[Bug tree-optimization/110541] Invalid VEC_PERM_EXPR mask element size

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110541

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-07-05
             Status|UNCONFIRMED                 |ASSIGNED

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The restriction as documented in tree.def applies to non-constant MASKs only,
the case for constant MASKs was relaxed.  Like

/* Vector permutation expression.  A = VEC_PERM_EXPR<v0, v1, mask> means

   N = length(mask)
   foreach i in N:
     M = mask[i] % (length(v0) + length(v1))
     A[i] = M < length(v0) ? v0[M] : v1[M - length(v0)]

   V0 and V1 are vectors of the same type.

   When MASK is not constant:
     MASK is an integer-typed vector.  The number of MASK elements must 
     be the same with the number of elements in V0 and V1.  The size of 
     the inner type of the MASK and of the V0 and V1 must be the same.

   When MASK is constant:
     MASK is an integer-typed vector.   MASK elements outside of 
     [0, length(V0) + length(V1) - 1] invoke undefined behavior (the 
     modulo operation above doesn't apply).
*/
DEFTREECODE (VEC_PERM_EXPR, "vec_perm_expr", tcc_expression, 3)

I will submit this change.