do here, yet } //------------------------------------------------- // set_default_codeptr - change the default // codeptr //------------------------------------------------- void drc_hash_table::set_default_codeptr(drccodeptr nocodeptr) { // nothing to do if the same drccodeptr old = m_nocodeptr; if (old == nocodeptr) return; m_nocodeptr = nocodeptr; // update the empty L2 table first for (int l2entry = 0; l2entry < (1 << m_l2bits); l2entry++) m_emptyl2[l2entry] = nocodeptr; // now scan all existing hashtables for entries for (int modenum = 0; modenum < m_modes; modenum++) if (m_base[modenum] != m_emptyl1) for (int l1entry = 0; l1entry < (1 << m_l1bits); l1entry++) if (m_base[modenum][l1entry] != m_emptyl2) for (int l2entry = 0; l2entry < (1 << m_l2bits); l2entry++) if (m_base[modenum][l1entry][l2entry] == old) m_base[modenum][l1entry][l2entry] = nocodeptr; } //------------------------------------------------- // set_codeptr - set the codeptr for the given // mode/pc //------------------------------------------------- bool drc_hash_table::set_codeptr(uint32_t mode, uint32_t pc, drccodeptr code) { // copy-on-write for the l1 hash table assert(mode < m_modes); if (m_base[mode] == m_emptyl1) { drccodeptr **newtable = (drccodeptr **)m_cache.alloc_temporary(sizeof(drccodeptr *) << m_l1bits); if (newtable == nullptr) return false; memcpy(newtable, m_emptyl1, sizeof(drccodeptr *) << m_l1bits); m_base[mode] = newtable; } // copy-on-write for the l2 hash table uint32_t l1 = (pc >> m_l1shift) & m_l1mask; if (m_base[mode][l1] == m_emptyl2) { drccodeptr *newtable = (drccodeptr *)m_cache.alloc_temporary(sizeof(drccodeptr) << m_l2bits); if (newtable == nullptr) return false; memcpy(newtable, m_emptyl2, sizeof(drccodeptr) << m_l2bits); m_base[mode][l1] = newtable; } // set the new entry uint32_t l2 = (pc >> m_l2shift) & m_l2mask; m_base[mode][l1][l2] = code; return true; } //************************************************************************** // DRC MAP VARIABLES //************************************************************************** //------------------------------------------------- // drc_map_variables - constructor //------------------------------------------------- drc_map_variables::drc_map_variables(drc_cache &cache, uint64_t uniquevalue) : m_cache(cache), m_uniquevalue(uniquevalue) { memset(m_mapvalue, 0, sizeof(m_mapvalue)); } //------------------------------------------------- // ~drc_map_variables - destructor //------------------------------------------------- drc_map_variables::~drc_map_variables() { // must detach all items from the entry list so that the list object // doesn't try to free them on exit m_entry_list.detach_all(); } //------------------------------------------------- // block_begin - note the beginning of a block //------------------------------------------------- void drc_map_variables::block_begin(drcuml_block &block) { // release any remaining live entries map_entry *entry; while ((entry = m_entry_list.detach_head()) != nullptr) m_cache.dealloc(entry, sizeof(*entry)); // reset the variable values memset(m_mapvalue, 0, sizeof(m_mapvalue)); } //------------------------------------------------- // block_end - note the end of a block //------------------------------------------------- void drc_map_variables::block_end(drcuml_block &block) { // only process if we have data if (m_entry_list.first() == nullptr) return; // begin "code generation" aligned to an 8-byte boundary drccodeptr *top = m_cache.begin_codegen(sizeof(uint64_t) + sizeof(uint32_t) + 2 * sizeof(uint32_t) * m_entry_list.count()); if (top == nullptr) block.abort(); uint32_t *dest = (uint32_t *)(((uintptr_t)*top + 7) & ~7); // store the cookie first *(uint64_t *)dest = m_uniquevalue; dest += 2; // get the pointer to the first item and store an initial backwards offset drccodeptr lastptr = m_entry_list.first()->m_codeptr; *dest = (drccodeptr)dest - lastptr; dest++; // now iterate over entries and store them uint32_t curvalue[MAPVAR_COUNT] = { 0 }; bool changed[MAPVAR_COUNT] = { false }; for (map_entry *entry = m_entry_list.first(); entry != nullptr; entry = entry->next()) { // update the current value of the variable and