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2018-11-21x86: Get rid of a problematic DPRINTF in PremFp.Gabe Black
This DPRINTF shouldn't be necessary since it shows the operands and results of the instruction which the trace should already make available. Also by passing the destination register to DPRINTF, the ISA parser will assume that it's also a source when tracking dependencies. Change-Id: I820387c82578bdbb8d2e3d91652a6c0185077f54 Reviewed-on: https://gem5-review.googlesource.com/c/14475 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-05-24x86: Add op classes to the MediaOps.Gabe Black
The ISA parser had been assuming these microops were all FloatAddOp which is usually not correct. Change-Id: Ic54881d16f16b50c3d6a8c74b94bff9ae3b1f43e Reviewed-on: https://gem5-review.googlesource.com/10541 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com> Reviewed-by: Tariq Azmy <tariqslayer01@gmail.com> Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
2018-05-02arch-x86: implement movntps/movntpd SSE instsSteve Reinhardt
These are non-temporal packed SSE stores. Change-Id: I526cd6551b38d6d35010bc6173f23d017106b466 Reviewed-on: https://gem5-review.googlesource.com/9861 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-05-02x86: Add a ld/st microop flag for marking an access uncacheable.Gabe Black
This percolates down to the memory request object which will have its "UNCACHEABLE" flag set. Change-Id: Ie73f4249bfcd57f45a473f220d0988856715a9ce Reviewed-on: https://gem5-review.googlesource.com/9881 Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
2018-03-15x86: Add bitfields which can gather/scatter bases and limits.Gabe Black
Add bitfields which can gather/scatter base and limit fields within "normal" segment descriptors, and in TSS descriptors which have the same bitfields in the same positions for those two values. This centralizes the code which manages those bitfields and makes it less likely that a local implementation will be buggy. Change-Id: I9809aa626fc31388595c3d3b225c25a0ec6a1275 Reviewed-on: https://gem5-review.googlesource.com/7661 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-03-14x86: Simplify the implementations of RDTSC and RDTSCP slightly.Gabe Black
These instructions originally read the TSC into t1 and then unpacked it into eax and edx using a move, a right shift, and then another move. We can combine the second shift and move. The shift will move the upper 32 bits into the lower 32 bits, and clear the upper 32 bits to zero. This has the same effect as moving the lower 32 bits post-shift into another register, since the upper 32 bits will be cleared to zero based on x86 partial register access semantics. Change-Id: Iba85e501c7e84147ad0047f5c555e61bdf8f032b Reviewed-on: https://gem5-review.googlesource.com/9044 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-03-14x86: Implement the RDTSCP instruction.Gabe Black
This is very similar to RDTSC, except that it requires all younger instructions to retire before it completes, and it writes the TSC_AUX MSR into ECX. I've added an mfence as an iniitial microop to ensure that memory accesses complete before RDTSCP runs, and added an rdval microop at the end to read the TSC_AUX value into ECX. Change-Id: I9766af562b7fd0c22e331b56e06e8818a9e268c9 Reviewed-on: https://gem5-review.googlesource.com/9043 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-03-14x86: Mark the RDTSC instruction as .serialize_before.Gabe Black
Change-Id: I20bf6a57ea4354aac9267845bb37b70b83d6fcde Reviewed-on: https://gem5-review.googlesource.com/9042 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-03-14x86: Replace the .serializing directive with .serialize_(before|after).Gabe Black
This makes it explicit which type of serialization you want, and also makes it possible to make a macroop serialize before. The old serializing directive was renamed .serialize_after in the microcode assembler, and throughout the microcode implementation, and its behavior is unchanged. More specifically, it still marks the last microop within the macroop as IsSerializing and IsSerializeAfter. The new .serialize_before directive does something similar and marks the first microop as IsSerializing and IsSerializeBefore. Change-Id: Ia53466c734c651c65400809de7ef903c4a6c3e7e Reviewed-on: https://gem5-review.googlesource.com/9041 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2018-01-23arch-x86: Adding clflush, clflushopt, clwb instructionsSwapnil Haria
This patch adds support for cache flushing instructions in x86. It piggybacks on support for similar instructions in arm ISA added by Nikos Nikoleris. I have tested each instruction using microbenchmarks. Change-Id: I72b6b8dc30c236a21eff7958fa231f0663532d7d Reviewed-on: https://gem5-review.googlesource.com/7401 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-12-23riscv,x86: Stop using the arch Nop machine instruction unnecessarily.Gabe Black
