| /* Vectorizer Specific Loop Manipulations |
| Copyright (C) 2003-2022 Free Software Foundation, Inc. |
| Contributed by Dorit Naishlos <dorit@il.ibm.com> |
| and Ira Rosen <irar@il.ibm.com> |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "tree.h" |
| #include "gimple.h" |
| #include "cfghooks.h" |
| #include "tree-pass.h" |
| #include "ssa.h" |
| #include "fold-const.h" |
| #include "cfganal.h" |
| #include "gimplify.h" |
| #include "gimple-iterator.h" |
| #include "gimplify-me.h" |
| #include "tree-cfg.h" |
| #include "tree-ssa-loop-manip.h" |
| #include "tree-into-ssa.h" |
| #include "tree-ssa.h" |
| #include "cfgloop.h" |
| #include "tree-scalar-evolution.h" |
| #include "tree-vectorizer.h" |
| #include "tree-ssa-loop-ivopts.h" |
| #include "gimple-fold.h" |
| #include "tree-ssa-loop-niter.h" |
| #include "internal-fn.h" |
| #include "stor-layout.h" |
| #include "optabs-query.h" |
| #include "vec-perm-indices.h" |
| #include "insn-config.h" |
| #include "rtl.h" |
| #include "recog.h" |
| |
| /************************************************************************* |
| Simple Loop Peeling Utilities |
| |
| Utilities to support loop peeling for vectorization purposes. |
| *************************************************************************/ |
| |
| |
| /* Renames the use *OP_P. */ |
| |
| static void |
| rename_use_op (use_operand_p op_p) |
| { |
| tree new_name; |
| |
| if (TREE_CODE (USE_FROM_PTR (op_p)) != SSA_NAME) |
| return; |
| |
| new_name = get_current_def (USE_FROM_PTR (op_p)); |
| |
| /* Something defined outside of the loop. */ |
| if (!new_name) |
| return; |
| |
| /* An ordinary ssa name defined in the loop. */ |
| |
| SET_USE (op_p, new_name); |
| } |
| |
| |
| /* Renames the variables in basic block BB. Allow renaming of PHI arguments |
| on edges incoming from outer-block header if RENAME_FROM_OUTER_LOOP is |
| true. */ |
| |
| static void |
| rename_variables_in_bb (basic_block bb, bool rename_from_outer_loop) |
| { |
| gimple *stmt; |
| use_operand_p use_p; |
| ssa_op_iter iter; |
| edge e; |
| edge_iterator ei; |
| class loop *loop = bb->loop_father; |
| class loop *outer_loop = NULL; |
| |
| if (rename_from_outer_loop) |
| { |
| gcc_assert (loop); |
| outer_loop = loop_outer (loop); |
| } |
| |
| for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); |
| gsi_next (&gsi)) |
| { |
| stmt = gsi_stmt (gsi); |
| FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES) |
| rename_use_op (use_p); |
| } |
| |
| FOR_EACH_EDGE (e, ei, bb->preds) |
| { |
| if (!flow_bb_inside_loop_p (loop, e->src)) |
| { |
| if (!rename_from_outer_loop) |
| continue; |
| if (e->src != outer_loop->header) |
| { |
| if (outer_loop->inner->next) |
| { |
| /* If outer_loop has 2 inner loops, allow there to |
| be an extra basic block which decides which of the |
| two loops to use using LOOP_VECTORIZED. */ |
| if (!single_pred_p (e->src) |
| || single_pred (e->src) != outer_loop->header) |
| continue; |
| } |
| } |
| } |
| for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
| gsi_next (&gsi)) |
| rename_use_op (PHI_ARG_DEF_PTR_FROM_EDGE (gsi.phi (), e)); |
| } |
| } |
| |
| |
| struct adjust_info |
| { |
| tree from, to; |
| basic_block bb; |
| }; |
| |
| /* A stack of values to be adjusted in debug stmts. We have to |
| process them LIFO, so that the closest substitution applies. If we |
| processed them FIFO, without the stack, we might substitute uses |
| with a PHI DEF that would soon become non-dominant, and when we got |
| to the suitable one, it wouldn't have anything to substitute any |
| more. */ |
| static vec<adjust_info, va_heap> adjust_vec; |
| |
| /* Adjust any debug stmts that referenced AI->from values to use the |
| loop-closed AI->to, if the references are dominated by AI->bb and |
| not by the definition of AI->from. */ |
| |
| static void |
| adjust_debug_stmts_now (adjust_info *ai) |
| { |
| basic_block bbphi = ai->bb; |
| tree orig_def = ai->from; |
| tree new_def = ai->to; |
| imm_use_iterator imm_iter; |
| gimple *stmt; |
| basic_block bbdef = gimple_bb (SSA_NAME_DEF_STMT (orig_def)); |
| |
| gcc_assert (dom_info_available_p (CDI_DOMINATORS)); |
| |
| /* Adjust any debug stmts that held onto non-loop-closed |
| references. */ |
| FOR_EACH_IMM_USE_STMT (stmt, imm_iter, orig_def) |
| { |
| use_operand_p use_p; |
| basic_block bbuse; |
| |
| if (!is_gimple_debug (stmt)) |
| continue; |
| |
| gcc_assert (gimple_debug_bind_p (stmt)); |
| |
| bbuse = gimple_bb (stmt); |
| |
| if ((bbuse == bbphi |
| || dominated_by_p (CDI_DOMINATORS, bbuse, bbphi)) |
| && !(bbuse == bbdef |
| || dominated_by_p (CDI_DOMINATORS, bbuse, bbdef))) |
| { |
| if (new_def) |
| FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) |
| SET_USE (use_p, new_def); |
| else |
| { |
| gimple_debug_bind_reset_value (stmt); |
| update_stmt (stmt); |
| } |
| } |
| } |
| } |
| |
| /* Adjust debug stmts as scheduled before. */ |
| |
| static void |
| adjust_vec_debug_stmts (void) |
| { |
| if (!MAY_HAVE_DEBUG_BIND_STMTS) |
| return; |
| |
| gcc_assert (adjust_vec.exists ()); |
| |
| while (!adjust_vec.is_empty ()) |
| { |
| adjust_debug_stmts_now (&adjust_vec.last ()); |
| adjust_vec.pop (); |
| } |
| } |
| |
| /* Adjust any debug stmts that referenced FROM values to use the |
| loop-closed TO, if the references are dominated by BB and not by |
| the definition of FROM. If adjust_vec is non-NULL, adjustments |
| will be postponed until adjust_vec_debug_stmts is called. */ |
| |
| static void |
| adjust_debug_stmts (tree from, tree to, basic_block bb) |
| { |
| adjust_info ai; |
| |
| if (MAY_HAVE_DEBUG_BIND_STMTS |
| && TREE_CODE (from) == SSA_NAME |
| && ! SSA_NAME_IS_DEFAULT_DEF (from) |
| && ! virtual_operand_p (from)) |
| { |
| ai.from = from; |
| ai.to = to; |
| ai.bb = bb; |
| |
| if (adjust_vec.exists ()) |
| adjust_vec.safe_push (ai); |
| else |
| adjust_debug_stmts_now (&ai); |
| } |
| } |
| |
| /* Change E's phi arg in UPDATE_PHI to NEW_DEF, and record information |
| to adjust any debug stmts that referenced the old phi arg, |
| presumably non-loop-closed references left over from other |
| transformations. */ |
| |
| static void |
| adjust_phi_and_debug_stmts (gimple *update_phi, edge e, tree new_def) |
| { |
| tree orig_def = PHI_ARG_DEF_FROM_EDGE (update_phi, e); |
| |
| SET_PHI_ARG_DEF (update_phi, e->dest_idx, new_def); |
| |
| if (MAY_HAVE_DEBUG_BIND_STMTS) |
| adjust_debug_stmts (orig_def, PHI_RESULT (update_phi), |
| gimple_bb (update_phi)); |
| } |
| |
| /* Define one loop rgroup control CTRL from loop LOOP. INIT_CTRL is the value |
| that the control should have during the first iteration and NEXT_CTRL is the |
| value that it should have on subsequent iterations. */ |
| |
| static void |
| vect_set_loop_control (class loop *loop, tree ctrl, tree init_ctrl, |
| tree next_ctrl) |
| { |
| gphi *phi = create_phi_node (ctrl, loop->header); |
| add_phi_arg (phi, init_ctrl, loop_preheader_edge (loop), UNKNOWN_LOCATION); |
| add_phi_arg (phi, next_ctrl, loop_latch_edge (loop), UNKNOWN_LOCATION); |
| } |
| |
| /* Add SEQ to the end of LOOP's preheader block. */ |
| |
| static void |
| add_preheader_seq (class loop *loop, gimple_seq seq) |
| { |
| if (seq) |
| { |
| edge pe = loop_preheader_edge (loop); |
| basic_block new_bb = gsi_insert_seq_on_edge_immediate (pe, seq); |
| gcc_assert (!new_bb); |
| } |
| } |
| |
| /* Add SEQ to the beginning of LOOP's header block. */ |
| |
| static void |
| add_header_seq (class loop *loop, gimple_seq seq) |
| { |
| if (seq) |
| { |
| gimple_stmt_iterator gsi = gsi_after_labels (loop->header); |
| gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT); |
| } |
| } |
| |
| /* Return true if the target can interleave elements of two vectors. |
| OFFSET is 0 if the first half of the vectors should be interleaved |
| or 1 if the second half should. When returning true, store the |
| associated permutation in INDICES. */ |
| |
| static bool |
| interleave_supported_p (vec_perm_indices *indices, tree vectype, |
| unsigned int offset) |
| { |
| poly_uint64 nelts = TYPE_VECTOR_SUBPARTS (vectype); |
| poly_uint64 base = exact_div (nelts, 2) * offset; |
| vec_perm_builder sel (nelts, 2, 3); |
| for (unsigned int i = 0; i < 3; ++i) |
| { |
| sel.quick_push (base + i); |
| sel.quick_push (base + i + nelts); |
| } |
| indices->new_vector (sel, 2, nelts); |
| return can_vec_perm_const_p (TYPE_MODE (vectype), *indices); |
| } |
| |
| /* Try to use permutes to define the masks in DEST_RGM using the masks |
| in SRC_RGM, given that the former has twice as many masks as the |
| latter. Return true on success, adding any new statements to SEQ. */ |
| |
| static bool |
| vect_maybe_permute_loop_masks (gimple_seq *seq, rgroup_controls *dest_rgm, |
| rgroup_controls *src_rgm) |
| { |
| tree src_masktype = src_rgm->type; |
| tree dest_masktype = dest_rgm->type; |
| machine_mode src_mode = TYPE_MODE (src_masktype); |
| insn_code icode1, icode2; |
| if (dest_rgm->max_nscalars_per_iter <= src_rgm->max_nscalars_per_iter |
| && (icode1 = optab_handler (vec_unpacku_hi_optab, |
| src_mode)) != CODE_FOR_nothing |
| && (icode2 = optab_handler (vec_unpacku_lo_optab, |
| src_mode)) != CODE_FOR_nothing) |
| { |
| /* Unpacking the source masks gives at least as many mask bits as |
| we need. We can then VIEW_CONVERT any excess bits away. */ |
| machine_mode dest_mode = insn_data[icode1].operand[0].mode; |
| gcc_assert (dest_mode == insn_data[icode2].operand[0].mode); |
| tree unpack_masktype = vect_halve_mask_nunits (src_masktype, dest_mode); |
| for (unsigned int i = 0; i < dest_rgm->controls.length (); ++i) |
| { |
| tree src = src_rgm->controls[i / 2]; |
| tree dest = dest_rgm->controls[i]; |
| tree_code code = ((i & 1) == (BYTES_BIG_ENDIAN ? 0 : 1) |
| ? VEC_UNPACK_HI_EXPR |
| : VEC_UNPACK_LO_EXPR); |
| gassign *stmt; |
| if (dest_masktype == unpack_masktype) |
| stmt = gimple_build_assign (dest, code, src); |
| else |
| { |
| tree temp = make_ssa_name (unpack_masktype); |
| stmt = gimple_build_assign (temp, code, src); |
| gimple_seq_add_stmt (seq, stmt); |
| stmt = gimple_build_assign (dest, VIEW_CONVERT_EXPR, |
| build1 (VIEW_CONVERT_EXPR, |
| dest_masktype, temp)); |
| } |
| gimple_seq_add_stmt (seq, stmt); |
| } |
| return true; |
| } |
| vec_perm_indices indices[2]; |
| if (dest_masktype == src_masktype |
| && interleave_supported_p (&indices[0], src_masktype, 0) |
| && interleave_supported_p (&indices[1], src_masktype, 1)) |
| { |
| /* The destination requires twice as many mask bits as the source, so |
| we can use interleaving permutes to double up the number of bits. */ |
| tree masks[2]; |
| for (unsigned int i = 0; i < 2; ++i) |
| masks[i] = vect_gen_perm_mask_checked (src_masktype, indices[i]); |
| for (unsigned int i = 0; i < dest_rgm->controls.length (); ++i) |
| { |
| tree src = src_rgm->controls[i / 2]; |
| tree dest = dest_rgm->controls[i]; |
| gimple *stmt = gimple_build_assign (dest, VEC_PERM_EXPR, |
| src, src, masks[i & 1]); |
| gimple_seq_add_stmt (seq, stmt); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| /* Helper for vect_set_loop_condition_partial_vectors. Generate definitions |
| for all the rgroup controls in RGC and return a control that is nonzero |
| when the loop needs to iterate. Add any new preheader statements to |
| PREHEADER_SEQ. Use LOOP_COND_GSI to insert code before the exit gcond. |
| |
| RGC belongs to loop LOOP. The loop originally iterated NITERS |
| times and has been vectorized according to LOOP_VINFO. |
| |
| If NITERS_SKIP is nonnull, the first iteration of the vectorized loop |
| starts with NITERS_SKIP dummy iterations of the scalar loop before |
| the real work starts. The mask elements for these dummy iterations |
| must be 0, to ensure that the extra iterations do not have an effect. |
| |
| It is known that: |
| |
| NITERS * RGC->max_nscalars_per_iter * RGC->factor |
| |
| does not overflow. However, MIGHT_WRAP_P says whether an induction |
| variable that starts at 0 and has step: |
| |
| VF * RGC->max_nscalars_per_iter * RGC->factor |
| |
| might overflow before hitting a value above: |
| |
| (NITERS + NITERS_SKIP) * RGC->max_nscalars_per_iter * RGC->factor |
| |
| This means that we cannot guarantee that such an induction variable |
| would ever hit a value that produces a set of all-false masks or zero |
| lengths for RGC. |
| |
| Note: the cost of the code generated by this function is modeled |
