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2013-09-30x86: Add support routines to load and store 80-bit floatsAndreas Sandberg
The x87 FPU on x86 supports extended floating point. We currently handle all floating point on x86 as double and don't support 80-bit loads/stores. This changeset add a utility function to load and convert 80-bit floats to doubles (loadFloat80) and another function to store doubles as 80-bit floats (storeFloat80). Both functions use libfputils to do the conversion in software. The functions are currently not used, but are required to handle floating point in KVM and to properly support all x87 loads/stores.
2013-09-19x86: Add support routines to convert between x87 tag formatsAndreas Sandberg
This changeset adds the convX87XTagsToTags() and convX87TagsToXTags() which convert between the tag formats in the FTW register and the format used in the xsave area. The conversion from to the x87 FTW representation is currently loses some information since it does not reconstruct the valid/zero/special flags which are not included in the xsave representation.
2013-06-18x86: Add support for maintaining the x87 tag wordAndreas Sandberg
The current implementation of the x87 never updates the x87 tag word. This is currently not a big issue since the simulated x87 never checks for stack overflows, however this becomes an issue when switching between a virtualized CPU and a simulated CPU. This changeset adds support, which is enabled by default, for updating the tag register to every floating point microop that updates the stack top using the spm mechanism. The new tag words is generated by the helper function X86ISA::genX87Tags(). This function is currently limited to flagging a stack position as valid or invalid and does not try to distinguish between the valid, zero, and special states.
2013-06-18x86: Fix loading of floating point constantsAndreas Sandberg
This changeset actually fixes two issues: * The lfpimm instruction didn't work correctly when applied to a floating point constant (it did work for integers containing the bit string representation of a constant) since it used reinterpret_cast to convert a double to a uint64_t. This caused a compilation error, at least, in gcc 4.6.3. * The instructions loading floating point constants in the x87 processor didn't work correctly since they just stored a truncated integer instead of a double in the floating point register. This changeset fixes the old microcode by using lfpimm instruction instead of the limm instructions.
2013-06-18x86: Add helper functions to access rflagsAndreas Sandberg
The rflags register is spread across several different registers. Most of the flags are stored in MISCREG_RFLAGS, but some are stored in microcode registers. When accessing RFLAGS, we need to reconstruct it from these registers. This changeset adds two functions, X86ISA::getRFlags() and X86ISA::setRFlags(), that take care of this magic.
2012-03-19gcc: Clean-up of non-C++0x compliant code, first stepsAndreas Hansson
This patch cleans up a number of minor issues aiming to get closer to compliance with the C++0x standard as interpreted by gcc and clang (compile with std=c++0x and -pedantic-errors). In particular, the patch cleans up enums where the last item was succeded by a comma, namespaces closed by a curcly brace followed by a semi-colon, and the use of the GNU-extension typeof (replaced by templated functions). It does not address variable-length arrays, zero-size arrays, anonymous structs, range expressions in switch statements, and the use of long long. The generated CPU code also has a large number of issues that remain to be fixed, mainly related to overflows in implicit constant conversion (due to shifts).
2011-10-30X86: Get rid of more uses of FULL_SYSTEM.Gabe Black
2011-05-13Trace: Allow printing ASIDs and selectively tracing based on user/kernel code.Chander Sudanthi
Debug flags are ExecUser, ExecKernel, and ExecAsid. ExecUser and ExecKernel are set by default when Exec is specified. Use minus sign with ExecUser or ExecKernel to remove user or kernel tracing respectively.
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.
2010-10-15GetArgument: Rework getArgument so that X86_FS compiles again.Gabe Black
When no size is specified for an argument, push the decision about what size to use into the ISA by passing a size of -1.
2010-10-01Debug: Implement getArgument() and function skipping for ARM.Ali Saidi
In the process make add skipFuction() to handle isa specific function skipping instead of ifdefs and other ugliness. For almost all ABIs, 64 bit arguments can only start in even registers. Size is now passed to getArgument() so that 32 bit systems can make decisions about register selection for 64 bit arguments. The number argument is now passed by reference because getArgument() will need to change it based on the size of the argument and the current argument number. For ARM, if the argument number is odd and a 64-bit register is requested the number must first be incremented to because all 64 bit arguments are passed in an even argument register. Then the number will be incremented again to access both halves of the argument.
2010-09-14CPU: Trim unnecessary includes from some common files.Gabe Black
This reduces the scope of those includes and makes it less likely for there to be a dependency loop. This also moves the hashing functions associated with ExtMachInst objects to be with the ExtMachInst definitions and out of utility.hh.
2010-08-23X86: Create a directory for files that define register indexes.Gabe Black
This is to help tidy up arch/x86. These files should not be used external to the ISA. --HG-- rename : src/arch/x86/apicregs.hh => src/arch/x86/regs/apic.hh rename : src/arch/x86/floatregs.hh => src/arch/x86/regs/float.hh rename : src/arch/x86/intregs.hh => src/arch/x86/regs/int.hh rename : src/arch/x86/miscregs.hh => src/arch/x86/regs/misc.hh rename : src/arch/x86/segmentregs.hh => src/arch/x86/regs/segment.hh
2010-08-23ISA: Get rid of old, unused utility functions cluttering up the ISAs.Gabe Black
2010-05-23copyright: Change HP copyright on x86 code to be more friendlyNathan Binkert
2009-08-03X86: Fix segment override prefixes on instructions that use rbp/rsp and a ↵Gabe Black
displacement.