That particular ExtMachInst is a convenient placeholder, but a value of 0 in RISCV or a static uninitialized ExtMachInst (which will therefore be all zeroes) on x86 works just as well, and removes the need for an ISA specific constant. Also, the idea of a universal Nop doesn't always make sense since it could be that what, exactly, doesn't do anything depends on context which would be lost on a constant value of an ExtMachInst. For instance, the value of an ExtMachInst that makes sense might depend on what mode the CPU was in, etc. Change-Id: I1f1a43a5c607a667e11b79bcf6e059e4f7141b3f Reviewed-on: https://gem5-review.googlesource.com/6825 Reviewed-by: Gabe Black <gabeblack@google.com> Reviewed-by: Alec Roelke <ar4jc@virginia.edu> Maintainer: Gabe Black <gabeblack@google.com>
2017-12-14misc: Updates for gcc7.2 for x86Jason Lowe-Power
GCC 7.2 is much stricter than previous GCC versions. The following changes are needed: * There is now a warning if there is an implicit fallthrough between two case statments. C++17 adds the [[fallthrough]]; declaration. However, to support non C++17 standards (i.e., C++11), we use M5_FALLTHROUGH. M5_FALLTHROUGH checks for [[fallthrough]] compliant C++17 compiler and if that doesn't exist, it defaults to nothing (no older compilers generate warnings). * The above resulted in a couple of bugs that were found. This is noted in the review request on gerrit. * throw() for dynamic exception specification is deprecated * There were a couple of new uninitialized variable warnings * Can no longer perform bitwise operations on a bool. * Must now include <functional> for std::function * Compiler bug for void* lambda. Changed to auto as work around. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82878 Change-Id: I5d4c782a4e133fa4cdb119e35d9aff68c6e2958e Signed-off-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-on: https://gem5-review.googlesource.com/5802 Reviewed-by: Gabe Black <gabeblack@google.com>
2017-12-14x86: Use operand size 4 when it would be 2 for cmpxchg8b.Gabe Black
This means the instruction is treated as cmpxchg8b when the effective operand size is 16 bits. Change-Id: I4d9bb295f96097e1746a9bbccb2c579d14738fab Reviewed-on: https://gem5-review.googlesource.com/6603 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-12-13arm,sparc,x86,base,cpu,sim: Replace the Twin(32|64)_t types with.Gabe Black
Replace them with std::array<>s. Change-Id: I76624c87a1cd9b21c386a96147a18de92b8a8a34 Reviewed-on: https://gem5-review.googlesource.com/6602 Maintainer: Gabe Black <gabeblack@google.com> Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2017-12-13x86: Rework how "split" loads/stores are handled.Gabe Black
Explicitly separate the way the data is represented in the underlying representation from how it's represented in the instruction. In order to make the ISA parser happy, the Mem operand needs to have a single, particular type. To handle that with scalar types, we just used uint64_ts and then worked with values that were smaller than the maximum we could hold. To work with these new array values, we also use an underlying uint64_t for each element. To make accessing the underlying memory system more natural, when we go to actually read or write values, we translate the access into an array of the actual, correct underlying type. That way we don't have non-exact asserts which confuse gcc, or weird endianness conversion which assumes that the data should be flipped 8 bytes at a time. Because the functions involved are generally inline, the syntactic niceness should all boil off, and the final implementation in the binary should be simple and efficient for the given data types. Change-Id: I14ce7a2fe0dc2cbaf6ad4a0d19f743c45ee78e26 Reviewed-on: https://gem5-review.googlesource.com/6582 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-12-06x86: Split apart x87's FSW and TOP, and add a missing break.Gabe Black
The FSW and TOP values are technically part of the same register, but they have very different behaviors. One of them can be renamed and float along without affecting global state, while the other requires serialization. They just need to *look* like the same register when read by the user. Also, there was a missing break in setMiscRegNoEffect. Change-Id: If58de0f566f65068208240f4001209fb9e1826d6 Reviewed-on: https://gem5-review.googlesource.com/6441 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-12-05x86: LOOP's operand size defaults to 64 bits in 64 bit mode.Gabe Black
The microcode for those instructions needs a directive which overrides that setting in the instructions emulation environment. Reported-by: Matt Sinclair <mattdsinclair@gmail.com> Change-Id: I474d938c0b3cf01da92ec817a58b08de783f1967 Reviewed-on: https://gem5-review.googlesource.com/6301 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-12-04misc: Rename misc.(hh|cc) to logging.(hh|cc)Gabe Black
These files aren't a collection of miscellaneous stuff, they're the definition of the Logger interface, and a few utility macros for calling into that interface (panic, warn, etc.). Change-Id: I84267ac3f45896a83c0ef027f8f19c5e9a5667d1 Reviewed-on: https://gem5-review.googlesource.com/6226 Reviewed-by: Brandon Potter <Brandon.Potter@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-11-07alpha,arm,mips,power,riscv,sparc,x86: Merge exec decl templates.Gabe Black