| by vect_estimate_min_profitable_iters, so changes here may need |
| corresponding changes there. */ |
| |
| static tree |
| vect_set_loop_controls_directly (class loop *loop, loop_vec_info loop_vinfo, |
| gimple_seq *preheader_seq, |
| gimple_seq *header_seq, |
| gimple_stmt_iterator loop_cond_gsi, |
| rgroup_controls *rgc, tree niters, |
| tree niters_skip, bool might_wrap_p) |
| { |
| tree compare_type = LOOP_VINFO_RGROUP_COMPARE_TYPE (loop_vinfo); |
| tree iv_type = LOOP_VINFO_RGROUP_IV_TYPE (loop_vinfo); |
| bool use_masks_p = LOOP_VINFO_FULLY_MASKED_P (loop_vinfo); |
| |
| tree ctrl_type = rgc->type; |
| unsigned int nitems_per_iter = rgc->max_nscalars_per_iter * rgc->factor; |
| poly_uint64 nitems_per_ctrl = TYPE_VECTOR_SUBPARTS (ctrl_type) * rgc->factor; |
| poly_uint64 vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); |
| tree length_limit = NULL_TREE; |
| /* For length, we need length_limit to ensure length in range. */ |
| if (!use_masks_p) |
| length_limit = build_int_cst (compare_type, nitems_per_ctrl); |
| |
| /* Calculate the maximum number of item values that the rgroup |
| handles in total, the number that it handles for each iteration |
| of the vector loop, and the number that it should skip during the |
| first iteration of the vector loop. */ |
| tree nitems_total = niters; |
| tree nitems_step = build_int_cst (iv_type, vf); |
| tree nitems_skip = niters_skip; |
| if (nitems_per_iter != 1) |
| { |
| /* We checked before setting LOOP_VINFO_USING_PARTIAL_VECTORS_P that |
| these multiplications don't overflow. */ |
| tree compare_factor = build_int_cst (compare_type, nitems_per_iter); |
| tree iv_factor = build_int_cst (iv_type, nitems_per_iter); |
| nitems_total = gimple_build (preheader_seq, MULT_EXPR, compare_type, |
| nitems_total, compare_factor); |
| nitems_step = gimple_build (preheader_seq, MULT_EXPR, iv_type, |
| nitems_step, iv_factor); |
| if (nitems_skip) |
| nitems_skip = gimple_build (preheader_seq, MULT_EXPR, compare_type, |
| nitems_skip, compare_factor); |
| } |
| |
| /* Create an induction variable that counts the number of items |
| processed. */ |
| tree index_before_incr, index_after_incr; |
| gimple_stmt_iterator incr_gsi; |
| bool insert_after; |
| standard_iv_increment_position (loop, &incr_gsi, &insert_after); |
| create_iv (build_int_cst (iv_type, 0), nitems_step, NULL_TREE, loop, |
| &incr_gsi, insert_after, &index_before_incr, &index_after_incr); |
| |
| tree zero_index = build_int_cst (compare_type, 0); |
| tree test_index, test_limit, first_limit; |
| gimple_stmt_iterator *test_gsi; |
| if (might_wrap_p) |
| { |
| /* In principle the loop should stop iterating once the incremented |
| IV reaches a value greater than or equal to: |
| |
| NITEMS_TOTAL +[infinite-prec] NITEMS_SKIP |
| |
| However, there's no guarantee that this addition doesn't overflow |
| the comparison type, or that the IV hits a value above it before |
| wrapping around. We therefore adjust the limit down by one |
| IV step: |
| |
| (NITEMS_TOTAL +[infinite-prec] NITEMS_SKIP) |
| -[infinite-prec] NITEMS_STEP |
| |
| and compare the IV against this limit _before_ incrementing it. |
| Since the comparison type is unsigned, we actually want the |
| subtraction to saturate at zero: |
| |
| (NITEMS_TOTAL +[infinite-prec] NITEMS_SKIP) |
| -[sat] NITEMS_STEP |
| |
| And since NITEMS_SKIP < NITEMS_STEP, we can reassociate this as: |
| |
| NITEMS_TOTAL -[sat] (NITEMS_STEP - NITEMS_SKIP) |
| |
| where the rightmost subtraction can be done directly in |
| COMPARE_TYPE. */ |
| test_index = index_before_incr; |
| tree adjust = gimple_convert (preheader_seq, compare_type, |
| nitems_step); |
| if (nitems_skip) |
| adjust = gimple_build (preheader_seq, MINUS_EXPR, compare_type, |
| adjust, nitems_skip); |
| test_limit = gimple_build (preheader_seq, MAX_EXPR, compare_type, |
| nitems_total, adjust); |
| test_limit = gimple_build (preheader_seq, MINUS_EXPR, compare_type, |
| test_limit, adjust); |
| test_gsi = &incr_gsi; |
| |
| /* Get a safe limit for the first iteration. */ |
| if (nitems_skip) |
| { |
| /* The first vector iteration can handle at most NITEMS_STEP |
| items. NITEMS_STEP <= CONST_LIMIT, and adding |
| NITEMS_SKIP to that cannot overflow. */ |
| tree const_limit = build_int_cst (compare_type, |
| LOOP_VINFO_VECT_FACTOR (loop_vinfo) |
| * nitems_per_iter); |
| first_limit = gimple_build (preheader_seq, MIN_EXPR, compare_type, |
| nitems_total, const_limit); |
| first_limit = gimple_build (preheader_seq, PLUS_EXPR, compare_type, |
| first_limit, nitems_skip); |
| } |
| else |
| /* For the first iteration it doesn't matter whether the IV hits |
| a value above NITEMS_TOTAL. That only matters for the latch |
| condition. */ |
| first_limit = nitems_total; |
| } |
| else |
| { |
| /* Test the incremented IV, which will always hit a value above |
| the bound before wrapping. */ |
| test_index = index_after_incr; |
| test_limit = nitems_total; |
| if (nitems_skip) |
| test_limit = gimple_build (preheader_seq, PLUS_EXPR, compare_type, |
| test_limit, nitems_skip); |
| test_gsi = &loop_cond_gsi; |
| |
| first_limit = test_limit; |
| } |
| |
| /* Convert the IV value to the comparison type (either a no-op or |
| a demotion). */ |
| gimple_seq test_seq = NULL; |
| test_index = gimple_convert (&test_seq, compare_type, test_index); |
| gsi_insert_seq_before (test_gsi, test_seq, GSI_SAME_STMT); |
| |
| /* Provide a definition of each control in the group. */ |
| tree next_ctrl = NULL_TREE; |
| tree ctrl; |
| unsigned int i; |
| FOR_EACH_VEC_ELT_REVERSE (rgc->controls, i, ctrl) |
| { |
| /* Previous controls will cover BIAS items. This control covers the |
| next batch. */ |
| poly_uint64 bias = nitems_per_ctrl * i; |
| tree bias_tree = build_int_cst (compare_type, bias); |
| |
| /* See whether the first iteration of the vector loop is known |
| to have a full control. */ |
| poly_uint64 const_limit; |
| bool first_iteration_full |
| = (poly_int_tree_p (first_limit, &const_limit) |
| && known_ge (const_limit, (i + 1) * nitems_per_ctrl)); |
| |
| /* Rather than have a new IV that starts at BIAS and goes up to |
| TEST_LIMIT, prefer to use the same 0-based IV for each control |
| and adjust the bound down by BIAS. */ |
| tree this_test_limit = test_limit; |
| if (i != 0) |
| { |
| this_test_limit = gimple_build (preheader_seq, MAX_EXPR, |
| compare_type, this_test_limit, |
| bias_tree); |
| this_test_limit = gimple_build (preheader_seq, MINUS_EXPR, |
| compare_type, this_test_limit, |
| bias_tree); |
| } |
| |
| /* Create the initial control. First include all items that |
| are within the loop limit. */ |
| tree init_ctrl = NULL_TREE; |
| if (!first_iteration_full) |
| { |
| tree start, end; |
| if (first_limit == test_limit) |
| { |
| /* Use a natural test between zero (the initial IV value) |
| and the loop limit. The "else" block would be valid too, |
| but this choice can avoid the need to load BIAS_TREE into |
| a register. */ |
| start = zero_index; |
| end = this_test_limit; |
| } |
| else |
| { |
| /* FIRST_LIMIT is the maximum number of items handled by the |
| first iteration of the vector loop. Test the portion |
| associated with this control. */ |
| start = bias_tree; |
| end = first_limit; |
| } |
| |
| if (use_masks_p) |
| init_ctrl = vect_gen_while (preheader_seq, ctrl_type, |
| start, end, "max_mask"); |
| else |
| { |
| init_ctrl = make_temp_ssa_name (compare_type, NULL, "max_len"); |
| gimple_seq seq = vect_gen_len (init_ctrl, start, |
| end, length_limit); |
| gimple_seq_add_seq (preheader_seq, seq); |
| } |
| } |
| |
| /* Now AND out the bits that are within the number of skipped |
| items. */ |
| poly_uint64 const_skip; |
| if (nitems_skip |
| && !(poly_int_tree_p (nitems_skip, &const_skip) |
| && known_le (const_skip, bias))) |
| { |
| gcc_assert (use_masks_p); |
| tree unskipped_mask = vect_gen_while_not (preheader_seq, ctrl_type, |
| bias_tree, nitems_skip); |
| if (init_ctrl) |
| init_ctrl = gimple_build (preheader_seq, BIT_AND_EXPR, ctrl_type, |
| init_ctrl, unskipped_mask); |
| else |
| init_ctrl = unskipped_mask; |
| } |
| |
| if (!init_ctrl) |
| { |
| /* First iteration is full. */ |
| if (use_masks_p) |
| init_ctrl = build_minus_one_cst (ctrl_type); |
| else |
| init_ctrl = length_limit; |
| } |
| |
| /* Get the control value for the next iteration of the loop. */ |
| if (use_masks_p) |
| { |
| gimple_seq stmts = NULL; |
| next_ctrl = vect_gen_while (&stmts, ctrl_type, test_index, |
| this_test_limit, "next_mask"); |
| gsi_insert_seq_before (test_gsi, stmts, GSI_SAME_STMT); |
| } |
| else |
| { |
| next_ctrl = make_temp_ssa_name (compare_type, NULL, "next_len"); |
| gimple_seq seq = vect_gen_len (next_ctrl, test_index, this_test_limit, |
| length_limit); |
| gsi_insert_seq_before (test_gsi, seq, GSI_SAME_STMT); |
| } |
| |
| vect_set_loop_control (loop, ctrl, init_ctrl, next_ctrl); |
| } |
| |
| int partial_load_bias = LOOP_VINFO_PARTIAL_LOAD_STORE_BIAS (loop_vinfo); |
| if (partial_load_bias != 0) |
| { |
| tree adjusted_len = rgc->bias_adjusted_ctrl; |
| gassign *minus = gimple_build_assign (adjusted_len, PLUS_EXPR, |
| rgc->controls[0], |
| build_int_cst |
| (TREE_TYPE (rgc->controls[0]), |
| partial_load_bias)); |
| gimple_seq_add_stmt (header_seq, minus); |
| } |
| |
| return next_ctrl; |
| } |
| |
| /* Set up the iteration condition and rgroup controls for LOOP, given |
| that LOOP_VINFO_USING_PARTIAL_VECTORS_P is true for the vectorized |
| loop. LOOP_VINFO describes the vectorization of LOOP. NITERS is |
| the number of iterations of the original scalar loop that should be |
| handled by the vector loop. NITERS_MAYBE_ZERO and FINAL_IV are as |
| for vect_set_loop_condition. |
| |
| Insert the branch-back condition before LOOP_COND_GSI and return the |
| final gcond. */ |
| |
| static gcond * |
| vect_set_loop_condition_partial_vectors (class loop *loop, |
| loop_vec_info loop_vinfo, tree niters, |
| tree final_iv, bool niters_maybe_zero, |
| gimple_stmt_iterator loop_cond_gsi) |
| { |
| gimple_seq preheader_seq = NULL; |
| gimple_seq header_seq = NULL; |
| |
| bool use_masks_p = LOOP_VINFO_FULLY_MASKED_P (loop_vinfo); |
| tree compare_type = LOOP_VINFO_RGROUP_COMPARE_TYPE (loop_vinfo); |
| unsigned int compare_precision = TYPE_PRECISION (compare_type); |
| tree orig_niters = niters; |
| |
| /* Type of the initial value of NITERS. */ |
| tree ni_actual_type = TREE_TYPE (niters); |
| unsigned int ni_actual_precision = TYPE_PRECISION (ni_actual_type); |
| tree niters_skip = LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo); |
| |
| /* Convert NITERS to the same size as the compare. */ |
| if (compare_precision > ni_actual_precision |
| && niters_maybe_zero) |
| { |
| /* We know that there is always at least one iteration, so if the |
| count is zero then it must have wrapped. Cope with this by |
| subtracting 1 before the conversion and adding 1 to the result. */ |
| gcc_assert (TYPE_UNSIGNED (ni_actual_type)); |
| niters = gimple_build (&preheader_seq, PLUS_EXPR, ni_actual_type, |
| niters, build_minus_one_cst (ni_actual_type)); |
| niters = gimple_convert (&preheader_seq, compare_type, niters); |
| niters = gimple_build (&preheader_seq, PLUS_EXPR, compare_type, |
| niters, build_one_cst (compare_type)); |
| } |
| else |
| niters = gimple_convert (&preheader_seq, compare_type, niters); |
| |
| /* Iterate over all the rgroups and fill in their controls. We could use |
| the first control from any rgroup for the loop condition; here we |
| arbitrarily pick the last. */ |
| tree test_ctrl = NULL_TREE; |
| rgroup_controls *rgc; |
| unsigned int i; |
| auto_vec<rgroup_controls> *controls = use_masks_p |
| ? &LOOP_VINFO_MASKS (loop_vinfo) |
| : &LOOP_VINFO_LENS (loop_vinfo); |
| FOR_EACH_VEC_ELT (*controls, i, rgc) |
| if (!rgc->controls.is_empty ()) |
| { |
| /* First try using permutes. This adds a single vector |
| instruction to the loop for each mask, but needs no extra |
| loop invariants or IVs. */ |
| unsigned int nmasks = i + 1; |
| if (use_masks_p && (nmasks & 1) == 0) |
| { |
| rgroup_controls *half_rgc = &(*controls)[nmasks / 2 - 1]; |
| if (!half_rgc->controls.is_empty () |
| && vect_maybe_permute_loop_masks (&header_seq, rgc, half_rgc)) |
| continue; |
| } |
| |
| /* See whether zero-based IV would ever generate all-false masks |
| or zero length before wrapping around. */ |
