arch, x86: Rework the debug faults and microops.

This makes the non-fatal microops advance the PC, and adds missing
functions. The *_once Faults now also can be run once per *something*.
They would previously be run once per Fault invoke function which is
common to all M5WarnOnceFaults. The warn_once microop will now warn
once per message.

Change-Id: I05974b93f3b2700077a411b243679c2ff0e8c2cb
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20739
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

x86: Stop using/defining some ISA specific register types.

These have been replaced with the generic RegVal type.

Change-Id: I75c1134212067dea43aa0903d813633e06f3d6c6
Reviewed-on: https://gem5-review.googlesource.com/c/14476
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch: cpu: Rename *FloatRegBits* to *FloatReg*.

Now that there's no plain FloatReg, there's no reason to distinguish
FloatRegBits with a special suffix since it's the only way to read or
write FP registers.

Change-Id: I3a60168c1d4302aed55223ea8e37b421f21efded
Reviewed-on: https://gem5-review.googlesource.com/c/14460
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>

x86: Get rid of a problematic DPRINTF in PremFp.

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>

x86: Add op classes to the MediaOps.

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>

x86: Add a ld/st microop flag for marking an access uncacheable.

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>

x86: Add bitfields which can gather/scatter bases and limits.

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>

arch-x86: Adding clflush, clflushopt, clwb instructions

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>

riscv,x86: Stop using the arch Nop machine instruction unnecessarily.

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>

misc: Updates for gcc7.2 for x86

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>

x86: Rework how "split" loads/stores are handled.

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>

alpha,arm,mips,power,riscv,sparc,x86: Merge exec decl templates.

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>

alpha,arm,mips,power,riscv,sparc,x86,isa: De-specialize ExecContexts.

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>

cpu: Simplify the rename interface and use RegId

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

arch, cpu: Architectural Register structural indexing

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

x86: Fix the multiplication microops.

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>

x86: Fix implicit stack addressing in 64-bit mode

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>

x86: fix issue with casting in Cvtf2i

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.

x86: revamp cmpxchg8b/cmpxchg16b implementation

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.

arch, x86: add support for arrays as memory operands

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.

style: remove trailing whitespace

Result of running 'hg m5style --skip-all --fix-white -a'.

cpu. arch: add initiateMemRead() to ExecContext interface

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.

x86: implement rcpps and rcpss SSE insts

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.

x86: implement fild, fucomi, and fucomip x87 insts

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++.

x86: change divide-by-zero fault to divide-error
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.

mem: rename Locked/LOCKED to LockedRMW/LOCKED_RMW

Makes x86-style locked operations even more distinct from
LLSC operations. Using "locked" by itself should be
obviously ambiguous now.

arch: Use shared_ptr for all Faults

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".

x86: Flag instructions that call suspend as IsQuiesce

The o3 cpu relies upon instructions that suspend a thread context being
flagged as "IsQuiesce". If they are not, unpredictable behavior can occur.
This patch fixes that for the x86 ISA.

x86: set op class of two fp instructions
This patch sets op class of two fp instructions: movfp and pop x87 stack
as IntAluOp since these instructions do not make use of the fp alu.

arch: teach ISA parser how to split code across files

This patch encompasses several interrelated and interdependent changes
to the ISA generation step. The end goal is to reduce the size of the
generated compilation units for instruction execution and decoding so
that batch compilation can proceed with all CPUs active without
exhausting physical memory.

The ISA parser (src/arch/isa_parser.py) has been improved so that it can
accept 'split [output_type];' directives at the top level of the grammar
and 'split(output_type)' python calls within 'exec {{ ... }}' blocks.
This has the effect of "splitting" the files into smaller compilation
units. I use air-quotes around "splitting" because the files themselves
are not split, but preprocessing directives are inserted to have the same
effect.

Architecturally, the ISA parser has had some changes in how it works.
In general, it emits code sooner. It doesn't generate per-CPU files,
and instead defers to the C preprocessor to create the duplicate copies
for each CPU type. Likewise there are more files emitted and the C
preprocessor does more substitution that used to be done by the ISA parser.