In the ISA instruction definitions, some classes were declared with execute, etc., functions outside of the main template because they had CPU specific signatures and would need to be duplicated with each CPU plugged into them. Now that the instructions always just use an ExecContext, there's no reason for those templates to be separate. This change folds those templates together. Change-Id: I13bda247d3d1cc07c0ea06968e48aa5b4aace7fa Reviewed-on: https://gem5-review.googlesource.com/5401 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-by: Alec Roelke <ar4jc@virginia.edu> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2017-11-02alpha,arm,mips,power,riscv,sparc,x86,isa: De-specialize ExecContexts.Gabe Black
The ISA parser used to generate different copies of exec functions for each exec context class a particular CPU wanted to use. That's since been changed so that those functions take a pointer to the base ExecContext, so the code which would generate those extra functions can be removed, and some functions which used to be templated on an ExecContext subclass can be untemplated, or minimally less templated. Now that some functions aren't going to be instantiated multiple times with different signatures, there are also opportunities to collapse templates and make many instruction definitions simpler within the parser. Since those changes will be less mechanical, they're left for later changes and will probably be done in smaller increments. Change-Id: I0015307bb02dfb9c60380b56d2a820f12169ebea Reviewed-on: https://gem5-review.googlesource.com/5381 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
2017-09-27arch-x86: fix CondInst decoding for MOV to Control RegistersBjoern A. Zeeb
MOV Rd,Cd is MR encoded but the control register is operand 2 not operand 1 hence this needs to be MODRM_REG not MODRM_RM. While MOV Cd,Rd is RM encoded registers are also swapped, so it also needs to be MODRM_REG as well (as it already correctly is). This fixes incorrect UD2 reportings leading to invalid traps reported in O3 on X86 FS introduced with 4e939a7 . Change-Id: Ib33c8ba87b00e0264d33da44fff64ed9e4d2d9d8 Reviewed-on: https://gem5-review.googlesource.com/4861 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Jason Lowe-Power <jason@lowepower.com>
2017-08-28x86: Use the new CondInst format for moves to/from control registers.Gabe Black
The condition is whether the control register index is valid. Change-Id: I8a225fcfd4955032b5bbf7d3392ee5bcc7d6bc64 Reviewed-on: https://gem5-review.googlesource.com/4581 Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-08-28x86: Add a "CondInst" format for conditionally decoded instructions.Gabe Black
A condition can be specified which will tell the decoder whether to return the instruction being requested, or, if the condition fails, UD2. Change-Id: I0f1c075deb10754ce1dd88be1726a196294e41fd Reviewed-on: https://gem5-review.googlesource.com/4580 Reviewed-by: Michael LeBeane <Michael.Lebeane@amd.com> Maintainer: Gabe Black <gabeblack@google.com>
2017-07-05cpu: Simplify the rename interface and use RegIdRekai Gonzalez-Alberquilla
With the hierarchical RegId there are a lot of functions that are redundant now. The idea behind the simplification is that instead of having the regId, telling which kind of register read/write/rename/lookup/etc. and then the function panic_if'ing if the regId is not of the appropriate type, we provide an interface that decides what kind of register to read depending on the register type of the given regId. Change-Id: I7d52e9e21fc01205ae365d86921a4ceb67a57178 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> [ Fix RISCV build issues ] Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/2702
2017-07-05arch, cpu: Architectural Register structural indexingNathanael Premillieu
Replace the unified register mapping with a structure associating a class and an index. It is now much easier to know which class of register the index is referring to. Also, when adding a new class there is no need to modify existing ones. Change-Id: I55b3ac80763702aa2cd3ed2cbff0a75ef7620373 Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com> [ Fix RISCV build issues ] Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com> Reviewed-on: https://gem5-review.googlesource.com/2700
2017-05-26x86: Rework how VEX prefixes are decoded.Gabe Black
Remove redundant information from the ExtMachInst, hash the vex information to ensure the decode cache works properly, print the vex info when printing an ExtMachInst, consider the vex info when comparing two ExtMachInsts, fold the info from the vex prefixes into existing settings, remove redundant decode code, handle vex prefixes one byte at a time and don't bother building up the entire prefix, and let instructions that care about vex use it in their implementation, instead of developing an entire parallel decode tree. This also eliminates the error prone vex immediate decode table which was incomplete and would result in an out of bounds access for incorrectly encoded instructions or when the CPU was mispeculating, as it was (as far as I can tell) redundant with the tables that already existed for two and three byte opcodes. There were differences, but I think those may have been mistakes based on the documentation I found. Also, in 32 bit mode, the VEX prefixes might actually be LDS or LES instructions which are still legal in that mode. A valid VEX prefix would look like an LDS/LES with an otherwise invalid modrm encoding, so use that as a signal to abort processing the VEX and turn the instruction into an LES/LDS as appropriate. Change-Id: Icb367eaaa35590692df1c98862f315da4c139f5c Reviewed-on: https://gem5-review.googlesource.com/3501 Reviewed-by: Joe Gross <joe.gross@amd.com> Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
