Vyper compiler fails to compile long unsafe expression

[pcaversaccio]

Version Information

• vyper Version (output of vyper --version): 0.3.7+commit.6020b8b
• OS: linux
• Python Version (output of python --version): 3.9.2

What's your issue about?

The Vyper compiler fails to compile the following function (waited for around 10mins without success):

@external
@pure
def wad_exp(x: int256) -> uint256:
    value: int256 = x
    if (x <= -42139678854452767551):
        return empty(uint256)

    assert x < 135305999368893231589, "Math: wad_exp overflow"

    value = unsafe_div(shift(x, 78), 5 ** 18)
    k: int256 = shift(unsafe_add(unsafe_div(shift(value, 96), 54916777467707473351141471128), 2 ** 95), -96)
    value = unsafe_sub(value, unsafe_mul(k, 54916777467707473351141471128))

    y: int256 = unsafe_add(shift(unsafe_mul(unsafe_add(value, 1346386616545796478920950773328), value), -96), 57155421227552351082224309758442)
    p: int256 = unsafe_add(unsafe_mul(unsafe_add(shift(unsafe_mul(unsafe_sub(unsafe_add(y, value), 94201549194550492254356042504812), y), -96), 28719021644029726153956944680412240), value), shift(4385272521454847904659076985693276, 96))

    q: int256 = unsafe_add(shift(unsafe_mul(unsafe_sub\
                (shift(unsafe_mul(unsafe_add(shift(unsafe_mul\
                (unsafe_sub(shift(unsafe_mul(unsafe_add(shift(unsafe_mul\
                (unsafe_sub(value, convert(2855989394907223263936484059900, int256)),\
                value), convert(-96, int256)), convert(50020603652535783019961831881945,\
                int256)), value), convert(-96, int256)), convert(533845033583426703283633433725380, int256)),\
                value), convert(-96, int256)), convert(3604857256930695427073651918091429, int256)), value),\
                convert(-96, int256)), convert(14423608567350463180887372962807573, int256)), value),\
                convert(-96, int256)), convert(26449188498355588339934803723976023, int256))

    r: int256 = unsafe_div(p, q)

    return convert(shift(unsafe_mul(r, 3822833074963236453042738258902158003155416615667), -unsafe_sub(195, k)), uint256)

How can it be fixed?

The Vyper compiler should be able to successfully compile the above or similar long unsafe expressions.

[pcaversaccio]

Tagging @michwill: maybe you can share your example with the same issue?