Finally, the build system (SCons) needs to be able to cope with a
dynamic list of source files coming out of the ISA parser. The changes
to the SCons{cript,truct} files support this. In broad strokes, the
targets requested on the command line are hidden from SCons until all
the build dependencies are determined, otherwise it would try, realize
it can't reach the goal, and terminate in failure. Since build steps
(i.e. running the ISA parser) must be taken to determine the file list,
several new build stages have been inserted at the very start of the
build. First, the build dependencies from the ISA parser will be emitted
to arch/$ISA/generated/inc.d, which is then read by a new SCons builder
to finalize the dependencies. (Once inc.d exists, the ISA parser will not
need to be run to complete this step.) Once the dependencies are known,
the 'Environments' are made by the makeEnv() function. This function used
to be called before the build began but now happens during the build.
It is easy to see that this step is quite slow; this is a known issue
and it's important to realize that it was already slow, but there was
no obvious cause to attribute it to since nothing was displayed to the
terminal. Since new steps that used to be performed serially are now in a
potentially-parallel build phase, the pathname handling in the SCons scripts
has been tightened up to deal with chdir() race conditions. In general,
pathnames are computed earlier and more likely to be stored, passed around,
and processed as absolute paths rather than relative paths. In the end,
some of these issues had to be fixed by inserting serializing dependencies
in the build.

Minor note:
For the null ISA, we just provide a dummy inc.d so SCons is never
compelled to try to generate it. While it seems slightly wrong to have
anything in src/arch/*/generated (i.e. a non-generated 'generated' file),
it's by far the simplest solution.

arch: remove inline specifiers on all inst constrs, all ISAs

With (upcoming) separate compilation, they are useless. Only
link-time optimization could re-inline them, but ideally
feedback-directed optimization would choose to do so only for
profitable (i.e. common) instructions.

x86: correct error in emms instruction.

x86: Add support for FXSAVE, FXSAVE64, FXRSTOR, and FXRSTOR64

x86: Add support for loading 32-bit and 80-bit floats in the x87

The x87 FPU supports three floating point formats: 32-bit, 64-bit, and
80-bit floats. The current gem5 implementation supports 32-bit and
64-bit floats, but only works correctly for 64-bit floats. This
changeset fixes the 32-bit float handling by correctly loading and
rounding (using truncation) 32-bit floats instead of simply truncating
the bit pattern.

80-bit floats are loaded by first loading the 80-bits of the float to
two temporary integer registers. A micro-op (cvtint_fp80) then
converts the contents of the two integer registers to the internal FP
representation (double). Similarly, when storing an 80-bit float,
there are two conversion routines (ctvfp80h_int and cvtfp80l_int) that
convert an internal FP register to 80-bit and stores the upper 64-bits
or lower 32-bits to an integer register, which is the written to
memory using normal integer stores.

x86: Fix re-entrancy problems in x87 store instructions

X87 store instructions typically loads and pops the top value of the
stack and stores it in memory. The current implementation pops the
stack at the same time as the floating point value is loaded to a
temporary register. This will corrupt the state of the x87 stack if
the store fails. This changeset introduces a pop87 micro-instruction
that pops the stack and uses this instruction in the affected
macro-instructions to pop the stack after storing the value to memory.

x86: Add support for maintaining the x87 tag word

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.

x86: Fix loading of floating point constants

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.

x86: Make fprem like the fprem on a real x87

The current implementation of fprem simply does an fmod and doesn't
simulate any of the iterative behavior in a real fprem. This isn't
normally a problem, however, it can lead to problems when switching
between CPU models. If switching from a real CPU in the middle of an
fprem loop to a simulated CPU, the output of the fprem loop becomes
correupted. This changeset changes the fprem implementation to work
like the one on real hardware.

x86: Fix the flag handling code in FABS and FCHS

This changeset fixes two problems in the FABS and FCHS
implementation. First, the ISA parser expects the assignment in
flag_code to be a pure assignment and not an and-assignment, which
leads to the isa_parser omitting the misc reg update. Second, the FCHS
and FABS macro-ops don't set the SetStatus flag, which means that the
default micro-op version, which doesn't update FSW, is executed.

x86: add op class for int and fp microops in isa description
Currently all the integer microops are marked as IntAluOp and the floating
point microops are marked as FloatAddOp. This patch adds support for marking
different microops differently. Now IntMultOp, IntDivOp, FloatDivOp,
FloatMultOp, FloatCvtOp, FloatSqrtOp classes will be used as well. This will
help in providing different latencies for different op class.

x86: implement some of the x87 instructions
This patch implements ftan, fprem, fyl2x, fld* floating-point instructions.

x86: implements emms instruction

x86: implement fabs, fchs instructions

x86: implement x87 fp instruction fsincos
This patch implements the fsincos instruction. The code was originally written
by Vince Weaver. Gabe had made some comments about the code, but those were
never addressed. This patch addresses those comments.

