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path: root/src/cpu/o3/fetch.hh
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2019-08-28cpu: Move the instruction port into o3's fetch stage.Gabe Black
That's where it's used, and that avoids having to pass it around using the top level getInstPort accessor. Change-Id: I489a3f3239b3116292f3dcd78a3945fb468c6311 Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20239 Tested-by: kokoro <noreply+kokoro@google.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Gabe Black <gabeblack@google.com>
2019-02-08cpu: fixed how O3 CPU executes an exit system callTuan Ta
When a thread executed an exit syscall in SE mode, the thread context was removed immediately in the same cycle, which left inflight squash operations and trap event incomplete. The problem happened when a new thread was assigned to the CPU later. The new thread started with some incomplete transactions of the previous thread (e.g., squashing). This problem could cause incorrect execution flow for the new thread (i.e., pc was not reset properly at the exit point), deadlock (i.e., some stage-to-stage signals were not reset) and incorrect rename map between logical and physical registers. This patch adds a new state called 'Halting' to the thread context and defers removing thread context from a CPU until a trap event initiated by an exit syscall execution is processed. This patch also makes sure that the removal of a thread context happens after all inflight transactions of the to-be-removed thread in the pipeline complete. Change-Id: If7ef1462fb8864e22b45371ee7ae67e2a5ad38b8 Reviewed-on: https://gem5-review.googlesource.com/c/8184 Reviewed-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2019-01-17cpu-o3: Make the smtFetchPolicy a Param.ScopedEnumNikos Nikoleris
The smtFetchPolicy is a parameter in the o3 cpu that can have 5 different values. Previously this setting was done through a string and a parser function would turn it into a c++ enum value. This changeset turns the string into a python Param.ScopedEnum. Change-Id: Iafb4b4b27587541185ea912e5ed581bce09695f5 Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com> Reviewed-on: https://gem5-review.googlesource.com/c/15396 Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com> Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
2018-11-28cpu,arch-arm: Initialise data membersRekai Gonzalez-Alberquilla
The value that is not initialized has a bogus value that manifests when using some debug-flags what makes the usage of tracediff a bit more challenging. In addition, while debugging with other techniques, it introduces the problem of understanding if the value of a field is 'intended' or just an effect of the lack of initialisation. Change-Id: Ied88caa77479c6f1d5166d80d1a1a057503cb106 Signed-off-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com> Reviewed-on: https://gem5-review.googlesource.com/c/13125 Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2018-11-16cpu: Fix the usage of const DynInstPtrRekai Gonzalez-Alberquilla
Summary: Usage of const DynInstPtr& when possible and introduction of move operators to RefCountingPtr. In many places, scoped references to dynamic instructions do a copy of the DynInstPtr when a reference would do. This is detrimental to performance. On top of that, in case there is a need for reference tracking for debugging, the redundant copies make the process much more painful than it already is. Also, from the theoretical point of view, a function/method that defines a convenience name to access an instruction should not be considered an owner of the data, i.e., doing a copy and not a reference is not justified. On a related topic, C++11 introduces move semantics, and those are useful when, for example, there is a class modelling a HW structure that contains a list, and has a getHeadOfList function, to prevent doing a copy to an internal variable -> update pointer, remove from the list -> update pointer, return value making a copy to the assined variable -> update pointer, destroy the returned value -> update pointer. Change-Id: I3bb46c20ef23b6873b469fd22befb251ac44d2f6 Signed-off-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com> Reviewed-on: https://gem5-review.googlesource.com/c/13105 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2018-06-11misc: Using smart pointers for memory RequestsGiacomo Travaglini
This patch is changing the underlying type for RequestPtr from Request* to shared_ptr<Request>. Having memory requests being managed by smart pointers will simplify the code; it will also prevent memory leakage and dangling pointers. Change-Id: I7749af38a11ac8eb4d53d8df1252951e0890fde3 Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/10996 Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com> Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
2018-03-27cpu: Remove ExtMachInst typedefs from the O3 CPU model.Gabe Black
These typedefs aren't used, and they expose ISA specific types outside the ISA implementations. Change-Id: I64b9cec18d6f92765eebbdf8c8f1de15c0deba34 Reviewed-on: https://gem5-review.googlesource.com/9404 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Gabe Black <gabeblack@google.com>
2015-12-07probe: Add probe in Fetch, IEW, Rename and CommitRadhika Jagtap
This patch adds probe points in Fetch, IEW, Rename and Commit stages as follows. A probe point is added in the Fetch stage for probing when a fetch request is sent. Notify is fired on the probe point when a request is sent succesfully in the first attempt as well as on a retry attempt. Probe points are added in the IEW stage when an instruction begins to execute and when execution is complete. This points can be used for monitoring the execution time of an instruction. Probe points are added in the Rename stage to probe renaming of source and destination registers and when there is squashing. These probe points can be used to track register dependencies and remove when there is squashing. A probe point for squashing is added in Commit to probe squashed instructions.