2017-05-16x86: Fix the multiplication microops.Gabe Black
If the operands were 64 bit, an intermediate calculation could lose a carry bit. This change rearranges that intermediate calculation if the operand width is large, and reworks the microop implementation in general in an attempt to make it easier to understand. Change-Id: Ib36333f3f2695a33cd9623e43682de22ebd2e7ea Reviewed-on: https://gem5-review.googlesource.com/3381 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com> Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
2015-07-20syscall_emul: [patch 13/22] add system call retry capabilityBrandon Potter
This changeset adds functionality that allows system calls to retry without affecting thread context state such as the program counter or register values for the associated thread context (when system calls return with a retry fault). This functionality is needed to solve problems with blocking system calls in multi-process or multi-threaded simulations where information is passed between processes/threads. Blocking system calls can cause deadlock because the simulator itself is single threaded. There is only a single thread servicing the event queue which can cause deadlock if the thread hits a blocking system call instruction. To illustrate the problem, consider two processes using the producer/consumer sharing model. The processes can use file descriptors and the read and write calls to pass information to one another. If the consumer calls the blocking read system call before the producer has produced anything, the call will block the event queue (while executing the system call instruction) and deadlock the simulation. The solution implemented in this changeset is to recognize that the system calls will block and then generate a special retry fault. The fault will be sent back up through the function call chain until it is exposed to the cpu model's pipeline where the fault becomes visible. The fault will trigger the cpu model to replay the instruction at a future tick where the call has a chance to succeed without actually going into a blocking state. In subsequent patches, we recognize that a syscall will block by calling a non-blocking poll (from inside the system call implementation) and checking for events. When events show up during the poll, it signifies that the call would not have blocked and the syscall is allowed to proceed (calling an underlying host system call if necessary). If no events are returned from the poll, we generate the fault and try the instruction for the thread context at a distant tick. Note that retrying every tick is not efficient. As an aside, the simulator has some multi-threading support for the event queue, but it is not used by default and needs work. Even if the event queue was completely multi-threaded, meaning that there is a hardware thread on the host servicing a single simulator thread contexts with a 1:1 mapping between them, it's still possible to run into deadlock due to the event queue barriers on quantum boundaries. The solution of replaying at a later tick is the simplest solution and solves the problem generally.
2017-02-10x86: Fix implicit stack addressing in 64-bit modeJason Lowe-Power
When in 64-bit mode, if the stack is accessed implicitly by an instruction the alternate address prefix should be ignored if present. This patch adds an extra flag to the ldstop which signifies when the address override should be ignored. Then, for all of the affected instructions, this patch adds two options to the ld and st opcode to use the current stack addressing mode for all addresses and to ignore the AddressSizeFlagBit. Finally, this patch updates the x86 TLB to not truncate the address if it is in 64-bit mode and the IgnoreAddrSizeFlagBit is set. This fixes a problem when calling __libc_start_main with a binary that is linked with a recent version of ld. This version of ld uses the address override prefix (0x67) on the call instruction instead of a nop. Note: This has not been tested in compatibility mode and only the call instruction with the address override prefix has been tested. See [1] page 9 (pdf page 45) For instructions that are affected see [1] page 519 (pdf page 555). [1] http://support.amd.com/TechDocs/24594.pdf Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
2016-11-21x86: fix issue with casting in Cvtf2iTony Gutierrez
UBSAN flags this operation because it detects that arg is being cast directly to an unsigned type, argBits. this patch fixes this by first casting the value to a signed int type, then reintrepreting the raw bits of the signed int into argBits.
