[llvm-dev] Floor-integer-div and integer sign operations?

[edA-qa mort-ora-y via llvm-dev]

I'm looking for ways to do some basic operations without using branches.

The key operation I want is a floored/round-to-negative-infinity integer
division (as opposed to the default round-to-zero).

    7 floordiv 5 = 1
    -3 floordiv 5 = -1
    -6 floordiv 5 = -2

As I guess that doesn't exist, the operation can be constructed as:

   (a/b) + (a>>31)

Assuming a is 32 bits. I can probably check the bit count, but perhaps
there's an op that does this already.


I'm also looking for a `sign(a) => (-1,0,1)` operation. Is there some
easy way to do this without branches? That is, have I overlooked from IR
function?

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