On Wed, 2012-06-13 at 11:26 +0200, Richard Guenther wrote:
> On Tue, 12 Jun 2012, William J. Schmidt wrote:
>
> > This patch is a follow-up to the discussion generated by
> > http://gcc.gnu.org/ml/gcc-patches/2012-06/msg00546.html. I've added
> > vec_construct to the cost model for use in vect_model_load_cost, and
> > implemented a cost calculation that makes sense to me for PowerPC. I'm
> > less certain about the default, i386, and spu implementations. I took a
> > guess at i386 from the discussions we had, and used the same calculation
> > for the default and for spu. I'm hoping you or others can fill in the
> > blanks if I guessed badly.
> >
> > The i386 cost for vec_construct is different from all the others, which
> > are parameterized for each processor description. This should probably
> > be parameterized in some way as well, but thought you'd know better than
> > I how that should be. Perhaps instead of
> >
> > elements / 2 + 1
> >
> > it should be
> >
> > (elements / 2) * X + Y
> >
> > where X and Y are taken from the processor description, and represent
> > the cost of a merge and a permute, respectively. Let me know what you
> > think.
>
> Looks good to me with the gcc_asserts removed - TYPE_VECTOR_SUBPARTS
> might be 1 for V1TImode for example (heh, not that the vectorizer would
> vectorize to that). But I don't see any possible breakage with
> elements == 1, do you?
No, that was some unnecessary sanity testing I was doing for my own
curiosity. I'll pull them out and pop this in today. Thanks for the
review!
Bill
>
> Target maintainers can improve on the cost calculation if they wish,
> the default looks sensible to me.
>
> Thanks,
> Richard.
>
> > Thanks,
> > Bill
> >
> >
> > 2012-06-12 Bill Schmidt <wschm...@linux.ibm.com>
> >
> > * targhooks.c (default_builtin_vectorized_conversion): Handle
> > vec_construct, using vectype to base cost on subparts.
> > * target.h (enum vect_cost_for_stmt): Add vec_construct.
> > * tree-vect-stmts.c (vect_model_load_cost): Use vec_construct
> > instead of scalar_to-vec.
> > * config/spu/spu.c (spu_builtin_vectorization_cost): Handle
> > vec_construct in same way as default for now.
> > * config/i386/i386.c (ix86_builtin_vectorization_cost): Likewise.
> > * config/rs6000/rs6000.c (rs6000_builtin_vectorization_cost):
> > Handle vec_construct, including special case for 32-bit loads.
> >
> >
> > Index: gcc/targhooks.c
> > ===================================================================
> > --- gcc/targhooks.c (revision 188482)
> > +++ gcc/targhooks.c (working copy)
> > @@ -499,9 +499,11 @@ default_builtin_vectorized_conversion (unsigned in
> >
> > int
> > default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
> > - tree vectype ATTRIBUTE_UNUSED,
> > + tree vectype,
> > int misalign ATTRIBUTE_UNUSED)
> > {
> > + unsigned elements;
> > +
> > switch (type_of_cost)
> > {
> > case scalar_stmt:
> > @@ -524,6 +526,11 @@ default_builtin_vectorization_cost (enum vect_cost
> > case cond_branch_taken:
> > return 3;
> >
> > + case vec_construct:
> > + elements = TYPE_VECTOR_SUBPARTS (vectype);
> > + gcc_assert (elements > 1);
> > + return elements / 2 + 1;
> > +
> > default:
> > gcc_unreachable ();
> > }
> > Index: gcc/target.h
> > ===================================================================
> > --- gcc/target.h (revision 188482)
> > +++ gcc/target.h (working copy)
> > @@ -146,7 +146,8 @@ enum vect_cost_for_stmt
> > cond_branch_not_taken,
> > cond_branch_taken,
> > vec_perm,
> > - vec_promote_demote
> > + vec_promote_demote,
> > + vec_construct
> > };
> >
> > /* The target structure. This holds all the backend hooks. */
> > Index: gcc/tree-vect-stmts.c
> > ===================================================================
> > --- gcc/tree-vect-stmts.c (revision 188482)
> > +++ gcc/tree-vect-stmts.c (working copy)
> > @@ -1031,11 +1031,13 @@ vect_model_load_cost (stmt_vec_info stmt_info, int
> > /* The loads themselves. */
> > if (STMT_VINFO_STRIDE_LOAD_P (stmt_info))
> > {
> > - /* N scalar loads plus gathering them into a vector.
