[llvm] [RISCV][VLOPT] Add support for 11.14 widening integer mul-add instructions (PR #112219)

[Craig Topper via llvm-commits]

topperc wrote:

This does not test getOperandInfo for the multiplicands. Should we have tests where these instructions are the ones providing the VL?

https://github.com/llvm/llvm-project/pull/112219