> -----Original Message-----
> From: Richard Biener <rguent...@suse.de>
> Sent: Wednesday, May 29, 2024 5:41 PM
> To: Hu, Lin1 <lin1...@intel.com>
> Cc: gcc-patches@gcc.gnu.org; Liu, Hongtao <hongtao....@intel.com>;
> ubiz...@gmail.com
> Subject: Re: [PATCH 1/3] vect: generate suitable convert insn for int -> int,
> float
> -> float and int <-> float.
>
> On Thu, 23 May 2024, Hu, Lin1 wrote:
>
> > gcc/ChangeLog:
> >
> > PR target/107432
> > * tree-vect-generic.cc
> > (supportable_indirect_narrowing_operation): New function for
> > support indirect narrowing convert.
> > (supportable_indirect_widening_operation): New function for
> > support indirect widening convert.
> > (expand_vector_conversion): Support convert for int -> int,
> > float -> float and int <-> float.
> >
> > gcc/testsuite/ChangeLog:
> >
> > PR target/107432
> > * gcc.target/i386/pr107432-1.c: New test.
> > * gcc.target/i386/pr107432-2.c: Ditto.
> > * gcc.target/i386/pr107432-3.c: Ditto.
> > * gcc.target/i386/pr107432-4.c: Ditto.
> > * gcc.target/i386/pr107432-5.c: Ditto.
> > * gcc.target/i386/pr107432-6.c: Ditto.
> > * gcc.target/i386/pr107432-7.c: Ditto.
> > ---
> > diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc index
> > ab640096ca2..0bedb53d9f9 100644
> > --- a/gcc/tree-vect-generic.cc
> > +++ b/gcc/tree-vect-generic.cc
> > @@ -45,6 +45,8 @@ along with GCC; see the file COPYING3. If not see
> > #include "gimple-match.h"
> > #include "recog.h" /* FIXME: for insn_data */
> > #include "optabs-libfuncs.h"
> > +#include "cfgloop.h"
> > +#include "tree-vectorizer.h"
> >
> >
> > /* Build a ternary operation and gimplify it. Emit code before GSI.
> > @@ -1834,6 +1836,142 @@ do_vec_narrow_conversion
> (gimple_stmt_iterator *gsi, tree inner_type, tree a,
> > return gimplify_build2 (gsi, code, outer_type, b, c); }
> >
> > +/* A subroutine of expand_vector_conversion, support indirect conversion
> for
> > + float <-> int, like double -> char. */ bool
> > +supportable_indirect_narrowing_operation (gimple_stmt_iterator *gsi,
> > + enum tree_code code,
> > + tree lhs,
> > + tree arg)
> > +{
> > + gimple *g;
> > + tree ret_type = TREE_TYPE (lhs);
> > + tree arg_type = TREE_TYPE (arg);
> > + tree new_rhs;
> > +
> > + unsigned int ret_elt_bits = vector_element_bits (ret_type);
> > + unsigned int arg_elt_bits = vector_element_bits (arg_type); if
> > + (code != FIX_TRUNC_EXPR || flag_trapping_math || ret_elt_bits >=
> arg_elt_bits)
> > + return false;
> > +
> > + unsigned short target_size;
> > + scalar_mode tmp_cvt_mode;
> > + scalar_mode lhs_mode = GET_MODE_INNER (TYPE_MODE (ret_type));
> > + scalar_mode rhs_mode = GET_MODE_INNER (TYPE_MODE (arg_type)); tree
> > + cvt_type = NULL_TREE; tmp_cvt_mode = lhs_mode; target_size =
> > + GET_MODE_SIZE (rhs_mode);
> > +
> > + opt_scalar_mode mode_iter;
> > + enum tree_code tc1, tc2;
> > + unsigned HOST_WIDE_INT nelts
> > + = constant_lower_bound (TYPE_VECTOR_SUBPARTS (arg_type));
> > +
> > + FOR_EACH_2XWIDER_MODE (mode_iter, tmp_cvt_mode)
> > + {
