diff options
Diffstat (limited to 'src/cpu/o3/mem_dep_unit_impl.hh')
-rw-r--r-- | src/cpu/o3/mem_dep_unit_impl.hh | 550 |
1 files changed, 341 insertions, 209 deletions
diff --git a/src/cpu/o3/mem_dep_unit_impl.hh b/src/cpu/o3/mem_dep_unit_impl.hh index 296db4c4e..8b195baab 100644 --- a/src/cpu/o3/mem_dep_unit_impl.hh +++ b/src/cpu/o3/mem_dep_unit_impl.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2004-2005 The Regents of The University of Michigan + * Copyright (c) 2004-2006 The Regents of The University of Michigan * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -28,13 +28,56 @@ #include <map> +#include "cpu/o3/inst_queue.hh" #include "cpu/o3/mem_dep_unit.hh" template <class MemDepPred, class Impl> -MemDepUnit<MemDepPred, Impl>::MemDepUnit(Params ¶ms) - : depPred(params.SSITSize, params.LFSTSize) +MemDepUnit<MemDepPred, Impl>::MemDepUnit(Params *params) + : depPred(params->SSITSize, params->LFSTSize), loadBarrier(false), + loadBarrierSN(0), storeBarrier(false), storeBarrierSN(0), iqPtr(NULL) { - DPRINTF(MemDepUnit, "MemDepUnit: Creating MemDepUnit object.\n"); + DPRINTF(MemDepUnit, "Creating MemDepUnit object.\n"); +} + +template <class MemDepPred, class Impl> +MemDepUnit<MemDepPred, Impl>::~MemDepUnit() +{ + for (int tid=0; tid < Impl::MaxThreads; tid++) { + + ListIt inst_list_it = instList[tid].begin(); + + MemDepHashIt hash_it; + + while (!instList[tid].empty()) { + hash_it = memDepHash.find((*inst_list_it)->seqNum); + + assert(hash_it != memDepHash.end()); + + memDepHash.erase(hash_it); + + instList[tid].erase(inst_list_it++); + } + } + + assert(MemDepEntry::memdep_count == 0); +} + +template <class MemDepPred, class Impl> +std::string +MemDepUnit<MemDepPred, Impl>::name() const +{ + return "memdepunit"; +} + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::init(Params *params, int tid) +{ + DPRINTF(MemDepUnit, "Creating MemDepUnit %i object.\n",tid); + + id = tid; + + depPred.init(params->SSITSize, params->LFSTSize); } template <class MemDepPred, class Impl> @@ -60,56 +103,95 @@ MemDepUnit<MemDepPred, Impl>::regStats() template <class MemDepPred, class Impl> void +MemDepUnit<MemDepPred, Impl>::switchOut() +{ + for (int i = 0; i < Impl::MaxThreads; ++i) { + instList[i].clear(); + } + instsToReplay.clear(); + memDepHash.clear(); +} + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::takeOverFrom() +{ + loadBarrier = storeBarrier = false; + loadBarrierSN = storeBarrierSN = 0; + depPred.clear(); +} + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::setIQ(InstructionQueue<Impl> *iq_ptr) +{ + iqPtr = iq_ptr; +} + +template <class MemDepPred, class Impl> +void MemDepUnit<MemDepPred, Impl>::insert(DynInstPtr &inst) { - InstSeqNum inst_seq_num = inst->seqNum; + unsigned tid = inst->threadNumber; + + MemDepEntryPtr inst_entry = new MemDepEntry(inst); + + // Add the MemDepEntry to the hash. + memDepHash.insert( + std::pair<InstSeqNum, MemDepEntryPtr>(inst->seqNum, inst_entry)); + MemDepEntry::memdep_insert++; + + instList[tid].push_back(inst); + + inst_entry->listIt = --(instList[tid].end()); + + // Check any barriers and the dependence predictor for any + // producing stores. + InstSeqNum producing_store; + if (inst->isLoad() && loadBarrier) { + producing_store = loadBarrierSN; + } else if (inst->isStore() && storeBarrier) { + producing_store = storeBarrierSN; + } else { + producing_store = depPred.checkInst(inst->readPC()); + } - Dependency