2016-10-26dev: Add m5 op to toggle synchronization for dist-gem5.Michael LeBeane
This patch adds the ability for an application to request dist-gem5 to begin/ end synchronization using an m5 op. When toggling on sync, all nodes agree on the next sync point based on the maximum of all nodes' ticks. CPUs are suspended until the sync point to avoid sending network messages until sync has been enabled. Toggling off sync acts like a global execution barrier, where all CPUs are disabled until every node reaches the toggle off point. This avoids tricky situations such as one node hitting a toggle off followed by a toggle on before the other nodes hit the first toggle off.
2016-02-06x86: revamp cmpxchg8b/cmpxchg16b implementationAlexandru Dutu
The previous implementation did a pair of nested RMW operations, which isn't compatible with the way that locked RMW operations are implemented in the cache models. It was convenient though in that it didn't require any new micro-ops, and supported cmpxchg16b using 64-bit memory ops. It also worked in AtomicSimpleCPU where atomicity was guaranteed by the core and not by the memory system. It did not work with timing CPU models though. This new implementation defines new 'split' load and store micro-ops which allow a single memory operation to use a pair of registers as the source or destination, then uses a single ldsplit/stsplit RMW pair to implement cmpxchg. This patch requires support for 128-bit memory accesses in the ISA (added via a separate patch) to support cmpxchg16b.
2016-02-06arch, x86: add support for arrays as memory operandsSteve Reinhardt
Although the cache models support wider accesses, the ISA descriptions assume that (for the most part) memory operands are integer types, which makes it difficult to define instructions that do memory accesses larger than 64 bits. This patch adds some generic support for memory operands that are arrays of uint64_t, and specifically a 'u2qw' operand type for x86 that is an array of 2 uint64_ts (128 bits). This support is unused at this point, but will be needed shortly for cmpxchg16b. Ideally the 128-bit SSE memory accesses will also be rewritten to use this support. Support for 128-bit accesses could also have been added using the gcc __int128_t extension, which would have been less disruptive. However, although clang also supports __int128_t, it's still non-standard. Also, more importantly, this approach creates a path to defining 256- and 512-byte operands as well, which will be useful for eventual AVX support.
2016-02-06style: remove trailing whitespaceSteve Reinhardt
Result of running 'hg m5style --skip-all --fix-white -a'.
2016-01-17cpu. arch: add initiateMemRead() to ExecContext interfaceSteve Reinhardt
For historical reasons, the ExecContext interface had a single function, readMem(), that did two different things depending on whether the ExecContext supported atomic memory mode (i.e., AtomicSimpleCPU) or timing memory mode (all the other models). In the former case, it actually performed a memory read; in the latter case, it merely initiated a read access, and the read completion did not happen until later when a response packet arrived from the memory system. This led to some confusing things, including timing accesses being required to provide a pointer for the return data even though that pointer was only used in atomic mode. This patch splits this interface, adding a new initiateMemRead() function to the ExecContext interface to replace the timing-mode use of readMem(). For consistency and clarity, the readMemTiming() helper function in the ISA definitions is renamed to initiateMemRead() as well. For x86, where the access size is passed in explicitly, we can also get rid of the data parameter at this level. For other ISAs, where the access size is determined from the type of the data parameter, we have to keep the parameter for that purpose.
2016-01-07pseudo inst,util: Add optional key to initparam pseudo instructionGabor Dozsa
The key parameter can be used to read out various config parameters from within the simulated software.
2015-10-06x86: implement rcpps and rcpss SSE instsSteve Reinhardt
These are packed single-precision approximate reciprocal operations, vector and scalar versions, respectively. This code was basically developed by copying the code for sqrtps and sqrtss. The mrcp micro-op was simplified relative to msqrt since there are no double-precision versions of this operation.
2015-10-06x86: implement fild, fucomi, and fucomip x87 instsSteve Reinhardt
fild loads an integer value into the x87 top of stack register. fucomi/fucomip compare two x87 register values (the latter also doing a stack pop). These instructions are used by some versions of GNU libstdc++.
