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Several Problems when running tutorial-7.py #358

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#380
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Several Problems when running tutorial-7.py#358
#380

Description

@cheng-wei-huang0612
cheng-wei-huang0612
opened on Nov 2, 2025

Abstract

I encountered three problems when I run tutorial-7.py:

  1. slothy.targets.common.FatalParsingException: Inconsistent dt:
  2. slothy.targets.common.UnknownInstruction: Multiple matches found for <class 'slothy.targets.aarch64.aarch64_neon.x_str_sp_imm'> for str x1, [sp, #STACK_A_32]
  3. slothy.helper.LLVM_Mc_Error

I personally solved the first two in my branch https://github.com/cheng-wei-huang0612/slothy/tree/Patch--fixing-tutorial-7.py
But I do not know how to deal with the third.

Description

In the main branch, when I run python3 tutorial-7.py, I got

(venv) huangchengwei@huangchengweis-MacBook-Air tutorial % python3 tutorial-7.py
INFO:slothy.mainloop:SLOTHY version: unknown
INFO:slothy:Instructions in body: 958
Traceback (most recent call last):
  File "/Users/huangchengwei/Documents/slothy/tutorial/tutorial-7.py", line 24, in <module>
    slothy.optimize(start="mainloop", end="end_label")
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/slothy.py", line 397, in optimize
    early, core, late, num_exceptional = Heuristics.periodic(body, logger, c)
                                         ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 364, in periodic
    dfg = DFG(
        body, logger.getChild("dfg_generate_outputs"), DFGConfig(conf.copy())
    )
  File "/Users/huangchengwei/Documents/slothy/slothy/core/dataflow.py", line 720, in __init__
    self.src = self._parse_source(src)
               ~~~~~~~~~~~~~~~~~~^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/dataflow.py", line 798, in _parse_source
    return list(map(self._parse_line, src_lines))
  File "/Users/huangchengwei/Documents/slothy/slothy/core/dataflow.py", line 787, in _parse_line
    insts = self.arch.Instruction.parser(line)
  File "/Users/huangchengwei/Documents/slothy/slothy/targets/aarch64/aarch64_neon.py", line 884, in parser
    inst = inst_class.make(src)
  File "/Users/huangchengwei/Documents/slothy/slothy/targets/aarch64/aarch64_neon.py", line 1246, in make
    return AArch64Instruction.build(cls, src)
           ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/targets/aarch64/aarch64_neon.py", line 1230, in build
    AArch64Instruction._enforce_datatype_matching(pattern, res)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/targets/aarch64/aarch64_neon.py", line 942, in _enforce_datatype_matching
    raise FatalParsingException(f"Inconsistent dt: {dt}")
slothy.targets.common.FatalParsingException: Inconsistent dt: <dt1>

It turns out that SLOTHY is complaining about the parsing of usra instruction, whose parser definition is originally:

class vusra(AArch64Instruction):
    pattern = "usra <Vd>.<dt0>, <Va>.<dt1>, <imm>"
    inputs = ["Va"]
    in_outs = ["Vd"]

I modified it into

class vusra(AArch64Instruction):
    pattern = "usra <Vd>.<dt>, <Va>.<dt>, <imm>"
    inputs = ["Va"]
    in_outs = ["Vd"]

and then the second issue arise:

(venv) huangchengwei@huangchengweis-MacBook-Air tutorial % python3 tutorial-7.py
INFO:slothy.mainloop:SLOTHY version: unknown
INFO:slothy:Instructions in body: 958
INFO:slothy.mainloop.slothy:Objective: None (any satisfying solution is fine)
INFO:slothy.mainloop.slothy:Invoking external constraint solver (OR-Tools CP-SAT v9.12.4544) ...
INFO:slothy.mainloop.slothy:[74.0876s]: Found 1 solutions so far... objective (no objective): currently 0.0, bound 0.0
INFO:slothy.mainloop.slothy:OPTIMAL, wall time: 74.309375 s
INFO:slothy.mainloop.slothy:Booleans in result: 16950
INFO:slothy.mainloop.slothy.selfcheck:OK!
INFO:slothy.mainloop.slothy.selftest:Skipping selftest as input contains symbolic registers.
INFO:slothy.mainloop:SLOTHY version: unknown
INFO:slothy:Instructions in body: 958
INFO:slothy.mainloop.split.0_96:Perform internal binary search for minimal number of stalls...
INFO:slothy.mainloop.split.0_96:Attempt optimization with max 32 stalls...
INFO:slothy.mainloop.split.0_96:Objective: minimize cycles
INFO:slothy.mainloop.split.0_96:Invoking external constraint solver (OR-Tools CP-SAT v9.12.4544) ...
INFO:slothy.mainloop.split.0_96:[2.3609s]: Found 1 solutions so far... objective (minimize cycles): currently  (Cycles ~ 60.0, IPC ~ 1.60), bound  (Cycles ~ 54.0, IPC ~ 1.78)
INFO:slothy.mainloop.split.0_96:OPTIMAL, wall time: 3.732789 s
INFO:slothy.mainloop.split.0_96:Booleans in result: 8125
INFO:slothy.mainloop.split.0_96.selfcheck:OK!
INFO:slothy.mainloop.split.0_96.selftest:Skipping selftest as input contains symbolic registers.
INFO:slothy.mainloop.split.0_96:Minimum number of stalls: 12
INFO:slothy.mainloop.split.96_192:Perform internal binary search for minimal number of stalls...
INFO:slothy.mainloop.split.96_192:Attempt optimization with max 32 stalls...
Traceback (most recent call last):
  File "/Users/huangchengwei/Documents/slothy/tutorial/tutorial-7.py", line 36, in <module>
    slothy.optimize(start="mainloop", end="end_label")
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/slothy.py", line 397, in optimize
    early, core, late, num_exceptional = Heuristics.periodic(body, logger, c)
                                         ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 373, in periodic
    res = Heuristics.linear(body, logger=logger, conf=conf)
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 462, in linear
    return Heuristics._split(body, logger, conf)
           ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 986, in _split
    return Heuristics._split_inner(body, logger, c)
           ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 882, in _split_inner
    cur_body, stalls, _ = optimize_chunks_many(
                          ~~~~~~~~~~~~~~~~~~~~^
        idx_lst, cur_body, stalls, show_stalls=False
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 831, in optimize_chunks_many
    body, stalls, cur_stalls, local_perm = optimize_chunk(
                                           ~~~~~~~~~~~~~~^
        start_idx, end_idx, body, stalls, **kwargs
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 795, in optimize_chunk
    result = Heuristics.optimize_binsearch(
        cur_body,
    ...<3 lines>...
        suffix_len=suffix_len,
    )
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 145, in optimize_binsearch
    return Heuristics.optimize_binsearch_internal(
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        source, logger, conf, flexible=flexible, **kwargs
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 290, in optimize_binsearch_internal
    success = core.optimize(source, **kwargs)
  File "/Users/huangchengwei/Documents/slothy/slothy/core/core.py", line 1701, in optimize
    self._add_variables_functional_units()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/core.py", line 2633, in _add_variables_functional_units
    cycles_unit_occupied = self.target.get_inverse_throughput(t.inst)
  File "/Users/huangchengwei/Documents/slothy/slothy/targets/aarch64/cortex_a55.py", line 659, in get_inverse_throughput
    return lookup_multidict(inverse_throughput, src, instclass_src)
  File "/Users/huangchengwei/Documents/slothy/slothy/helper.py", line 1874, in lookup_multidict
    raise UnknownInstruction(
        f"Multiple matches found for {instclass} for {inst}"
    )
slothy.targets.common.UnknownInstruction: Multiple matches found for <class 'slothy.targets.aarch64.aarch64_neon.x_str_sp_imm'> for str x1, [sp, #STACK_A_32]

It turns out that the instructions: x_str_sp_imm x_ldr_stack_imm are already contained in Str_X and Ldr_X, respectively, so numbers (latency, etc) are specified twice.
Besides that, the execution unit of q_ldr1_stack is redefined in two places:

    # q-form vector instructions
    (
        ...
        Str_Q,
        q_ldr1_stack,
        q_ldr1_post_inc,
        ...
    ): [
        [ExecutionUnit.VEC0, ExecutionUnit.VEC1]
    ],  # these instructions use both VEC0 and VEC1
...
    # non-q-form vector instructions
    (
        ...
        d_ldr_stack_with_inc,
        q_ldr1_stack,
        Q_Ld2_Lane_Post_Inc,
        ...
    ): [
        ExecutionUnit.VEC0,
        ExecutionUnit.VEC1,
    ],  # these instructions use VEC0 or VEC1

After fixing these two, I finally got the LLVM-Mc Error as follows:

(venv) huangchengwei@huangchengweis-MacBook-Air tutorial % python3 tutorial-7.py
INFO:slothy.mainloop:SLOTHY version: unknown
INFO:slothy:Instructions in body: 958
INFO:slothy.mainloop.slothy:Objective: None (any satisfying solution is fine)
INFO:slothy.mainloop.slothy:Invoking external constraint solver (OR-Tools CP-SAT v9.12.4544) ...
INFO:slothy.mainloop.slothy:[75.8771s]: Found 1 solutions so far... objective (no objective): currently 0.0, bound 0.0
INFO:slothy.mainloop.slothy:OPTIMAL, wall time: 76.141257 s
INFO:slothy.mainloop.slothy:Booleans in result: 17265
INFO:slothy.mainloop.slothy.selfcheck:OK!
INFO:slothy.mainloop.slothy.selftest:Skipping selftest as input contains symbolic registers.
INFO:slothy.mainloop:SLOTHY version: unknown
INFO:slothy:Instructions in body: 958
INFO:slothy.mainloop.split.0_96:Perform internal binary search for minimal number of stalls...
INFO:slothy.mainloop.split.0_96:Attempt optimization with max 32 stalls...
INFO:slothy.mainloop.split.0_96:Objective: minimize cycles
INFO:slothy.mainloop.split.0_96:Invoking external constraint solver (OR-Tools CP-SAT v9.12.4544) ...
INFO:slothy.mainloop.split.0_96:[2.9688s]: Found 1 solutions so far... objective (minimize cycles): currently  (Cycles ~ 60.0, IPC ~ 1.60), bound  (Cycles ~ 54.0, IPC ~ 1.78)
INFO:slothy.mainloop.split.0_96:OPTIMAL, wall time: 3.721717 s
INFO:slothy.mainloop.split.0_96:Booleans in result: 8125
INFO:slothy.mainloop.split.0_96.selfcheck:OK!
INFO:slothy.mainloop.split.0_96.selftest:Skipping selftest as input contains symbolic registers.
INFO:slothy.mainloop.split.0_96:Minimum number of stalls: 12
INFO:slothy.mainloop.split.96_192:Perform internal binary search for minimal number of stalls...
INFO:slothy.mainloop.split.96_192:Attempt optimization with max 32 stalls...
INFO:slothy.mainloop.split.96_192:Objective: minimize cycles



...



INFO:slothy.mainloop.split.479_575:OPTIMAL, wall time: 0.180550 s
INFO:slothy.mainloop.split.479_575:Booleans in result: 67
INFO:slothy.mainloop.split.479_575.selfcheck:OK!
INFO:slothy.mainloop.split.479_575.selftest:Skipping selftest as input contains symbolic registers.
INFO:slothy.mainloop.split.479_575:Minimum number of stalls: 77
INFO:slothy.mainloop.split.575_671:Perform internal binary search for minimal number of stalls...
INFO:slothy.mainloop.split.575_671:Attempt optimization with max 32 stalls...
INFO:slothy.mainloop.split.575_671:Objective: minimize cycles
INFO:slothy.mainloop.split.575_671:Invoking external constraint solver (OR-Tools CP-SAT v9.12.4544) ...
INFO:slothy.mainloop.split.575_671:INFEASIBLE, wall time: 0.007577 s
INFO:slothy.mainloop.split.575_671:Attempt optimization with max 64 stalls...
INFO:slothy.mainloop.split.575_671:Objective: minimize cycles
INFO:slothy.mainloop.split.575_671:Invoking external constraint solver (OR-Tools CP-SAT v9.12.4544) ...
INFO:slothy.mainloop.split.575_671:INFEASIBLE, wall time: 0.040110 s
INFO:slothy.mainloop.split.575_671:Attempt optimization with max 128 stalls...
INFO:slothy.mainloop.split.575_671:Objective: minimize cycles
INFO:slothy.mainloop.split.575_671:Invoking external constraint solver (OR-Tools CP-SAT v9.12.4544) ...
INFO:slothy.mainloop.split.575_671:[0.1387s]: Found 1 solutions so far... objective (minimize cycles): currently  (Cycles ~ 116.0, IPC ~ 0.83), bound  (Cycles ~ 110.0, IPC ~ 0.87)
INFO:slothy.mainloop.split.575_671:OPTIMAL, wall time: 0.152324 s
INFO:slothy.mainloop.split.575_671:Booleans in result: 30
INFO:slothy.mainloop.split.575_671.selfcheck:OK!
INFO:slothy.mainloop.split.575_671.selftest:Running selftest (10 iterations)...
INFO:slothy.mainloop.split.575_671.selftest:Inferred that the following registers seem to act as pointers: set()
INFO:slothy.mainloop.split.575_671.selftest:Using default buffer size of 1024 bytes. If you want different buffer sizes, set selftest_address_registers manually.
ERROR:slothy.mainloop.split.575_671.selftest:llvm-mc failed to handle the following code
ERROR:slothy.mainloop.split.575_671.selftest:.global harness
harness:
        umlal v19.2D, v1.2S, v18.2S // ...............................................................................................................................................................................................................................................................................................*...............................................................................................................................................................................................
        mul v25.2S, v5.2S, v31.2S // ................................................................................................................................................................................................................................................................................................*..............................................................................................................................................................................................
        umull v13.2D, v16.2S, v20.2S // ................................................................................................................................................................................................................................................................................................*..............................................................................................................................................................................................