2009-07-08Registers: Add a registers.hh file as an ISA switched header.Gabe Black
This file is for register indices, Num* constants, and register types. copyRegs and copyMiscRegs were moved to utility.hh and utility.cc. --HG-- rename : src/arch/alpha/regfile.hh => src/arch/alpha/registers.hh rename : src/arch/arm/regfile.hh => src/arch/arm/registers.hh rename : src/arch/mips/regfile.hh => src/arch/mips/registers.hh rename : src/arch/sparc/regfile.hh => src/arch/sparc/registers.hh rename : src/arch/x86/regfile.hh => src/arch/x86/registers.hh
2009-07-08Registers: Add an ISA object which replaces the MiscRegFile.Gabe Black
This object encapsulates (or will eventually) the identity and characteristics of the ISA in the CPU.
2009-05-17includes: sort includes againNathan Binkert
2009-05-17types: Move stuff for global types into src/base/types.hhNathan Binkert
--HG-- rename : src/sim/host.hh => src/base/types.hh
2009-02-25X86: Implement inUserMode for x86.Gabe Black
2007-10-07X86: Make initCPU and startupCPU do something basic.Gabe Black
--HG-- extra : convert_revision : 1a04f4402f4f31e4e5cd482c7983d853fe117df5
2007-09-24X86: Get X86_FS to compile.Gabe Black
--HG-- extra : convert_revision : fb973bcf13648876d5691231845dd47a2be50f01
2007-06-19Get rid of the immediate and displacement components of the EmulEnv struct ↵Gabe Black
and use them directly out of the instruction. The extra copies are conceptually realistic but are just innefficient as implemented. Also don't use the zeroeth microcode register for general storage since it's now the zero register, and implement a load and a store microops. --HG-- extra : convert_revision : 0686296ca8b72940d961ecc6051063bfda1e932d
2007-06-14Put the mode in the ExtMachInst.Gabe Black
--HG-- extra : convert_revision : 7fc6567ab3d35c06901e6c8a0435f7cab819e17e
2007-04-06Clean up the code a little, fix (I think) a perceived problem with immediate ↵Gabe Black
sizes, and sign extend the 32-bit-acting-like-64-bit-immediates. --HG-- extra : convert_revision : e59b747198cc79d50045bd2dc45b2e2b97bbffcc
2007-04-04Made x86 ExtMachInsts distinguishable from each other by defining a real == ↵Gabe Black
and a real hash function. --HG-- extra : convert_revision : 30f29a36f6ab44e67e62aaf81b685fbe1267c746
2007-03-15Compile fixGabe Black
--HG-- extra : convert_revision : 4a66d04404beee9656e3e33089afcec10d7ee5ff
2007-03-15Merge zizzer.eecs.umich.edu:/bk/newmemGabe Black
into ahchoo.blinky.homelinux.org:/home/gblack/m5/newmem-x86 src/arch/mips/utility.hh: src/arch/x86/SConscript: Hand merge --HG-- extra : convert_revision : 0ba457aab52bf6ffc9191fd1fe1006ca7704b5b0
2007-03-15Make the predecoder an object with it's own switched header file. Start ↵Gabe Black
adding predecoding functionality to x86. src/arch/SConscript: src/arch/alpha/utility.hh: src/arch/mips/utility.hh: src/arch/sparc/utility.hh: src/cpu/base.hh: src/cpu/o3/fetch.hh: src/cpu/o3/fetch_impl.hh: src/cpu/simple/atomic.cc: src/cpu/simple/base.cc: src/cpu/simple/base.hh: src/cpu/static_inst.hh: src/arch/alpha/predecoder.hh: src/arch/mips/predecoder.hh: src/arch/sparc/predecoder.hh: Make the predecoder an object with it's own switched header file. --HG-- extra : convert_revision : 77206e29089130e86b97164c30022a062699ba86
2007-03-13Replaced makeExtMI with predecode.Gabe Black
Removed the getOpcode function from StaticInst which only made sense for Alpha. Started implementing the x86 predecoder. --HG-- extra : convert_revision : a13ea257c8943ef25e9bc573024a99abacf4a70d
2007-03-09implement ipi stufff for SPARCAli Saidi
src/arch/alpha/utility.hh: src/arch/mips/utility.hh: src/arch/sparc/utility.hh: src/arch/x86/utility.hh: add hook for system to startup the cpu or not... in the case of FS sparc, only the first cpu would get spunup.. the rest sit in an idle state until they get an ipi src/arch/sparc/isa/decoder.isa: handle writable bits of strandstatus register in miscregfile src/arch/sparc/miscregfile.hh: some constants for the strand status register src/arch/sparc/ua2005.cc: properly implement the strand status register src/dev/sparc/iob.cc: implement ipi generation properly src/sim/system.cc: call into the ISA to start the CPU (or not) --HG-- extra : convert_revision : 0003b2032337d8a031a9fc044da726dbb2a9e36f
2007-03-05Added missing include.Gabe Black
--HG-- extra : convert_revision : 9d00209e5c0ae8aa5ac37f9558627ee212a72c9b
2007-03-05Added stub implementations or prototypes for all the functions in this file.Gabe Black
--HG-- extra : convert_revision : c0170eae8aeae130f81618ae49a60f879c2b523f
2007-03-03Add build hooks for x86.Gabe Black
--HG-- extra : convert_revision : 438eb74f14e6ea60bab5012110f3946c9213786e