| bool might_wrap_p = vect_rgroup_iv_might_wrap_p (loop_vinfo, rgc); |
| |
| /* Set up all controls for this group. */ |
| test_ctrl = vect_set_loop_controls_directly (loop, loop_vinfo, |
| &preheader_seq, |
| &header_seq, |
| loop_cond_gsi, rgc, |
| niters, niters_skip, |
| might_wrap_p); |
| } |
| |
| /* Emit all accumulated statements. */ |
| add_preheader_seq (loop, preheader_seq); |
| add_header_seq (loop, header_seq); |
| |
| /* Get a boolean result that tells us whether to iterate. */ |
| edge exit_edge = single_exit (loop); |
| tree_code code = (exit_edge->flags & EDGE_TRUE_VALUE) ? EQ_EXPR : NE_EXPR; |
| tree zero_ctrl = build_zero_cst (TREE_TYPE (test_ctrl)); |
| gcond *cond_stmt = gimple_build_cond (code, test_ctrl, zero_ctrl, |
| NULL_TREE, NULL_TREE); |
| gsi_insert_before (&loop_cond_gsi, cond_stmt, GSI_SAME_STMT); |
| |
| /* The loop iterates (NITERS - 1) / VF + 1 times. |
| Subtract one from this to get the latch count. */ |
| tree step = build_int_cst (compare_type, |
| LOOP_VINFO_VECT_FACTOR (loop_vinfo)); |
| tree niters_minus_one = fold_build2 (PLUS_EXPR, compare_type, niters, |
| build_minus_one_cst (compare_type)); |
| loop->nb_iterations = fold_build2 (TRUNC_DIV_EXPR, compare_type, |
| niters_minus_one, step); |
| |
| if (final_iv) |
| { |
| gassign *assign = gimple_build_assign (final_iv, orig_niters); |
| gsi_insert_on_edge_immediate (single_exit (loop), assign); |
| } |
| |
| return cond_stmt; |
| } |
| |
| /* Like vect_set_loop_condition, but handle the case in which the vector |
| loop handles exactly VF scalars per iteration. */ |
| |
| static gcond * |
| vect_set_loop_condition_normal (class loop *loop, tree niters, tree step, |
| tree final_iv, bool niters_maybe_zero, |
| gimple_stmt_iterator loop_cond_gsi) |
| { |
| tree indx_before_incr, indx_after_incr; |
| gcond *cond_stmt; |
| gcond *orig_cond; |
| edge pe = loop_preheader_edge (loop); |
| edge exit_edge = single_exit (loop); |
| gimple_stmt_iterator incr_gsi; |
| bool insert_after; |
| enum tree_code code; |
| tree niters_type = TREE_TYPE (niters); |
| |
| orig_cond = get_loop_exit_condition (loop); |
| gcc_assert (orig_cond); |
| loop_cond_gsi = gsi_for_stmt (orig_cond); |
| |
| tree init, limit; |
| if (!niters_maybe_zero && integer_onep (step)) |
| { |
| /* In this case we can use a simple 0-based IV: |
| |
| A: |
| x = 0; |
| do |
| { |
| ... |
| x += 1; |
| } |
| while (x < NITERS); */ |
| code = (exit_edge->flags & EDGE_TRUE_VALUE) ? GE_EXPR : LT_EXPR; |
| init = build_zero_cst (niters_type); |
| limit = niters; |
| } |
| else |
| { |
| /* The following works for all values of NITERS except 0: |
| |
| B: |
| x = 0; |
| do |
| { |
| ... |
| x += STEP; |
| } |
| while (x <= NITERS - STEP); |
| |
| so that the loop continues to iterate if x + STEP - 1 < NITERS |
| but stops if x + STEP - 1 >= NITERS. |
| |
| However, if NITERS is zero, x never hits a value above NITERS - STEP |
| before wrapping around. There are two obvious ways of dealing with |
| this: |
| |
| - start at STEP - 1 and compare x before incrementing it |
| - start at -1 and compare x after incrementing it |
| |
| The latter is simpler and is what we use. The loop in this case |
| looks like: |
| |
| C: |
| x = -1; |
| do |
| { |
| ... |
| x += STEP; |
| } |
| while (x < NITERS - STEP); |
| |
| In both cases the loop limit is NITERS - STEP. */ |
| gimple_seq seq = NULL; |
| limit = force_gimple_operand (niters, &seq, true, NULL_TREE); |
| limit = gimple_build (&seq, MINUS_EXPR, TREE_TYPE (limit), limit, step); |
| if (seq) |
| { |
| basic_block new_bb = gsi_insert_seq_on_edge_immediate (pe, seq); |
| gcc_assert (!new_bb); |
| } |
| if (niters_maybe_zero) |
| { |
| /* Case C. */ |
| code = (exit_edge->flags & EDGE_TRUE_VALUE) ? GE_EXPR : LT_EXPR; |
| init = build_all_ones_cst (niters_type); |
| } |
| else |
| { |
| /* Case B. */ |
| code = (exit_edge->flags & EDGE_TRUE_VALUE) ? GT_EXPR : LE_EXPR; |
| init = build_zero_cst (niters_type); |
| } |
| } |
| |
| standard_iv_increment_position (loop, &incr_gsi, &insert_after); |
| create_iv (init, step, NULL_TREE, loop, |
| &incr_gsi, insert_after, &indx_before_incr, &indx_after_incr); |
| indx_after_incr = force_gimple_operand_gsi (&loop_cond_gsi, indx_after_incr, |
| true, NULL_TREE, true, |
| GSI_SAME_STMT); |
| limit = force_gimple_operand_gsi (&loop_cond_gsi, limit, true, NULL_TREE, |
| true, GSI_SAME_STMT); |
| |
| cond_stmt = gimple_build_cond (code, indx_after_incr, limit, NULL_TREE, |
| NULL_TREE); |
| |
| gsi_insert_before (&loop_cond_gsi, cond_stmt, GSI_SAME_STMT); |
| |
| /* Record the number of latch iterations. */ |
| if (limit == niters) |
| /* Case A: the loop iterates NITERS times. Subtract one to get the |
| latch count. */ |
| loop->nb_iterations = fold_build2 (MINUS_EXPR, niters_type, niters, |
| build_int_cst (niters_type, 1)); |
| else |
| /* Case B or C: the loop iterates (NITERS - STEP) / STEP + 1 times. |
| Subtract one from this to get the latch count. */ |
| loop->nb_iterations = fold_build2 (TRUNC_DIV_EXPR, niters_type, |
| limit, step); |
| |
| if (final_iv) |
| { |
| gassign *assign = gimple_build_assign (final_iv, MINUS_EXPR, |
| indx_after_incr, init); |
| gsi_insert_on_edge_immediate (single_exit (loop), assign); |
| } |
| |
| return cond_stmt; |
| } |
| |
| /* If we're using fully-masked loops, make LOOP iterate: |
| |
| N == (NITERS - 1) / STEP + 1 |
| |
| times. When NITERS is zero, this is equivalent to making the loop |
| execute (1 << M) / STEP times, where M is the precision of NITERS. |
| NITERS_MAYBE_ZERO is true if this last case might occur. |
| |
| If we're not using fully-masked loops, make LOOP iterate: |
| |
| N == (NITERS - STEP) / STEP + 1 |
| |
| times, where NITERS is known to be outside the range [1, STEP - 1]. |
| This is equivalent to making the loop execute NITERS / STEP times |
| when NITERS is nonzero and (1 << M) / STEP times otherwise. |
| NITERS_MAYBE_ZERO again indicates whether this last case might occur. |
| |
| If FINAL_IV is nonnull, it is an SSA name that should be set to |
| N * STEP on exit from the loop. |
| |
| Assumption: the exit-condition of LOOP is the last stmt in the loop. */ |
| |
| void |
| vect_set_loop_condition (class loop *loop, loop_vec_info loop_vinfo, |
| tree niters, tree step, tree final_iv, |
| bool niters_maybe_zero) |
| { |
| gcond *cond_stmt; |
| gcond *orig_cond = get_loop_exit_condition (loop); |
| gimple_stmt_iterator loop_cond_gsi = gsi_for_stmt (orig_cond); |
| |
| if (loop_vinfo && LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo)) |
| cond_stmt = vect_set_loop_condition_partial_vectors (loop, loop_vinfo, |
| niters, final_iv, |
| niters_maybe_zero, |
| loop_cond_gsi); |
| else |
| cond_stmt = vect_set_loop_condition_normal (loop, niters, step, final_iv, |
| niters_maybe_zero, |
| loop_cond_gsi); |
| |
| /* Remove old loop exit test. */ |
| stmt_vec_info orig_cond_info; |
| if (loop_vinfo |
| && (orig_cond_info = loop_vinfo->lookup_stmt (orig_cond))) |
| loop_vinfo->remove_stmt (orig_cond_info); |
| else |
| gsi_remove (&loop_cond_gsi, true); |
| |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, "New loop exit condition: %G", |
| cond_stmt); |
| } |
| |
| /* Helper routine of slpeel_tree_duplicate_loop_to_edge_cfg. |
| For all PHI arguments in FROM->dest and TO->dest from those |
| edges ensure that TO->dest PHI arguments have current_def |
| to that in from. */ |
| |
| static void |
| slpeel_duplicate_current_defs_from_edges (edge from, edge to) |
| { |
| gimple_stmt_iterator gsi_from, gsi_to; |
| |
| for (gsi_from = gsi_start_phis (from->dest), |
| gsi_to = gsi_start_phis (to->dest); |
| !gsi_end_p (gsi_from) && !gsi_end_p (gsi_to);) |
| { |
| gimple *from_phi = gsi_stmt (gsi_from); |
| gimple *to_phi = gsi_stmt (gsi_to); |
| tree from_arg = PHI_ARG_DEF_FROM_EDGE (from_phi, from); |
| tree to_arg = PHI_ARG_DEF_FROM_EDGE (to_phi, to); |
| if (virtual_operand_p (from_arg)) |
| { |
| gsi_next (&gsi_from); |
| continue; |
| } |
| if (virtual_operand_p (to_arg)) |
| { |
| gsi_next (&gsi_to); |
| continue; |
| } |
| if (TREE_CODE (from_arg) != SSA_NAME) |
| gcc_assert (operand_equal_p (from_arg, to_arg, 0)); |
| else if (TREE_CODE (to_arg) == SSA_NAME |
| && from_arg != to_arg) |
| { |
| if (get_current_def (to_arg) == NULL_TREE) |
| { |
| gcc_assert (types_compatible_p (TREE_TYPE (to_arg), |
| TREE_TYPE (get_current_def |
| (from_arg)))); |
| set_current_def (to_arg, get_current_def (from_arg)); |
| } |
| } |
| gsi_next (&gsi_from); |
| gsi_next (&gsi_to); |
| } |
| |
| gphi *from_phi = get_virtual_phi (from->dest); |
| gphi *to_phi = get_virtual_phi (to->dest); |
| if (from_phi) |
| set_current_def (PHI_ARG_DEF_FROM_EDGE (to_phi, to), |
| get_current_def (PHI_ARG_DEF_FROM_EDGE (from_phi, from))); |
| } |
| |
| |
| /* Given LOOP this function generates a new copy of it and puts it |
| on E which is either the entry or exit of LOOP. If SCALAR_LOOP is |
| non-NULL, assume LOOP and SCALAR_LOOP are equivalent and copy the |
| basic blocks from SCALAR_LOOP instead of LOOP, but to either the |
| entry or exit of LOOP. */ |
| |
| class loop * |
| slpeel_tree_duplicate_loop_to_edge_cfg (class loop *loop, |
| class loop *scalar_loop, edge e) |
| { |
| class loop *new_loop; |
| basic_block *new_bbs, *bbs, *pbbs; |
| bool at_exit; |
| bool was_imm_dom; |
| basic_block exit_dest; |
| edge exit, new_exit; |
| bool duplicate_outer_loop = false; |
| |
| exit = single_exit (loop); |
| at_exit = (e == exit); |
| if (!at_exit && e != loop_preheader_edge (loop)) |
| return NULL; |
| |
| if (scalar_loop == NULL) |
| scalar_loop = loop; |
| |
| bbs = XNEWVEC (basic_block, scalar_loop->num_nodes + 1); |
| pbbs = bbs + 1; |
| get_loop_body_with_size (scalar_loop, pbbs, scalar_loop->num_nodes); |
| /* Allow duplication of outer loops. */ |
| if (scalar_loop->inner) |
| duplicate_outer_loop = true; |
| /* Check whether duplication is possible. */ |
| if (!can_copy_bbs_p (pbbs, scalar_loop->num_nodes)) |
| { |
| free (bbs); |
| return NULL; |
| } |
| |
| /* Generate new loop structure. */ |
| new_loop = duplicate_loop (scalar_loop, loop_outer (scalar_loop)); |
| duplicate_subloops (scalar_loop, new_loop); |
| |
| exit_dest = exit->dest; |
| was_imm_dom = (get_immediate_dominator (CDI_DOMINATORS, |
| exit_dest) == loop->header ? |
| true : false); |
| |
| /* Also copy the pre-header, this avoids jumping through hoops to |
| duplicate the loop entry PHI arguments. Create an empty |
| pre-header unconditionally for this. */ |
| basic_block preheader = split_edge (loop_preheader_edge (scalar_loop)); |
| edge entry_e = single_pred_edge (preheader); |
| bbs[0] = preheader; |
| new_bbs = XNEWVEC (basic_block, scalar_loop->num_nodes + 1); |
| |
| exit = single_exit (scalar_loop); |
| copy_bbs (bbs, scalar_loop->num_nodes + 1, new_bbs, |
| &exit, 1, &new_exit, NULL, |
| at_exit ? loop->latch : e->src, true); |
| exit = single_exit (loop); |
| basic_block new_preheader = new_bbs[0]; |
| |
| /* Before installing PHI arguments make sure that the edges |
| into them match that of the scalar loop we analyzed. This |
| makes sure the SLP tree matches up between the main vectorized |
| loop and the epilogue vectorized copies. */ |
| if (single_succ_edge (preheader)->dest_idx |
| != single_succ_edge (new_bbs[0])->dest_idx) |
| { |
| basic_block swap_bb = new_bbs[1]; |
| gcc_assert (EDGE_COUNT (swap_bb->preds) == 2); |
| std::swap (EDGE_PRED (swap_bb, 0), EDGE_PRED (swap_bb, 1)); |
| EDGE_PRED (swap_bb, 0)->dest_idx = 0; |
| EDGE_PRED (swap_bb, 1)->dest_idx = 1; |
| } |
| if (duplicate_outer_loop) |
| { |
| class loop *new_inner_loop = get_loop_copy (scalar_loop->inner); |
| if (loop_preheader_edge (scalar_loop)->dest_idx |
| != loop_preheader_edge (new_inner_loop)->dest_idx) |
| { |
| basic_block swap_bb = new_inner_loop->header; |
| gcc_assert (EDGE_COUNT (swap_bb->preds) == 2); |
| std::swap (EDGE_PRED (swap_bb, 0), EDGE_PRED (swap_bb, 1)); |
| EDGE_PRED (swap_bb, 0)->dest_idx = 0; |
| EDGE_PRED (swap_bb, 1)->dest_idx = 1; |
| } |
| } |
| |
| add_phi_args_after_copy (new_bbs, scalar_loop->num_nodes + 1, NULL); |
| |
| /* Skip new preheader since it's deleted if copy loop is added at entry. */ |
| for (unsigned i = (at_exit ? 0 : 1); i < scalar_loop->num_nodes + 1; i++) |
| rename_variables_in_bb (new_bbs[i], duplicate_outer_loop); |
| |
| if (scalar_loop != loop) |
| { |