unresolved_dependencies(inst_seq_num); + MemDepEntryPtr store_entry = NULL; - InstSeqNum producing_store = depPred.checkInst(inst->readPC()); + // If there is a producing store, try to find the entry. + if (producing_store != 0) { + MemDepHashIt hash_it = memDepHash.find(producing_store); - if (producing_store == 0 || - storeDependents.find(producing_store) == storeDependents.end()) { + if (hash_it != memDepHash.end()) { + store_entry = (*hash_it).second; + } + } - DPRINTF(MemDepUnit, "MemDepUnit: No dependency for inst PC " - "%#x.\n", inst->readPC()); + // If no store entry, then instruction can issue as soon as the registers + // are ready. + if (!store_entry) { + DPRINTF(MemDepUnit, "No dependency for inst PC " + "%#x [sn:%lli].\n", inst->readPC(), inst->seqNum); - unresolved_dependencies.storeDep = storeDependents.end(); + inst_entry->memDepReady = true; if (inst->readyToIssue()) { - readyInsts.insert(inst_seq_num); - } else { - unresolved_dependencies.memDepReady = true; + inst_entry->regsReady = true; - waitingInsts.insert(unresolved_dependencies); + moveToReady(inst_entry); } } else { - DPRINTF(MemDepUnit, "MemDepUnit: Adding to dependency list; " - "inst PC %#x is dependent on seq num %i.\n", + // Otherwise make the instruction dependent on the store/barrier. + DPRINTF(MemDepUnit, "Adding to dependency list; " + "inst PC %#x is dependent on [sn:%lli].\n", inst->readPC(), producing_store); if (inst->readyToIssue()) { - unresolved_dependencies.regsReady = true; + inst_entry->regsReady = true; } - // Find the store that this instruction is dependent on. - sd_it_t store_loc = storeDependents.find(producing_store); - - assert(store_loc != storeDependents.end()); - - // Record the location of the store that this instruction is - // dependent on. - unresolved_dependencies.storeDep = store_loc; - - // If it's not already ready, then add it to the renamed - // list and the dependencies. - dep_it_t inst_loc = - (waitingInsts.insert(unresolved_dependencies)).first; - // Add this instruction to the list of dependents. - (*store_loc).second.push_back(inst_loc); - - assert(!(*store_loc).second.empty()); + store_entry->dependInsts.push_back(inst_entry); if (inst->isLoad()) { ++conflictingLoads; @@ -119,277 +201,278 @@ MemDepUnit<MemDepPred, Impl>::insert(DynInstPtr &inst) } if (inst->isStore()) { - DPRINTF(MemDepUnit, "MemDepUnit: Inserting store PC %#x.\n", - inst->readPC()); - - depPred.insertStore(inst->readPC(), inst_seq_num); - - // Make sure this store isn't already in this list. - assert(storeDependents.find(inst_seq_num) == storeDependents.end()); - - // Put a dependency entry in at the store's sequence number. - // Uh, not sure how this works...I want to create an entry but - // I don't have anything to put into the value yet. - storeDependents[inst_seq_num]; + DPRINTF(MemDepUnit, "Inserting store PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); - assert(storeDependents.size() != 0); + depPred.insertStore(inst->readPC(), inst->seqNum, inst->threadNumber); ++insertedStores; - } else if (inst->isLoad()) { ++insertedLoads; } else { - panic("MemDepUnit: Unknown type! (most likely a barrier)."); + panic("Unknown type! (most likely a barrier)."); } - - memInsts[inst_seq_num] = inst; } template <class MemDepPred, class Impl> void MemDepUnit<MemDepPred, Impl>::insertNonSpec(DynInstPtr &inst) { - InstSeqNum inst_seq_num = inst->seqNum; + unsigned tid = inst->threadNumber; + + MemDepEntryPtr