riscv-dv breaks with riscv64-unknown-elf-gcc version tags 2023.04.18 and up

[5hayanB]

I am using the following command to generate arithmetic tests for rv32i target

python3 run.py --target rv32i -o $HOME/temporary/riscv-dv -tn riscv_arithmetic_basic_test -i 10 -si pyflow --iss spike -v

However, I am receiving assembler errors at the compilation step

lib.py:198   DEBUG    $HOME/applications/riscv/toolchain/bin/riscv64-unknown-elf-gcc -static -mcmodel=medany -fvisibility=hidden -nostdlib -nostartfiles $HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.S -I$HOME/repositories/other_repositories/github/riscv-dv/user_extension -T$HOME/repositories/other_repositories/github/riscv-dv/scripts/link.ld -o $HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.o -march=rv32i -mabi=ilp32
$HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.S: Assembler messages:
$HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.S:7: Error: unrecognized opcode `csrr x5,0xf14', extension `zicsr' required
$HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.S:15: Error: unrecognized opcode `csrw 0x301,x24', extension `zicsr' required
$HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.S:22: Error: unrecognized opcode `csrw 0x305,x24', extension `zicsr' required
...

Fri, 24 Nov 2023 12:48:42 lib.py:206   DEBUG    b''
Traceback (most recent call last):
  File "$HOME/repositories/other_repositories/github/riscv-dv/run.py", line 1170, in <module>
    main()
  File "$HOME/repositories/other_repositories/github/riscv-dv/run.py", line 1147, in main
    gcc_compile(matched_list, output_dir, args.isa, args.mabi,
  File "$HOME/repositories/other_repositories/github/riscv-dv/run.py", line 457, in gcc_compile
    run_cmd_output(cmd.split(), debug_cmd=debug_cmd)
  File "$HOME/repositories/other_repositories/github/riscv-dv/scripts/lib.py", line 207, in run_cmd_output
    raise exc
  File "$HOME/repositories/other_repositories/github/riscv-dv/scripts/lib.py", line 204, in run_cmd_output
    output = subprocess.check_output(cmd)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/subprocess.py", line 466, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/subprocess.py", line 571, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['$HOME/applications/riscv/toolchain/bin/riscv64-unknown-elf-gcc', '-static', '-mcmodel=medany', '-fvisibility=hidden', '-nostdlib', '-nostartfiles', '$HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.S', '-I$HOME/repositories/other_repositories/github/riscv-dv/user_extension', '-T$HOME/repositories/other_repositories/github/riscv-dv/scripts/link.ld', '-o', '$HOME/temporary/riscv-dv/asm_test/riscv_arithmetic_basic_test_0.o', '-march=rv32i', '-mabi=ilp32']' returned non-zero exit status 1.

I verified the .S files generated by dv and indeed that is the case. I tried emptying implemented_csr in pygen/pygen_src/target/rv32i/riscv_core_setting.py but to no avail. Do I need to specify rv32iZicsr to --target?

[5hayanB]

I looked further into the problem and have found out that the riscv-dv is generating the wrong .S file. On compiling the the assembly file with

riscv64-unknown-elf-gcc -static -mcmodel=medany -fvisibility=hidden -nostdlib -nostartfiles riscv_arithmetic_basic_test_0.S -I/dv/user_extension -T/dv/scripts/link.ld -o riscv_arithmetic_basic_test_0.o -march=rv32izicsr -mabi=ilp32

the compilation works and .o object file is being created successfully. Why would riscv-dv generate a the wrong assembly test when the --target rv32i is already given? The riscv_arithmetic_basic_test field of the testlist yaml even has +no_csr_instr=1, meaning no CSR instruction is to be created and yet csr instructions are generated in the assembly file.

[5hayanB]

Seems like riscv-dv broke with riscv64-unknown-elf-gcc version 13.2.0 as I tested riscv-dv with riscv64-unknown-elf-gcc version 11.1.0 and is working. I am now changing issue topic to the specific problem at hand.

[5hayanB]

After loads of compiling and testing different tags of the riscv-gnu-toolchain, tags 2023.04.18 and up are incompatible with riscv-dv as of yet. I do not know if I should leave the issue open to keep track of toolchain compatibility or close it to after finding out the working version. I will leave the issue open and let the maintainers take the required action as they see fit.

[Sai-Manish]

Hi @5hayanB, Could you figure out which version is working or why it was not working?

[5hayanB]

@Sai-Manish, I was able to find that the tags 2023.03.14 and below of the riscv-gnu-toolchain work with riscv-dv. I think the problem is that riscv-dv uses initial csr instructions in program initialization and assumes that the rv32i extension supports csr extensions. However, the spec now states that the csr extensions be implemented in Zicsr which is not a part of rv32i which is also updated in the latest riscv-gnu-toolchain.