| /* If we copied from SCALAR_LOOP rather than LOOP, SSA_NAMEs from |
| SCALAR_LOOP will have current_def set to SSA_NAMEs in the new_loop, |
| but LOOP will not. slpeel_update_phi_nodes_for_guard{1,2} expects |
| the LOOP SSA_NAMEs (on the exit edge and edge from latch to |
| header) to have current_def set, so copy them over. */ |
| slpeel_duplicate_current_defs_from_edges (single_exit (scalar_loop), |
| exit); |
| slpeel_duplicate_current_defs_from_edges (EDGE_SUCC (scalar_loop->latch, |
| 0), |
| EDGE_SUCC (loop->latch, 0)); |
| } |
| |
| if (at_exit) /* Add the loop copy at exit. */ |
| { |
| if (scalar_loop != loop) |
| { |
| gphi_iterator gsi; |
| new_exit = redirect_edge_and_branch (new_exit, exit_dest); |
| |
| for (gsi = gsi_start_phis (exit_dest); !gsi_end_p (gsi); |
| gsi_next (&gsi)) |
| { |
| gphi *phi = gsi.phi (); |
| tree orig_arg = PHI_ARG_DEF_FROM_EDGE (phi, e); |
| location_t orig_locus |
| = gimple_phi_arg_location_from_edge (phi, e); |
| |
| add_phi_arg (phi, orig_arg, new_exit, orig_locus); |
| } |
| } |
| redirect_edge_and_branch_force (e, new_preheader); |
| flush_pending_stmts (e); |
| set_immediate_dominator (CDI_DOMINATORS, new_preheader, e->src); |
| if (was_imm_dom || duplicate_outer_loop) |
| set_immediate_dominator (CDI_DOMINATORS, exit_dest, new_exit->src); |
| |
| /* And remove the non-necessary forwarder again. Keep the other |
| one so we have a proper pre-header for the loop at the exit edge. */ |
| redirect_edge_pred (single_succ_edge (preheader), |
| single_pred (preheader)); |
| delete_basic_block (preheader); |
| set_immediate_dominator (CDI_DOMINATORS, scalar_loop->header, |
| loop_preheader_edge (scalar_loop)->src); |
| } |
| else /* Add the copy at entry. */ |
| { |
| if (scalar_loop != loop) |
| { |
| /* Remove the non-necessary forwarder of scalar_loop again. */ |
| redirect_edge_pred (single_succ_edge (preheader), |
| single_pred (preheader)); |
| delete_basic_block (preheader); |
| set_immediate_dominator (CDI_DOMINATORS, scalar_loop->header, |
| loop_preheader_edge (scalar_loop)->src); |
| preheader = split_edge (loop_preheader_edge (loop)); |
| entry_e = single_pred_edge (preheader); |
| } |
| |
| redirect_edge_and_branch_force (entry_e, new_preheader); |
| flush_pending_stmts (entry_e); |
| set_immediate_dominator (CDI_DOMINATORS, new_preheader, entry_e->src); |
| |
| redirect_edge_and_branch_force (new_exit, preheader); |
| flush_pending_stmts (new_exit); |
| set_immediate_dominator (CDI_DOMINATORS, preheader, new_exit->src); |
| |
| /* And remove the non-necessary forwarder again. Keep the other |
| one so we have a proper pre-header for the loop at the exit edge. */ |
| redirect_edge_pred (single_succ_edge (new_preheader), |
| single_pred (new_preheader)); |
| delete_basic_block (new_preheader); |
| set_immediate_dominator (CDI_DOMINATORS, new_loop->header, |
| loop_preheader_edge (new_loop)->src); |
| } |
| |
| if (scalar_loop != loop) |
| { |
| /* Update new_loop->header PHIs, so that on the preheader |
| edge they are the ones from loop rather than scalar_loop. */ |
| gphi_iterator gsi_orig, gsi_new; |
| edge orig_e = loop_preheader_edge (loop); |
| edge new_e = loop_preheader_edge (new_loop); |
| |
| for (gsi_orig = gsi_start_phis (loop->header), |
| gsi_new = gsi_start_phis (new_loop->header); |
| !gsi_end_p (gsi_orig) && !gsi_end_p (gsi_new); |
| gsi_next (&gsi_orig), gsi_next (&gsi_new)) |
| { |
| gphi *orig_phi = gsi_orig.phi (); |
| gphi *new_phi = gsi_new.phi (); |
| tree orig_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, orig_e); |
| location_t orig_locus |
| = gimple_phi_arg_location_from_edge (orig_phi, orig_e); |
| |
| add_phi_arg (new_phi, orig_arg, new_e, orig_locus); |
| } |
| } |
| |
| free (new_bbs); |
| free (bbs); |
| |
| checking_verify_dominators (CDI_DOMINATORS); |
| |
| return new_loop; |
| } |
| |
| |
| /* Given the condition expression COND, put it as the last statement of |
| GUARD_BB; set both edges' probability; set dominator of GUARD_TO to |
| DOM_BB; return the skip edge. GUARD_TO is the target basic block to |
| skip the loop. PROBABILITY is the skip edge's probability. Mark the |
| new edge as irreducible if IRREDUCIBLE_P is true. */ |
| |
| static edge |
| slpeel_add_loop_guard (basic_block guard_bb, tree cond, |
| basic_block guard_to, basic_block dom_bb, |
| profile_probability probability, bool irreducible_p) |
| { |
| gimple_stmt_iterator gsi; |
| edge new_e, enter_e; |
| gcond *cond_stmt; |
| gimple_seq gimplify_stmt_list = NULL; |
| |
| enter_e = EDGE_SUCC (guard_bb, 0); |
| enter_e->flags &= ~EDGE_FALLTHRU; |
| enter_e->flags |= EDGE_FALSE_VALUE; |
| gsi = gsi_last_bb (guard_bb); |
| |
| cond = force_gimple_operand_1 (cond, &gimplify_stmt_list, is_gimple_condexpr, |
| NULL_TREE); |
| if (gimplify_stmt_list) |
| gsi_insert_seq_after (&gsi, gimplify_stmt_list, GSI_NEW_STMT); |
| |
| cond_stmt = gimple_build_cond_from_tree (cond, NULL_TREE, NULL_TREE); |
| gsi = gsi_last_bb (guard_bb); |
| gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT); |
| |
| /* Add new edge to connect guard block to the merge/loop-exit block. */ |
| new_e = make_edge (guard_bb, guard_to, EDGE_TRUE_VALUE); |
| |
| new_e->probability = probability; |
| if (irreducible_p) |
| new_e->flags |= EDGE_IRREDUCIBLE_LOOP; |
| |
| enter_e->probability = probability.invert (); |
| set_immediate_dominator (CDI_DOMINATORS, guard_to, dom_bb); |
| |
| /* Split enter_e to preserve LOOPS_HAVE_PREHEADERS. */ |
| if (enter_e->dest->loop_father->header == enter_e->dest) |
| split_edge (enter_e); |
| |
| return new_e; |
| } |
| |
| |
| /* This function verifies that the following restrictions apply to LOOP: |
| (1) it consists of exactly 2 basic blocks - header, and an empty latch |
| for innermost loop and 5 basic blocks for outer-loop. |
| (2) it is single entry, single exit |
| (3) its exit condition is the last stmt in the header |
| (4) E is the entry/exit edge of LOOP. |
| */ |
| |
| bool |
| slpeel_can_duplicate_loop_p (const class loop *loop, const_edge e) |
| { |
| edge exit_e = single_exit (loop); |
| edge entry_e = loop_preheader_edge (loop); |
| gcond *orig_cond = get_loop_exit_condition (loop); |
| gimple_stmt_iterator loop_exit_gsi = gsi_last_bb (exit_e->src); |
| unsigned int num_bb = loop->inner? 5 : 2; |
| |
| /* All loops have an outer scope; the only case loop->outer is NULL is for |
| the function itself. */ |
| if (!loop_outer (loop) |
| || loop->num_nodes != num_bb |
| || !empty_block_p (loop->latch) |
| || !single_exit (loop) |
| /* Verify that new loop exit condition can be trivially modified. */ |
| || (!orig_cond || orig_cond != gsi_stmt (loop_exit_gsi)) |
| || (e != exit_e && e != entry_e)) |
| return false; |
| |
| return true; |
| } |
| |
| /* If the loop has a virtual PHI, but exit bb doesn't, create a virtual PHI |
| in the exit bb and rename all the uses after the loop. This simplifies |
| the *guard[12] routines, which assume loop closed SSA form for all PHIs |
| (but normally loop closed SSA form doesn't require virtual PHIs to be |
| in the same form). Doing this early simplifies the checking what |
| uses should be renamed. |
| |
| If we create a new phi after the loop, return the definition that |
| applies on entry to the loop, otherwise return null. */ |
| |
| static tree |
| create_lcssa_for_virtual_phi (class loop *loop) |
| { |
| gphi_iterator gsi; |
| edge exit_e = single_exit (loop); |
| |
| for (gsi = gsi_start_phis (loop->header); !gsi_end_p (gsi); gsi_next (&gsi)) |
| if (virtual_operand_p (gimple_phi_result (gsi_stmt (gsi)))) |
| { |
| gphi *phi = gsi.phi (); |
| for (gsi = gsi_start_phis (exit_e->dest); |
| !gsi_end_p (gsi); gsi_next (&gsi)) |
| if (virtual_operand_p (gimple_phi_result (gsi_stmt (gsi)))) |
| break; |
| if (gsi_end_p (gsi)) |
| { |
| tree new_vop = copy_ssa_name (PHI_RESULT (phi)); |
| gphi *new_phi = create_phi_node (new_vop, exit_e->dest); |
| tree vop = PHI_ARG_DEF_FROM_EDGE (phi, EDGE_SUCC (loop->latch, 0)); |
| imm_use_iterator imm_iter; |
| gimple *stmt; |
| use_operand_p use_p; |
| |
| SSA_NAME_OCCURS_IN_ABNORMAL_PHI (new_vop) |
| = SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vop); |
| add_phi_arg (new_phi, vop, exit_e, UNKNOWN_LOCATION); |
| gimple_phi_set_result (new_phi, new_vop); |
| FOR_EACH_IMM_USE_STMT (stmt, imm_iter, vop) |
| if (stmt != new_phi |
| && !flow_bb_inside_loop_p (loop, gimple_bb (stmt))) |
| FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) |
| SET_USE (use_p, new_vop); |
| |
| return PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); |
| } |
| break; |
| } |
| return NULL_TREE; |
| } |
| |
| /* Function vect_get_loop_location. |
| |
| Extract the location of the loop in the source code. |
| If the loop is not well formed for vectorization, an estimated |
| location is calculated. |
| Return the loop location if succeed and NULL if not. */ |
| |
| dump_user_location_t |
| find_loop_location (class loop *loop) |
| { |
| gimple *stmt = NULL; |
| basic_block bb; |
| gimple_stmt_iterator si; |
| |
| if (!loop) |
| return dump_user_location_t (); |
| |
| stmt = get_loop_exit_condition (loop); |
| |
| if (stmt |
| && LOCATION_LOCUS (gimple_location (stmt)) > BUILTINS_LOCATION) |
| return stmt; |
| |
| /* If we got here the loop is probably not "well formed", |
| try to estimate the loop location */ |
| |
| if (!loop->header) |
| return dump_user_location_t (); |
| |
| bb = loop->header; |
| |
| for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) |
| { |
| stmt = gsi_stmt (si); |
| if (LOCATION_LOCUS (gimple_location (stmt)) > BUILTINS_LOCATION) |
| return stmt; |
| } |
| |
| return dump_user_location_t (); |
| } |
| |
| /* Return true if the phi described by STMT_INFO defines an IV of the |
| loop to be vectorized. */ |
| |
| static bool |
| iv_phi_p (stmt_vec_info stmt_info) |
| { |
| gphi *phi = as_a <gphi *> (stmt_info->stmt); |
| if (virtual_operand_p (PHI_RESULT (phi))) |
| return false; |
| |
| if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def |
| || STMT_VINFO_DEF_TYPE (stmt_info) == vect_double_reduction_def) |
| return false; |
| |
| return true; |
| } |
| |
| /* Function vect_can_advance_ivs_p |
| |
| In case the number of iterations that LOOP iterates is unknown at compile |
| time, an epilog loop will be generated, and the loop induction variables |
| (IVs) will be "advanced" to the value they are supposed to take just before |
| the epilog loop. Here we check that the access function of the loop IVs |
| and the expression that represents the loop bound are simple enough. |
| These restrictions will be relaxed in the future. */ |
| |
| bool |
| vect_can_advance_ivs_p (loop_vec_info loop_vinfo) |
| { |
| class loop *loop = LOOP_VINFO_LOOP (loop_vinfo); |
| basic_block bb = loop->header; |
| gphi_iterator gsi; |
| |
| /* Analyze phi functions of the loop header. */ |
| |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, "vect_can_advance_ivs_p:\n"); |
| for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
| { |
| tree evolution_part; |
| |
| gphi *phi = gsi.phi (); |
| stmt_vec_info phi_info = loop_vinfo->lookup_stmt (phi); |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, "Analyze phi: %G", |
| phi_info->stmt); |
| |
| /* Skip virtual phi's. The data dependences that are associated with |
| virtual defs/uses (i.e., memory accesses) are analyzed elsewhere. |
| |
| Skip reduction phis. */ |
| if (!iv_phi_p (phi_info)) |
| { |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, |
| "reduc or virtual phi. skip.\n"); |
| continue; |
| } |
| |
| /* Analyze the evolution function. */ |
| |
| evolution_part = STMT_VINFO_LOOP_PHI_EVOLUTION_PART (phi_info); |
| if (evolution_part == NULL_TREE) |
| { |
| if (dump_enabled_p ()) |
| dump_printf (MSG_MISSED_OPTIMIZATION, |
| "No access function or evolution.\n"); |
| return false; |
| } |
| |
| /* FORNOW: We do not transform initial conditions of IVs |
| which evolution functions are not invariants in the loop. */ |
| |
| if (!expr_invariant_in_loop_p (loop, evolution_part)) |
| { |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, |
| "evolution not invariant in loop.\n"); |
| return false; |
| } |
| |
| /* FORNOW: We do not transform initial conditions of IVs |
| which evolution functions are a polynomial of degree >= 2. */ |
| |
| if (tree_is_chrec (evolution_part)) |
| { |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, |
