Numpy fill accepts also variables

[philip-paul-mueller]

This PR is for addressing issue #1389.

[philip-paul-mueller]

While this PR allows for code such as:

import dace
import numpy as np

N = dace.symbol("N", dace.int32)

@dace.program
def fill_dace(A: dace.float64[N, N], value: dace.float64):
    A.fill(value)

it does currently not allows for code such as:

@dace.program
def fill_dace_not_working(A: dace.float64[N, N], value: dace.float64):
    A.fill(value + 1)

The reason is that the argument to fill is an expression and not a scalar, however, it could be evaluated to a scalar.

What is funny though is that the code:

@dace.program
def fill_dace_does_also_not_work(A: dace.float64[N, N], value: dace.float64):
    value2 = value + 1
    A.fill(value2)

will also not work but:

@dace.program
def fill_dace_will_work_but_why(A: dace.float64[N, N], value: dace.float64):
    value2 = value + 1
    A.fill(value2)
    return value2

will work, for some strange reason and I have no idea why?

Disturbingly this:

@dace.program
def fill_dace_why_god_does_this_not_work(A: dace.float64[N, N], value: dace.float64):
    value2 = value + 1
    A.fill(value2)
    return value

does not work, and I have no idea why?

For more see samples/simple/numpy_fill.py

[philip-paul-mueller]

Current State:
To summarize the current state:

• A.fill(value): Where value is an argument -> Works
• A.fill(Expr): Where Expr is an expression, such as value + 1 -> Does not work (probably need some big changes)
• c = value + 2; A.fill(c): Where value is an argument -> Does not work (This is probably a bug in the Python frontend, see above)

[philip-paul-mueller]

Commit a29ae4a should now solve everything of the above list.