From: Richard Sandiford Date: Wed, 3 Jan 2018 07:15:47 +0000 (+0000) Subject: poly_int: vectorizable_reduction X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e54dd6d3a791536543d4769aa09508b89d882f37;p=gcc.git poly_int: vectorizable_reduction This patch makes vectorizable_reduction cope with variable-length vectors. We can handle the simple case of an inner loop reduction for which the target has native support for the epilogue operation. For now we punt on other cases, but patches after the main SVE submission allow SLP and double reductions too. 2018-01-03 Richard Sandiford Alan Hayward David Sherwood gcc/ * tree.h (build_index_vector): Declare. * tree.c (build_index_vector): New function. * tree-vect-loop.c (get_initial_defs_for_reduction): Treat the number of units as polynomial, forcibly converting it to a constant if vectorizable_reduction has already enforced the condition. (vect_create_epilog_for_reduction): Likewise. Use build_index_vector to create a {1,2,3,...} vector. (vectorizable_reduction): Treat the number of units as polynomial. Choose vectype_in based on the largest scalar element size rather than the smallest number of units. Enforce the restrictions relied on above. Co-Authored-By: Alan Hayward Co-Authored-By: David Sherwood From-SVN: r256133 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e42270c4019..eda66257b47 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,19 @@ +2018-01-03 Richard Sandiford + Alan Hayward + David Sherwood + + * tree.h (build_index_vector): Declare. + * tree.c (build_index_vector): New function. + * tree-vect-loop.c (get_initial_defs_for_reduction): Treat the number + of units as polynomial, forcibly converting it to a constant if + vectorizable_reduction has already enforced the condition. + (vect_create_epilog_for_reduction): Likewise. Use build_index_vector + to create a {1,2,3,...} vector. + (vectorizable_reduction): Treat the number of units as polynomial. + Choose vectype_in based on the largest scalar element size rather + than the smallest number of units. Enforce the restrictions + relied on above. + 2018-01-03 Richard Sandiford Alan Hayward David Sherwood diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c index 557522c2ee5..93e430c7a56 100644 --- a/gcc/tree-vect-loop.c +++ b/gcc/tree-vect-loop.c @@ -4150,6 +4150,8 @@ get_initial_defs_for_reduction (slp_tree slp_node, vector_type = STMT_VINFO_VECTYPE (stmt_vinfo); scalar_type = TREE_TYPE (vector_type); + /* vectorizable_reduction has already rejected SLP reductions on + variable-length vectors. */ nunits = TYPE_VECTOR_SUBPARTS (vector_type); gcc_assert (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_reduction_def); @@ -4537,8 +4539,7 @@ vect_create_epilog_for_reduction (vec vect_defs, gimple *stmt, if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION) { tree indx_before_incr, indx_after_incr; - int nunits_out = TYPE_VECTOR_SUBPARTS (vectype); - int k; + poly_uint64 nunits_out = TYPE_VECTOR_SUBPARTS (vectype); gimple *vec_stmt = STMT_VINFO_VEC_STMT (stmt_info); gcc_assert (gimple_assign_rhs_code (vec_stmt) == VEC_COND_EXPR); @@ -4554,10 +4555,7 @@ vect_create_epilog_for_reduction (vec vect_defs, gimple *stmt, vector size (STEP). */ /* Create a {1,2,3,...} vector. */ - tree_vector_builder vtemp (cr_index_vector_type, 1, 3); - for (k = 0; k < 3; ++k) - vtemp.quick_push (build_int_cst (cr_index_scalar_type, k + 1)); - tree series_vect = vtemp.build (); + tree series_vect = build_index_vector (cr_index_vector_type, 1, 1); /* Create a vector of the step value. */ tree step = build_int_cst (cr_index_scalar_type, nunits_out); @@ -4935,8 +4933,11 @@ vect_create_epilog_for_reduction (vec vect_defs, gimple *stmt, tree data_eltype = TREE_TYPE (TREE_TYPE (new_phi_result)); tree idx_eltype = TREE_TYPE (TREE_TYPE (induction_index)); unsigned HOST_WIDE_INT el_size = tree_to_uhwi (TYPE_SIZE (idx_eltype)); - unsigned HOST_WIDE_INT v_size - = el_size * TYPE_VECTOR_SUBPARTS (TREE_TYPE (induction_index)); + poly_uint64 nunits = TYPE_VECTOR_SUBPARTS (TREE_TYPE (induction_index)); + /* Enforced by vectorizable_reduction, which ensures we have target + support before allowing a conditional reduction on variable-length + vectors. */ + unsigned HOST_WIDE_INT v_size = el_size * nunits.to_constant (); tree idx_val = NULL_TREE, val = NULL_TREE; for (unsigned HOST_WIDE_INT off = 0; off < v_size; off += el_size) { @@ -5055,6 +5056,9 @@ vect_create_epilog_for_reduction (vec vect_defs, gimple *stmt, { bool reduce_with_shift = have_whole_vector_shift (mode); int element_bitsize = tree_to_uhwi (bitsize); + /* Enforced by vectorizable_reduction, which disallows SLP reductions + for variable-length vectors and also requires direct target support + for loop reductions. */ int