inst_entry = new MemDepEntry(inst); - Dependency non_spec_inst(inst_seq_num); + // Insert the MemDepEntry into the hash. + memDepHash.insert( + std::pair<InstSeqNum, MemDepEntryPtr>(inst->seqNum, inst_entry)); + MemDepEntry::memdep_insert++; - non_spec_inst.storeDep = storeDependents.end(); + // Add the instruction to the list. + instList[tid].push_back(inst); - waitingInsts.insert(non_spec_inst); + inst_entry->listIt = --(instList[tid].end()); // Might want to turn this part into an inline function or something. // It's shared between both insert functions. if (inst->isStore()) { - DPRINTF(MemDepUnit, "MemDepUnit: Inserting store PC %#x.\n", - inst->readPC()); - - depPred.insertStore(inst->readPC(), inst_seq_num); - - // Make sure this store isn't already in this list. - assert(storeDependents.find(inst_seq_num) == storeDependents.end()); - - // Put a dependency entry in at the store's sequence number. - // Uh, not sure how this works...I want to create an entry but - // I don't have anything to put into the value yet. - storeDependents[inst_seq_num]; + DPRINTF(MemDepUnit, "Inserting store PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); - assert(storeDependents.size() != 0); + depPred.insertStore(inst->readPC(), inst->seqNum, inst->threadNumber); ++insertedStores; - } else if (inst->isLoad()) { ++insertedLoads; } else { - panic("MemDepUnit: Unknown type! (most likely a barrier)."); + panic("Unknown type! (most likely a barrier)."); } - - memInsts[inst_seq_num] = inst; } template <class MemDepPred, class Impl> -typename Impl::DynInstPtr & -MemDepUnit<MemDepPred, Impl>::top() +void +MemDepUnit<MemDepPred, Impl>::insertBarrier(DynInstPtr &barr_inst) { - topInst = memInsts.find( (*readyInsts.begin()) ); + InstSeqNum barr_sn = barr_inst->seqNum; + if (barr_inst->isMemBarrier()) { + loadBarrier = true; + loadBarrierSN = barr_sn; + storeBarrier = true; + storeBarrierSN = barr_sn; + DPRINTF(MemDepUnit, "Inserted a memory barrier\n"); + } else if (barr_inst->isWriteBarrier()) { + storeBarrier = true; + storeBarrierSN = barr_sn; + DPRINTF(MemDepUnit, "Inserted a write barrier\n"); + } + + unsigned tid = barr_inst->threadNumber; + + MemDepEntryPtr inst_entry = new MemDepEntry(barr_inst); + + // Add the MemDepEntry to the hash. + memDepHash.insert( + std::pair<InstSeqNum, MemDepEntryPtr>(barr_sn, inst_entry)); + MemDepEntry::memdep_insert++; - DPRINTF(MemDepUnit, "MemDepUnit: Top instruction is PC %#x.\n", - (*topInst).second->readPC()); + // Add the instruction to the instruction list. + instList[tid].push_back(barr_inst); - return (*topInst).second; + inst_entry->listIt = --(instList[tid].end()); } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::pop() +MemDepUnit<MemDepPred, Impl>::regsReady(DynInstPtr &inst) { - DPRINTF(MemDepUnit, "MemDepUnit: Removing instruction PC %#x.\n", - (*topInst).second->readPC()); + DPRINTF(MemDepUnit, "Marking registers as ready for " + "instruction PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); - wakeDependents((*topInst).second); + MemDepEntryPtr inst_entry = findInHash(inst); - issue((*topInst).second); + inst_entry->regsReady = true; - memInsts.erase(topInst); + if (inst_entry->memDepReady) { + DPRINTF(MemDepUnit, "Instruction has its memory " + "dependencies resolved, adding it to the ready list.\n"); - topInst = memInsts.end(); + moveToReady(inst_entry); + } else { + DPRINTF(MemDepUnit, "Instruction still waiting on " + "memory dependency.