Uday Bondhugula 6d242fcf4b Simplify affine binary op expression class hierarchy ... - Drop sub-classing of affine binary op expressions. - Drop affine expr op kind sub. Represent it as multiply by -1 and add. This will also be in line with the math form when we'll need to represent a system of linear equalities/inequalities: the negative number goes into the coefficient of an affine form. (For eg. x_1 + (-1)*x_2 + 3*x_3 + (-2) >= 0). The folding simplification will transparently deal with multiplying the -1 with any other constants. This also means we won't need to simplify a multiply expression like in x_1 + (-2)*x_2 to a subtract expression (x_1 - 2*x_2) for canonicalization/uniquing. - When we print the IR, we will still pretty print to a subtract when possible. PiperOrigin-RevId: 205298958		2019-03-29 12:36:46 -07:00
mlir	Simplify affine binary op expression class hierarchy	2019-03-29 12:36:46 -07:00