X86: make use of register predication
The patch introduces two predicates for condition code registers -- one
tests if a register needs to be read, the other tests whether a register
needs to be written to. These predicates are evaluated twice -- during
construction of the microop and during its execution. Register reads
and writes are elided depending on how the predicates evaluate.

x86: Add a separate register for D flag bit
The D flag bit is part of the cc flag bit register currently. But since it
is not being used any where in the implementation, it creates an unnecessary
dependency. Hence, it is being moved to a separate register.

X86: Split Condition Code register
This patch moves the ECF and EZF bits to individual registers (ecfBit and
ezfBit) and the CF and OF bits to cfofFlag registers. This is being done
so as to lower the read after write dependencies on the the condition code
register. Ultimately we will have the following registers [ZAPS], [OF],
[CF], [ECF], [EZF] and [DF]. Note that this is only one part of the
solution for lowering the dependencies. The other part will check whether
or not the condition code register needs to be actually read. This would
be done through a separate patch.

clang/gcc: Fix compilation issues with clang 3.0 and gcc 4.6

This patch addresses a number of minor issues that cause problems when
compiling with clang >= 3.0 and gcc >= 4.6. Most importantly, it
avoids using the deprecated ext/hash_map and instead uses
unordered_map (and similarly so for the hash_set). To make use of the
new STL containers, g++ and clang has to be invoked with "-std=c++0x",
and this is now added for all gcc versions >= 4.6, and for clang >=
3.0. For gcc >= 4.3 and <= 4.5 and clang <= 3.0 we use the tr1
unordered_map to avoid the deprecation warning.

The addition of c++0x in turn causes a few problems, as the
compiler is more stringent and adds a number of new warnings. Below,
the most important issues are enumerated:

1) the use of namespaces is more strict, e.g. for isnan, and all
headers opening the entire namespace std are now fixed.

2) another other issue caused by the more stringent compiler is the
narrowing of the embedded python, which used to be a char array,
and is now unsigned char since there were values larger than 128.

3) a particularly odd issue that arose with the new c++0x behaviour is
found in range.hh, where the operator< causes gcc to complain about
the template type parsing (the "<" is interpreted as the beginning
of a template argument), and the problem seems to be related to the
begin/end members introduced for the range-type iteration, which is
a new feature in c++11.

As a minor update, this patch also fixes the build flags for the clang
debug target that used to be shared with gcc and incorrectly use
"-ggdb".

X86: Fix address size handling so real mode works properly.

Virtual (pre-segmentation) addresses are truncated based on address size, and
any non-64 bit linear address is truncated to 32 bits. This means that real
mode addresses aren't truncated down to 16 bits after their segment bases are
added in.

X86: Use the M5PanicFault fault in execute methods instead of calling panic.

If an instruction is executed speculatively and hits a situation where it
wants to panic, it should return a fault instead. If the instruction was
misspeculated, the fault can be thrown away. If the instruction wasn't
misspeculated, the fault will be invoked and the panic will still happen.

X86: Fix a bad segmentation check for the stack segment.

x86: Add microop for fence
This patch adds a new microop for memory barrier. The microop itself does
nothing, but since it is marked as a memory barrier, the O3 CPU should flush
all the pending loads and stores before the fence to the memory system.

GCC: Get everything working with gcc 4.6.1.

And by "everything" I mean all the quick regressions.

ISA parser: Use '_' instead of '.' to delimit type modifiers on operands.

By using an underscore, the "." is still available and can unambiguously be
used to refer to members of a structure if an operand is a structure, class,
etc. This change mostly just replaces the appropriate "."s with "_"s, but
there were also a few places where the ISA descriptions where handling the
extensions themselves and had their own regular expressions to update. The
regular expressions in the isa parser were updated as well. It also now
looks for one of the defined type extensions specifically after connecting "_"
where before it would look for any sequence of characters after a "."
following an operand name and try to use it as the extension. This helps to
disambiguate cases where a "_" may legitimately be part of an operand name but
not separate the name from the type suffix.