2015-03-02mem: Split port retry for all different packet classesAndreas Hansson
This patch fixes a long-standing isue with the port flow control. Before this patch the retry mechanism was shared between all different packet classes. As a result, a snoop response could get stuck behind a request waiting for a retry, even if the send/recv functions were split. This caused message-dependent deadlocks in stress-test scenarios. The patch splits the retry into one per packet (message) class. Thus, sendTimingReq has a corresponding recvReqRetry, sendTimingResp has recvRespRetry etc. Most of the changes to the code involve simply clarifying what type of request a specific object was accepting. The biggest change in functionality is in the cache downstream packet queue, facing the memory. This queue was shared by requests and snoop responses, and it is now split into two queues, each with their own flow control, but the same physical MasterPort. These changes fixes the previously seen deadlocks.
2014-09-19arch: Pass faults by const reference where possibleAndreas Hansson
This patch changes how faults are passed between methods in an attempt to copy as few reference-counting pointer instances as possible. This should avoid unecessary copies being created, contributing to the increment/decrement of the reference counters.
2014-09-03cpu: Fix SMT scheduling issue with the O3 cpuMitch Hayenga
The o3 cpu could attempt to schedule inactive threads under round-robin SMT mode. This is because it maintained an independent priority list of threads from the active thread list. This priority list could be come stale once threads were inactive, leading to the cpu trying to fetch/commit from inactive threads. Additionally the fetch queue is now forcibly flushed of instrctuctions from the de-scheduled thread. Relevant output: 24557000: system.cpu: [tid:1]: Calling deactivate thread. 24557000: system.cpu: [tid:1]: Removing from active threads list 24557500: system.cpu: FullO3CPU: Ticking main, FullO3CPU. 24557500: system.cpu.fetch: Running stage. 24557500: system.cpu.fetch: Attempting to fetch from [tid:1]
2014-09-03cpu: Add a fetch queue to the o3 cpuMitch Hayenga
This patch adds a fetch queue that sits between fetch and decode to the o3 cpu. This effectively decouples fetch from decode stalls allowing it to be more aggressive, running futher ahead in the instruction stream.
2014-09-03cpu: Fix o3 front-end pipeline interlock behaviorMitch Hayenga
The o3 pipeline interlock/stall logic is incorrect. o3 unnecessicarily stalled fetch and decode due to later stages in the pipeline. In general, a stage should usually only consider if it is stalled by the adjacent, downstream stage. Forcing stalls due to later stages creates and results in bubbles in the pipeline. Additionally, o3 stalled the entire frontend (fetch, decode, rename) on a branch mispredict while the ROB is being serially walked to update the RAT (robSquashing). Only should have stalled at rename.
