lowering error in certain conditions #7389

auderson · 2021-09-09T02:15:25Z

Reporting a bug

I have tried using the latest released version of Numba (most recent is
visible in the change log (https://github.com/numba/numba/blob/master/CHANGE_LOG).
I have included a self contained code sample to reproduce the problem.
i.e. it's possible to run as 'python bug.py'.

Hi,
I wonder if this is a bug:

@njit(nogil=True)
def inner_open(arr, kind='mergesort'):
    if kind == 'mergesort':
        return np.argsort(arr, kind='mergesort')
    if kind == 'quicksort':
        return np.argsort(arr, kind='quicksort')


@njit(nogil=True)
def inner_closed(arr, kind='mergesort'):
    if kind == 'mergesort':
        return np.argsort(arr, kind='mergesort')
    else:
        return np.argsort(arr, kind='quicksort')

the difference of these 2 inner functions is the way of using if-else, the first one is not closed.

no errors

@njit(parallel=True)
def outer_close_div(matrix):
    result = matrix.copy()
    for i, mat in enumerate(matrix):
        result[i] = inner_closed(mat) / (i + 1)
    return result

outer_close_div(np.random.randn(10, 10))

@njit(parallel=True)
def outer_open(matrix):
    result = matrix.copy()
    for i, mat in enumerate(matrix):
        result[i] = inner_open(mat)
    return result

outer_open(np.random.randn(10, 10))

error:

It's strange that inner_open can be used alone but can't be used with other operations including itself:

@njit(parallel=True)
def outer_open_div(matrix):
    result = matrix.copy()
    for i, mat in enumerate(matrix):
        result[i] = inner_open(mat) / (i + 1)
    return result

outer_open_div(np.random.randn(10, 10))

@njit(parallel=True)
def outer_open_open(matrix):
    result = matrix.copy()
    for i, mat in enumerate(matrix):
        result[i] = inner_open(mat) + inner_open(mat)
    return result

outer_open_open(np.random.randn(10, 10))

Traceback (most recent call last):
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/errors.py", line 776, in new_error_context
    yield
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 235, in lower_block
    self.lower_inst(inst)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 497, in lower_inst
    func(self, inst)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/parfors/parfor_lowering.py", line 90, in _lower_parfor_parallel
    lowerer.lower_inst(instr)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 380, in lower_inst
    val = self.lower_assign(ty, inst)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 556, in lower_assign
    return self.lower_expr(ty, value)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 1084, in lower_expr
    res = self.lower_call(resty, expr)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 815, in lower_call
    res = self._lower_call_normal(fnty, expr, signature)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 1037, in _lower_call_normal
    argvals = self.fold_call_args(
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 754, in fold_call_args
    argvals = typing.fold_arguments(pysig,
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/typing/templates.py", line 243, in fold_arguments
    ba.arguments[name] = normal_handler(i, param, ba.arguments[name])
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 741, in normal_handler
    return self._cast_var(var, signature.args[index])
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 719, in _cast_var
    val = self.loadvar(var.name)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 1327, in loadvar
    ptr = self.getvar(name)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 1319, in getvar
    return self.varmap[name]
KeyError: '$38binary_true_divide.11_size0.6936'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/IPython/core/interactiveshell.py", line 3441, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-49-66d3935fd7b7>", line 8, in <module>
    outer_open_div(np.random.randn(10, 10))
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/dispatcher.py", line 501, in _compile_for_args
    raise e
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/dispatcher.py", line 434, in _compile_for_args
    return_val = self.compile(tuple(argtypes))
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/dispatcher.py", line 979, in compile
    cres = self._compiler.compile(args, return_type)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/dispatcher.py", line 141, in compile
    status, retval = self._compile_cached(args, return_type)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/dispatcher.py", line 155, in _compile_cached
    retval = self._compile_core(args, return_type)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/dispatcher.py", line 168, in _compile_core
    cres = compiler.compile_extra(self.targetdescr.typing_context,
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler.py", line 686, in compile_extra
    return pipeline.compile_extra(func)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler.py", line 428, in compile_extra
    return self._compile_bytecode()
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler.py", line 492, in _compile_bytecode
    return self._compile_core()
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler.py", line 471, in _compile_core
    raise e
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler.py", line 462, in _compile_core
    pm.run(self.state)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 343, in run
    raise patched_exception
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 334, in run
    self._runPass(idx, pass_inst, state)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler_lock.py", line 35, in _acquire_compile_lock
    return func(*args, **kwargs)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 289, in _runPass
    mutated |= check(pss.run_pass, internal_state)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/compiler_machinery.py", line 262, in check
    mangled = func(compiler_state)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/typed_passes.py", line 396, in run_pass
    lower.lower()
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 138, in lower
    self.lower_normal_function(self.fndesc)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 192, in lower_normal_function
    entry_block_tail = self.lower_function_body()
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 221, in lower_function_body
    self.lower_block(block)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/lowering.py", line 235, in lower_block
    self.lower_inst(inst)
  File "/home/auderson/miniconda3/lib/python3.8/contextlib.py", line 131, in __exit__
    self.gen.throw(type, value, traceback)
  File "/home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/errors.py", line 786, in new_error_context
    raise newerr.with_traceback(tb)
numba.core.errors.LoweringError: Failed in nopython mode pipeline (step: native lowering)
'$38binary_true_divide.11_size0.6936'
File "<ipython-input-49-66d3935fd7b7>", line 5:
def outer_open_div(matrix):
    <source elided>
    for i, mat in enumerate(matrix):
        result[i] = inner_open(mat) / (i + 1)
        ^
During: lowering "id=60[LoopNest(index_variable = parfor_index.6937, range = (0, $38binary_true_divide.11_size0.6936, 1))]{2596: <ir.Block at <ipython-input-49-66d3935fd7b7> (5)>}Var(parfor_index.6937, <ipython-input-49-66d3935fd7b7>:5)" at <ipython-input-49-66d3935fd7b7> (5)

The text was updated successfully, but these errors were encountered:

stuartarchibald · 2021-09-10T17:23:59Z

Thanks for the report, I can reproduce. I think the issue is because the inner_open function could return None.
MWR:

from numba import njit
import numpy as np

@njit
def bar(arr, predicate=True):
    if predicate:
        return np.ones(5)

@njit(parallel=True)
def foo(x):
    bar(x) / 1

foo(np.ones(1,))

This "fixes" the original problem by making the case where None is returned unreachable:

from numba import njit
import numpy as np

@njit
def bar(arr, kind='mergesort'):
    if kind == 'mergesort':
        return np.argsort(arr, kind='mergesort')
    if kind == 'quicksort':
        return np.argsort(arr, kind='quicksort')
    assert 0

@njit(parallel=True)
def foo(x):
    bar(x) / 1

foo(np.ones(1,))

CC @DrTodd13 think this is a parfors issue.

stuartarchibald added bug - failure to compile Bugs: failed to compile valid code ParallelAccelerator labels Sep 10, 2021

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lowering error in certain conditions #7389

lowering error in certain conditions #7389

auderson commented Sep 9, 2021 •

edited

stuartarchibald commented Sep 10, 2021

lowering error in certain conditions #7389

lowering error in certain conditions #7389

Comments

auderson commented Sep 9, 2021 • edited

Reporting a bug

no errors

error:

stuartarchibald commented Sep 10, 2021

auderson commented Sep 9, 2021 •

edited