> > + tmp_cvt_mode = mode_iter.require ();
> > +
> > + if (GET_MODE_SIZE (tmp_cvt_mode) > target_size)
> > + break;
> > +
> > + scalar_mode cvt_mode;
> > + int tmp_cvt_size = GET_MODE_BITSIZE (tmp_cvt_mode);
> > + if (!int_mode_for_size (tmp_cvt_size, 0).exists (&cvt_mode))
> > + break;
> > +
> > + int cvt_size = GET_MODE_BITSIZE (cvt_mode);
> > + bool isUnsigned = TYPE_UNSIGNED (ret_type) || TYPE_UNSIGNED
> (arg_type);
> > + cvt_type = build_nonstandard_integer_type (cvt_size,
> > + isUnsigned);
> > +
> > + cvt_type = build_vector_type (cvt_type, nelts);
> > + if (cvt_type == NULL_TREE
> > + || !supportable_convert_operation ((tree_code) NOP_EXPR,
> > + ret_type,
> > + cvt_type, &tc1)
> > + || !supportable_convert_operation ((tree_code) code,
> > + cvt_type,
> > + arg_type, &tc2))
> > + continue;
> > +
> > + new_rhs = make_ssa_name (cvt_type);
> > + g = vect_gimple_build (new_rhs, tc2, arg);
> > + gsi_insert_before (gsi, g, GSI_SAME_STMT);
> > + g = gimple_build_assign (lhs, tc1, new_rhs);
> > + gsi_replace (gsi, g, false);
> > + return true;
> > + }
> > + return false;
> > +}
> > +
> > +/* A subroutine of expand_vector_conversion, support indirect conversion
> for
> > + float <-> int, like char -> double. */ bool
> > +supportable_indirect_widening_operation (gimple_stmt_iterator *gsi,
> > + enum tree_code code,
> > + tree lhs,
> > + tree arg)
> > +{
> > + gimple *g;
> > + tree ret_type = TREE_TYPE (lhs);
> > + tree arg_type = TREE_TYPE (arg);
> > + tree new_rhs;
> > +
> > + unsigned int ret_elt_bits = vector_element_bits (ret_type);
> > + unsigned int arg_elt_bits = vector_element_bits (arg_type); if
> > + (ret_elt_bits <= arg_elt_bits || code != FLOAT_EXPR)
> > + return false;
> > +
> > + unsigned short target_size;
> > + scalar_mode tmp_cvt_mode;
> > + scalar_mode lhs_mode = GET_MODE_INNER (TYPE_MODE (ret_type));
> > + scalar_mode rhs_mode = GET_MODE_INNER (TYPE_MODE (arg_type)); tree
> > + cvt_type = NULL_TREE; target_size = GET_MODE_SIZE (lhs_mode); int
> > + rhs_size = GET_MODE_BITSIZE (rhs_mode); if (!int_mode_for_size
> > + (rhs_size, 0).exists (&tmp_cvt_mode))
> > + return false;
> > +
> > + opt_scalar_mode mode_iter;
> > + enum tree_code tc1, tc2;
> > + unsigned HOST_WIDE_INT nelts
> > + = constant_lower_bound (TYPE_VECTOR_SUBPARTS (arg_type));
> > +
> > + FOR_EACH_2XWIDER_MODE (mode_iter, tmp_cvt_mode)
> > + {
> > + tmp_cvt_mode = mode_iter.require ();
> > +
> > + if (GET_MODE_SIZE (tmp_cvt_mode) > target_size)
> > + break;
> > +
> > + scalar_mode cvt_mode;
> > + int tmp_cvt_size = GET_MODE_BITSIZE (tmp_cvt_mode);
> > + if (!int_mode_for_size (tmp_cvt_size, 0).exists (&cvt_mode))
> > + break;
> > +
> > + int cvt_size = GET_MODE_BITSIZE (cvt_mode);
> > + bool isUnsigned = TYPE_UNSIGNED (ret_type) || TYPE_UNSIGNED
> (arg_type);
> > + cvt_type = build_nonstandard_integer_type (cvt_size,
> > + isUnsigned);
> > +
> > + cvt_type = build_vector_type (cvt_type, nelts);
> > + if (cvt_type == NULL_TREE
> > + || !supportable_convert_operation ((tree_code) code,