2014-01-24base: add support for probe points and common probesMatt Horsnell
The probe patch is motivated by the desire to move analytical and trace code away from functional code. This is achieved by the probe interface which is essentially a glorified observer model. What this means to users: * add a probe point and a "notify" call at the source of an "event" * add an isolated module, that is being used to carry out *your* analysis (e.g. generate a trace) * register that module as a probe listener Note: an example is given for reference in src/cpu/o3/simple_trace.[hh|cc] and src/cpu/SimpleTrace.py What is happening under the hood: * every SimObject maintains has a ProbeManager. * during initialization (src/python/m5/simulate.py) first regProbePoints and the regProbeListeners is called on each SimObject. this hooks up the probe point notify calls with the listeners. FAQs: Why did you develop probe points: * to remove trace, stats gathering, analytical code out of the functional code. * the belief that probes could be generically useful. What is a probe point: * a probe point is used to notify upon a given event (e.g. cpu commits an instruction) What is a probe listener: * a class that handles whatever the user wishes to do when they are notified about an event. What can be passed on notify: * probe points are templates, and so the user can generate probes that pass any type of argument (by const reference) to a listener. What relationships can be generated (1:1, 1:N, N:M etc): * there isn't a restriction. You can hook probe points and listeners up in a 1:1, 1:N, N:M relationship. They become useful when a number of modules listen to the same probe points. The idea being that you can add a small number of probes into the source code and develop a larger number of useful analysis modules that use information passed by the probes. Can you give examples: * adding a probe point to the cpu's commit method allows you to build a trace module (outputting assembler), you could re-use this to gather instruction distribution (arithmetic, load/store, conditional, control flow) stats. Why is the probe interface currently restricted to passing a const reference: * the desire, initially at least, is to allow an interface to observe functionality, but not to change functionality. * of course this can be subverted by const-casting. What is the performance impact of adding probes: * when nothing is actively listening to the probes they should have a relatively minor impact. Profiling has suggested even with a large number of probes (60) the impact of them (when not active) is very minimal (<1%).
2013-11-15cpu: allow the fetch buffer to be smaller than a cache lineAnthony Gutierrez
the current implementation of the fetch buffer in the o3 cpu is only allowed to be the size of a cache line. some architectures, e.g., ARM, have fetch buffers smaller than a cache line, see slide 22 at: http://www.arm.com/files/pdf/at-exploring_the_design_of_the_cortex-a15.pdf this patch allows the fetch buffer to be set to values smaller than a cache line.
2013-07-18mem: Set the cache line size on a system levelAndreas Hansson
This patch removes the notion of a peer block size and instead sets the cache line size on the system level. Previously the size was set per cache, and communicated through the interconnect. There were plenty checks to ensure that everyone had the same size specified, and these checks are now removed. Another benefit that is not yet harnessed is that the cache line size is now known at construction time, rather than after the port binding. Hence, the block size can be locally stored and does not have to be queried every time it is used. A follow-on patch updates the configuration scripts accordingly.
2013-01-24branch predictor: move out of o3 and inorder cpusNilay Vaish ext:(%2C%20Timothy%20Jones%20%3Ctimothy.jones%40cl.cam.ac.uk%3E)
This patch moves the branch predictor files in the o3 and inorder directories to src/cpu/pred. This allows sharing the branch predictor across different cpu models. This patch was originally posted by Timothy Jones in July 2010 but never made it to the repository. --HG-- rename : src/cpu/o3/bpred_unit.cc => src/cpu/pred/bpred_unit.cc rename : src/cpu/o3/bpred_unit.hh => src/cpu/pred/bpred_unit.hh rename : src/cpu/o3/bpred_unit_impl.hh => src/cpu/pred/bpred_unit_impl.hh rename : src/cpu/o3/sat_counter.hh => src/cpu/pred/sat_counter.hh
2013-01-07cpu: Rewrite O3 draining to avoid stopping in microcodeAndreas Sandberg
Previously, the O3 CPU could stop in the middle of a microcode sequence. This patch makes sure that the pipeline stops when it has committed a normal instruction or exited from a microcode sequence. Additionally, it makes sure that the pipeline has no instructions in flight when it is drained, which should make draining more robust. Draining is controlled in the commit stage, which checks if the next PC after a committed instruction is in microcode. If this isn't the case, it requests a squash of all instructions after that the instruction that just committed and immediately signals a drain stall to the fetch stage. The CPU then continues to execute until the pipeline and all associated buffers are empty.