> > - ??? scalar_to_vec isn't the cost for that. */
> > + /* N scalar loads plus gathering them into a vector. */
> > + tree vectype = STMT_VINFO_VECTYPE (stmt_info);
> > inside_cost += (vect_get_stmt_cost (scalar_load) * ncopies
> > - * TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info)));
> > - inside_cost += ncopies * vect_get_stmt_cost (scalar_to_vec);
> > + * TYPE_VECTOR_SUBPARTS (vectype));
> > + inside_cost += ncopies
> > + * targetm.vectorize.builtin_vectorization_cost (vec_construct,
> > + vectype, 0);
> > }
> > else
> > vect_get_load_cost (first_dr, ncopies,
> > Index: gcc/config/spu/spu.c
> > ===================================================================
> > --- gcc/config/spu/spu.c (revision 188482)
> > +++ gcc/config/spu/spu.c (working copy)
> > @@ -6908,9 +6908,11 @@ spu_builtin_mask_for_load (void)
> > /* Implement targetm.vectorize.builtin_vectorization_cost. */
> > static int
> > spu_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
> > - tree vectype ATTRIBUTE_UNUSED,
> > + tree vectype,
> > int misalign ATTRIBUTE_UNUSED)
> > {
> > + unsigned elements;
> > +
> > switch (type_of_cost)
> > {
> > case scalar_stmt:
> > @@ -6937,6 +6939,11 @@ spu_builtin_vectorization_cost (enum vect_cost_for
> > case cond_branch_taken:
> > return 6;
> >
> > + case vec_construct:
> > + elements = TYPE_VECTOR_SUBPARTS (vectype);
> > + gcc_assert (elements > 1);
> > + return elements / 2 + 1;
> > +
> > default:
> > gcc_unreachable ();
> > }
> > Index: gcc/config/i386/i386.c
> > ===================================================================
> > --- gcc/config/i386/i386.c (revision 188482)
> > +++ gcc/config/i386/i386.c (working copy)
> > @@ -36072,9 +36072,11 @@ static const struct attribute_spec ix86_attribute_
> > /* Implement targetm.vectorize.builtin_vectorization_cost. */
> > static int
> > ix86_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost,
> > - tree vectype ATTRIBUTE_UNUSED,
> > + tree vectype,
> > int misalign ATTRIBUTE_UNUSED)
> > {
> > + unsigned elements;
> > +
> > switch (type_of_cost)
> > {
> > case scalar_stmt:
> > @@ -36115,6 +36117,11 @@ ix86_builtin_vectorization_cost (enum vect_cost_fo
> > case vec_promote_demote:
> > return ix86_cost->vec_stmt_cost;
> >
> > + case vec_construct:
> > + elements = TYPE_VECTOR_SUBPARTS (vectype);
> > + gcc_assert (elements > 1);
> > + return elements / 2 + 1;
> > +
> > default:
> > gcc_unreachable ();
> > }
> > Index: gcc/config/rs6000/rs6000.c
> > ===================================================================
> > --- gcc/config/rs6000/rs6000.c (revision 188482)
> > +++ gcc/config/rs6000/rs6000.c (working copy)
> > @@ -3405,6 +3405,7 @@ rs6000_builtin_vectorization_cost (enum vect_cost_
> > tree vectype, int misalign)
> > {
> > unsigned elements;
> > + tree elem_type;
> >
> > switch (type_of_cost)
> > {
> > @@ -3504,6 +3505,19 @@ rs6000_builtin_vectorization_cost (enum vect_cost_
> >
> > return 2;
> >
> > + case vec_construct:
> > + elements = TYPE_VECTOR_SUBPARTS (vectype);
> > + elem_type = TREE_TYPE (vectype);
> > + gcc_assert (elements > 1);
> > + /* 32-bit vectors loaded into registers are stored as double
> > + precision, so we need n/2 converts in addition to the usual
> > + n/2 merges to construct a vector of short floats from them. */
> > + if (SCALAR_FLOAT_TYPE_P (elem_type)
> > + && TYPE_PRECISION (elem_type) == 32)
> > + return elements + 1;
> > + else
> > + return elements / 2 + 1;
> > +
> > default:
> > gcc_unreachable ();
> > }
> >
> >
> >
>
