[Bug target/104124] Poor optimization for vector splat DW with small consts

[avinashd at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104124

Avinash Jayakar <avinashd at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |avinashd at gcc dot gnu.org

--- Comment #7 from Avinash Jayakar <avinashd at gcc dot gnu.org> ---
I had a question regarding the patch that fixed this PR. 
In the commit message it is mentioned that for 0 and -1 the splat and unpack
will not work.
1. But in the code, the check is for +1
  value = INTVAL (elt);
  if (value == 0 || value == 1
      || !EASY_VECTOR_15 (value))
    return false;

should this be corrected?

2. Any reason why not for 0 and -1?