tree 668f059ac57b5a5ca12e43e6fcc042e18ac1a148
parent 34c485201507de2602b70b0df368dbc6c0b0fecb
author Ben Shi <powerman1st@163.com> 1594172926 -0700
committer Fangrui Song <maskray@google.com> 1594173024 -0700

[RISCV] Optimize multiplication by constant

... to shift/add or shift/sub.

Do not enable it on riscv32 with the M extension where decomposeMulByConstant
may not be an optimization.

Reviewed By: luismarques, MaskRay

Differential Revision: https://reviews.llvm.org/D82660