     ......


        zip2 v6.4S, v0.4S, v11.4S // ............................................................................................................................................................................................................................................................................................................................................*..................................................................................................................................................
        zip1 v22.4S, v25.4S, v12.4S // .............................................................................................................................................................................................................................................................................................................................................*.................................................................................................................................................
        zip2 v23.4S, v25.4S, v12.4S // .............................................................................................................................................................................................................................................................................................................................................*.................................................................................................................................................
        zip1 v25.2S, v13.2S, v2.2S // ..............................................................................................................................................................................................................................................................................................................................................*................................................................................................................................................
        zip2 v0.2S, v13.2S, v2.2S // ..............................................................................................................................................................................................................................................................................................................................................*................................................................................................................................................
        mov v16.d[0], v18.d[1] // ...............................................................................................................................................................................................................................................................................................................................................*...............................................................................................................................................
ERROR:slothy.mainloop.split.575_671.selftest:Output from llvm-mc
ERROR:slothy.mainloop.split.575_671.selftest:<stdin>:76:23: error: index must be an integer in range [-256, 255].
        ldr b29, [sp, #STACK_MASK2] // ....................................................................................................................................................................................................................................................................................................................................*..........................................................................................................................................................  // @slothy:reads=mask2
                      ^

Traceback (most recent call last):
  File "/Users/huangchengwei/Documents/slothy/slothy/helper.py", line 1383, in assemble
    r = subprocess.run(
        ["llvm-mc"] + args, input=code.encode(), capture_output=True, check=True
    )
  File "/opt/homebrew/Cellar/python@3.13/3.13.3_1/Frameworks/Python.framework/Versions/3.13/lib/python3.13/subprocess.py", line 577, in run
    raise CalledProcessError(retcode, process.args,
                             output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['llvm-mc', '--arch=aarch64', '--assemble', '--filetype=obj', '--mattr=aes']' returned non-zero exit status 1.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/Users/huangchengwei/Documents/slothy/tutorial/tutorial-7.py", line 36, in <module>
    slothy.optimize(start="mainloop", end="end_label")
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/slothy.py", line 397, in optimize
    early, core, late, num_exceptional = Heuristics.periodic(body, logger, c)
                                         ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 373, in periodic
    res = Heuristics.linear(body, logger=logger, conf=conf)
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 462, in linear
    return Heuristics._split(body, logger, conf)
           ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 986, in _split
    return Heuristics._split_inner(body, logger, c)
           ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 882, in _split_inner
    cur_body, stalls, _ = optimize_chunks_many(
                          ~~~~~~~~~~~~~~~~~~~~^
        idx_lst, cur_body, stalls, show_stalls=False
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 831, in optimize_chunks_many
    body, stalls, cur_stalls, local_perm = optimize_chunk(
                                           ~~~~~~~~~~~~~~^
        start_idx, end_idx, body, stalls, **kwargs
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 795, in optimize_chunk
    result = Heuristics.optimize_binsearch(
        cur_body,
    ...<3 lines>...
        suffix_len=suffix_len,
    )
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 145, in optimize_binsearch
    return Heuristics.optimize_binsearch_internal(
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        source, logger, conf, flexible=flexible, **kwargs
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/heuristics.py", line 290, in optimize_binsearch_internal
    success = core.optimize(source, **kwargs)
  File "/Users/huangchengwei/Documents/slothy/slothy/core/core.py", line 1738, in optimize
    self._extract_result()
    ~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/core.py", line 2198, in _extract_result
    self._result.selftest(self.logger.getChild("selftest"))
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/core/core.py", line 978, in selftest
    SelfTest.run(
    ~~~~~~~~~~~~^
        self.config,
        ^^^^^^^^^^^^
    ...<5 lines>...
        self.config.selftest_iterations,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/helper.py", line 1580, in run
    final_regs_old, final_mem_old = run_code(codeA, txt="old")
                                    ~~~~~~~~^^^^^^^^^^^^^^^^^^
  File "/Users/huangchengwei/Documents/slothy/slothy/helper.py", line 1492, in run_code
    objcode, offset = LLVM_Mc.assemble(
                      ~~~~~~~~~~~~~~~~^
        code,
        ^^^^^
    ...<5 lines>...
        include_paths=config.compiler_include_paths,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/Users/huangchengwei/Documents/slothy/slothy/helper.py", line 1391, in assemble
    raise LLVM_Mc_Error from exc
slothy.helper.LLVM_Mc_Error

I think this is a issue related to slothy's functionality, since the error occurs when touching instructions with comment @slothy:reads=mask2.
I did not attempt to fix this because I am not familiar with how those @slothy:reads=mask2 syntax being processed in SLOTHY

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