llvm-project

a3c2d8c0 - [RISCV] Combine ({s,u}{div,rem} (zext, zext)) -> (zext ({s,u}{div,rem} (zext, zext))) (#86779)

[RISCV] Combine ({s,u}{div,rem} (zext, zext)) -> (zext ({s,u}{div,rem} (zext, zext))) (#86779) This narrows unsigned and signed div and rem nodes via combineBinOpOfZExt. Unlike other binary ops, there are no widening div or rem instructions. So we will end up with an extra vzext.vf2. However I'm assuming that div/rem are expensive enough that by reducing their EMUL we will gain back the cost. Alive2 proof: https://alive2.llvm.org/ce/z/Et_L6y