arch: Fix all override related warnings.

Clang has started(?) reporting override related warnings, something gcc
apparently did before, but was disabled in the SConstruct. Rather than
disable the warnings in for clang as well, this change fixes the
warnings. A future change will re-enable the warnings for gcc.

Change-Id: I3cc79e45749b2ae0f9bebb1acadc56a3d3a942da
Reviewed-on: https://gem5-review.googlesource.com/9343
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>

sparc: Pull StaticInst base classes out of the ISA description.

Also, do some minor refactoring to use a BitUnion to pull apart
condition codes, etc.

Change-Id: I0c88878b07a731d0c0fe30f264f53dd795db99ae
Reviewed-on: https://gem5-review.googlesource.com/5421
Reviewed-by: Jason Lowe-Power <jason@lowepower.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>

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.

SPARC: Minor style fix.

I forgot to fix this as well per Ali's feedback.

SPARC: Isolate FP operations enough to prevent code/rounding mode reordering.

SPARC: Clean up some historical style issues.

SPARC: Clean up the branch instructions a bit.

create base/fenv.c to standerdize fenv across platforms. It's a c file and not a cpp file because c99
(which defines fenv) doesn't necessarily extend to c++ and it is a problem with solaris. If really
desired this could wrap the ieeefp interface found in bsd* as well, but I see no need at the moment.

src/arch/alpha/isa/fp.isa:
src/arch/sparc/isa/formats/basic.isa:
use m5_fesetround()/m5_fegetround() istead of fenv interface directly
src/arch/sparc/isa/includes.isa:
use base/fenv instead of fenv directly
src/base/SConscript:
add fenv to sconscript
src/base/fenv.hh:
src/base/random.cc:
m5 implementation to standerdize fenv across platforms.

Create a filter and a union to translate the SPARC instruction implementations from using doubles to using concatenated singles.

more fp fixes
fix unaligned accesses in mmaped disk device

src/arch/sparc/isa/decoder.isa:
get (ld|st)fsr ops working right. In reality the fp enable check needs to go higher up in the emitted code
src/arch/sparc/isa/formats/basic.isa:
move the cexec into the aexec field
src/cpu/exetrace.cc:
copy the exception state from legion when we get it wrong. We aren't going to get it right without an fp emulation layer
src/dev/sparc/mm_disk.cc:
src/dev/sparc/mm_disk.hh:
fix unaligned accesses in the memory mapped disk device

fix mostly floating point related

src/arch/sparc/floatregfile.cc:
fix fp read/writing to registers... looking for suggestions on cleaner ways if anyone has them
src/arch/sparc/isa/decoder.isa:
fix some fp implementations
src/arch/sparc/isa/formats/basic.isa:
add new fp op class that 0 cexec in fsr and sets rounding mode for the up comming op
src/arch/sparc/isa/includes.isa:
include the appropriate header files for the rounding code
src/arch/sparc/miscregfile.cc:
print fsr out when it's read/written and the Sparc traceflgas in on
src/cpu/exetrace.cc:
fix printing of float registers

Merge zizzer:/bk/newmem
into zower.eecs.umich.edu:/eecshome/m5/newmem

src/arch/sparc/isa/formats/mem/util.isa:
src/arch/sparc/isa_traits.hh:
src/arch/sparc/system.cc:
Hand Merge

Merge zizzer:/bk/newmem
into zeep.pool:/z/saidi/work/m5.newmem

Make Sparc traceflag even more chatty
some fixes to fp instructions to use the single precision registers
if this is an fp op emit fp check code
add fpregs to m5legion struct

src/arch/sparc/floatregfile.cc:
Make Sparc traceflag even more chatty
src/arch/sparc/isa/base.isa:
add code to check if the fpu is enabled
src/arch/sparc/isa/decoder.isa:
some fixes to fp instructions to use the single precision registers
fix smul again
fix subc/subcc/subccc condition code setting
src/arch/sparc/isa/formats/basic.isa:
src/arch/sparc/isa/formats/mem/util.isa:
if this is an fp op emit fp check code
src/cpu/exetrace.cc:
check fp regs as well as int regs
src/cpu/m5legion_interface.h:
add fpregs to m5legion struct

make our code a little more standards compliant
pretty close to compiling w/ suns compiler

briefly:
add dummy return after panic()/fatal()
split out flags by compiler vendor
include cstring and cmath where appropriate
use std namespace for string ops