2013-01-07cpu: Initialize the O3 pipeline from startup()Andreas Sandberg
The entire O3 pipeline used to be initialized from init(), which is called before initState() or unserialize(). This causes the pipeline to be initialized from an incorrect thread context. This doesn't currently lead to correctness problems as instructions fetched from the incorrect start PC will be squashed a few cycles after initialization. This patch will affect the regressions since the O3 CPU now issues its first instruction fetch to the correct PC instead of 0x0.
2012-09-07Param: Transition to Cycles for relevant parametersAndreas Hansson
This patch is a first step to using Cycles as a parameter type. The main affected modules are the CPUs and the Ruby caches. There are definitely plenty more places that are affected, but this patch serves as a starting point to making the transition. An important part of this patch is to actually enable parameters to be specified as Param.Cycles which involves some changes to params.py.
2012-05-26CPU: Merge the predecoder and decoder.Gabe Black
These classes are always used together, and merging them will give the ISAs more flexibility in how they cache things and manage the process. --HG-- rename : src/arch/x86/predecoder_tables.cc => src/arch/x86/decoder_tables.cc
2012-05-25Decode: Make the Decoder class defined per ISA.Gabe Black
--HG-- rename : src/cpu/decode.cc => src/arch/generic/decoder.cc rename : src/cpu/decode.hh => src/arch/generic/decoder.hh
2012-01-31clang: Enable compiling gem5 using clang 2.9 and 3.0Koan-Sin Tan
This patch adds the necessary flags to the SConstruct and SConscript files for compiling using clang 2.9 and later (on Ubuntu et al and OSX XCode 4.2), and also cleans up a bunch of compiler warnings found by clang. Most of the warnings are related to hidden virtual functions, comparisons with unsigneds >= 0, and if-statements with empty bodies. A number of mismatches between struct and class are also fixed. clang 2.8 is not working as it has problems with class names that occur in multiple namespaces (e.g. Statistics in kernel_stats.hh). clang has a bug (http://llvm.org/bugs/show_bug.cgi?id=7247) which causes confusion between the container std::set and the function Packet::set, and this is currently addressed by not including the entire namespace std, but rather selecting e.g. "using std::vector" in the appropriate places.
2012-01-17CPU: Moving towards a more general port across CPU modelsAndreas Hansson
This patch performs minimal changes to move the instruction and data ports from specialised subclasses to the base CPU (to the largest degree possible). Ultimately it servers to make the CPU(s) have a well-defined interface to the memory sub-system.
2011-09-09Decode: Pull instruction decoding out of the StaticInst class into its own.Gabe Black
This change pulls the instruction decoding machinery (including caches) out of the StaticInst class and puts it into its own class. This has a few intrinsic benefits. First, the StaticInst code, which has gotten to be quite large, gets simpler. Second, the code that handles decode caching is now separated out into its own component and can be looked at in isolation, making it easier to understand. I took the opportunity to restructure the code a bit which will hopefully also help. Beyond that, this change also lays some ground work for each ISA to have its own, potentially stateful decode object. We'd be able to include less contextualizing information in the ExtMachInst objects since that context would be applied at the decoder. Also, the decoder could "know" ahead of time that all the instructions it's going to see are going to be, for instance, 64 bit mode, and it will have one less thing to check when it decodes them. Because the decode caching mechanism has been separated out, it's now possible to have multiple caches which correspond to different types of decoding context. Having one cache for each element of the cross product of different configurations may become prohibitive, so it may be desirable to clear out the cache when relatively static state changes and not to have one for each setting. Because the decode function is no longer universally accessible as a static member of the StaticInst class, a new function was added to the ThreadContexts that returns the applicable decode object.