Because leaving the "_" and suffix on the variable name still leaves a valid
C++ identifier and all extensions need to be consistent in a given context, I
considered leaving them on as a breadcrumb that would show what the intended
type was for that operand. Unfortunately the operands can be referred to in
code templates, the Mem operand in particular, and since the exact type of Mem
can be different for different uses of the same template, that broke things.

ISA: Use readBytes/writeBytes for all instruction level memory operations.

X86: Fix store microops so they don't drop faults in timing mode.

If a fault was returned by the CPU when a store initiated it's write, the
store instruction would ignore the fault. This change fixes that.

X86: Eliminate an unused argument for building store microops.

X86: Mark IO reads and writes as non-speculative.

X86: Mark prefetches as such in their instruction and request flags.

X86: Get rid of "inline" on the MicroPanic constructor in decoder.cc.

This was making certain versions of gcc omit the function from the object file
which would break the build.

X86: Put the result used for flags in an intermediate variable.

Using the destination register directly causes the ISA parser to treat it as a
source even if none of the original bits are used.

X86: Don't read in dest regs if all bits are replaced.

In x86, 32 and 64 bit writes to registers in which registers appear to be 32 or
64 bits wide overwrite all bits of the destination register. This change
removes false dependencies in these cases where the previous value of a
register doesn't need to be read to write a new value. New versions of most
microops are created that have a "Big" suffix which simply overwrite their
destination, and the right version to use is selected during microop
allocation based on the selected data size.

This does not change the performance of the O3 CPU model significantly, I
assume because there are other false dependencies from the condition code bits
in the flags register.

X86: Define fault objects to carry debug messages.

These faults can panic/warn/warn_once, etc., instead of instructions doing
that themselves directly. That way, instructions can be speculatively
executed, and only if they're actually going to commit will their fault be
invoked and the panic, etc., happen.

x86: set IsCondControl flag for the appropriate microops

X86: Get rid of the stupd microop.

X86: Take advantage of new PCState syntax.

ISA,CPU,etc: Create an ISA defined PC type that abstracts out ISA behaviors.



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.

X86: Fault on divide by zero instead of panicing.

X86: Make the halt microop non-speculative.

Executing this microop makes the CPU halt even if it was misspeculated.

X86: Get rid of the flagless microop constructor.

This will reduce clutter in the source and hopefully speed up compilation.

X86: Consolidate extra microop flags into one parameter.

This single parameter replaces the collection of bools that set up various
flavors of microops. A flag parameter also allows other flags to be set like
the serialize before/after flags, etc., without having to change the
constructor.

X86: Get rid of the unused getAllocator on the python base microop class.

This function is always overridden, and doesn't actually have the right
signature.

X86: Fix div2 flag calculation.

copyright: Change HP copyright on x86 code to be more friendly

X86: Make the cvti2f microop sign extend its integer source correctly.

The code was using the wrong bit as the sign bit. Other similar bits of code
seem to be correct.

X86: Actual change that fixes div. How did that happen?

X86: Finally fix a division corner case.

When doing an unsigned 64 bit division with a divisor that has its most
significant bit set, the division code would spill a bit off of the end of a
uint64_t trying to shift the dividend into position. This change adds code
that handles that case specially by purposefully letting it spill and then
going ahead assuming there was a 65th one bit.

X86: Add a common named flag for signed media operations.

X86: Create a common flag with a name to indicate high multiplies.

X86: Create a common flag with a name to indicate scalar media instructions.

X86: add ULL to 1's being shifted in 64-bit values

Some of the micro-ops weren't casting 1 to ULL before shifting,
which can cause problems. On the perl makerand input this
caused some values to be negative that shouldn't have been.

The casts are done as ULL(1) instead of 1ULL to match others
in the m5 code base.

X86: Make x86 use PREFETCH instead of PF_EXCLUSIVE.

X86: Remove double-cast in Cvtf2i micro-op

This double cast led to rounding errors which caused
some benchmarks to get the wrong values, most notably lucas
which failed spectacularly due to CVTTSD2SI returning an
off-by-one value. equake was also broken.

X86: Sign extend the immediate of wripi like the register version.

X86: Make the imm8 member of immediate microops really 8 bits consistently.

X86: Preserve the NO_ACCESS flag when giving CDA a specialized interface.

X86: fix some simple compile issues
static should not be used for constants that are not inside a class definition.