SConstruct:
Add code to detect compiler and choose cflags based on detected compiler
Fix zlib check to work with suncc
src/SConscript:
split out flags by compiler vendor
src/arch/sparc/isa/decoder.isa:
use correct namespace for sqrt
src/arch/sparc/isa/formats/basic.isa:
add dummy return around panic
src/arch/sparc/isa/formats/integerop.isa:
use correct namespace for stringops
src/arch/sparc/isa/includes.isa:
include cstring and cmath where appropriate
src/arch/sparc/isa_traits.hh:
remove dangling comma
src/arch/sparc/system.cc:
dummy return to make sun cc front end happy
src/arch/sparc/tlb.cc:
src/base/compression/lzss_compression.cc:
use std namespace for string ops
src/arch/sparc/utility.hh:
no reason to say something is unsigned unsigned int
src/base/compression/null_compression.hh:
dummy returns to for suncc front end
src/base/cprintf.hh:
use standard variadic argument syntax instead of gnuc specefic renaming
src/base/hashmap.hh:
don't need to define hash for suncc
src/base/hostinfo.cc:
need stdio.h for sprintf
src/base/loader/object_file.cc:
munmap is in std namespace not null
src/base/misc.hh:
use M5 generic noreturn macros
use standard variadic macro __VA_ARGS__
src/base/pollevent.cc:
we need file.h for file flags
src/base/random.cc:
mess with include files to make suncc happy
src/base/remote_gdb.cc:
malloc memory for function instead of having a non-constant in an array size
src/base/statistics.hh:
use std namespace for floor
src/base/stats/text.cc:
include math.h for rint (cmath won't work)
src/base/time.cc:
use suncc version of ctime_r
src/base/time.hh:
change macro to work with both gcc and suncc
src/base/timebuf.hh:
include cstring from memset and use std::
src/base/trace.hh:
change variadic macros to be normal format
src/cpu/SConscript:
add dummy returns where appropriate
src/cpu/activity.cc:
include cstring for memset
src/cpu/exetrace.hh:
include cstring fro memcpy
src/cpu/simple/base.hh:
add dummy return for panic
src/dev/baddev.cc:
src/dev/pciconfigall.cc:
src/dev/platform.cc:
src/dev/sparc/t1000.cc:
add dummy return where appropriate
src/dev/ide_atareg.h:
make define work for both gnuc and suncc
src/dev/io_device.hh:
add dummy returns where approirate
src/dev/pcidev.hh:
src/mem/cache/cache_impl.hh:
src/mem/cache/miss/blocking_buffer.cc:
src/mem/cache/tags/lru.hh:
src/mem/cache/tags/split.hh:
src/mem/cache/tags/split_lifo.hh:
src/mem/cache/tags/split_lru.hh:
src/mem/dram.cc:
src/mem/packet.cc:
src/mem/port.cc:
include cstring for string ops
src/dev/sparc/mm_disk.cc:
add dummy return where appropriate
include cstring for string ops
src/mem/cache/miss/blocking_buffer.hh:
src/mem/port.hh:
Add dummy return where appropriate
src/mem/cache/tags/iic.cc:
cast hastSets to double for log() call
src/mem/physical.cc:
cast pmemAddr to char* for munmap
src/sim/byteswap.hh:
make define work for suncc and gnuc

Changes to the isa_parser and affected files to fix an indexing problem with split execute instructions and miscregs aliasing with integer registers.

src/arch/isa_parser.py:
Rearranged things so that classes with more than one execute function treat operands properly.
1. Eliminated the CodeBlock class
2. Created a SubOperandList
3. Redefined how InstObjParams is constructed

To define an InstObjParam, you can either pass in a single code literal which will be named "code", or you can pass in a dictionary of code snippets which will be substituted into the Templates. In order to get this to work, there is a new restriction that each template has only one function in it. These changes should only affect memory instructions which have regular and split execute functions.

Also changed the MiscRegs so that they use the instrunctions srcReg and destReg arrays.
src/arch/sparc/isa/formats/basic.isa:
src/arch/sparc/isa/formats/branch.isa:
src/arch/sparc/isa/formats/integerop.isa:
src/arch/sparc/isa/formats/mem/basicmem.isa:
src/arch/sparc/isa/formats/mem/blockmem.isa:
src/arch/sparc/isa/formats/mem/util.isa:
src/arch/sparc/isa/formats/nop.isa:
src/arch/sparc/isa/formats/priv.isa:
src/arch/sparc/isa/formats/trap.isa:
Rearranged to work with new InstObjParam scheme.
src/cpu/o3/sparc/dyn_inst.hh:
Added functions to access the miscregs using the indexes from instructions srcReg and destReg arrays. Also changed the names of the other accessors so that they have the suffix "Operand" if they use those arrays.
src/cpu/simple/base.hh:
Added functions to access the miscregs using the indexes from instructions srcReg and destReg arrays.

Change the default constructors to take ExtMachInsts rather than regular MachInsts

Added an execute function to the macro op so it can be instantiated.

Some support for handling block loads and stores and ASIs properly.

src/arch/sparc/isa/bitfields.isa:
Added a field to retrieve the asi from the ExtMachInst
src/arch/sparc/isa/decoder.isa:
Fixed up how the size of memory operations where handled, and use the new EXT_ASI bit field.
src/arch/sparc/isa/formats.isa:
add includes for the new formats.
src/arch/sparc/isa/formats/basic.isa:
Add a template for BasicDecodeWithMnemonic which is needed by the unimp format.
src/arch/sparc/isa/formats/mem.isa:
Change around the memory format to figure out the memory access width on its own.
src/arch/sparc/isa/operands.isa:
Added support for the operands of block loads/stores which are offset from Frd.
src/arch/sparc/utility.hh:
Encoded the ASI into the ExtMachInst

Cleaned things up a little.

New directory structure:
- simulator source now in 'src' subdirectory
- imported files from 'ext' repository
- support building in arbitrary places, including
outside of the source tree. See comment at top
of SConstruct file for more details.
Regression tests are temporarily disabled; that
syetem needs more extensive revisions.

SConstruct:
Update for new directory structure.
Modify to support build trees that are not subdirectories
of the source tree. See comment at top of file for
more details.
Regression tests are temporarily disabled.
src/arch/SConscript:
src/arch/isa_parser.py:
src/python/SConscript:
Update for new directory structure.