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2016-10-13isa,arm: Add missing AArch32 FP instructionsMitch Hayenga
This commit adds missing non-predicated, scalar floating point instructions. Specifically VRINT* floating point integer rounding instructions and VSEL* floating point conditional selects. Change-Id: I23cbd1389f151389ac8beb28a7d18d5f93d000e7 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Nathanael Premillieu <nathanael.premillieu@arm.com>
2016-08-02arm: change instruction classes to catch hyp trapsDylan Johnson
Change-Id: I122918d0e3dfd01ae1a4ca4f19240a069115c8b7
2016-06-02arm: Rewrite ERET to behave according to the ARMv8 ARMAndreas Sandberg
The ERET instruction doesn't set PSTATE correctly in some cases (particularly when returning to aarch32 code). Among other things, this breaks EL0 thumb code when using a 64-bit kernel. This changeset updates the ERET implementation to match the ARM ARM. Change-Id: I408e7c69a23cce437859313dfe84e68744b07c98 Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Nathanael Premillieu <nathanael.premillieu@arm.com>
2016-06-02arm: Correctly check FP/SIMD access permission in aarch32Andreas Sandberg
The current implementation of aarch32 FP/SIMD in gem5 assumes that EL1 and higher are all 32-bit. This breaks interprocessing since an aarch64 EL1 uses different enable/disable bits. This change updates the permission checks to according to what is prescribed by the ARM ARM. Change-Id: Icdcef31b00644cfeebec00216b3993aa1de12b88 Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Mitch Hayenga <mitch.hayenga@arm.com> Reviewed-by: Nathanael Premillieu <nathanael.premillieu@arm.com>
2016-03-16arm: Fix disasm printingNathanael Premillieu
Fix the printDataInst function to properly print the immediate value.
2016-02-06style: fix missing spaces in control statementsSteve Reinhardt
Result of running 'hg m5style --skip-all --fix-control -a'.
2015-11-22arm: Fix fplib 128-bit shift operatorsNathanael Premillieu
Appease clang.
2015-07-28revert 5af8f40d8f2cNilay Vaish
2015-07-26cpu: implements vector registersNilay Vaish
This adds a vector register type. The type is defined as a std::array of a fixed number of uint64_ts. The isa_parser.py has been modified to parse vector register operands and generate the required code. Different cpus have vector register files now.
2015-02-16arm: Merge ISA files with pseudo instructionsAndreas Sandberg
This changeset moves the pseudo instructions used to signal unknown instructions and unimplemented instructions to the same source files as the decoder fault.
2015-01-25arm: always set the IsFirstMicroop flagAli Saidi
While the IsFirstMicroop flag exists it was only occasionally used in the ARM instructions that gem5 microOps and therefore couldn't be relied on to be correct.
2014-12-23arm: Raise an alignment fault if a PC has illegal alignmentAndreas Sandberg
We currently don't handle unaligned PCs correctly. There is one check for unaligned PCs in the TLB when running in aarch64 mode, but this check does not cover cases where the CPU does not do a TLB lookup when decoding an instruction (e.g., a branch stays within the same cache line). Additionally, the Decoder class sometimes throws an assertion for unaligned PCs which breaks speculation. This changeset introduces a decoder fault bit field in the ExtMachInst structure. This field can be used to signal a decoder failure. If set, the decoder generates an internal gem5fault instruction instead of a normal instruction. This instruction in turns either panics (fault type PANIC), returns an PCAlignmentFault (fault type UNALIGNED, aarch64) or PrefetchAbort (fault type UNALIGNED, aarch32). The patch causes minor changes to the realview64 regressions, and a stats bump will follow.
2014-11-14arm: Fixes based on UBSan and static analysisAndreas Hansson
Another churn to clean up undefined behaviour, mostly ARM, but some parts also touching the generic part of the code base. Most of the fixes are simply ensuring that proper intialisation. One of the more subtle changes is the return type of the sign-extension, which is changed to uint64_t. This is to avoid shifting negative values (undefined behaviour) in the ISA code.