X86: Implement a microop for converting fp values to ints.

X86: Implement a microop that compares fp values and writes a mask as a result.

X86: Implement a microop that compares fp values and writes to rflags.

X86: Implement a shuffle media microop.

X86: Implement a mask move microop.

X86: Implement a microop that moves sign bits.

X86: Extend mov2int and mov2fp so they can support insert and extract instructions.

X86: Implement a media average microop.

X86: Let the integer multiply microop use every other possible source value.

X86: Implement the media shift microops. These don't handle full 128 bit wide shifts.

X86: Implement a "sum of absolute differences" microop.

X86: Implement an integer media subtract microop.

X86: Implement a media integer multiply microop.

X86: Implement an integer media max microop.

X86: Add a media integer min microop.

X86: Implement an integer media addition microop with optional saturation.

X86: Implement a media microop that converts between floating point data types.

X86: Implement a microop that compares fp values and writes a mask as its result.

X86: Implement a media microop for converting integer values to floating point.

X86: Implement a floating point media divide microop.

X86: Implement a floating point media multiply microop.

X86: Implement a media floating point subtract microop.

X86: Implement a floating point media add microop.

X86: Implement a media square root microop.

X86: Implement the floating point media max microop.

X86: Implement a floating point media min microop.

X86: Create a pack media microop.

X86: Rename sel to ext for media microops.

X86: Implement a multimedia andn microop.

X86: Implement a multimedia and microop.

X86: Implement a media or microop.

X86: Implement a media xor microop.

X86: Implement the lfpimm microop.

X86: Implement an unpack microop.

X86: Set up a media microop framework and create mov2int and mov2fp microops.

X86: Make not taken conditional moves leave the destination alone. Adjust CMOVcc.
The manuals from both AMD and Intel say that when writing to a 32 bit
destination in 64 bit mode, the upper 32 bits of the register are filled with
zeros. They also both say that the CMOV instructions leave their destination
alone when their condition fails. Unfortunately, it seems that CMOV will zero
extend its destination register whether or not it was supposed to actually do
a move on both platforms. This seems to be the only case where this happens,
but it would be hard to say for sure.

X86: Implement shift right/left double microops.
This is my best guess as far as what these should do. Other existing microops
use implicit registers, mul1s and mul1u for instance, so this should be ok.
The microop that loads the implicit DoubleBits register would fall into one
of the microop slots for moving to/from special registers.

X86: Make conditional moves zero extend their 32 bit destinations always.

X86: Fix condition code setting for signed multiplies with negative results.

X86: Make the check for negative operands for sign multiply more direct.

X86: Make sure immediate values are truncated properly.
Register values will be "picked" which will assure they don't have junk beyond
the part we're using. Immediate values don't go through a similar process, so
we should truncate them explicitly.

X86: Handle rotate left with carry instructions that go all the way around or more.

X86: Handle rotate right with carry instructions that go all the way around or more.

X86: Fix the overflow bit for rotate right with carry.

X86: Fix the computation of the bottom part of rotate right with carry.

X86: Fix the computation of the upper part of rotate right with carry.

X86: Handle rotating right all the way around or more.

X86: Make shifts/rotations that write to 32 bits of a register zero extend.

X86: Handle left rotations that go all the way around or more.

X86: Fix the sar carry flag.

X86: Fix sign extension when doing an arithmetic shift right by 0.

X86: Fix the carry flag for shr.

X86: Fix the carry flag for shl.

X86: Fix the high result of mul1s, and removed undefined shifts from the mult microops.

X86: Take limitted advantage of the compilers type checking for microop operands.

X86: Keep track of more descriptor state to accomodate KVM.

X86: Put the StoreCheck flag with the others, and don't collide with other flags.

X86: Implement the stul microop.
This microop does a store and unlocks the requested address. The RISC86
microop ISA doesn't seem to have an equivalent to this, so I'm guessing that
the store following an ldstl is automatically unlocking. We don't do it this
way for performance reasons since the behavior is the same.

X86: Implement the ldstl microop.
This microop does a load, checks that a store would succeed, and locks the
requested address.

X86: Implement far jmp.

X86: Fix a bug in the chks microop where it ignored that it found a fault.

X86: LEA calculates an address before segmentation.

X86: Fix the halt microop.

X86: Take address size into account when computing an effective address.

X86: Fix segment limit checks.

