Use the whole gammut of constant immediates available to set up a vector.
Instead of using, for example, `mov w0, #0xffff; dup v0.4s, w0`, which
transfers between register files, use the more efficient `movi v0.4s, #-1`
instead. Not limited to just a few values, but any immediate value that can
be encoded by all the variants of `FMOV`, `MOVI`, `MVNI`, thus eliminating
the need to there be patterns to optimize special cases.
Differential revision: https://reviews.llvm.org/D42133
llvm-svn: 326718
Get rid of icky goto loops and make the code easier to maintain. Otherwise,
NFC.
Restore r324903 and fix PR36369.
Differentail revision: https://reviews.llvm.org/D43364
llvm-svn: 325621
Instead of using, for example, `dup v0.4s, wzr`, which transfers between
register files, use the more efficient `movi v0.4s, #0` instead.
Differential revision: https://reviews.llvm.org/D41515
llvm-svn: 321824