2014-10-16arch: Use shared_ptr for all FaultsAndreas Hansson
This patch takes quite a large step in transitioning from the ad-hoc RefCountingPtr to the c++11 shared_ptr by adopting its use for all Faults. There are no changes in behaviour, and the code modifications are mostly just replacing "new" with "make_shared".
2014-10-01arm: More UBSan cleanups after additional full-system runsAndreas Hansson
Some incorrect casting to IntRegIndex, and a few uninitialized members in the i8254xGBe device.
2014-09-27arm: Fixed undefined behaviours identified by gccAndreas Hansson
This patch fixes the runtime errors highlighted by the undefined behaviour sanitizer. In the end there were two issues. First, when rotating an immediate, we ended up shifting an uint32_t by 32 in some cases. This case is fixed by checking for a rotation by 0 positions. Second, the Mrc15 and Mcr15 are operating on an IntReg and a MiscReg, but we used the type RegRegImmOp and passed a MiscRegIndex as an IntRegIndex. This issue is resolved by introducing a MiscRegRegImmOp and RegMiscRegImmOp with the appropriate types. With these fixes there are no runtime errors identified for the full ARM regressions.
2014-09-03arm: Make memory ops work on 64bit/128-bit quantitiesMitch Hayenga
Multiple instructions assume only 32-bit load operations are available, this patch increases load sizes to 64-bit or 128-bit for many load pair and load multiple instructions.
2014-09-03arm: Fix v8 neon latency issue for loads/storesMitch Hayenga
Neon memory ops that operate on multiple registers currently have very poor performance because of interleave/deinterleave micro-ops. This patch marks the deinterleave/interleave micro-ops as "No_OpClass" such that they take minumum cycles to execute and are never resource constrained. Additionaly the micro-ops over-read registers. Although one form may need to read up to 20 sources, not all do. This adds in new forms so false dependencies are not modeled. Instructions read their minimum number of sources.
2014-04-29arm: use condition code registers for ARM ISACurtis Dunham
Analogous to ee049bf (for x86). Requires a bump of the checkpoint version and corresponding upgrader code to move the condition code register values to the new register file.
2014-03-11arm: remove dead code fplib mul64x64Curtis Dunham
2014-05-09arm: Add branch flags onto macroopsAndrew Bardsley
Mark branch flags onto macroops to allow branch prediction before microop decomposition
2014-04-23arm: Correctly display disassembly of vldmia/vstmiaCurtis Dunham
The MicroMemOp class generates the disassembly for both integer and floating point instructions, but it would always print its first operand as an integer register without considering that the op may be a floating instruction in which case a float register should be displayed instead.
2014-03-07scons: Fixes uninitialized warnings issued by clangMitch Hayenga
Small fixes to appease recent clang versions.
2014-01-24arm: Add support for ARMv8 (AArch64 & AArch32)ARM gem5 Developers
Note: AArch64 and AArch32 interworking is not supported. If you use an AArch64 kernel you are restricted to AArch64 user-mode binaries. This will be addressed in a later patch. Note: Virtualization is only supported in AArch32 mode. This will also be fixed in a later patch. Contributors: Giacomo Gabrielli (TrustZone, LPAE, system-level AArch64, AArch64 NEON, validation) Thomas Grocutt (AArch32 Virtualization, AArch64 FP, validation) Mbou Eyole (AArch64 NEON, validation) Ali Saidi (AArch64 Linux support, code integration, validation) Edmund Grimley-Evans (AArch64 FP) William Wang (AArch64 Linux support) Rene De Jong (AArch64 Linux support, performance opt.) Matt Horsnell (AArch64 MP, validation) Matt Evans (device models, code integration, validation) Chris Adeniyi-Jones (AArch64 syscall-emulation) Prakash Ramrakhyani (validation) Dam Sunwoo (validation) Chander Sudanthi (validation) Stephan Diestelhorst (validation) Andreas Hansson (code integration, performance opt.) Eric Van Hensbergen (performance opt.) Gabe Black
2013-10-15cpu: add a condition-code register classYasuko Eckert
Add a third register class for condition codes, in parallel with the integer and FP classes. No ISAs use the CC class at this point though.