X86: Add segmentation checks for ldt related descriptors and selectors.

X86: Make the TSS type check actually return a fault if it fails.

X86: Make rdcr use merge and the mov to control register instructions use the right operand size.

X86: Make the segment register reading microops use merge.

X86: Do a merge for the zero extension microop.

X86: Add microops for reading/writing debug registers.

X86: Check src1 for illegal values since that's the index we actually use.

X86: Implement a basic prefetch instruction.

X86: Use the right portion of a register for stores.

X86: Add a flag to force memory accesses to happen at CPL 0.

X86: Add a wrattr microop.

X86: Fix segment limit checking.

X86: Add a check to chks to verify a task state segment descriptor.

X86: Add a check to chks which raises #GP(selector) if selector is NULL or not in the GDT.

X86: Make the stupd microop not update registers in initiateAcc.

CPU: Get rid of translate... functions from various interface classes.

Quell g++ 4.3 warning about operator ambiguity

X86: Make the fault classes handle error codes better.

X86: Distinguish between hardware and software interrupts/exceptions

X86: Make the chks microop check for the right int descriptor type.

X86: Autogenerate macroop generateDisassemble function.

X86: Fix completeAcc get call.

X86: Set the delayed commit flag in x86 microops appropriately.

X86: Add wrval/rdval microops for reading significant miscregs.

X86: Make sure register microops set fault rather than returning one.

X86: Implement an wrdh microop which loads bases/offsets from 16 byte descriptors.

X86: Implement the chks check of interrupt gate target code segments.

X86: Add a check type for interrupt gates.

X86: Fix chks checking the submode for stack segments.

X86: Let segment manipulation microops be conditional.

X86: Fix the rdbase microop

X86: Create a handy way to access labels from the ROM in microcode.

X86: Make X86's microcode ROM actually do something.

X86: Create an eret microop which returns from ROM to combinational decoding.

X86: Make Br never report itself as the last microop.

X86: Create a SeqOp class of microops and make Br one of them.

X86: Fix the debugging microops. The debug functions can't handle a string object format.

X86: Make the disassembly for halt conform with the other microops.

X86: Change how segment loading is performed.

X86: Keep handy values like the operating mode in one register.

X86: Change what the microop chks does.
Instead of computing the segment descriptor address, this now checks if a
selector value/descriptor are legal for a particular purpose.

X86: Add a microop to read a segments attribute register.

X86: Add microops and supporting code to manipulate the whole rflags register.

X86: Add microops which panic, fatal, warn, and warn_once.

X86: Truncate descriptors to 16 bits.

X86: Add in some support for the tsc register.

X86: Implement the INVLPG instruction and the TIA microop.

X86: Implement mov from control register.

X86: First crack at far returns. This is grossly approximate.

X86: Reorganize segmentation and implement segment selector movs.

X86: Make the "fault" microop predicated.

X86: Implement the lgdt instruction.

X86: Implement wrbase and wrlimit for loading pseudo descriptors.

X86: Make microcode use presegmentation RIPs and the rest of m5 use post segmentation RIPS.

X86: Implement the wrcr microop which writes a control register, and some control register work.

X86: Change the meaning of the sext and zext width operand, and make sext set zext if the sign bit is 0.

X86: Various fixes to indexing segmentation related registers

X86: Compile fixes for 32 bit/debug/opt.

X86: Implement the cda microop which checks if an address is legal to write to.

X86: Implement the stupd microop ("store with update", not "stupid") and use it in ENTER.

X86: Impelement the HLT instruction and fix the "halt" microop.

X86: Implement a "halt" microop.

X86: Make the "fault" microop predicated.

X86: Make wrip sign extend its second operand.

X86: Implement MSR reads and writes and the wrsmr and rdmsr instructions.
There are no priviledge checks, so these instructions will all work in all
modes.

X86: Significantly filled out misc regs.

X86: Fix the movfp microop.

X86: Implement the ldst microop and put it in existing microcode where appropriate.

X86: Get rid of a hack for ruflag which is no longer necessary.

X86: Allow logic instructions to set ECF as well as CF.

X86: Move the fp microops to their own file with their own base classes in C++ and python.

X86: Make the shift and rotate instructions set the carry flag(s) and overflow flags like they're supposed to.

X86: Total overhaul of the division instructions and microops.

X86: Move a comment to be next to the code it describes.