> > + ret_type,
> > + cvt_type, &tc1)
> > + || !supportable_convert_operation ((tree_code) NOP_EXPR,
> > + cvt_type,
> > + arg_type, &tc2))
> > + continue;
> > +
> > + new_rhs = make_ssa_name (cvt_type);
> > + g = vect_gimple_build (new_rhs, tc2, arg);
> > + gsi_insert_before (gsi, g, GSI_SAME_STMT);
> > + g = gimple_build_assign (lhs, tc1, new_rhs);
> > + gsi_replace (gsi, g, false);
> > + return true;
> > + }
> > + return false;
> > +}
> > +
>
> So the above improve the situation where the target can handle the two-step
> conversion. It doesn't really allow this to work for too large vectors
> AFAICS (nor
> does it try pack/unpack for any of the conversions). It also still
> duplicates code
> that's in the vectorizer. I think you should be able to use
> supportable_narrowing_operation and possibly even
> supportable_widening_operation (though that needs refatoring to avoid the
> vectorizer internal stmt_vec_info type - possibly simply by gating the
> respective
> code on a non-NULL vinfo). Both support multi-step conversions.
>
I tried to use supportable_narrowing_operation and I met two questions:
1) supportable_narrowing_operation support v2df->v16qi, but I don't know which
optab can help me convert v16qi to v2qi.
2) I tried a testcase (https://godbolt.org/z/z88xYW85e), this result is not
what I expected, because it only use vec_pack_trunc. I expect it can use
vcvttpd2dq + vpmovdw.
If I can solve the first question and the function be better (maybe support
trunc<vectype_in><vectype_out>), I'd be happy to use it directly. I prefer my
scheme for now. My functions is more like supportable_convert_operation.
Perhaps, we can modify supportable_narrowing_operation, but I think it should
be another patch, it will influence vectorizer.
BRs,
Lin
>
> > /* Expand VEC_CONVERT ifn call. */
> >
> > static void
> > @@ -1871,14 +2009,21 @@ expand_vector_conversion
> (gimple_stmt_iterator *gsi)
> > else if (ret_elt_bits > arg_elt_bits)
> > modifier = WIDEN;
> >
> > + if (supportable_convert_operation (code, ret_type, arg_type, &code1))
> > + {
> > + g = gimple_build_assign (lhs, code1, arg);
> > + gsi_replace (gsi, g, false);
> > + return;
> > + }
> > +
> > + if (supportable_indirect_narrowing_operation(gsi, code, lhs, arg))
> > + return;
> > +
> > + if (supportable_indirect_widening_operation(gsi, code, lhs, arg))
> > + return;
> > +
> > if (modifier == NONE && (code == FIX_TRUNC_EXPR || code ==
> FLOAT_EXPR))
> > {
> > - if (supportable_convert_operation (code, ret_type, arg_type, &code1))
> > - {
> > - g = gimple_build_assign (lhs, code1, arg);
> > - gsi_replace (gsi, g, false);
> > - return;
> > - }
> > /* Can't use get_compute_type here, as supportable_convert_operation
> > doesn't necessarily use an optab and needs two arguments. */
> > tree vec_compute_type
> >
>
> --
> Richard Biener <rguent...@suse.de>
> SUSE Software Solutions Germany GmbH,
> Frankenstrasse 146, 90461 Nuernberg, Germany;
> GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