2011-08-14O3: When squashing, restore the macroop that should be used for fetching.Gabe Black
2011-07-10O3: Fix up pipelining icache accesses in fetch stage to function properlyGeoffrey Blake
Fixed up the patch from Yasuko Watanabe that enabled pipelining of fetch accessess to icache to work with recent changes to main repository. Also added in ability for fetch stage to delay issuing the fault carrying nop when a pipeline fetch causes a fault and no fetch bandwidth is available until the next cycle.
2011-07-10O3: Make sure fetch doesn't go off into the weeds during speculation.Ali Saidi
2011-05-23O3: Fix issue with interrupts/faults occuring in the middle of a macro-opGeoffrey Blake
This patch fixes two problems with the O3 cpu model. The first is an issue with an instruction fetch causing a fault on the next address while the current macro-op is being issued. This happens when the micro-ops exceed the fetch bandwdith and then on the next cycle the fetch stage attempts to issue a request to the next line while it still has micro-ops to issue if the next line faults a fault is attached to a micro-op in the currently executing macro-op rather than a "nop" from the next instruction block. This leads to an instruction incorrectly faulting when on fetch when it had no reason to fault. A similar problem occurs with interrupts. When an interrupt occurs the fetch stage nominally stops issuing instructions immediately. This is incorrect in the case of a macro-op as the current location might not be interruptable.
2011-04-15includes: sort all includesNathan Binkert
2011-03-17O3: Send instruction back to fetch on squash to seed predecoder correctly.Ali Saidi
2011-02-23O3: Fix bug when a squash occurs right before TLB miss returns.Ali Saidi
In this case we need to throw away the TLB miss, not assume it was the one we were waiting for.
2011-02-11O3: Enhance data address translation by supporting hardware page table walkers.Giacomo Gabrielli
Some ISAs (like ARM) relies on hardware page table walkers. For those ISAs, when a TLB miss occurs, initiateTranslation() can return with NoFault but with the translation unfinished. Instructions experiencing a delayed translation due to a hardware page table walk are deferred until the translation completes and kept into the IQ. In order to keep track of them, the IQ has been augmented with a queue of the outstanding delayed memory instructions. When their translation completes, instructions are re-executed (only their initiateAccess() was already executed; their DTB translation is now skipped). The IEW stage has been modified to support such a 2-pass execution.
2011-01-18O3: Support timing translations for O3 CPU fetch.Ali Saidi
2011-01-18O3: Fixes fetch deadlock when the interrupt clears before CPU handles it.Min Kyu Jeong
When this condition occurs the cpu should restart the fetch stage to fetch from the original execution path. Fault handling in the commit stage is cleaned up a little bit so the control flow is simplier. Finally, if an instruction is being used to carry a fault it isn't executed, so the fault propagates appropriately.