| "evolution is chrec.\n"); |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| |
| /* Function vect_update_ivs_after_vectorizer. |
| |
| "Advance" the induction variables of LOOP to the value they should take |
| after the execution of LOOP. This is currently necessary because the |
| vectorizer does not handle induction variables that are used after the |
| loop. Such a situation occurs when the last iterations of LOOP are |
| peeled, because: |
| 1. We introduced new uses after LOOP for IVs that were not originally used |
| after LOOP: the IVs of LOOP are now used by an epilog loop. |
| 2. LOOP is going to be vectorized; this means that it will iterate N/VF |
| times, whereas the loop IVs should be bumped N times. |
| |
| Input: |
| - LOOP - a loop that is going to be vectorized. The last few iterations |
| of LOOP were peeled. |
| - NITERS - the number of iterations that LOOP executes (before it is |
| vectorized). i.e, the number of times the ivs should be bumped. |
| - UPDATE_E - a successor edge of LOOP->exit that is on the (only) path |
| coming out from LOOP on which there are uses of the LOOP ivs |
| (this is the path from LOOP->exit to epilog_loop->preheader). |
| |
| The new definitions of the ivs are placed in LOOP->exit. |
| The phi args associated with the edge UPDATE_E in the bb |
| UPDATE_E->dest are updated accordingly. |
| |
| Assumption 1: Like the rest of the vectorizer, this function assumes |
| a single loop exit that has a single predecessor. |
| |
| Assumption 2: The phi nodes in the LOOP header and in update_bb are |
| organized in the same order. |
| |
| Assumption 3: The access function of the ivs is simple enough (see |
| vect_can_advance_ivs_p). This assumption will be relaxed in the future. |
| |
| Assumption 4: Exactly one of the successors of LOOP exit-bb is on a path |
| coming out of LOOP on which the ivs of LOOP are used (this is the path |
| that leads to the epilog loop; other paths skip the epilog loop). This |
| path starts with the edge UPDATE_E, and its destination (denoted update_bb) |
| needs to have its phis updated. |
| */ |
| |
| static void |
| vect_update_ivs_after_vectorizer (loop_vec_info loop_vinfo, |
| tree niters, edge update_e) |
| { |
| gphi_iterator gsi, gsi1; |
| class loop *loop = LOOP_VINFO_LOOP (loop_vinfo); |
| basic_block update_bb = update_e->dest; |
| basic_block exit_bb = single_exit (loop)->dest; |
| |
| /* Make sure there exists a single-predecessor exit bb: */ |
| gcc_assert (single_pred_p (exit_bb)); |
| gcc_assert (single_succ_edge (exit_bb) == update_e); |
| |
| for (gsi = gsi_start_phis (loop->header), gsi1 = gsi_start_phis (update_bb); |
| !gsi_end_p (gsi) && !gsi_end_p (gsi1); |
| gsi_next (&gsi), gsi_next (&gsi1)) |
| { |
| tree init_expr; |
| tree step_expr, off; |
| tree type; |
| tree var, ni, ni_name; |
| gimple_stmt_iterator last_gsi; |
| |
| gphi *phi = gsi.phi (); |
| gphi *phi1 = gsi1.phi (); |
| stmt_vec_info phi_info = loop_vinfo->lookup_stmt (phi); |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, |
| "vect_update_ivs_after_vectorizer: phi: %G", phi); |
| |
| /* Skip reduction and virtual phis. */ |
| if (!iv_phi_p (phi_info)) |
| { |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, |
| "reduc or virtual phi. skip.\n"); |
| continue; |
| } |
| |
| type = TREE_TYPE (gimple_phi_result (phi)); |
| step_expr = STMT_VINFO_LOOP_PHI_EVOLUTION_PART (phi_info); |
| step_expr = unshare_expr (step_expr); |
| |
| /* FORNOW: We do not support IVs whose evolution function is a polynomial |
| of degree >= 2 or exponential. */ |
| gcc_assert (!tree_is_chrec (step_expr)); |
| |
| init_expr = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop)); |
| |
| off = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr), |
| fold_convert (TREE_TYPE (step_expr), niters), |
| step_expr); |
| if (POINTER_TYPE_P (type)) |
| ni = fold_build_pointer_plus (init_expr, off); |
| else |
| ni = fold_build2 (PLUS_EXPR, type, |
| init_expr, fold_convert (type, off)); |
| |
| var = create_tmp_var (type, "tmp"); |
| |
| last_gsi = gsi_last_bb (exit_bb); |
| gimple_seq new_stmts = NULL; |
| ni_name = force_gimple_operand (ni, &new_stmts, false, var); |
| /* Exit_bb shouldn't be empty. */ |
| if (!gsi_end_p (last_gsi)) |
| gsi_insert_seq_after (&last_gsi, new_stmts, GSI_SAME_STMT); |
| else |
| gsi_insert_seq_before (&last_gsi, new_stmts, GSI_SAME_STMT); |
| |
| /* Fix phi expressions in the successor bb. */ |
| adjust_phi_and_debug_stmts (phi1, update_e, ni_name); |
| } |
| } |
| |
| /* Return a gimple value containing the misalignment (measured in vector |
| elements) for the loop described by LOOP_VINFO, i.e. how many elements |
| it is away from a perfectly aligned address. Add any new statements |
| to SEQ. */ |
| |
| static tree |
| get_misalign_in_elems (gimple **seq, loop_vec_info loop_vinfo) |
| { |
| dr_vec_info *dr_info = LOOP_VINFO_UNALIGNED_DR (loop_vinfo); |
| stmt_vec_info stmt_info = dr_info->stmt; |
| tree vectype = STMT_VINFO_VECTYPE (stmt_info); |
| |
| poly_uint64 target_align = DR_TARGET_ALIGNMENT (dr_info); |
| unsigned HOST_WIDE_INT target_align_c; |
| tree target_align_minus_1; |
| |
| bool negative = tree_int_cst_compare (DR_STEP (dr_info->dr), |
| size_zero_node) < 0; |
| tree offset = (negative |
| ? size_int ((-TYPE_VECTOR_SUBPARTS (vectype) + 1) |
| * TREE_INT_CST_LOW |
| (TYPE_SIZE_UNIT (TREE_TYPE (vectype)))) |
| : size_zero_node); |
| tree start_addr = vect_create_addr_base_for_vector_ref (loop_vinfo, |
| stmt_info, seq, |
| offset); |
| tree type = unsigned_type_for (TREE_TYPE (start_addr)); |
| if (target_align.is_constant (&target_align_c)) |
| target_align_minus_1 = build_int_cst (type, target_align_c - 1); |
| else |
| { |
| tree vla = build_int_cst (type, target_align); |
| tree vla_align = fold_build2 (BIT_AND_EXPR, type, vla, |
| fold_build2 (MINUS_EXPR, type, |
| build_int_cst (type, 0), vla)); |
| target_align_minus_1 = fold_build2 (MINUS_EXPR, type, vla_align, |
| build_int_cst (type, 1)); |
| } |
| |
| HOST_WIDE_INT elem_size |
| = int_cst_value (TYPE_SIZE_UNIT (TREE_TYPE (vectype))); |
| tree elem_size_log = build_int_cst (type, exact_log2 (elem_size)); |
| |
| /* Create: misalign_in_bytes = addr & (target_align - 1). */ |
| tree int_start_addr = fold_convert (type, start_addr); |
| tree misalign_in_bytes = fold_build2 (BIT_AND_EXPR, type, int_start_addr, |
| target_align_minus_1); |
| |
| /* Create: misalign_in_elems = misalign_in_bytes / element_size. */ |
| tree misalign_in_elems = fold_build2 (RSHIFT_EXPR, type, misalign_in_bytes, |
| elem_size_log); |
| |
| return misalign_in_elems; |
| } |
| |
| /* Function vect_gen_prolog_loop_niters |
| |
| Generate the number of iterations which should be peeled as prolog for the |
| loop represented by LOOP_VINFO. It is calculated as the misalignment of |
| DR - the data reference recorded in LOOP_VINFO_UNALIGNED_DR (LOOP_VINFO). |
| As a result, after the execution of this loop, the data reference DR will |
| refer to an aligned location. The following computation is generated: |
| |
| If the misalignment of DR is known at compile time: |
| addr_mis = int mis = DR_MISALIGNMENT (dr); |
| Else, compute address misalignment in bytes: |
| addr_mis = addr & (target_align - 1) |
| |
| prolog_niters = ((VF - addr_mis/elem_size)&(VF-1))/step |
| |
| (elem_size = element type size; an element is the scalar element whose type |
| is the inner type of the vectype) |
| |
| The computations will be emitted at the end of BB. We also compute and |
| store upper bound (included) of the result in BOUND. |
| |
| When the step of the data-ref in the loop is not 1 (as in interleaved data |
| and SLP), the number of iterations of the prolog must be divided by the step |
| (which is equal to the size of interleaved group). |
| |
| The above formulas assume that VF == number of elements in the vector. This |
| may not hold when there are multiple-types in the loop. |
| In this case, for some data-references in the loop the VF does not represent |
| the number of elements that fit in the vector. Therefore, instead of VF we |
| use TYPE_VECTOR_SUBPARTS. */ |
| |
| static tree |
| vect_gen_prolog_loop_niters (loop_vec_info loop_vinfo, |
| basic_block bb, int *bound) |
| { |
| dr_vec_info *dr_info = LOOP_VINFO_UNALIGNED_DR (loop_vinfo); |
| tree var; |
| tree niters_type = TREE_TYPE (LOOP_VINFO_NITERS (loop_vinfo)); |
| gimple_seq stmts = NULL, new_stmts = NULL; |
| tree iters, iters_name; |
| stmt_vec_info stmt_info = dr_info->stmt; |
| tree vectype = STMT_VINFO_VECTYPE (stmt_info); |
| poly_uint64 target_align = DR_TARGET_ALIGNMENT (dr_info); |
| |
| if (LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) > 0) |
| { |
| int npeel = LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo); |
| |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, |
| "known peeling = %d.\n", npeel); |
| |
| iters = build_int_cst (niters_type, npeel); |
| *bound = LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo); |
| } |
| else |
| { |
| tree misalign_in_elems = get_misalign_in_elems (&stmts, loop_vinfo); |
| tree type = TREE_TYPE (misalign_in_elems); |
| HOST_WIDE_INT elem_size |
| = int_cst_value (TYPE_SIZE_UNIT (TREE_TYPE (vectype))); |
| /* We only do prolog peeling if the target alignment is known at compile |
| time. */ |
| poly_uint64 align_in_elems = |
| exact_div (target_align, elem_size); |
| tree align_in_elems_minus_1 = |
| build_int_cst (type, align_in_elems - 1); |
| tree align_in_elems_tree = build_int_cst (type, align_in_elems); |
| |
| /* Create: (niters_type) ((align_in_elems - misalign_in_elems) |
| & (align_in_elems - 1)). */ |
| bool negative = tree_int_cst_compare (DR_STEP (dr_info->dr), |
| size_zero_node) < 0; |
| if (negative) |
| iters = fold_build2 (MINUS_EXPR, type, misalign_in_elems, |
| align_in_elems_tree); |
| else |
| iters = fold_build2 (MINUS_EXPR, type, align_in_elems_tree, |
| misalign_in_elems); |
| iters = fold_build2 (BIT_AND_EXPR, type, iters, align_in_elems_minus_1); |
| iters = fold_convert (niters_type, iters); |
| unsigned HOST_WIDE_INT align_in_elems_c; |
| if (align_in_elems.is_constant (&align_in_elems_c)) |
| *bound = align_in_elems_c - 1; |
| else |
| *bound = -1; |
| } |
| |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, |
| "niters for prolog loop: %T\n", iters); |
| |
| var = create_tmp_var (niters_type, "prolog_loop_niters"); |
| iters_name = force_gimple_operand (iters, &new_stmts, false, var); |
| |
| if (new_stmts) |
| gimple_seq_add_seq (&stmts, new_stmts); |
| if (stmts) |
| { |
| gcc_assert (single_succ_p (bb)); |
| gimple_stmt_iterator gsi = gsi_last_bb (bb); |
| if (gsi_end_p (gsi)) |
| gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT); |
| else |
| gsi_insert_seq_after (&gsi, stmts, GSI_SAME_STMT); |
| } |
| return iters_name; |
| } |
| |
| |
| /* Function vect_update_init_of_dr |
| |
| If CODE is PLUS, the vector loop starts NITERS iterations after the |
| scalar one, otherwise CODE is MINUS and the vector loop starts NITERS |
| iterations before the scalar one (using masking to skip inactive |
| elements). This function updates the information recorded in DR to |
| account for the difference. Specifically, it updates the OFFSET |
| field of DR_INFO. */ |
| |
| static void |
| vect_update_init_of_dr (dr_vec_info *dr_info, tree niters, tree_code code) |
| { |
| struct data_reference *dr = dr_info->dr; |
| tree offset = dr_info->offset; |
| if (!offset) |
| offset = build_zero_cst (sizetype); |
| |
| niters = fold_build2 (MULT_EXPR, sizetype, |
| fold_convert (sizetype, niters), |
| fold_convert (sizetype, DR_STEP (dr))); |
| offset = fold_build2 (code, sizetype, |
| fold_convert (sizetype, offset), niters); |
| dr_info->offset = offset; |
| } |
| |
| |
| /* Function vect_update_inits_of_drs |
| |
| Apply vect_update_inits_of_dr to all accesses in LOOP_VINFO. |
| CODE and NITERS are as for vect_update_inits_of_dr. */ |
| |
| void |
| vect_update_inits_of_drs (loop_vec_info loop_vinfo, tree niters, |
| tree_code code) |
| { |
| unsigned int i; |
| vec<data_reference_p> datarefs = LOOP_VINFO_DATAREFS (loop_vinfo); |
| struct data_reference *dr; |
| |
| DUMP_VECT_SCOPE ("vect_update_inits_of_dr"); |
| |
| /* Adjust niters to sizetype. We used to insert the stmts on loop preheader |
| here, but since we might use these niters to update the epilogues niters |
