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path: root/src/arch/riscv/decoder.cc
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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>
2017-07-14riscv: Fix bugs with RISC-V decoder and detailed CPUsAlec Roelke
This patch fixes some bugs that were missed with the changes to the decoder that enabled compatibility with compressed instructions. In order to accommodate speculation with variable instruction widths, a few assertions in decoder had to be changed to returning faults as the specification describes should normally happen. The rest of these assertions will be changed in a later patch. [Remove commented-out debugging line and add clarifying comment to registerName in utility.hh.] Change-Id: I3f333008430d4a905cb59547a3513f5149b43b95 Reviewed-on: https://gem5-review.googlesource.com/4041 Reviewed-by: Jason Lowe-Power <jason@lowepower.com> Maintainer: Alec Roelke <ar4jc@virginia.edu>
2017-07-11arch-riscv: Add support for compressed extension RV64CAlec Roelke
This patch adds compatibility with the 64-bit compressed extension to the RISC-V ISA, RV64C. Current versions of the toolchain may use compressed instructions in glibc by default, which can only be overridden by recompiling the entire toolchain (simply adding "-march=rv64g" or "-march=rv64imafd" when compiling a binary is not sufficient to use uncompressed instructions in glibc functions in the binary). [Update diassembly generation for new RegId type.] [Rebase onto master.] Change-Id: Ifd5a5ea746704ce7e1b111442c3eb84c509a98b4 Reviewed-on: https://gem5-review.googlesource.com/3860 Reviewed-by: Alec Roelke <ar4jc@virginia.edu> Maintainer: Alec Roelke <ar4jc@virginia.edu>
2016-11-30arch: [Patch 1/5] Added RISC-V base instruction set RV64IAlec Roelke
First of five patches adding RISC-V to GEM5. This patch introduces the base 64-bit ISA (RV64I) in src/arch/riscv for use with syscall emulation. The multiply, floating point, and atomic memory instructions will be added in additional patches, as well as support for more detailed CPU models. The loader is also modified to be able to parse RISC-V ELF files, and a "Hello world\!" example for RISC-V is added to test-progs. Patch 2 will implement the multiply extension, RV64M; patch 3 will implement the floating point (single- and double-precision) extensions, RV64FD; patch 4 will implement the atomic memory instructions, RV64A, and patch 5 will add support for timing, minor, and detailed CPU models that is missing from the first four patches (such as handling locked memory). [Removed several unused parameters and imports from RiscvInterrupts.py, RiscvISA.py, and RiscvSystem.py.] [Fixed copyright information in RISC-V files copied from elsewhere that had ARM licenses attached.] [Reorganized instruction definitions in decoder.isa so that they are sorted by opcode in preparation for the addition of ISA extensions M, A, F, D.] [Fixed formatting of several files, removed some variables and instructions that were missed when moving them to other patches, fixed RISC-V Foundation copyright attribution, and fixed history of files copied from other architectures using hg copy.] [Fixed indentation of switch cases in isa.cc.] [Reorganized syscall descriptions in linux/process.cc to remove large number of repeated unimplemented system calls and added implmementations to functions that have received them since it process.cc was first created.] [Fixed spacing for some copyright attributions.] [Replaced the rest of the file copies using hg copy.] [Fixed style check errors and corrected unaligned memory accesses.] [Fix some minor formatting mistakes.] Signed-off by: Alec Roelke Signed-off by: Jason Lowe-Power <jason@lowepower.com>