2011-01-03Move sched_list.hh and timebuf.hh from src/base to src/cpu.Steve Reinhardt
These files really aren't general enough to belong in src/base. This patch doesn't reorder include lines, leaving them unsorted in many cases, but Nate's magic script will fix that up shortly. --HG-- rename : src/base/sched_list.hh => src/cpu/sched_list.hh rename : src/base/timebuf.hh => src/cpu/timebuf.hh
2010-11-15O3: Make O3 support variably lengthed instructions.Gabe Black
2010-10-31ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors.Gabe Black
This change is a low level and pervasive reorganization of how PCs are managed in M5. Back when Alpha was the only ISA, there were only 2 PCs to worry about, the PC and the NPC, and the lsb of the PC signaled whether or not you were in PAL mode. As other ISAs were added, we had to add an NNPC, micro PC and next micropc, x86 and ARM introduced variable length instruction sets, and ARM started to keep track of mode bits in the PC. Each CPU model handled PCs in its own custom way that needed to be updated individually to handle the new dimensions of variability, or, in the case of ARMs mode-bit-in-the-pc hack, the complexity could be hidden in the ISA at the ISA implementation's expense. Areas like the branch predictor hadn't been updated to handle branch delay slots or micropcs, and it turns out that had introduced a significant (10s of percent) performance bug in SPARC and to a lesser extend MIPS. Rather than perpetuate the problem by reworking O3 again to handle the PC features needed by x86, this change was introduced to rework PC handling in a more modular, transparent, and hopefully efficient way. PC type: Rather than having the superset of all possible elements of PC state declared in each of the CPU models, each ISA defines its own PCState type which has exactly the elements it needs. A cross product of canned PCState classes are defined in the new "generic" ISA directory for ISAs with/without delay slots and microcode. These are either typedef-ed or subclassed by each ISA. To read or write this structure through a *Context, you use the new pcState() accessor which reads or writes depending on whether it has an argument. If you just want the address of the current or next instruction or the current micro PC, you can get those through read-only accessors on either the PCState type or the *Contexts. These are instAddr(), nextInstAddr(), and microPC(). Note the move away from readPC. That name is ambiguous since it's not clear whether or not it should be the actual address to fetch from, or if it should have extra bits in it like the PAL mode bit. Each class is free to define its own functions to get at whatever values it needs however it needs to to be used in ISA specific code. Eventually Alpha's PAL mode bit could be moved out of the PC and into a separate field like ARM. These types can be reset to a particular pc (where npc = pc + sizeof(MachInst), nnpc = npc + sizeof(MachInst), upc = 0, nupc = 1 as appropriate), printed, serialized, and compared. There is a branching() function which encapsulates code in the CPU models that checked if an instruction branched or not. Exactly what that means in the context of branch delay slots which can skip an instruction when not taken is ambiguous, and ideally this function and its uses can be eliminated. PCStates also generally know how to advance themselves in various ways depending on if they point at an instruction, a microop, or the last microop of a macroop. More on that later. Ideally, accessing all the PCs at once when setting them will improve performance of M5 even though more data needs to be moved around. This is because often all the PCs need to be manipulated together, and by getting them all at once you avoid multiple function calls. Also, the PCs of a particular thread will have spatial locality in the cache. Previously they were grouped by element in arrays which spread out accesses. Advancing the PC: The PCs were previously managed entirely by the CPU which had to know about PC semantics, try to figure out which dimension to increment the PC in, what to set NPC/NNPC, etc. These decisions are best left to the ISA in conjunction with the PC type itself. Because most of the information about how to increment the PC (mainly what type of instruction it refers to) is contained in the instruction object, a new advancePC virtual function was added to the StaticInst class. Subclasses provide an implementation that moves around the right element of the PC with a minimal amount of decision making. In ISAs like Alpha, the instructions always simply assign NPC to PC without having to worry about micropcs, nnpcs, etc. The added cost of a virtual function call should be outweighed by not having to figure out as much about what to do with the PCs and mucking around with the extra elements. One drawback of making the StaticInsts advance the PC is that you have to actually have one to advance the PC. This would, superficially, seem to require decoding an instruction before fetch could advance. This is, as far as I can tell, realistic. fetch would advance through memory addresses, not