2013-10-15cpu: rename *_DepTag constants to *_Reg_BaseSteve Reinhardt
Make these names more meaningful. Specifically, made these substitutions: s/FP_Base_DepTag/FP_Reg_Base/g; s/Ctrl_Base_DepTag/Misc_Reg_Base/g; s/Max_DepTag/Max_Reg_Index/g;
2013-10-15cpu: clean up architectural register classificationSteve Reinhardt
Move from a poorly documented scheme where the mapping of unified architectural register indices to register classes is hardcoded all over to one where there's an enum for the register classes and a function that encapsulates the mapping.
2013-04-17arm: set ldr_ret_uop as conditional or unconditional controlNathanael Premillieu
This patch adds a missing flag to the ldr_ret_uop microop instruction. The flag is added when the instruction is used, not directly in the constructor of the instruction. Committed by: Nilay Vaish <nilay@cs.wisc.edu>"
2013-02-19scons: Fix up numerous warnings about name shadowingAndreas Hansson
This patch address the most important name shadowing warnings (as produced when using gcc/clang with -Wshadow). There are many locations where constructor parameters and function parameters shadow local variables, but these are left unchanged.
2013-02-15ARM: Fix an issue with clang generating wrong code.Ali Saidi
Clang generated executables would enter the if condition when it wasn't supposted to, resulting in the wrong simulated behavior. Implementing the operation this way is a bit faster anyway.
2012-12-12arm: set movret_uop as conditional or unconditional controlNathanael Premillieu
A flag was missing for the movret_uop microop instruction. This patch adds that flag when the instruction is used, not directly in the constructor of the instruction. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2012-09-25ARM: Predict target of more instructions that modify PC.Ali Saidi
2012-04-23ISA: Put parser generated files in a "generated" directory.Gabe Black
This is to avoid collision with non-generated files.
2012-03-21ARM: Clean up condCodes in IT blocks.Ali Saidi
2012-03-01ARM: fix bits-to-fp conversion function declarations.Giacomo Gabrielli
Add extra declarations to allow the compiler to pick up the right function. Please note that these declarations have been added as part of the clang-related changes.
2012-01-31Merge with head, hopefully the last time for this batch.Gabe Black
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.
2011-11-02SE/FS: Get rid of FULL_SYSTEM in the ARM ISA.Gabe Black
2011-09-09StaticInst: Merge StaticInst and StaticInstBase.Gabe Black
Having two StaticInst classes, one nominally ISA dependent and the other ISA dependent, has not been historically useful and makes the StaticInst class more complicated that it needs to be. This change merges StaticInstBase into StaticInst.
2011-04-15includes: sort all includesNathan Binkert
2011-04-04ARM: Remove debugging warn that was accidently left in.Ali Saidi
2011-03-17ARM: Fix subtle bug in LDM.Ali Saidi
If the instruction faults mid-op the base register shouldn't be written back.
2011-03-17ARM: Identify branches as conditional or unconditional and direct or indirect.Ali Saidi
2011-03-17ARM: Fix RFE macrop.Matt Horsnell
This changes the RFE macroop into 3 microops: URa = [sp]; URb = [sp+4]; // load CPSR,PC values from stack sp = sp + offset; // optionally auto-increment PC = URa; CPSR = URb; // write to the PC and CPSR. Importantly: - writing to PC is handled in the last micro-op. - loading occurs prior to state changes.
2011-01-18ARM: The ARM decoder should not panic when decoding undefined holes is arch.Matt Horsnell
This can abort simulations when the fetch unit runs ahead and speculatively decodes instructions that are off the execution path.
2011-01-18ARM: fix mismatched new/delete.Ali Saidi
2010-11-15ARM: Use the correct delete operator for RFEAli Saidi
2010-11-08ARM: Make all ARM uops delayed commit.Ali Saidi
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.
2010-10-01ARM: Clean up use of TBit and JBit.Ali Saidi
Rather tha constantly using ULL(1) << PcXBitShift define those directly. Additionally, add some helper functions to further clean up the code.