detect changes if (curvalue[entry->m_mapvar] != entry->m_newval) { curvalue[entry->m_mapvar] = entry->m_newval; changed[entry->m_mapvar] = true; } // if the next code pointer is different, or if we're at the end, flush changes if (entry->next() == nullptr || entry->next()->m_codeptr != entry->m_codeptr) { // build a mask of changed variables int numchanged = 0; uint32_t varmask = 0; for (int varnum = 0; varnum < ARRAY_LENGTH(changed); varnum++) if (changed[varnum]) { changed[varnum] = false; varmask |= 1 << varnum; numchanged++; } // if nothing really changed, skip it if (numchanged == 0) continue; // first word is a code delta plus mask of changed variables uint32_t codedelta = entry->m_codeptr - lastptr; while (codedelta > 0xffff) { *dest++ = 0xffff << 16; codedelta -= 0xffff; } *dest++ = (codedelta << 16) | (varmask << 4) | numchanged; // now output updated variable values for (int varnum = 0; varnum < ARRAY_LENGTH(changed); varnum++) if ((varmask >> varnum) & 1) *dest++ = curvalue[varnum]; // remember our lastptr lastptr = entry->m_codeptr; } } // add a terminator *dest++ = 0; // complete codegen *top = (drccodeptr)dest; m_cache.end_codegen(); } //------------------------------------------------- // set_value - set a map value for the given // code pointer //------------------------------------------------- void drc_map_variables::set_value(drccodeptr codebase, uint32_t mapvar, uint32_t newvalue) { assert(mapvar >= MAPVAR_M0 && mapvar < MAPVAR_END); // if this value isn't different, skip it if (m_mapvalue[mapvar - MAPVAR_M0] == newvalue) return; // allocate a new entry and fill it in map_entry *entry = (map_entry *)m_cache.alloc(sizeof(*entry)); entry->m_next = nullptr; entry->m_codeptr = codebase; entry->m_mapvar = mapvar - MAPVAR_M0; entry->m_newval = newvalue; // hook us into the end of the list m_entry_list.append(*entry); // update our state in the table as well m_mapvalue[mapvar - MAPVAR_M0] = newvalue; } //------------------------------------------------- // get_value - return a map value for the given // code pointer //------------------------------------------------- uint32_t drc_map_variables::get_value(drccodeptr codebase, uint32_t mapvar) const { assert(mapvar >= MAPVAR_M0 && mapvar < MAPVAR_END); mapvar -= MAPVAR_M0; // get an aligned pointer to start scanning uint64_t *curscan = (uint64_t *)(((uintptr_t)codebase | 7) + 1); uint64_t *endscan = (uint64_t *)m_cache.top(); // look for the signature while (curscan < endscan && *curscan++ != m_uniquevalue) {}; if (curscan >= endscan) return 0; // switch to 32-bit pointers for processing the rest uint32_t *data = (uint32_t *)curscan; // first get the 32-bit starting offset to the code drccodeptr curcode = (drccodeptr)data - *data; data++; // now loop until we advance past our target uint32_t varmask = 0x10 << mapvar; uint32_t result = 0; while (true) { // a 0 is a terminator uint32_t controlword = *data++; if (controlword == 0) break; // update the codeptr; if this puts us past the end, we're done curcode += (controlword >> 16) & 0xffff; if (curcode > codebase) break; // if our mapvar has changed, process this word if ((controlword & varmask) != 0) { // count how many words precede the one we care about int dataoffs = 0; for (uint32_t skipmask = (controlword & (varmask - 1)) >> 4; skipmask != 0; skipmask = skipmask & (skipmask - 1)) dataoffs++; // fetch the one we want result = data[dataoffs]; } // low 4 bits contain the total number of words of data data += controlword & 0x0f; } if (LOG_RECOVER) printf("recover %d @ %p = %08X\n", mapvar, codebase, result); return result; } uint32_t drc_map_variables::static_get_value(drc_map_variables &map, drccodeptr codebase, uint32_t mapvar) { return map.get_value(codebase, mapvar); } //------------------------------------------------- // get_last_value - return the most recently set // map value //------------------------------------------------- uint32_t drc_map_variables::get_last_value(uint32_t mapvar) { assert(mapvar >= MAPVAR_M0 && mapvar < MAPVAR_END); return m_mapvalue[mapvar - MAPVAR_M0]; } //************************************************************************** // DRC LABEL LIST //************************************************************************** //------------------------------------------------- // drc_label_list - constructor //------------------------------------------------- drc_label_list::drc_label_list(drc_cache &cache) : m_cache(cache), m_oob_callback_delegate(&drc_label_list::oob_callback, this) { } //------------------------------------------------- // ~drc_label_list - destructor //------------------------------------------------- drc_label_list::~drc_label_list() { // must detach all items from the entry list so that the list object // doesn't try to free them on exit m_list.detach_all(); } //------------------------------------------------- // block_begin - note the beginning of a block //------------------------------------------------- void drc_label_list::block_begin(drcuml_block &block) { // make sure the label list is clear, but don't fatalerror reset(false); } //------------------------------------------------- // block_end - note the end of a block //------------------------------------------------- void drc_label_list::block_end(drcuml_block &block) { // can't free until the cache is clean of our OOB requests assert(!m_cache.generating_code()); // free all of the pending fixup requests label_fixup *fixup; while ((fixup = m_fixup_list.detach_head()) != nullptr) { fixup->~label_fixup(); m_cache.dealloc(fixup, sizeof(*fixup)); } // make sure the label list is clear, and fatalerror if we missed anything reset(true); } //------------------------------------------------- // get_codeptr - find or allocate a new label; // returns nullptr and requests an OOB callback if // undefined //------------------------------------------------- drccodeptr drc_label_list::get_codeptr(uml::code_label label, drc_label_fixup_delegate const &callback, void *param) { label_entry *const curlabel = find_or_allocate(label); // if no code pointer, request an OOB callback if (!curlabel->m_codeptr && !callback.isnull()) { label_fixup *fixup = reinterpret_cast(m_cache.alloc(sizeof(*fixup))); new (fixup) label_fixup{ nullptr, curlabel, callback }; m_fixup_list.append(*fixup); m_cache.request_oob_codegen(m_oob_callback_delegate, fixup, param); } return curlabel->m_codeptr; } //------------------------------------------------- // set_codeptr - set the pointer to a new label //------------------------------------------------- void drc_label_list::set_codeptr(uml::code_label label, drccodeptr codeptr) { // set the code pointer label_entry *curlabel = find_or_allocate(label); assert(curlabel->m_codeptr == nullptr); curlabel->m_codeptr = codeptr; } //------------------------------------------------- // reset - reset a label list (add all entries to // the free list) //------------------------------------------------- void drc_label_list::reset(bool fatal_on_leftovers) { // loop until out of labels label_entry *curlabel; while ((curlabel = m_list.detach_head()) != nullptr) { // fatal if we were a leftover if (fatal_on_leftovers && curlabel->m_codeptr == nullptr) fatalerror("Label %08X never defined!\n", curlabel->m_label.label()); // free the label m_cache.dealloc(curlabel, sizeof(*curlabel)); } } //------------------------------------------------- // find_or_allocate - look up a label and // allocate a new one if not found //------------------------------------------------- drc_label_list::label_entry *drc_label_list::find_or_allocate(uml::code_label label) { // find the label, or else allocate a new one label_entry *curlabel; for (curlabel = m_list.first(); curlabel != nullptr; curlabel = curlabel->next()) if (curlabel->m_label == label) break; // if none found, allocate if (curlabel == nullptr) { curlabel = (label_entry *)m_cache.alloc(sizeof(*curlabel)); curlabel->m_label = label; curlabel->m_codeptr = nullptr; m_list.append(*curlabel); } return curlabel; } //------------------------------------------------- // oob_callback - out-of-band codegen callback // for labels //------------------------------------------------- void drc_label_list::oob_callback(drccodeptr *codeptr, void *param1, void *param2) { label_fixup *fixup = reinterpret_cast(param1); fixup->m_callback(param2, fixup->m_label->m_codeptr); }