| and data references we can't insert them here as this definition might not |
| always dominate its uses. */ |
| if (!types_compatible_p (sizetype, TREE_TYPE (niters))) |
| niters = fold_convert (sizetype, niters); |
| |
| FOR_EACH_VEC_ELT (datarefs, i, dr) |
| { |
| dr_vec_info *dr_info = loop_vinfo->lookup_dr (dr); |
| if (!STMT_VINFO_GATHER_SCATTER_P (dr_info->stmt) |
| && !STMT_VINFO_SIMD_LANE_ACCESS_P (dr_info->stmt)) |
| vect_update_init_of_dr (dr_info, niters, code); |
| } |
| } |
| |
| /* For the information recorded in LOOP_VINFO prepare the loop for peeling |
| by masking. This involves calculating the number of iterations to |
| be peeled and then aligning all memory references appropriately. */ |
| |
| void |
| vect_prepare_for_masked_peels (loop_vec_info loop_vinfo) |
| { |
| tree misalign_in_elems; |
| tree type = LOOP_VINFO_RGROUP_COMPARE_TYPE (loop_vinfo); |
| |
| gcc_assert (vect_use_loop_mask_for_alignment_p (loop_vinfo)); |
| |
| /* From the information recorded in LOOP_VINFO get the number of iterations |
| that need to be skipped via masking. */ |
| if (LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) > 0) |
| { |
| poly_int64 misalign = (LOOP_VINFO_VECT_FACTOR (loop_vinfo) |
| - LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo)); |
| misalign_in_elems = build_int_cst (type, misalign); |
| } |
| else |
| { |
| gimple_seq seq1 = NULL, seq2 = NULL; |
| misalign_in_elems = get_misalign_in_elems (&seq1, loop_vinfo); |
| misalign_in_elems = fold_convert (type, misalign_in_elems); |
| misalign_in_elems = force_gimple_operand (misalign_in_elems, |
| &seq2, true, NULL_TREE); |
| gimple_seq_add_seq (&seq1, seq2); |
| if (seq1) |
| { |
| edge pe = loop_preheader_edge (LOOP_VINFO_LOOP (loop_vinfo)); |
| basic_block new_bb = gsi_insert_seq_on_edge_immediate (pe, seq1); |
| gcc_assert (!new_bb); |
| } |
| } |
| |
| if (dump_enabled_p ()) |
| dump_printf_loc (MSG_NOTE, vect_location, |
| "misalignment for fully-masked loop: %T\n", |
| misalign_in_elems); |
| |
| LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo) = misalign_in_elems; |
| |
| vect_update_inits_of_drs (loop_vinfo, misalign_in_elems, MINUS_EXPR); |
| } |
| |
| /* This function builds ni_name = number of iterations. Statements |
| are emitted on the loop preheader edge. If NEW_VAR_P is not NULL, set |
| it to TRUE if new ssa_var is generated. */ |
| |
| tree |
| vect_build_loop_niters (loop_vec_info loop_vinfo, bool *new_var_p) |
| { |
| tree ni = unshare_expr (LOOP_VINFO_NITERS (loop_vinfo)); |
| if (TREE_CODE (ni) == INTEGER_CST) |
| return ni; |
| else |
| { |
| tree ni_name, var; |
| gimple_seq stmts = NULL; |
| edge pe = loop_preheader_edge (LOOP_VINFO_LOOP (loop_vinfo)); |
| |
| var = create_tmp_var (TREE_TYPE (ni), "niters"); |
| ni_name = force_gimple_operand (ni, &stmts, false, var); |
| if (stmts) |
| { |
| gsi_insert_seq_on_edge_immediate (pe, stmts); |
| if (new_var_p != NULL) |
| *new_var_p = true; |
| } |
| |
| return ni_name; |
| } |
| } |
| |
| /* Calculate the number of iterations above which vectorized loop will be |
| preferred than scalar loop. NITERS_PROLOG is the number of iterations |
| of prolog loop. If it's integer const, the integer number is also passed |
| in INT_NITERS_PROLOG. BOUND_PROLOG is the upper bound (inclusive) of the |
| number of iterations of the prolog loop. BOUND_EPILOG is the corresponding |
| value for the epilog loop. If CHECK_PROFITABILITY is true, TH is the |
| threshold below which the scalar (rather than vectorized) loop will be |
| executed. This function stores the upper bound (inclusive) of the result |
| in BOUND_SCALAR. */ |
| |
| static tree |
| vect_gen_scalar_loop_niters (tree niters_prolog, int int_niters_prolog, |
| int bound_prolog, poly_int64 bound_epilog, int th, |
| poly_uint64 *bound_scalar, |
| bool check_profitability) |
| { |
| tree type = TREE_TYPE (niters_prolog); |
| tree niters = fold_build2 (PLUS_EXPR, type, niters_prolog, |
| build_int_cst (type, bound_epilog)); |
| |
| *bound_scalar = bound_prolog + bound_epilog; |
| if (check_profitability) |
| { |
| /* TH indicates the minimum niters of vectorized loop, while we |
| compute the maximum niters of scalar loop. */ |
| th--; |
| /* Peeling for constant times. */ |
| if (int_niters_prolog >= 0) |
| { |
| *bound_scalar = upper_bound (int_niters_prolog + bound_epilog, th); |
| return build_int_cst (type, *bound_scalar); |
| } |
| /* Peeling an unknown number of times. Note that both BOUND_PROLOG |
| and BOUND_EPILOG are inclusive upper bounds. */ |
| if (known_ge (th, bound_prolog + bound_epilog)) |
| { |
| *bound_scalar = th; |
| return build_int_cst (type, th); |
| } |
| /* Need to do runtime comparison. */ |
| else if (maybe_gt (th, bound_epilog)) |
| { |
| *bound_scalar = upper_bound (*bound_scalar, th); |
| return fold_build2 (MAX_EXPR, type, |
| build_int_cst (type, th), niters); |
| } |
| } |
| return niters; |
| } |
| |
| /* NITERS is the number of times that the original scalar loop executes |
| after peeling. Work out the maximum number of iterations N that can |
| be handled by the vectorized form of the loop and then either: |
| |
| a) set *STEP_VECTOR_PTR to the vectorization factor and generate: |
| |
| niters_vector = N |
| |
| b) set *STEP_VECTOR_PTR to one and generate: |
| |
| niters_vector = N / vf |
| |
| In both cases, store niters_vector in *NITERS_VECTOR_PTR and add |
| any new statements on the loop preheader edge. NITERS_NO_OVERFLOW |
| is true if NITERS doesn't overflow (i.e. if NITERS is always nonzero). */ |
| |
| void |
| vect_gen_vector_loop_niters (loop_vec_info loop_vinfo, tree niters, |
| tree *niters_vector_ptr, tree *step_vector_ptr, |
| bool niters_no_overflow) |
| { |
| tree ni_minus_gap, var; |
| tree niters_vector, step_vector, type = TREE_TYPE (niters); |
| poly_uint64 vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); |
| edge pe = loop_preheader_edge (LOOP_VINFO_LOOP (loop_vinfo)); |
| tree log_vf = NULL_TREE; |
| |
| /* If epilogue loop is required because of data accesses with gaps, we |
| subtract one iteration from the total number of iterations here for |
| correct calculation of RATIO. */ |
| if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)) |
| { |
| ni_minus_gap = fold_build2 (MINUS_EXPR, type, niters, |
| build_one_cst (type)); |
| if (!is_gimple_val (ni_minus_gap)) |
| { |
| var = create_tmp_var (type, "ni_gap"); |
| gimple *stmts = NULL; |
| ni_minus_gap = force_gimple_operand (ni_minus_gap, &stmts, |
| true, var); |
| gsi_insert_seq_on_edge_immediate (pe, stmts); |
| } |
| } |
| else |
| ni_minus_gap = niters; |
| |
| unsigned HOST_WIDE_INT const_vf; |
| if (vf.is_constant (&const_vf) |
| && !LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo)) |
| { |
| /* Create: niters >> log2(vf) */ |
| /* If it's known that niters == number of latch executions + 1 doesn't |
| overflow, we can generate niters >> log2(vf); otherwise we generate |
| (niters - vf) >> log2(vf) + 1 by using the fact that we know ratio |
| will be at least one. */ |
| log_vf = build_int_cst (type, exact_log2 (const_vf)); |
| if (niters_no_overflow) |
| niters_vector = fold_build2 (RSHIFT_EXPR, type, ni_minus_gap, log_vf); |
| else |
| niters_vector |
| = fold_build2 (PLUS_EXPR, type, |
| fold_build2 (RSHIFT_EXPR, type, |
| fold_build2 (MINUS_EXPR, type, |
| ni_minus_gap, |
| build_int_cst (type, vf)), |
| log_vf), |
| build_int_cst (type, 1)); |
| step_vector = build_one_cst (type); |
| } |
| else |
| { |
| niters_vector = ni_minus_gap; |
| step_vector = build_int_cst (type, vf); |
| } |
| |
| if (!is_gimple_val (niters_vector)) |
| { |
| var = create_tmp_var (type, "bnd"); |
| gimple_seq stmts = NULL; |
| niters_vector = force_gimple_operand (niters_vector, &stmts, true, var); |
| gsi_insert_seq_on_edge_immediate (pe, stmts); |
| /* Peeling algorithm guarantees that vector loop bound is at least ONE, |
| we set range information to make niters analyzer's life easier. |
| Note the number of latch iteration value can be TYPE_MAX_VALUE so |
| we have to represent the vector niter TYPE_MAX_VALUE + 1 >> log_vf. */ |
| if (stmts != NULL && log_vf) |
| { |
| if (niters_no_overflow) |
| set_range_info (niters_vector, VR_RANGE, |
| wi::one (TYPE_PRECISION (type)), |
| wi::rshift (wi::max_value (TYPE_PRECISION (type), |
| TYPE_SIGN (type)), |
| exact_log2 (const_vf), |
| TYPE_SIGN (type))); |
| /* For VF == 1 the vector IV might also overflow so we cannot |
| assert a minimum value of 1. */ |
| else if (const_vf > 1) |
| set_range_info (niters_vector, VR_RANGE, |
| wi::one (TYPE_PRECISION (type)), |
| wi::rshift (wi::max_value (TYPE_PRECISION (type), |
| TYPE_SIGN (type)) |
| - (const_vf - 1), |
| exact_log2 (const_vf), TYPE_SIGN (type)) |
| + 1); |
| } |
| } |
| *niters_vector_ptr = niters_vector; |
| *step_vector_ptr = step_vector; |
| |
| return; |
| } |
| |
| /* Given NITERS_VECTOR which is the number of iterations for vectorized |
| loop specified by LOOP_VINFO after vectorization, compute the number |
| of iterations before vectorization (niters_vector * vf) and store it |
| to NITERS_VECTOR_MULT_VF_PTR. */ |
| |
| static void |
| vect_gen_vector_loop_niters_mult_vf (loop_vec_info loop_vinfo, |
| tree niters_vector, |
| tree *niters_vector_mult_vf_ptr) |
| { |
| /* We should be using a step_vector of VF if VF is variable. */ |
| int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo).to_constant (); |
| class loop *loop = LOOP_VINFO_LOOP (loop_vinfo); |
| tree type = TREE_TYPE (niters_vector); |
| tree log_vf = build_int_cst (type, exact_log2 (vf)); |
| basic_block exit_bb = single_exit (loop)->dest; |
| |
| gcc_assert (niters_vector_mult_vf_ptr != NULL); |
| tree niters_vector_mult_vf = fold_build2 (LSHIFT_EXPR, type, |
| niters_vector, log_vf); |
| if (!is_gimple_val (niters_vector_mult_vf)) |
| { |
| tree var = create_tmp_var (type, "niters_vector_mult_vf"); |
| gimple_seq stmts = NULL; |
| niters_vector_mult_vf = force_gimple_operand (niters_vector_mult_vf, |
| &stmts, true, var); |
| gimple_stmt_iterator gsi = gsi_start_bb (exit_bb); |
| gsi_insert_seq_before (&gsi, stmts, GSI_SAME_STMT); |
| } |
| *niters_vector_mult_vf_ptr = niters_vector_mult_vf; |
| } |
| |
| /* LCSSA_PHI is a lcssa phi of EPILOG loop which is copied from LOOP, |
| this function searches for the corresponding lcssa phi node in exit |
| bb of LOOP. If it is found, return the phi result; otherwise return |
| NULL. */ |
| |
| static tree |
| find_guard_arg (class loop *loop, class loop *epilog ATTRIBUTE_UNUSED, |
| gphi *lcssa_phi) |
| { |
| gphi_iterator gsi; |
| edge e = single_exit (loop); |
| |
| gcc_assert (single_pred_p (e->dest)); |
| for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi)) |
| { |
| gphi *phi = gsi.phi (); |
| if (operand_equal_p (PHI_ARG_DEF (phi, 0), |
| PHI_ARG_DEF (lcssa_phi, 0), 0)) |
| return PHI_RESULT (phi); |
| } |
| return NULL_TREE; |
| } |
| |
| /* Function slpeel_tree_duplicate_loop_to_edge_cfg duplciates FIRST/SECOND |
| from SECOND/FIRST and puts it at the original loop's preheader/exit |
| edge, the two loops are arranged as below: |
| |
| preheader_a: |
| first_loop: |
| header_a: |
| i_1 = PHI<i_0, i_2>; |
| ... |
| i_2 = i_1 + 1; |
| if (cond_a) |
| goto latch_a; |
| else |
| goto between_bb; |
| latch_a: |
| goto header_a; |
| |
| between_bb: |
| ;; i_x = PHI<i_2>; ;; LCSSA phi node to be created for FIRST, |
| |
| second_loop: |
| header_b: |
| i_3 = PHI<i_0, i_4>; ;; Use of i_0 to be replaced with i_x, |
| or with i_2 if no LCSSA phi is created |
| under condition of CREATE_LCSSA_FOR_IV_PHIS. |
| ... |
| i_4 = i_3 + 1; |
| if (cond_b) |
| goto latch_b; |
| else |
| goto exit_bb; |
| latch_b: |
| goto header_b; |
| |
| exit_bb: |
| |
| This function creates loop closed SSA for the first loop; update the |
| second loop's PHI nodes by replacing argument on incoming edge with the |
| result of newly created lcssa PHI nodes. IF CREATE_LCSSA_FOR_IV_PHIS |
| is false, Loop closed ssa phis will only be created for non-iv phis for |
| the first loop. |
| |
| This function assumes exit bb of the first loop is preheader bb of the |
| second loop, i.e, between_bb in the example code. With PHIs updated, |
| the second loop will execute rest iterations of the first. */ |
| |
| static void |
| slpeel_update_phi_nodes_for_loops (loop_vec_info loop_vinfo, |
| class loop *first, class loop *second, |