X86: Rework the multiplication microops so that they work like they would in the patent.

X86: Make signed multiplication do something different from unsigned.

X86: Make signed versions of partial register values available to microops.

X86: Correct how the hi portion of a product is computed.

X86: Add a square root microop and the SSE sqrt instruction.

X86: Add SSE comparison instructions and microops and move some FP microops to be with the other ones.

X86: Implement an SSE xor microop and instruction.

X86: Make the movfp microop use FloatRegBits instead of FloatRegs.
This fixes a problem where interpreting arbitrary bits as floating point would
change what the value was. These values are legitimate because the fp
registers could be used to move around arbitrary data.

X86: Implement some SSE fp microops and instructions.

X86: Add some SSE floating point/integer conversion microops.

X86: Fix a corner case where mul would overwrite an original register value it still needed.

X86: Major rework of how regop microops are generated.
The new implementation uses metaclass, and gives a lot more precise control
with a lot less verbosity. The flags/no flags reg/imm variants are all handled
by the same python class now which supplies a constructor to the right C++
class based on context.

X86: Fix the sra microop to get the sign bit from the right operand.

X86: Add an fp move microop.

X86: Add load and store microops that use the fp registers.

X86: Make the Ruflag microop work correctly, and make the code a little clearer.

X86: Fix the sign extension microop so it extends zeros correctly.

X86: Remove x86 code that attempted to fix misaligned accesses.

X86: Overhaul of ruflags to get it to work correctly.

X86: Make a microcode branch microop.
Also some touch up for ruflag.

X86: Implement microops and instructions that manipulate the flags register.

X86: Make 64 bit unaligned accesses work as well as the other sizes.
There is a fundemental flaw in how unaligned accesses are supported, but this
is still an improvement.

X86: Start implementing segmentation support.
Make instructions observe segment prefixes, default segment rules, segment
base addresses.
Also fix some microcode and add sib and riprel "keywords" to the x86
specialization of the microassembler.

X86: Fix for compilation bug with new cache code.

X86: Remove a naming conflict between the register index parameters and the "picked" register values.

X86: Make instructions use pick, and implement/adjust some multiplication microops and instructions.

X86: Make disassembly use the final register index. Add bits to indicate whether or not register indexes should be "folded".

X86: Make logic instructions flag setting work.
The instructions now ask for the appropriate flags to be set, and the microops do the "right thing" with the CF and OF flags, namely zero them.

X86: Make limm use merge and allow overriding the data size.

X86: Add functions to read and write to an exec context.
These functions take care of calling the thread contexts read and write functions with the right sized data type, and handle unaligned accesses.

X86: Fix carry calculation for subtraction based microops.
The carry flag should be calculated using the -complement- of the second operand, not it's negation. The carry in which is part of computing the 2's complement may induce a carry, but if you've already caused the carry before you get the carry computing logic involved, it will miss it.

Make the shift and rotate microops mask the shift/rotate amount correctly.

Implement rotate with carry microops.

Fixed the distinction between far and near versions of jmp, call and ret. Implemented some shifts, rotates, and pushes.

Implement adc and sbb instructions and microops.

Define and fill out a lot of different instructions and instruction versions. Added two of the shift microops.

Make load and store ops use the appropriate sized data access.

Fix carry flag for subtracts, and clean up code slightly.

x86 fixes
Make the emulation environment consider the rex prefix.
Implement and hook in forms of j, jmp, cmp, syscall, movzx
Added a format for an instruction to carry a call to the SE mode syscalls system
Made memory instructions which refer to the rip do so directly
Made the operand size overridable in the microassembly
Made the "ext" field of register operations 16 bits to hold a sparse encoding of flags to set or conditions to predicate on
Added an explicit "rax" operand for the syscall format
Implemented syscall returns.

Make instructions that conditionally set registers set them to their old value if they don't actually execute.

Make store microops actually store instead of load.

Make the data size used by regops overridable in the microassembly.

Add a generateDisassembly function to the MicroFault StaticInst.

Make disassembled x86 register indices reflect their size.
This doesn't handle high byte register accesses. It also highlights the fact that address size isn't actually being calculated, and that the size a microop uses needs to be overridable from the microassembly.

Add in support for condition code flags.
Some microops can set the condition codes, and some of them can be predicated on them. Some of the codes aren't implemented because it was unclear from the AMD patent what they actually did. They are used with string instructions, but they use variables IP, DTF, and SSTF which don't appear to be documented.

