[AArch64] Add tablegen patterns for fmla index with extract 0. (#114976)

We have tablegen patterns to produce an indexed `fmla s0, s1, v2.s[2]`
from
  `fma extract(Rn, lane), Rm, Ra -> fmla`
But for the case of lane==0, we want to prefer the simple `fmadd s0, s1,
s2`. So we have patterns for
  `fma extract(Rn, 0), Rm, Ra -> fmadd`

The problem arises when we have two extracts, as tablegen starts to
prefer the second pattern, as it looks more specialized. This patch adds
additional patterns to catch this case:
  `fma extract(Rn, index), extract(Rm, 0), Ra -> fmla`
To make sure the simpler fmadd keeps being selected when both lanes are
extracted from lane 0 we need to add patterns for that case too:
  `fma extract(Rn, 0), extract(Rm, 0), Ra -> fmadd`

0 files changed, 0 insertions, 0 deletions