2015-07-20x86: x86 instruction-implementation bug fixesDavid Hashe
Added explicit data sizes and an opcode type for correct execution.
2015-07-17x86: decode instructions with vex prefixNilay Vaish
This patch updates the x86 decoder so that it can decode instructions with vex prefix. It also updates the isa with opcodes from vex opcode maps 1, 2 and 3. Note that none of the instructions have been implemented yet. The implementations would be provided in due course of time.
2015-07-04x86: Adjust the size of the values written to the x87 misc registersNikos Nikoleris
All x87 misc registers are implemented in an array of 64 bit values but in real hardware the size of some of these registers is smaller. Previsouly all 64 bits where incorrectly set and then later read. To ensure correctness we mask the value in setMiscRegNoEffect to write only the valid bits. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-04-29x86: change divide-by-zero fault to divide-errorNilay Vaish
Same exception is raised whether division with zero is performed or the quotient is greater than the maximum value that the provided space can hold. Divide-by-Zero is the AMD terminology, while Divide-Error is Intel's.
2015-04-13x86: implements x87 mult/div instructionsNilay Vaish
2015-04-03x86: fix debug trace output for mwaitLena Olson
When running with the Exec flag, the mwait instruction attempted to print out its source registers, which were never actually initialized. This led to sporadic assertion failures when the value stored there was invalid. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-03-23mem: rename Locked/LOCKED to LockedRMW/LOCKED_RMWSteve Reinhardt
Makes x86-style locked operations even more distinct from LLSC operations. Using "locked" by itself should be obviously ambiguous now.
2015-01-10x86 : fxsave and fxrestore missing template codeEmilio Castillo
This patch corrects the FXSAVE and FXRSTOR Macroops. The actual code used for saving/restore the FP registers is in the file but it was not used. The FXSAVE and FXRSTOR instructions are used in the kernel for saving and loading the state of the mmx,xmm and fpu registers. This operation is triggered in FS by issuing a Device Not Available Fault. The cr0 register has a TS flag that is set upon each context change. Every time a task access any FP related register (SIMD as well) if the TS flag is set to one, the device not available fault is issued. The kernel saves the current state of the registers, and restore the previous state of the currently running task. Right now Gem5 lacks of this capability. the Device Not Available Fault is never issued, leading to several problems when different threads share the same CPU and SMT is not used. The PARSEC Ferret benchmark is an example of this behavior. In order to test this a hack in the atomic cpu code was done to detect if a static instruction has any FP operands and the cr0 reg TS bit is set. This check must be done in the ISA dependent code. But it seems to be tricky to access the cr0 register while executing an instruction. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-01-03x86: implements the simd128 ADDSUBPD instructionMaxime Martinasso
This patch implements the simd128 ADDSUBPD instruction for the x86 architecture. Tested with a simple program in assembly language which executes the instruction. Checked that different versions of the instruction are executed by using the execution tracing option. Committed by: Nilay Vaish <nilay@cs.wisc.edu
2014-12-04x86: Rework opcode parsing to support 3 byte opcodes properly.Gabe Black
Instead of counting the number of opcode bytes in an instruction and recording each byte before the actual opcode, we can represent the path we took to get to the actual opcode byte by using a type code. That has a couple of advantages. First, we can disambiguate the properties of opcodes of the same length which have different properties. Second, it reduces the amount of data stored in an ExtMachInst, making them slightly easier/faster to create and process. This also adds some flexibility as far as how different types of opcodes are handled, which might come in handy if we decide to support VEX or XOP instructions. This change also adds tables to support properly decoding 3 byte opcodes. Before we would fall off the end of some arrays, on top of the ambiguity described above. This change doesn't measureably affect performance on the twolf benchmark. --HG-- rename : src/arch/x86/isa/decoder/three_byte_opcodes.isa => src/arch/x86/isa/decoder/three_byte_0f38_opcodes.isa rename : src/arch/x86/isa/decoder/three_byte_opcodes.isa => src/arch/x86/isa/decoder/three_byte_0f3a_opcodes.isa
2014-11-17x86: Fix setting segment bases in real mode.Gabe Black
The data size used for actually writing the base value for the segment was the default size, but really it should set the entire value without any possible truncation.
2014-11-17x86: Fix some bugs in the real mode far jmp instruction.Gabe Black
The far pointer should be shifted right to get the selector value, not left. Also, when calculating the width of the offset, the wrong register was used in one spot.