vec_size_in_bits = tree_to_uhwi (TYPE_SIZE (vectype)); tree vec_temp; @@ -5743,10 +5747,10 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi, if (k == 1 && gimple_assign_rhs_code (reduc_stmt) == COND_EXPR) continue; - tem = get_vectype_for_scalar_type (TREE_TYPE (op)); - if (! vectype_in - || TYPE_VECTOR_SUBPARTS (tem) < TYPE_VECTOR_SUBPARTS (vectype_in)) - vectype_in = tem; + if (!vectype_in + || (GET_MODE_SIZE (SCALAR_TYPE_MODE (TREE_TYPE (vectype_in))) + < GET_MODE_SIZE (SCALAR_TYPE_MODE (TREE_TYPE (op))))) + vectype_in = get_vectype_for_scalar_type (TREE_TYPE (op)); break; } gcc_assert (vectype_in); @@ -5912,7 +5916,8 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi, /* To properly compute ncopies we are interested in the widest input type in case we're looking at a widening accumulation. */ if (!vectype_in - || TYPE_VECTOR_SUBPARTS (vectype_in) > TYPE_VECTOR_SUBPARTS (tem)) + || (GET_MODE_SIZE (SCALAR_TYPE_MODE (TREE_TYPE (vectype_in))) + < GET_MODE_SIZE (SCALAR_TYPE_MODE (TREE_TYPE (tem))))) vectype_in = tem; } @@ -6097,6 +6102,7 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi, gcc_assert (ncopies >= 1); vec_mode = TYPE_MODE (vectype_in); + poly_uint64 nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out); if (code == COND_EXPR) { @@ -6278,14 +6284,23 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi, int scalar_precision = GET_MODE_PRECISION (SCALAR_TYPE_MODE (scalar_type)); cr_index_scalar_type = make_unsigned_type (scalar_precision); - cr_index_vector_type = build_vector_type - (cr_index_scalar_type, TYPE_VECTOR_SUBPARTS (vectype_out)); + cr_index_vector_type = build_vector_type (cr_index_scalar_type, + nunits_out); if (direct_internal_fn_supported_p (IFN_REDUC_MAX, cr_index_vector_type, OPTIMIZE_FOR_SPEED)) reduc_fn = IFN_REDUC_MAX; } + if (reduc_fn == IFN_LAST && !nunits_out.is_constant ()) + { + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "missing target support for reduction on" + " variable-length vectors.\n"); + return false; + } + if ((double_reduc || STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) != TREE_CODE_REDUCTION) && ncopies > 1) @@ -6297,6 +6312,27 @@ vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi, return false; } + if (double_reduc && !nunits_out.is_constant ()) + { + /* The current double-reduction code creates the initial value + element-by-element. */ + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "double reduction not supported for variable-length" + " vectors.\n"); + return false; + } + + if (slp_node && !nunits_out.is_constant ()) + { + /* The current SLP code creates the initial value element-by-element. */ + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "SLP reduction not supported for variable-length" + " vectors.\n"); + return false; + } + /* In case of widenning multiplication by a constant, we update the type of the constant to be the type of the other operand. We check that the constant fits the type in the pattern recognition pass. */ diff --git a/gcc/tree.c b/gcc/tree.c index f13e2d8227d..93c4654309d 100644 --- a/gcc/tree.c +++ b/gcc/tree.c @@ -1930,6 +1930,29 @@ build_vec_series (tree type, tree base, tree step) return build2 (VEC_SERIES_EXPR, type, base, step); } +/* Return a vector with the same number of units and number of bits + as VEC_TYPE, but in which the elements are a linear series of unsigned + integers { BASE, BASE + STEP, BASE + STEP * 2, ... }. */ + +tree +build_index_vector (tree vec_type, poly_uint64 base, poly_uint64 step) +{ + tree index_vec_type = vec_type; + tree index_elt_type = TREE_TYPE (vec_type); + poly_uint64 nunits = TYPE_VECTOR_SUBPARTS (vec_type); + if (!INTEGRAL_TYPE_P (index_elt_type) || !TYPE_UNSIGNED (index_elt_type)) + { + index_elt_type = build_nonstandard_integer_type + (GET_MODE_BITSIZE (SCALAR_TYPE_MODE (index_elt_type)), true); + index_vec_type = build_vector_type (index_elt_type, nunits); + } + + tree_vector_builder v (index_vec_type, 1, 3); + for (unsigned int i = 0; i < 3; ++i) + v.quick_push (build_int_cstu (index_elt_type, base + i * step)); + return v.build (); +} + /* Something has messed with the elements of CONSTRUCTOR C after it was built; calculate TREE_CONSTANT and TREE_SIDE_EFFECTS. */ diff --git a/gcc/tree.h b/gcc/tree.h index f523a0850ca..a45c2cd5aa6 100644 --- a/gcc/tree.h +++ b/gcc/tree.h @@ -4062,6 +4062,7 @@ extern tree make_vector (unsigned, unsigned CXX_MEM_STAT_INFO); extern tree build_vector_from_ctor (tree, vec *); extern tree build_vector_from_val (tree, tree); extern tree build_vec_series (tree, tree, tree); +extern tree build_index_vector (tree, poly_uint64, poly_uint64); extern void recompute_constructor_flags (tree); extern void verify_constructor_flags (tree); extern tree build_constructor (tree, vec *);