On Tue, 28 Feb 2017, Jakub Jelinek wrote:
> Hi!
>
> This patch fixes ICE during lowering of VEC_COND_EXPR which has the
> AVX512-ish [QHSD]Imode VECTOR_BOOLEAN_TYPE_P type (where the TYPE_SIZE
> of the comp_inner_type and inner_type are different).
> In addition, it attempts to expand it into efficient code when possible
> (by performing the comparison if any into a [QHSD]Imode VECTOR_BOOLEAN_TYPE_P
> type temporary and then performing bitwise arithmetics).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Thanks,
Richard.
> 2017-02-28 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/79734
> * tree-vect-generic.c (expand_vector_condition): Optimize
> AVX512 vector boolean VEC_COND_EXPRs into bitwise operations.
> Handle VEC_COND_EXPR where comparison has different inner width from
> type's inner width.
>
> * g++.dg/opt/pr79734.C: New test.
>
> --- gcc/tree-vect-generic.c.jj 2017-01-01 12:45:37.000000000 +0100
> +++ gcc/tree-vect-generic.c 2017-02-28 19:45:26.916621857 +0100
> @@ -865,6 +865,8 @@ expand_vector_condition (gimple_stmt_ite
> tree comp_inner_type = cond_type;
> tree width = TYPE_SIZE (inner_type);
> tree index = bitsize_int (0);
> + tree comp_width = width;
> + tree comp_index = index;
> int nunits = TYPE_VECTOR_SUBPARTS (type);
> int i;
> location_t loc = gimple_location (gsi_stmt (*gsi));
> @@ -876,27 +878,60 @@ expand_vector_condition (gimple_stmt_ite
> a1 = TREE_OPERAND (a, 0);
> a2 = TREE_OPERAND (a, 1);
> comp_inner_type = TREE_TYPE (TREE_TYPE (a1));
> + comp_width = TYPE_SIZE (comp_inner_type);
> }
>
> if (expand_vec_cond_expr_p (type, TREE_TYPE (a1), TREE_CODE (a)))
> return;
>
> + /* Handle vector boolean types with bitmasks. If there is a comparison
> + and we can expand the comparison into the vector boolean bitmask,
> + or otherwise if it is compatible with type, we can transform
> + vbfld_1 = x_2 < y_3 ? vbfld_4 : vbfld_5;
> + into
> + tmp_6 = x_2 < y_3;
> + tmp_7 = tmp_6 & vbfld_4;
> + tmp_8 = ~tmp_6;
> + tmp_9 = tmp_8 & vbfld_5;
> + vbfld_1 = tmp_7 | tmp_9;
> + Similarly for vbfld_10 instead of x_2 < y_3. */
> + if (VECTOR_BOOLEAN_TYPE_P (type)
> + && SCALAR_INT_MODE_P (TYPE_MODE (type))
> + && (GET_MODE_BITSIZE (TYPE_MODE (type))
> + < (TYPE_VECTOR_SUBPARTS (type)
> + * GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type)))))
> + && (a_is_comparison
> + ? useless_type_conversion_p (type, TREE_TYPE (a))
> + : expand_vec_cmp_expr_p (TREE_TYPE (a1), type, TREE_CODE (a))))
> + {
> + if (a_is_comparison)
> + a = gimplify_build2 (gsi, TREE_CODE (a), type, a1, a2);
> + a1 = gimplify_build2 (gsi, BIT_AND_EXPR, type, a, b);
> + a2 = gimplify_build1 (gsi, BIT_NOT_EXPR, type, a);
> + a2 = gimplify_build2 (gsi, BIT_AND_EXPR, type, a2, c);
> + a = gimplify_build2 (gsi, BIT_IOR_EXPR, type, a1, a2);
> + gimple_assign_set_rhs_from_tree (gsi, a);
> + update_stmt (gsi_stmt (*gsi));
> + return;
> + }
> +
> /* TODO: try and find a smaller vector type. */
>
> warning_at (loc, OPT_Wvector_operation_performance,
> "vector condition will be expanded piecewise");
>
> vec_alloc (v, nunits);
> - for (i = 0; i < nunits;
> - i++, index = int_const_binop (PLUS_EXPR, index, width))
> + for (i = 0; i < nunits; i++)
> {
> tree aa, result;
> tree bb = tree_vec_extract (gsi, inner_type, b, width, index);
> tree cc = tree_vec_extract (gsi, inner_type, c, width, index);
> if (a_is_comparison)
> {
> - tree aa1 = tree_vec_extract (gsi, comp_inner_type, a1, width, index);
> - tree aa2 = tree_vec_extract (gsi, comp_inner_type, a2, width, index);
> + tree aa1 = tree_vec_extract (gsi, comp_inner_type, a1,
> + comp_width, comp_index);
> + tree aa2 = tree_vec_extract (gsi, comp_inner_type, a2,
> + comp_width, comp_index);
> aa = fold_build2 (TREE_CODE (a), cond_type, aa1, aa2);
> }
> else
> @@ -904,6 +939,11 @@ expand_vector_condition (gimple_stmt_ite
> result = gimplify_build3 (gsi, COND_EXPR, inner_type, aa, bb, cc);
> constructor_elt ce = {NULL_TREE, result};
> v->quick_push (ce);
> + index = int_const_binop (PLUS_EXPR, index, width);
> + if (width == comp_width)
> + comp_index = index;
> + else
> + comp_index = int_const_binop (PLUS_EXPR, comp_index, comp_width);
> }
>
> constr = build_constructor (type, v);
> --- gcc/testsuite/g++.dg/opt/pr79734.C.jj 2017-02-28 19:51:08.123171705
> +0100
> +++ gcc/testsuite/g++.dg/opt/pr79734.C 2017-02-28 19:50:21.000000000
> +0100
> @@ -0,0 +1,12 @@
> +// PR tree-optimization/79734
> +// { dg-do compile }
> +// { dg-options "-O2" }
> +// { dg-additional-options "-mavx512vl" { target i?86-*-* x86_64-*-* } }
> +
> +typedef float V __attribute__ ((vector_size (4 * sizeof (float))));
> +
> +void
> +foo (V *a, V *b)
> +{
> + *a = (*a < 1 && !(*b > 2)) ? *a + *b : 3;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