Pull some hard coded base classes out of the isa description.

Add in code that lays the ground work for setting flags.

Make memory instructions work better, add more macroop implementations, add an lea microop, move EmulEnv into it's own .cc and .hh.

More faithfulness to what instructions should work in what modes, and added the MOVSXD instruction.

Make instructions that are illegal in 64 bit mode not do the wrong thing in 64 bit mode. Also add in more versions of PUSH and POP, and a version of near CALL.

Renovate the "fault" microop implementation.

Get rid of the immediate and displacement components of the EmulEnv struct 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.

Add in incomplete pick and merge functions which read and write pieces of registers, and fill out microcode disassembly.

Fix limm.

Move load/store microops into their own file. They still don't do anything, though.

Fix the immediate version of register operations, and get their name to show up correctly.

Make microOp vs microop and macroOp vs macroop capitilization consistent.

src/arch/x86/isa/macroop.isa:
Make microOp vs microop and macroOp vs macroop capitilization consistent. Also fill out the emulation environment handling a little more, and use an object to pass around output code.
src/arch/x86/isa/microops/base.isa:
Make microOp vs microop and macroOp vs macroop capitilization consistent. Also adjust python to C++ bool translation.

Fix the formatting on a comment.

Big changes to use the new microcode assembler.

Make limm (load immediate) microop

Reworking x86's microcode system. This is a work in progress, and X86 doesn't compile.

src/arch/x86/isa/decoder/one_byte_opcodes.isa:
src/arch/x86/isa/macroop.isa:
src/arch/x86/isa/main.isa:
src/arch/x86/isa/microasm.isa:
src/arch/x86/isa/microops/base.isa:
src/arch/x86/isa/microops/microops.isa:
src/arch/x86/isa/operands.isa:
src/arch/x86/isa/microops/regop.isa:
src/arch/x86/isa/microops/specop.isa:
Reworking x86's microcode system

Include the new GenFault microop.

Reworked x86 a bit

Consolidated the microcode assembler to help separate it from more x86-centric stuff.

Refactored the x86 isa description some more. There should be more seperation between x86 specific parts, and those parts which are implemented in the isa description but could eventually be moved elsewhere.

The process of going from an instruction definition to an instruction to be returned by the decoder has been fleshed out more. The following steps describe how an instruction implementation becomes a StaticInst.

1. Microops are created. These are StaticInsts use templates to provide a basic form of polymorphism without having to make the microassembler smarter.
2. An instruction class is created which has a "templated" microcode program as it's docstring. The template parameters are refernced with ^ following by a number.
3. An instruction in the decoder references an instruction template using it's mnemonic. The parameters to it's format end up replacing the placeholders. These parameters describe a source for an operand which could be memory, a register, or an immediate. It it's a register, the register index is used. If it's memory, eventually a load/store will be pre/postpended to the instruction template and it's destination register will be used in place of the ^. If it's an immediate, the immediate is used. Some operand types, specifically those that come from the ModRM byte, need to be decoded further into memory vs. register versions. This is accomplished by making the decode_block text for these instructions another case statement based off ModRM.
4. Once all of the template parameters have been handled, the instruction goes throw the microcode assembler which resolves labels and creates a list of python op objects. If an operand is a register, it uses a % prefix, an immediate uses $, and a label uses @. If the operand is just letters, numbers, and underscores, it can appear immediately after the prefix. If it's not, it can be encolsed in non nested {}s.
5. If there is a single "op" object (which corresponds to a single microop) the decoder is set up to return it directly. If not, a macroop wrapper is created around it.

In the future, I'm considering seperating the operand type specialization from the template substitution step. A problem this introduces is that either the template arguments need to be kept around for the specialization step, or they need to be re-extracted. Re-extraction might be the way to go so that the operand formats can be coded directly into the micro assembler template without having to pass them in as parameters. I don't know if that's actually useful, though.

src/arch/x86/isa/decoder/one_byte_opcodes.isa:
src/arch/x86/isa/microasm.isa:
src/arch/x86/isa/microops/microops.isa:
src/arch/x86/isa/operands.isa:
src/arch/x86/isa/microops/base.isa:
Implemented polymorphic microops and changed around the microcode assembler syntax.

Add code to generate register and immediate based integer op microop classes.