Numba 0.54 NumbaIRAssumptionWarning

[mhostetter]

Numba 0.53.1

In [1]: import numba                                                                                                                                                                                                                 

In [2]: import galois                                                                                                                                                                                                                

In [3]: numba.__version__                                                                                                                                                                                                            
Out[3]: '0.53.1'

In [4]: galois.__version__                                                                                                                                                                                                           
Out[4]: '0.0.19'

In [5]: GF = galois.GF(2**8, compile="jit-calculate")                                                                                                                                                                                

In [6]: a = GF.Random(10); a                                                                                                                                                                                                         
Out[6]: GF([191, 116,  80,  93, 191,  52,  93, 174, 195, 244], order=2^8)

In [7]: b = GF.Random(10); b                                                                                                                                                                                                         
Out[7]: GF([251, 216, 189, 173,  24, 209, 184, 170, 154, 126], order=2^8)

In [8]: a * b                                                                                                                                                                                                                        
Out[8]: GF([ 21,  64,  99,  40, 174, 205, 165, 177, 104,  42], order=2^8)

Numba 0.54

In [1]: import numba                                                                                                                                                                                                                 

In [2]: import galois                                                                                                                                                                                                                

In [3]: numba.__version__                                                                                                                                                                                                            
Out[3]: '0.54.0'

In [4]: galois.__version__                                                                                                                                                                                                           
Out[4]: '0.0.19'

In [5]: GF = galois.GF(2**8, compile="jit-calculate")                                                                                                                                                                                

In [6]: a = GF.Random(10); a                                                                                                                                                                                                         
Out[6]: GF([ 89, 195, 178, 200, 222,  96,  53,   9,  20,  12], order=2^8)

In [7]: b = GF.Random(10); b                                                                                                                                                                                                         
Out[7]: GF([207,  45,  38, 249, 151,  37,   5, 139,  80, 198], order=2^8)

In [8]: a * b                                                                                                                                                                                                                        
/home/matt/.local/lib/python3.8/site-packages/numba/core/ssa.py:272: NumbaIRAssumptionWarning: variable 'b.1.1' is not in scope.

This warning came from an internal pedantic check. Please report the warning
message and traceback, along with a minimal reproducer at:
https://github.com/numba/numba/issues/new?template=bug_report.md

  warnings.warn(errors.NumbaIRAssumptionWarning(wmsg,
/home/matt/.local/lib/python3.8/site-packages/numba/core/ssa.py:272: NumbaIRAssumptionWarning: variable 'a.1.1' is not in scope.

This warning came from an internal pedantic check. Please report the warning
message and traceback, along with a minimal reproducer at:
https://github.com/numba/numba/issues/new?template=bug_report.md

  warnings.warn(errors.NumbaIRAssumptionWarning(wmsg,
Out[8]: GF([ 56, 251,  72, 114, 110,  97, 225, 167,  52,  65], order=2^8)

[mhostetter]

Pinned Numba to <0.54 in c14f2ca.

[mhostetter]

As of this date with galois v0.0.22, this warning still persists. This warning appears with Numba v0.54.0 and v0.54.1.

In [1]: import galois

In [2]: galois.__version__
Out[2]: '0.0.22'

In [3]: import numba

In [4]: numba.__version__
Out[4]: '0.54.0'

In [5]: GF = galois.GF(2**8, compile="jit-calculate")

In [6]: x = GF.Random(10); x
Out[6]: GF([ 65, 146, 183, 209, 229, 126,  21, 182,  85,  43], order=2^8)

In [7]: y = GF.Random(10); y
Out[7]: GF([193, 201,   2,   2, 123, 188,  14, 203, 128,  90], order=2^8)

In [8]: x * y
/home/matt/.local/lib/python3.8/site-packages/numba/core/ssa.py:272: NumbaIRAssumptionWarning: variable 'a.1.1' is not in scope.

This warning came from an internal pedantic check. Please report the warning
message and traceback, along with a minimal reproducer at:
https://github.com/numba/numba/issues/new?template=bug_report.md

  warnings.warn(errors.NumbaIRAssumptionWarning(wmsg,
/home/matt/.local/lib/python3.8/site-packages/numba/core/ssa.py:272: NumbaIRAssumptionWarning: variable 'b.1.1' is not in scope.

This warning came from an internal pedantic check. Please report the warning
message and traceback, along with a minimal reproducer at:
https://github.com/numba/numba/issues/new?template=bug_report.md

  warnings.warn(errors.NumbaIRAssumptionWarning(wmsg,
Out[8]: GF([203, 227, 115, 191, 177,  11, 214, 137, 213, 139], order=2^8)

[mhostetter]

Replacing the inputs a and b with aa and bb resolves the warning. Hmmm...

    @staticmethod
    @numba.extending.register_jitable(inline="always")
    def _multiply_calculate(aa, bb, CHARACTERISTIC, DEGREE, IRREDUCIBLE_POLY):
        """
        a in GF(2^m), can be represented as a degree m-1 polynomial a(x) in GF(2)[x]
        b in GF(2^m), can be represented as a degree m-1 polynomial b(x) in GF(2)[x]
        p(x) in GF(2)[x] with degree m is the irreducible polynomial of GF(2^m)

        a * b = c
            = (a(x) * b(x)) % p(x) in GF(2)
            = c(x)
            = c
        """
        ORDER = CHARACTERISTIC**DEGREE

        # Re-order operands such that a > b so the while loop has less loops
        if bb > aa:
            aa, bb = bb, aa

        c = 0
        while bb > 0:
            if bb & 0b1:
                c ^= aa  # Add aa(x) to c(x)

            bb >>= 1  # Divide bb(x) by x
            aa <<= 1  # Multiply aa(x) by x
            if aa >= ORDER:
                aa ^= IRREDUCIBLE_POLY  # Compute aa(x) % p(x)

        return c

In [1]: import galois

In [2]: galois.__version__
Out[2]: '0.0.22'

In [3]: import numba

In [4]: numba.__version__
Out[4]: '0.54.1'

In [5]: GF = galois.GF(2**8, compile="jit-calculate")

In [6]: x = GF.Random(10); x
Out[6]: GF([116,  50, 199, 161, 194, 123,  31,  58, 165,  93], order=2^8)

In [7]: y = GF.Random(10); y
Out[7]: GF([139, 204,   7,   0, 153, 132, 226,  80,  85,  14], order=2^8)

In [8]: x * y
Out[8]: GF([131,  97, 111,   0, 169, 186,  81, 161, 187,   1], order=2^8)

[mhostetter]

I filed numba/numba#7623. It appears renaming the lambda arguments resolves the issue as well.

For instance

            if cls._UFUNC_TYPE[name] == "unary":
                cls._UFUNC_CACHE_CALCULATE[key] = numba.vectorize(["int64(int64)"], nopython=True)(lambda a: function(a, characteristic, degree, irreducible_poly))
            else:
                cls._UFUNC_CACHE_CALCULATE[key] = numba.vectorize(["int64(int64, int64)"], nopython=True)(lambda a, b: function(a, b, characteristic, degree, irreducible_poly))

to

            if cls._UFUNC_TYPE[name] == "unary":
                cls._UFUNC_CACHE_CALCULATE[key] = numba.vectorize(["int64(int64)"], nopython=True)(lambda aa: function(aa, characteristic, degree, irreducible_poly))
            else:
                cls._UFUNC_CACHE_CALCULATE[key] = numba.vectorize(["int64(int64, int64)"], nopython=True)(lambda aa, bb: function(aa, bb, characteristic, degree, irreducible_poly))