PCs, perhaps predicting new memory addresses using existing ones. More sophisticated decisions about control flow would be made later on, after the instruction was decoded, and handed back to fetch. If branching needs to happen, some amount of decoding needs to happen to see that it's a branch, what the target is, etc. This could get a little more complicated if that gets done by the predecoder, but I'm choosing to ignore that for now. Variable length instructions: To handle variable length instructions in x86 and ARM, the predecoder now takes in the current PC by reference to the getExtMachInst function. It can modify the PC however it needs to (by setting NPC to be the PC + instruction length, for instance). This could be improved since the CPU doesn't know if the PC was modified and always has to write it back. ISA parser: To support the new API, all PC related operand types were removed from the parser and replaced with a PCState type. There are two warts on this implementation. First, as with all the other operand types, the PCState still has to have a valid operand type even though it doesn't use it. Second, using syntax like PCS.npc(target) doesn't work for two reasons, this looks like the syntax for operand type overriding, and the parser can't figure out if you're reading or writing. Instructions that use the PCS operand (which I've consistently called it) need to first read it into a local variable, manipulate it, and then write it back out. Return address stack: The return address stack needed a little extra help because, in the presence of branch delay slots, it has to merge together elements of the return PC and the call PC. To handle that, a buildRetPC utility function was added. There are basically only two versions in all the ISAs, but it didn't seem short enough to put into the generic ISA directory. Also, the branch predictor code in O3 and InOrder were adjusted so that they always store the PC of the actual call instruction in the RAS, not the next PC. If the call instruction is a microop, the next PC refers to the next microop in the same macroop which is probably not desirable. The buildRetPC function advances the PC intelligently to the next macroop (in an ISA specific way) so that that case works. Change in stats: There were no change in stats except in MIPS and SPARC in the O3 model. MIPS runs in about 9% fewer ticks. SPARC runs with 30%-50% fewer ticks, which could likely be improved further by setting call/return instruction flags and taking advantage of the RAS. TODO: Add != operators to the PCState classes, defined trivially to be !(a==b). Smooth out places where PCs are split apart, passed around, and put back together later. I think this might happen in SPARC's fault code. Add ISA specific constructors that allow setting PC elements without calling a bunch of accessors. Try to eliminate the need for the branching() function. Factor out Alpha's PAL mode pc bit into a separate flag field, and eliminate places where it's blindly masked out or tested in the PC.
2010-08-23ISA: Get rid of old, unused utility functions cluttering up the ISAs.Gabe Black
2009-09-23arch: nuke arch/isa_specific.hh and move stuff to generated config/the_isa.hhNathan Binkert
2009-05-26types: add a type for thread IDs and try to use it everywhereNathan Binkert
2009-03-05stats: Fix all stats usages to deal with template fixesNathan Binkert
2008-10-09eventq: convert all usage of events to use the new API.Nathan Binkert
For now, there is still a single global event queue, but this is necessary for making the steps towards a parallelized m5.
2008-08-11params: Convert the CPU objects to use the auto generated param structs.Nathan Binkert
A whole bunch of stuff has been converted to use the new params stuff, but the CPU wasn't one of them. While we're at it, make some things a bit more stylish. Most of the work was done by Gabe, I just cleaned stuff up a bit more at the end.
2008-06-28Backed out changeset 94a7bb476fca: caused memory leak.Steve Reinhardt
2008-06-21Generate more useful error messages for unconnected ports.Steve Reinhardt
Force all non-default ports to provide a name and an owner in the constructor.
2007-06-19Merge zizzer.eecs.umich.edu:/bk/newmemGabe Black
into doughnut.hpl.hp.com:/home/gblack/newmem-o3-micro src/cpu/base_dyn_inst_impl.hh: src/cpu/o3/fetch_impl.hh: Hand merge --HG-- extra : convert_revision : 0c0692033ac30133672d8dfe1f1a27e9d9e95a3d
2007-05-21Change getDeviceAddressRanges to use bool for snoop arg.Steve Reinhardt
--HG-- extra : convert_revision : 832e52ba80cbab2f5bb6d5b5977a499d41b4d638
2007-04-14Add support for microcode and pull out the special branch delay slot ↵Gabe Black
handling. Branch delay slots need to be squash on a mispredict as well because the nnpc they saw was incorrect. --HG-- extra : convert_revision : 8b9c603616bcad254417a7a3fa3edfb4c8728719
2007-04-13Remove most of the special handling for delay slots since they have to be ↵Gabe Black
squashed anyway on a mispredict. This is because the NNPC value they saw when executing was incorrect. --HG-- extra : convert_revision : b42c4eb28b4fbba66c65cbd0a5033bf886c1532d