| bool create_lcssa_for_iv_phis) |
| { |
| gphi_iterator gsi_update, gsi_orig; |
| class loop *loop = LOOP_VINFO_LOOP (loop_vinfo); |
| |
| edge first_latch_e = EDGE_SUCC (first->latch, 0); |
| edge second_preheader_e = loop_preheader_edge (second); |
| basic_block between_bb = single_exit (first)->dest; |
| |
| gcc_assert (between_bb == second_preheader_e->src); |
| gcc_assert (single_pred_p (between_bb) && single_succ_p (between_bb)); |
| /* Either the first loop or the second is the loop to be vectorized. */ |
| gcc_assert (loop == first || loop == second); |
| |
| for (gsi_orig = gsi_start_phis (first->header), |
| gsi_update = gsi_start_phis (second->header); |
| !gsi_end_p (gsi_orig) && !gsi_end_p (gsi_update); |
| gsi_next (&gsi_orig), gsi_next (&gsi_update)) |
| { |
| gphi *orig_phi = gsi_orig.phi (); |
| gphi *update_phi = gsi_update.phi (); |
| |
| tree arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, first_latch_e); |
| /* Generate lcssa PHI node for the first loop. */ |
| gphi *vect_phi = (loop == first) ? orig_phi : update_phi; |
| stmt_vec_info vect_phi_info = loop_vinfo->lookup_stmt (vect_phi); |
| if (create_lcssa_for_iv_phis || !iv_phi_p (vect_phi_info)) |
| { |
| tree new_res = copy_ssa_name (PHI_RESULT (orig_phi)); |
| gphi *lcssa_phi = create_phi_node (new_res, between_bb); |
| add_phi_arg (lcssa_phi, arg, single_exit (first), UNKNOWN_LOCATION); |
| arg = new_res; |
| } |
| |
| /* Update PHI node in the second loop by replacing arg on the loop's |
| incoming edge. */ |
| adjust_phi_and_debug_stmts (update_phi, second_preheader_e, arg); |
| } |
| |
| /* For epilogue peeling we have to make sure to copy all LC PHIs |
| for correct vectorization of live stmts. */ |
| if (loop == first) |
| { |
| basic_block orig_exit = single_exit (second)->dest; |
| for (gsi_orig = gsi_start_phis (orig_exit); |
| !gsi_end_p (gsi_orig); gsi_next (&gsi_orig)) |
| { |
| gphi *orig_phi = gsi_orig.phi (); |
| tree orig_arg = PHI_ARG_DEF (orig_phi, 0); |
| if (TREE_CODE (orig_arg) != SSA_NAME || virtual_operand_p (orig_arg)) |
| continue; |
| |
| /* Already created in the above loop. */ |
| if (find_guard_arg (first, second, orig_phi)) |
| continue; |
| |
| tree new_res = copy_ssa_name (orig_arg); |
| gphi *lcphi = create_phi_node (new_res, between_bb); |
| add_phi_arg (lcphi, orig_arg, single_exit (first), UNKNOWN_LOCATION); |
| } |
| } |
| } |
| |
| /* Function slpeel_add_loop_guard adds guard skipping from the beginning |
| of SKIP_LOOP to the beginning of UPDATE_LOOP. GUARD_EDGE and MERGE_EDGE |
| are two pred edges of the merge point before UPDATE_LOOP. The two loops |
| appear like below: |
| |
| guard_bb: |
| if (cond) |
| goto merge_bb; |
| else |
| goto skip_loop; |
| |
| skip_loop: |
| header_a: |
| i_1 = PHI<i_0, i_2>; |
| ... |
| i_2 = i_1 + 1; |
| if (cond_a) |
| goto latch_a; |
| else |
| goto exit_a; |
| latch_a: |
| goto header_a; |
| |
| exit_a: |
| i_5 = PHI<i_2>; |
| |
| merge_bb: |
| ;; PHI (i_x = PHI<i_0, i_5>) to be created at merge point. |
| |
| update_loop: |
| header_b: |
| i_3 = PHI<i_5, i_4>; ;; Use of i_5 to be replaced with i_x. |
| ... |
| i_4 = i_3 + 1; |
| if (cond_b) |
| goto latch_b; |
| else |
| goto exit_bb; |
| latch_b: |
| goto header_b; |
| |
| exit_bb: |
| |
| This function creates PHI nodes at merge_bb and replaces the use of i_5 |
| in the update_loop's PHI node with the result of new PHI result. */ |
| |
| static void |
| slpeel_update_phi_nodes_for_guard1 (class loop *skip_loop, |
| class loop *update_loop, |
| edge guard_edge, edge merge_edge) |
| { |
| location_t merge_loc, guard_loc; |
| edge orig_e = loop_preheader_edge (skip_loop); |
| edge update_e = loop_preheader_edge (update_loop); |
| gphi_iterator gsi_orig, gsi_update; |
| |
| for ((gsi_orig = gsi_start_phis (skip_loop->header), |
| gsi_update = gsi_start_phis (update_loop->header)); |
| !gsi_end_p (gsi_orig) && !gsi_end_p (gsi_update); |
| gsi_next (&gsi_orig), gsi_next (&gsi_update)) |
| { |
| gphi *orig_phi = gsi_orig.phi (); |
| gphi *update_phi = gsi_update.phi (); |
| |
| /* Generate new phi node at merge bb of the guard. */ |
| tree new_res = copy_ssa_name (PHI_RESULT (orig_phi)); |
| gphi *new_phi = create_phi_node (new_res, guard_edge->dest); |
| |
| /* Merge bb has two incoming edges: GUARD_EDGE and MERGE_EDGE. Set the |
| args in NEW_PHI for these edges. */ |
| tree merge_arg = PHI_ARG_DEF_FROM_EDGE (update_phi, update_e); |
| tree guard_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, orig_e); |
| merge_loc = gimple_phi_arg_location_from_edge (update_phi, update_e); |
| guard_loc = gimple_phi_arg_location_from_edge (orig_phi, orig_e); |
| add_phi_arg (new_phi, merge_arg, merge_edge, merge_loc); |
| add_phi_arg (new_phi, guard_arg, guard_edge, guard_loc); |
| |
| /* Update phi in UPDATE_PHI. */ |
| adjust_phi_and_debug_stmts (update_phi, update_e, new_res); |
| } |
| } |
| |
| /* LOOP and EPILOG are two consecutive loops in CFG and EPILOG is copied |
| from LOOP. Function slpeel_add_loop_guard adds guard skipping from a |
| point between the two loops to the end of EPILOG. Edges GUARD_EDGE |
| and MERGE_EDGE are the two pred edges of merge_bb at the end of EPILOG. |
| The CFG looks like: |
| |
| loop: |
| header_a: |
| i_1 = PHI<i_0, i_2>; |
| ... |
| i_2 = i_1 + 1; |
| if (cond_a) |
| goto latch_a; |
| else |
| goto exit_a; |
| latch_a: |
| goto header_a; |
| |
| exit_a: |
| |
| guard_bb: |
| if (cond) |
| goto merge_bb; |
| else |
| goto epilog_loop; |
| |
| ;; fall_through_bb |
| |
| epilog_loop: |
| header_b: |
| i_3 = PHI<i_2, i_4>; |
| ... |
| i_4 = i_3 + 1; |
| if (cond_b) |
| goto latch_b; |
| else |
| goto merge_bb; |
| latch_b: |
| goto header_b; |
| |
| merge_bb: |
| ; PHI node (i_y = PHI<i_2, i_4>) to be created at merge point. |
| |
| exit_bb: |
| i_x = PHI<i_4>; ;Use of i_4 to be replaced with i_y in merge_bb. |
| |
| For each name used out side EPILOG (i.e - for each name that has a lcssa |
| phi in exit_bb) we create a new PHI in merge_bb. The new PHI has two |
| args corresponding to GUARD_EDGE and MERGE_EDGE. Arg for MERGE_EDGE is |
| the arg of the original PHI in exit_bb, arg for GUARD_EDGE is defined |
| by LOOP and is found in the exit bb of LOOP. Arg of the original PHI |
| in exit_bb will also be updated. */ |
| |
| static void |
| slpeel_update_phi_nodes_for_guard2 (class loop *loop, class loop *epilog, |
| edge guard_edge, edge merge_edge) |
| { |
| gphi_iterator gsi; |
| basic_block merge_bb = guard_edge->dest; |
| |
| gcc_assert (single_succ_p (merge_bb)); |
| edge e = single_succ_edge (merge_bb); |
| basic_block exit_bb = e->dest; |
| gcc_assert (single_pred_p (exit_bb)); |
| gcc_assert (single_pred (exit_bb) == single_exit (epilog)->dest); |
| |
| for (gsi = gsi_start_phis (exit_bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
| { |
| gphi *update_phi = gsi.phi (); |
| tree old_arg = PHI_ARG_DEF (update_phi, 0); |
| |
| tree merge_arg = NULL_TREE; |
| |
| /* If the old argument is a SSA_NAME use its current_def. */ |
| if (TREE_CODE (old_arg) == SSA_NAME) |
| merge_arg = get_current_def (old_arg); |
| /* If it's a constant or doesn't have a current_def, just use the old |
| argument. */ |
| if (!merge_arg) |
| merge_arg = old_arg; |
| |
| tree guard_arg = find_guard_arg (loop, epilog, update_phi); |
| /* If the var is live after loop but not a reduction, we simply |
| use the old arg. */ |
| if (!guard_arg) |
| guard_arg = old_arg; |
| |
| /* Create new phi node in MERGE_BB: */ |
| tree new_res = copy_ssa_name (PHI_RESULT (update_phi)); |
| gphi *merge_phi = create_phi_node (new_res, merge_bb); |
| |
| /* MERGE_BB has two incoming edges: GUARD_EDGE and MERGE_EDGE, Set |
| the two PHI args in merge_phi for these edges. */ |
| add_phi_arg (merge_phi, merge_arg, merge_edge, UNKNOWN_LOCATION); |
| add_phi_arg (merge_phi, guard_arg, guard_edge, UNKNOWN_LOCATION); |
| |
| /* Update the original phi in exit_bb. */ |
| adjust_phi_and_debug_stmts (update_phi, e, new_res); |
| } |
| } |
| |
| /* EPILOG loop is duplicated from the original loop for vectorizing, |
| the arg of its loop closed ssa PHI needs to be updated. */ |
| |
| static void |
| slpeel_update_phi_nodes_for_lcssa (class loop *epilog) |
| { |
| gphi_iterator gsi; |
| basic_block exit_bb = single_exit (epilog)->dest; |
| |
| gcc_assert (single_pred_p (exit_bb)); |
| edge e = EDGE_PRED (exit_bb, 0); |
| for (gsi = gsi_start_phis (exit_bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
| rename_use_op (PHI_ARG_DEF_PTR_FROM_EDGE (gsi.phi (), e)); |
| } |
| |
| /* EPILOGUE_VINFO is an epilogue loop that we now know would need to |
| iterate exactly CONST_NITERS times. Make a final decision about |
| whether the epilogue loop should be used, returning true if so. */ |
| |
| static bool |
| vect_update_epilogue_niters (loop_vec_info epilogue_vinfo, |
| unsigned HOST_WIDE_INT const_niters) |
| { |
| /* Avoid wrap-around when computing const_niters - 1. Also reject |
| using an epilogue loop for a single scalar iteration, even if |
| we could in principle implement that using partial vectors. */ |
| unsigned int gap_niters = LOOP_VINFO_PEELING_FOR_GAPS (epilogue_vinfo); |
| if (const_niters <= gap_niters + 1) |
| return false; |
| |
| /* Install the number of iterations. */ |
| tree niters_type = TREE_TYPE (LOOP_VINFO_NITERS (epilogue_vinfo)); |
| tree niters_tree = build_int_cst (niters_type, const_niters); |
| tree nitersm1_tree = build_int_cst (niters_type, const_niters - 1); |
| |
| LOOP_VINFO_NITERS (epilogue_vinfo) = niters_tree; |
| LOOP_VINFO_NITERSM1 (epilogue_vinfo) = nitersm1_tree; |
| |
| /* Decide what to do if the number of epilogue iterations is not |
| a multiple of the epilogue loop's vectorization factor. */ |
| return vect_determine_partial_vectors_and_peeling (epilogue_vinfo, true); |
| } |
| |
| /* LOOP_VINFO is an epilogue loop whose corresponding main loop can be skipped. |
| Return a value that equals: |
| |
| - MAIN_LOOP_VALUE when LOOP_VINFO is entered from the main loop and |
| - SKIP_VALUE when the main loop is skipped. */ |
| |
| tree |
| vect_get_main_loop_result (loop_vec_info loop_vinfo, tree main_loop_value, |
| tree skip_value) |
| { |
| gcc_assert (loop_vinfo->main_loop_edge); |
| |
| tree phi_result = make_ssa_name (TREE_TYPE (main_loop_value)); |
| basic_block bb = loop_vinfo->main_loop_edge->dest; |
| gphi *new_phi = create_phi_node (phi_result, bb); |
| add_phi_arg (new_phi, main_loop_value, loop_vinfo->main_loop_edge, |
| UNKNOWN_LOCATION); |
| add_phi_arg (new_phi, skip_value, |
| loop_vinfo->skip_main_loop_edge, UNKNOWN_LOCATION); |
| return phi_result; |
| } |
| |
| /* Function vect_do_peeling. |
| |
| Input: |
| - LOOP_VINFO: Represent a loop to be vectorized, which looks like: |
| |
| preheader: |
| LOOP: |
| header_bb: |
| loop_body |
| if (exit_loop_cond) goto exit_bb |
| else goto header_bb |
| exit_bb: |
| |
| - NITERS: The number of iterations of the loop. |
| - NITERSM1: The number of iterations of the loop's latch. |
| - NITERS_NO_OVERFLOW: No overflow in computing NITERS. |
| - TH, CHECK_PROFITABILITY: Threshold of niters to vectorize loop if |
| CHECK_PROFITABILITY is true. |
| Output: |
| - *NITERS_VECTOR and *STEP_VECTOR describe how the main loop should |
| iterate after vectorization; see vect_set_loop_condition for details. |
| - *NITERS_VECTOR_MULT_VF_VAR is either null or an SSA name that |
| should be set to the number of scalar iterations handled by the |
| vector loop. The SSA name is only used on exit from the loop. |
| |
| This function peels prolog and epilog from the loop, adds guards skipping |
| PROLOG and EPILOG for various conditions. As a result, the changed CFG |
| would look like: |
| |
| guard_bb_1: |
| if (prefer_scalar_loop) goto merge_bb_1 |
| else goto guard_bb_2 |
| |
| guard_bb_2: |
| if (skip_prolog) goto merge_bb_2 |
| else goto prolog_preheader |
| |
| prolog_preheader: |
| PROLOG: |
| prolog_header_bb: |
| prolog_body |
| if (exit_prolog_cond) goto prolog_exit_bb |
| else goto prolog_header_bb |
| prolog_exit_bb: |
| |
| merge_bb_2: |
| |
| vector_preheader: |
| VECTOR LOOP: |
| vector_header_bb: |
| vector_body |
| if (exit_vector_cond) goto vector_exit_bb |
| else goto vector_header_bb |
| vector_exit_bb: |
| |
| guard_bb_3: |
| if (skip_epilog) goto merge_bb_3 |
| else goto epilog_preheader |
| |
| merge_bb_1: |
| |
| epilog_preheader: |
| EPILOG: |
