arch-riscv: Make use of ImmOp's polymorphism

This patch makes use of ImmOp's polymorphism to remove unnecessary
casting from the implementations of arithmetic instructions with
immediate operands and to remove the CUIOp format by combining it with
the CIOp format (compressed arithmetic instructions with immediate
operands). Interestingly, RISC-V specifies that instructions with
unsigned immediate operands still need to sign-extend the immediates
from 12 (or 20) bits to 64 bits, so that is left alone.

Change-Id: If20d70c1e90f379b9ed8a4155b2b9222b6defe16
Reviewed-on: https://gem5-review.googlesource.com/6401
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Tuan Ta <qtt2@cornell.edu>
Maintainer: Alec Roelke <ar4jc@virginia.edu>

tests: Upate RISC-V binaries and results

This patch updates the binaries and results for hello and insttest
regressions using the compressed extension.

Change-Id: I3d8f2248f490521d3e0dc05c48735cab82b1b04e
Reviewed-on: https://gem5-review.googlesource.com/4042
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

arch-riscv,tests: Add insttests for RV64C

This patch adds instruction tests for the RV64C extension
implementation. It also updates existing executables for the latest
riscv-tools now that they are compatible.

[Update for changes to parents.]

Change-Id: Id4cfd966a8cae39b0d728b02849622fd00ee7e0e
Reviewed-on: https://gem5-review.googlesource.com/3862
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

riscv: fix Linux problems with LR and SC ops

Some of the functions in the Linux toolchain that allocate memory make
use of paired LR and SC instructions, which didn't work properly for
that toolchain. This patch fixes that so attempting to use those
functions doesn't cause an endless loop of failed SC instructions.

Change-Id: If27696323dd6229a0277818e3744fbdf7180fca7
Reviewed-on: https://gem5-review.googlesource.com/2340
Maintainer: Alec Roelke <ar4jc@virginia.edu>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

riscv: fix compatibility with Linux toolchain

Previously, RISC-V in gem5 only supported RISC-V's Newlib toolchain
(riscv64-unknown-elf-*) due to incorrect assumptions made in the initial
setup of the user stack in SE mode. This patch fixes that by referring
to the RISC-V proxy kernel code (https://github.com/riscv/riscv-pk) and
setting up the stack according to how it does it. Now binaries compiled
using the Linux toolchain (riscv64-unknown-linux-gnu-*) will run as
well.

[Update for recent changes to MemState to add accessors and mutators to
get its members.]

Change-Id: I6d2c486df7688efe3df54273e9aa0fd686851285
Reviewed-on: https://gem5-review.googlesource.com/2305
Maintainer: Alec Roelke <ar4jc@virginia.edu>
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

riscv: [Patch 8/5] Added some regression tests to RISC-V

This patch is the eighth patch in a series adding RISC-V to gem5, and
third of the bonus patches to the original series of five. It adds some
regression tests to RISC-V.

Regression tests included:
- se/00.hello
- se/02.insttest (split into several binaries which are not included due
to large size)

The tests added to 00.insttest will need to be build manually; to
facilitate this, a Makefile is included. The required toolchain and
compiler (riscv64-unknown-elf-gcc) can be built from the riscv-tools
GitHub repository at https://github.com/riscv/riscv-tools.

Note that because EBREAK only makes sense when gdb is running or while in
FS mode, it is not included in the linux-rv64i insttest. ERET is not
included because it does not make sense in SE mode and, in fact, causes
a panic by design.

Note also that not every system call is tested in linux-rv64i; of the ones
defined in linux/process.hh, some have been given numbers but not
definitions for the toolchain, or are merely stubs that always return 0. Of
the ones that do work properly, only a subset are tested due to similar
functionality.

Signed-off by: Alec Roelke

Signed-off by: Jason Lowe-Power <jason@lowepower.com>