On Fri, 17 Dec 2021, Richard Sandiford wrote:
> Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> writes:
> > Hi,
> > The attached patch rearranges order of type-check for vec_perm_expr
> > and relaxes type checking for
> > lhs = vec_perm_expr<rhs1, rhs2, mask>
> >
> > when:
> > rhs1 == rhs2,
> > lhs is variable length vector,
> > rhs1 is fixed length vector,
> > TREE_TYPE (lhs) == TREE_TYPE (rhs1)
> >
> > I am not sure tho if this check is correct ? My intent was to capture
> > case when vec_perm_expr is used to "extend" fixed length vector to
> > it's VLA equivalent.
>
> VLAness isn't really the issue. We want the same thing to work for
> -msve-vector-bits=256, -msve-vector-bits=512, etc., even though the
> vectors are fixed-length in that case.
>
> The principle is that for:
>
> A = VEC_PERM_EXPR <B, C, D>;
>
> the requirements are:
>
> - A, B, C and D must be vectors
> - A, B and C must have the same element type
> - D must have an integer element type
> - A and D must have the same number of elements (NA)
> - B and C must have the same number of elements (NB)
>
> The semantics are that we create a joined vector BC (all elements of B
> followed by all element of C) and that:
>
> A[i] = BC[D[i] % (NB+NB)]
>
> for 0 ≤ i < NA.
>
> This operation makes sense even if NA != NB.
But note that we don't currently expect NA != NB and the optab just
has a single mode.
I'd rather go with the simpler patch I posted as reply to the earlier
mail rather such large refactoring at this point.
Richard.
> Thanks,
> Richard
>
> >
> > Thanks,
> > Prathamesh
> >
> > diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
> > index 672e384ef09..9f91878c468 100644
> > --- a/gcc/tree-cfg.c
> > +++ b/gcc/tree-cfg.c
> > @@ -4325,10 +4325,11 @@ verify_gimple_assign_ternary (gassign *stmt)
> > break;
> >
> > case VEC_PERM_EXPR:
> > - if (!useless_type_conversion_p (lhs_type, rhs1_type)
> > - || !useless_type_conversion_p (lhs_type, rhs2_type))
> > + if (TREE_CODE (rhs1_type) != VECTOR_TYPE
> > + || TREE_CODE (rhs2_type) != VECTOR_TYPE
> > + || TREE_CODE (rhs3_type) != VECTOR_TYPE)
> > {
> > - error ("type mismatch in %qs", code_name);
> > + error ("vector types expected in %qs", code_name);
> > debug_generic_expr (lhs_type);
> > debug_generic_expr (rhs1_type);
> > debug_generic_expr (rhs2_type);
> > @@ -4336,11 +4337,14 @@ verify_gimple_assign_ternary (gassign *stmt)
> > return true;
> > }
> >
> > - if (TREE_CODE (rhs1_type) != VECTOR_TYPE
> > - || TREE_CODE (rhs2_type) != VECTOR_TYPE
> > - || TREE_CODE (rhs3_type) != VECTOR_TYPE)
> > + if (TREE_CODE (TREE_TYPE (rhs3_type)) != INTEGER_TYPE
> > + || (TREE_CODE (rhs3) != VECTOR_CST
> > + && (GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE
> > + (TREE_TYPE (rhs3_type)))
> > + != GET_MODE_BITSIZE (SCALAR_TYPE_MODE
> > + (TREE_TYPE (rhs1_type))))))
> > {
> > - error ("vector types expected in %qs", code_name);
> > + error ("invalid mask type in %qs", code_name);
> > debug_generic_expr (lhs_type);
> > debug_generic_expr (rhs1_type);
> > debug_generic_expr (rhs2_type);
> > @@ -4348,15 +4352,18 @@ verify_gimple_assign_ternary (gassign *stmt)
> > return true;
> > }
> >
> > - if (maybe_ne (TYPE_VECTOR_SUBPARTS (rhs1_type),
> > - TYPE_VECTOR_SUBPARTS (rhs2_type))
> > - || maybe_ne (TYPE_VECTOR_SUBPARTS (rhs2_type),
> > - TYPE_VECTOR_SUBPARTS (rhs3_type))
> > - || maybe_ne (TYPE_VECTOR_SUBPARTS (rhs3_type),
> > - TYPE_VECTOR_SUBPARTS (lhs_type)))
> > + /* Accept lhs = vec_perm_expr<v, v, mask> if lhs is vector length
> > agnostic,
> > + and has same element type as v. */
> > + if (!TYPE_VECTOR_SUBPARTS (lhs_type).is_constant ()
> > + && operand_equal_p (rhs1, rhs2, 0)
> > + && TYPE_VECTOR_SUBPARTS (rhs1_type).is_constant ()
> > + && TREE_TYPE (lhs_type) == TREE_TYPE (rhs1_type))
> > + return false;
> > +
> > + if (!useless_type_conversion_p (lhs_type, rhs1_type)
> > + || !useless_type_conversion_p (lhs_type, rhs2_type))
> > {
> > - error ("vectors with different element number found in %qs",
> > - code_name);
> > + error ("type mismatch in %qs", code_name);
> > debug_generic_expr (lhs_type);
> > debug_generic_expr (rhs1_type);
> > debug_generic_expr (rhs2_type);
> > @@ -4364,21 +4371,21 @@ verify_gimple_assign_ternary (gassign *stmt)
> > return true;
> > }
> >
> > - if (TREE_CODE (TREE_TYPE (rhs3_type)) != INTEGER_TYPE
> > - || (TREE_CODE (rhs3) != VECTOR_CST
> > - && (GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE
> > - (TREE_TYPE (rhs3_type)))
> > - != GET_MODE_BITSIZE (SCALAR_TYPE_MODE
> > - (TREE_TYPE (rhs1_type))))))
> > + if (maybe_ne (TYPE_VECTOR_SUBPARTS (rhs1_type),
> > + TYPE_VECTOR_SUBPARTS (rhs2_type))
> > + || maybe_ne (TYPE_VECTOR_SUBPARTS (rhs2_type),
> > + TYPE_VECTOR_SUBPARTS (rhs3_type))
> > + || maybe_ne (TYPE_VECTOR_SUBPARTS (rhs3_type),
> > + TYPE_VECTOR_SUBPARTS (lhs_type)))
> > {
> > - error ("invalid mask type in %qs", code_name);
> > + error ("vectors with different element number found in %qs",
> > + code_name);
> > debug_generic_expr (lhs_type);
> > debug_generic_expr (rhs1_type);
> > debug_generic_expr (rhs2_type);
> > debug_generic_expr (rhs3_type);
> > return true;
> > }
> > -
> > return false;
> >
> > case SAD_EXPR:
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Ivo Totev; HRB 36809 (AG Nuernberg)