\n"); + } } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::regsReady(DynInstPtr &inst) +MemDepUnit<MemDepPred, Impl>::nonSpecInstReady(DynInstPtr &inst) { - DPRINTF(MemDepUnit, "MemDepUnit: Marking registers as ready for " - "instruction PC %#x.\n", - inst->readPC()); + DPRINTF(MemDepUnit, "Marking non speculative " + "instruction PC %#x as ready [sn:%lli].\n", + inst->readPC(), inst->seqNum); - InstSeqNum inst_seq_num = inst->seqNum; + MemDepEntryPtr inst_entry = findInHash(inst); - Dependency inst_to_find(inst_seq_num); + moveToReady(inst_entry); +} - dep_it_t waiting_inst = waitingInsts.find(inst_to_find); +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::reschedule(DynInstPtr &inst) +{ + instsToReplay.push_back(inst); +} - assert(waiting_inst != waitingInsts.end()); +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::replay(DynInstPtr &inst) +{ + DynInstPtr temp_inst; + bool found_inst = false; - if ((*waiting_inst).memDepReady) { - DPRINTF(MemDepUnit, "MemDepUnit: Instruction has its memory " - "dependencies resolved, adding it to the ready list.\n"); + while (!instsToReplay.empty()) { + temp_inst = instsToReplay.front(); - moveToReady(waiting_inst); - } else { - DPRINTF(MemDepUnit, "MemDepUnit: Instruction still waiting on " - "memory dependency.\n"); + MemDepEntryPtr inst_entry = findInHash(temp_inst); - (*waiting_inst).regsReady = true; + DPRINTF(MemDepUnit, "Replaying mem instruction PC %#x " + "[sn:%lli].\n", + temp_inst->readPC(), temp_inst->seqNum); + + moveToReady(inst_entry); + + if (temp_inst == inst) { + found_inst = true; + } + + instsToReplay.pop_front(); } + + assert(found_inst); } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::nonSpecInstReady(DynInstPtr &inst) +MemDepUnit<MemDepPred, Impl>::completed(DynInstPtr &inst) { - DPRINTF(MemDepUnit, "MemDepUnit: Marking non speculative " - "instruction PC %#x as ready.\n", - inst->readPC()); + DPRINTF(MemDepUnit, "Completed mem instruction PC %#x " + "[sn:%lli].\n", + inst->readPC(), inst->seqNum); + + unsigned tid = inst->threadNumber; - InstSeqNum inst_seq_num = inst->seqNum; + // Remove the instruction from the hash and the list. + MemDepHashIt hash_it = memDepHash.find(inst->seqNum); - Dependency inst_to_find(inst_seq_num); + assert(hash_it != memDepHash.end()); - dep_it_t waiting_inst = waitingInsts.find(inst_to_find); + instList[tid].erase((*hash_it).second->listIt); - assert(waiting_inst != waitingInsts.end()); + (*hash_it).second = NULL; - moveToReady(waiting_inst); + memDepHash.erase(hash_it); + MemDepEntry::memdep_erase++; } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::issue(DynInstPtr &inst) +MemDepUnit<MemDepPred, Impl>::completeBarrier(DynInstPtr &inst) { - assert(readyInsts.find(inst->seqNum) != readyInsts.end()); - - DPRINTF(MemDepUnit, "MemDepUnit: Issuing instruction PC %#x.\n", - inst->readPC()); - - // Remove the instruction from the ready list. - readyInsts.erase(inst->seqNum); - - depPred.issued(inst->readPC(), inst->seqNum, inst->isStore()); + wakeDependents(inst); + completed(inst); + + InstSeqNum barr_sn = inst->seqNum; + + if (inst->isMemBarrier()) { + assert(loadBarrier && storeBarrier); + if (loadBarrierSN == barr_sn) + loadBarrier = false; + if (storeBarrierSN == barr_sn) + storeBarrier = false; + } else if (inst->isWriteBarrier()) { + assert(storeBarrier); + if (storeBarrierSN == barr_sn) + storeBarrier = false; + } } template <class MemDepPred, class Impl> void MemDepUnit<MemDepPred, Impl>::wakeDependents(DynInstPtr &inst) { - // Only stores have dependents. - if (!inst->isStore()) { + // Only stores and barriers have dependents. + if (!inst->isStore() && !inst->isMemBarrier() && !inst->isWriteBarrier()) { return; } - // Wake any dependencies. - sd_it_t sd_it = storeDependents.find(inst->seqNum); + MemDepEntryPtr inst_entry = findInHash(inst); - // If there's no entry, then return. Really there should only be - // no entry if the instruction is a load. - if (sd_it == storeDependents.end()) { - DPRINTF(MemDepUnit, "MemDepUnit: Instruction PC %#x, sequence " - "number %i has no dependents.\n", - inst->readPC(), inst->seqNum); + for (int i = 0; i < inst_entry->dependInsts.size(); ++i ) { + MemDepEntryPtr woken_inst = inst_entry->dependInsts[i]; - return; - } - - for (int i = 0; i < (*sd_it).second.size(); ++i ) { - dep_it_t woken_inst = (*sd_it).second[i]; - - DPRINTF(MemDepUnit, "MemDepUnit: Waking up a dependent inst, " - "sequence number %i.\n", - (*woken_inst).seqNum); -#if 0 - // Should we have reached instructions that are actually squashed, - // there will be no more useful instructions in this dependency - // list. Break out early. - if (waitingInsts.find(woken_inst) == waitingInsts.end()) { - DPRINTF(MemDepUnit, "MemDepUnit: Dependents on inst PC %#x " - "are squashed, starting at SN %i. Breaking early.\n", - inst->readPC(), woken_inst); - break; + if (!woken_inst->inst) { + // Potentially removed mem dep entries could be on this list + continue; } -#endif - if ((*woken_inst).regsReady) { + DPRINTF(MemDepUnit, "Waking up a dependent inst, " + "[sn:%lli].\n", + woken_inst->inst->seqNum); + + if (woken_inst->regsReady && !woken_inst->squashed) { moveToReady(woken_inst); } else { - (*woken_inst).memDepReady = true; + woken_inst->memDepReady = true; } } - storeDependents.erase(sd_it); + inst_entry->dependInsts.clear(); } template <class MemDepPred, class Impl> void -MemDepUnit<MemDepPred, Impl>::squash(const InstSeqNum &squashed_num) +MemDepUnit<MemDepPred, Impl>::squash(const InstSeqNum &squashed_num, + unsigned tid) { - - if (!waitingInsts.empty()) { - dep_it_t waiting_it = waitingInsts.end(); - - --waiting_it; - - // Remove entries from the renamed list as long as we haven't reached - // the end and the entries continue to be younger than the squashed. - while (!waitingInsts.empty() && - (*waiting_it).seqNum > squashed_num) - { - if (!(*waiting_it).memDepReady && - (*waiting_it).storeDep != storeDependents.end()) { - sd_it_t sd_it = (*waiting_it).storeDep; - - // Make sure the iterator that the store has pointing - // back is actually to this instruction. - assert((*sd_it).second.back() == waiting_it); - - // Now remove this from the store's list of dependent - // instructions. - (*sd_it).second.pop_back(); + if (!instsToReplay.empty()) { + ListIt replay_it = instsToReplay.begin(); + while (replay_it != instsToReplay.end()) { + if ((*replay_it)->threadNumber == tid && + (*replay_it)->seqNum > squashed_num) { + instsToReplay.erase(replay_it++); + } else { + ++replay_it; } - - waitingInsts.erase(waiting_it--); } } - if (!readyInsts.empty()) { - sn_it_t ready_it = readyInsts.end(); + ListIt squash_it = instList[tid].end(); + --squash_it; - --ready_it; + MemDepHashIt hash_it; - // Same for the ready list. - while (!readyInsts.empty() && - (*ready_it) > squashed_num) - { - readyInsts.erase(ready_it--); - } - } + while (!instList[tid].empty() && + (*squash_it)->seqNum > squashed_num) { - if (!storeDependents.empty()) { - sd_it_t dep_it = storeDependents.end(); + DPRINTF(MemDepUnit, "Squashing inst [sn:%lli]\n", + (*squash_it)->seqNum); - --dep_it; + hash_it = memDepHash.find((*squash_it)->seqNum); - // Same for the dependencies list. - while (!storeDependents.empty() && - (*dep_it).first > squashed_num) - { - // This store's list of dependent instructions should be empty. - assert((*dep_it).second.empty()); + assert(hash_it != memDepHash.end()); - storeDependents.erase(dep_it--); - } + (*hash_it).second->squashed = true; + + (*hash_it).second = NULL; + + memDepHash.erase(hash_it); + MemDepEntry::memdep_erase++; + + instList[tid].erase(squash_it--); } // Tell the dependency predictor to squash as well. - depPred.squash(squashed_num); + depPred.squash(squashed_num, tid); } template <class MemDepPred, class Impl> @@ -397,7 +480,7 @@ void MemDepUnit<MemDepPred, Impl>::violation(DynInstPtr &store_inst, DynInstPtr &violating_load) { - DPRINTF(MemDepUnit, "MemDepUnit: Passing violating PCs to store sets," + DPRINTF(MemDepUnit, "Passing violating PCs to store sets," " load: %#x, store: %#x\n", violating_load->readPC(), store_inst->readPC()); // Tell the memory dependence unit of the violation. @@ -405,15 +488,64 @@ MemDepUnit<MemDepPred, Impl>::violation(DynInstPtr &store_inst, } template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::issue(DynInstPtr &inst) +{ + DPRINTF(MemDepUnit, "Issuing instruction PC %#x [sn:%lli].\n", + inst->readPC(), inst->seqNum); + + depPred.issued(inst->readPC(), inst->seqNum, inst->isStore()); +} + +template <class MemDepPred, class Impl> +inline typename MemDepUnit<MemDepPred,Impl>::MemDepEntryPtr & +MemDepUnit<MemDepPred, Impl>::findInHash(const DynInstPtr &inst) +{ + MemDepHashIt hash_it = memDepHash.find(inst->seqNum); + + assert(hash_it != memDepHash.end()); + + return (*hash_it).second; +} + +template <class MemDepPred, class Impl> inline void -MemDepUnit<MemDepPred, Impl>::moveToReady(dep_it_t &woken_inst) +MemDepUnit<MemDepPred, Impl>::moveToReady(MemDepEntryPtr &woken_inst_entry) +{ + DPRINTF(MemDepUnit, "Adding instruction [sn:%lli] " + "to the ready list.\n", woken_inst_entry->inst->seqNum); + + assert(!woken_inst_entry->squashed); + + iqPtr->addReadyMemInst(woken_inst_entry->inst); +} + + +template <class MemDepPred, class Impl> +void +MemDepUnit<MemDepPred, Impl>::dumpLists() { - DPRINTF(MemDepUnit, "MemDepUnit: Adding instruction sequence number %i " - "to the ready list.\n", (*woken_inst).seqNum); + for (unsigned tid=0; tid < Impl::MaxThreads; tid++) { + cprintf("Instruction list %i size: %i\n", + tid, instList[tid].size()); + + ListIt inst_list_it = instList[tid].begin(); + int num = 0; + + while (inst_list_it != instList[tid].end()) { + cprintf("Instruction:%i\nPC:%#x\n[sn:%i]\n[tid:%i]\nIssued:%i\n" + "Squashed:%i\n\n", + num, (*inst_list_it)->readPC(), + (*inst_list_it)->seqNum, + (*inst_list_it)->threadNumber, + (*inst_list_it)->isIssued(), + (*inst_list_it)->isSquashed()); + inst_list_it++; + ++num; + } + } - // Add it to the ready list. - readyInsts.insert((*woken_inst).seqNum); + cprintf("Memory dependence hash size: %i\n", memDepHash.size()); - // Remove it from the waiting instructions. - waitingInsts.erase(woken_inst); + cprintf("Memory dependence entries: %i\n", MemDepEntry::memdep_count); } |