| epilog_header_bb: |
| epilog_body |
| if (exit_epilog_cond) goto merge_bb_3 |
| else goto epilog_header_bb |
| |
| merge_bb_3: |
| |
| Note this function peels prolog and epilog only if it's necessary, |
| as well as guards. |
| This function returns the epilogue loop if a decision was made to vectorize |
| it, otherwise NULL. |
| |
| The analysis resulting in this epilogue loop's loop_vec_info was performed |
| in the same vect_analyze_loop call as the main loop's. At that time |
| vect_analyze_loop constructs a list of accepted loop_vec_info's for lower |
| vectorization factors than the main loop. This list is stored in the main |
| loop's loop_vec_info in the 'epilogue_vinfos' member. Everytime we decide to |
| vectorize the epilogue loop for a lower vectorization factor, the |
| loop_vec_info sitting at the top of the epilogue_vinfos list is removed, |
| updated and linked to the epilogue loop. This is later used to vectorize |
| the epilogue. The reason the loop_vec_info needs updating is that it was |
| constructed based on the original main loop, and the epilogue loop is a |
| copy of this loop, so all links pointing to statements in the original loop |
| need updating. Furthermore, these loop_vec_infos share the |
| data_reference's records, which will also need to be updated. |
| |
| TODO: Guard for prefer_scalar_loop should be emitted along with |
| versioning conditions if loop versioning is needed. */ |
| |
| |
| class loop * |
| vect_do_peeling (loop_vec_info loop_vinfo, tree niters, tree nitersm1, |
| tree *niters_vector, tree *step_vector, |
| tree *niters_vector_mult_vf_var, int th, |
| bool check_profitability, bool niters_no_overflow, |
| tree *advance) |
| { |
| edge e, guard_e; |
| tree type = TREE_TYPE (niters), guard_cond; |
| basic_block guard_bb, guard_to; |
| profile_probability prob_prolog, prob_vector, prob_epilog; |
| int estimated_vf; |
| int prolog_peeling = 0; |
| bool vect_epilogues = loop_vinfo->epilogue_vinfos.length () > 0; |
| bool vect_epilogues_updated_niters = false; |
| /* We currently do not support prolog peeling if the target alignment is not |
| known at compile time. 'vect_gen_prolog_loop_niters' depends on the |
| target alignment being constant. */ |
| dr_vec_info *dr_info = LOOP_VINFO_UNALIGNED_DR (loop_vinfo); |
| if (dr_info && !DR_TARGET_ALIGNMENT (dr_info).is_constant ()) |
| return NULL; |
| |
| if (!vect_use_loop_mask_for_alignment_p (loop_vinfo)) |
| prolog_peeling = LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo); |
| |
| poly_uint64 vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); |
| poly_uint64 bound_epilog = 0; |
| if (!LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo) |
| && LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo)) |
| bound_epilog += vf - 1; |
| if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)) |
| bound_epilog += 1; |
| bool epilog_peeling = maybe_ne (bound_epilog, 0U); |
| poly_uint64 bound_scalar = bound_epilog; |
| |
| if (!prolog_peeling && !epilog_peeling) |
| return NULL; |
| |
| /* Before doing any peeling make sure to reset debug binds outside of |
| the loop refering to defs not in LC SSA. */ |
| class loop *loop = LOOP_VINFO_LOOP (loop_vinfo); |
| for (unsigned i = 0; i < loop->num_nodes; ++i) |
| { |
| basic_block bb = LOOP_VINFO_BBS (loop_vinfo)[i]; |
| imm_use_iterator ui; |
| gimple *use_stmt; |
| for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
| gsi_next (&gsi)) |
| { |
| FOR_EACH_IMM_USE_STMT (use_stmt, ui, gimple_phi_result (gsi.phi ())) |
| if (gimple_debug_bind_p (use_stmt) |
| && loop != gimple_bb (use_stmt)->loop_father |
| && !flow_loop_nested_p (loop, |
| gimple_bb (use_stmt)->loop_father)) |
| { |
| gimple_debug_bind_reset_value (use_stmt); |
| update_stmt (use_stmt); |
| } |
| } |
| for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); |
| gsi_next (&gsi)) |
| { |
| ssa_op_iter op_iter; |
| def_operand_p def_p; |
| FOR_EACH_SSA_DEF_OPERAND (def_p, gsi_stmt (gsi), op_iter, SSA_OP_DEF) |
| FOR_EACH_IMM_USE_STMT (use_stmt, ui, DEF_FROM_PTR (def_p)) |
| if (gimple_debug_bind_p (use_stmt) |
| && loop != gimple_bb (use_stmt)->loop_father |
| && !flow_loop_nested_p (loop, |
| gimple_bb (use_stmt)->loop_father)) |
| { |
| gimple_debug_bind_reset_value (use_stmt); |
| update_stmt (use_stmt); |
| } |
| } |
| } |
| |
| prob_vector = profile_probability::guessed_always ().apply_scale (9, 10); |
| estimated_vf = vect_vf_for_cost (loop_vinfo); |
| if (estimated_vf == 2) |
| estimated_vf = 3; |
| prob_prolog = prob_epilog = profile_probability::guessed_always () |
| .apply_scale (estimated_vf - 1, estimated_vf); |
| |
| class loop *prolog, *epilog = NULL; |
| class loop *first_loop = loop; |
| bool irred_flag = loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP; |
| |
| /* We might have a queued need to update virtual SSA form. As we |
| delete the update SSA machinery below after doing a regular |
| incremental SSA update during loop copying make sure we don't |
| lose that fact. |
| ??? Needing to update virtual SSA form by renaming is unfortunate |
| but not all of the vectorizer code inserting new loads / stores |
| properly assigns virtual operands to those statements. */ |
| update_ssa (TODO_update_ssa_only_virtuals); |
| |
| create_lcssa_for_virtual_phi (loop); |
| |
| /* If we're vectorizing an epilogue loop, the update_ssa above will |
| have ensured that the virtual operand is in SSA form throughout the |
| vectorized main loop. Normally it is possible to trace the updated |
| vector-stmt vdefs back to scalar-stmt vdefs and vector-stmt vuses |
| back to scalar-stmt vuses, meaning that the effect of the SSA update |
| remains local to the main loop. However, there are rare cases in |
| which the vectorized loop has vdefs even when the original scalar |
| loop didn't. For example, vectorizing a load with IFN_LOAD_LANES |
| introduces clobbers of the temporary vector array, which in turn |
| needs new vdefs. If the scalar loop doesn't write to memory, these |
| new vdefs will be the only ones in the vector loop. |
| |
| In that case, update_ssa will have added a new virtual phi to the |
| main loop, which previously didn't need one. Ensure that we (locally) |
| maintain LCSSA form for the virtual operand, just as we would have |
| done if the virtual phi had existed from the outset. This makes it |
| easier to duplicate the scalar epilogue loop below. */ |
| tree vop_to_rename = NULL_TREE; |
| if (loop_vec_info orig_loop_vinfo = LOOP_VINFO_ORIG_LOOP_INFO (loop_vinfo)) |
| { |
| class loop *orig_loop = LOOP_VINFO_LOOP (orig_loop_vinfo); |
| vop_to_rename = create_lcssa_for_virtual_phi (orig_loop); |
| } |
| |
| if (MAY_HAVE_DEBUG_BIND_STMTS) |
| { |
| gcc_assert (!adjust_vec.exists ()); |
| adjust_vec.create (32); |
| } |
| initialize_original_copy_tables (); |
| |
| /* Record the anchor bb at which the guard should be placed if the scalar |
| loop might be preferred. */ |
| basic_block anchor = loop_preheader_edge (loop)->src; |
| |
| /* Generate the number of iterations for the prolog loop. We do this here |
| so that we can also get the upper bound on the number of iterations. */ |
| tree niters_prolog; |
| int bound_prolog = 0; |
| if (prolog_peeling) |
| niters_prolog = vect_gen_prolog_loop_niters (loop_vinfo, anchor, |
| &bound_prolog); |
| else |
| niters_prolog = build_int_cst (type, 0); |
| |
| loop_vec_info epilogue_vinfo = NULL; |
| if (vect_epilogues) |
| { |
| epilogue_vinfo = loop_vinfo->epilogue_vinfos[0]; |
| loop_vinfo->epilogue_vinfos.ordered_remove (0); |
| } |
| |
| tree niters_vector_mult_vf = NULL_TREE; |
| /* Saving NITERs before the loop, as this may be changed by prologue. */ |
| tree before_loop_niters = LOOP_VINFO_NITERS (loop_vinfo); |
| edge update_e = NULL, skip_e = NULL; |
| unsigned int lowest_vf = constant_lower_bound (vf); |
| /* If we know the number of scalar iterations for the main loop we should |
| check whether after the main loop there are enough iterations left over |
| for the epilogue. */ |
| if (vect_epilogues |
| && LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) |
| && prolog_peeling >= 0 |
| && known_eq (vf, lowest_vf)) |
| { |
| unsigned HOST_WIDE_INT eiters |
| = (LOOP_VINFO_INT_NITERS (loop_vinfo) |
| - LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)); |
| |
| eiters -= prolog_peeling; |
| eiters |
| = eiters % lowest_vf + LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo); |
| |
| while (!vect_update_epilogue_niters (epilogue_vinfo, eiters)) |
| { |
| delete epilogue_vinfo; |
| epilogue_vinfo = NULL; |
| if (loop_vinfo->epilogue_vinfos.length () == 0) |
| { |
| vect_epilogues = false; |
| break; |
| } |
| epilogue_vinfo = loop_vinfo->epilogue_vinfos[0]; |
| loop_vinfo->epilogue_vinfos.ordered_remove (0); |
| } |
| vect_epilogues_updated_niters = true; |
| } |
| /* Prolog loop may be skipped. */ |
| bool skip_prolog = (prolog_peeling != 0); |
| /* Skip this loop to epilog when there are not enough iterations to enter this |
| vectorized loop. If true we should perform runtime checks on the NITERS |
| to check whether we should skip the current vectorized loop. If we know |
| the number of scalar iterations we may choose to add a runtime check if |
| this number "maybe" smaller than the number of iterations required |
| when we know the number of scalar iterations may potentially |
| be smaller than the number of iterations required to enter this loop, for |
| this we use the upper bounds on the prolog and epilog peeling. When we |
| don't know the number of iterations and don't require versioning it is |
| because we have asserted that there are enough scalar iterations to enter |
| the main loop, so this skip is not necessary. When we are versioning then |
| we only add such a skip if we have chosen to vectorize the epilogue. */ |
| bool skip_vector = (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) |
| ? maybe_lt (LOOP_VINFO_INT_NITERS (loop_vinfo), |
| bound_prolog + bound_epilog) |
| : (!LOOP_REQUIRES_VERSIONING (loop_vinfo) |
| || vect_epilogues)); |
| /* Epilog loop must be executed if the number of iterations for epilog |
| loop is known at compile time, otherwise we need to add a check at |
| the end of vector loop and skip to the end of epilog loop. */ |
| bool skip_epilog = (prolog_peeling < 0 |
| || !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) |
| || !vf.is_constant ()); |
| /* PEELING_FOR_GAPS is special because epilog loop must be executed. */ |
| if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)) |
| skip_epilog = false; |
| |
| if (skip_vector) |
| { |
| split_edge (loop_preheader_edge (loop)); |
| |
| /* Due to the order in which we peel prolog and epilog, we first |
| propagate probability to the whole loop. The purpose is to |
| avoid adjusting probabilities of both prolog and vector loops |
| separately. Note in this case, the probability of epilog loop |
| needs to be scaled back later. */ |
| basic_block bb_before_loop = loop_preheader_edge (loop)->src; |
| if (prob_vector.initialized_p ()) |
| { |
| scale_bbs_frequencies (&bb_before_loop, 1, prob_vector); |
| scale_loop_profile (loop, prob_vector, 0); |
| } |
| } |
| |
| dump_user_location_t loop_loc = find_loop_location (loop); |
| class loop *scalar_loop = LOOP_VINFO_SCALAR_LOOP (loop_vinfo); |
| if (vect_epilogues) |
| /* Make sure to set the epilogue's epilogue scalar loop, such that we can |
| use the original scalar loop as remaining epilogue if necessary. */ |
| LOOP_VINFO_SCALAR_LOOP (epilogue_vinfo) |
| = LOOP_VINFO_SCALAR_LOOP (loop_vinfo); |
| |
| if (prolog_peeling) |
| { |
| e = loop_preheader_edge (loop); |
| if (!slpeel_can_duplicate_loop_p (loop, e)) |
| { |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc, |
| "loop can't be duplicated to preheader edge.\n"); |
| gcc_unreachable (); |
| } |
| /* Peel prolog and put it on preheader edge of loop. */ |
| prolog = slpeel_tree_duplicate_loop_to_edge_cfg (loop, scalar_loop, e); |
| if (!prolog) |
| { |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc, |
| "slpeel_tree_duplicate_loop_to_edge_cfg failed.\n"); |
| gcc_unreachable (); |
| } |
| prolog->force_vectorize = false; |
| slpeel_update_phi_nodes_for_loops (loop_vinfo, prolog, loop, true); |
| first_loop = prolog; |
| reset_original_copy_tables (); |
| |
| /* Update the number of iterations for prolog loop. */ |
| tree step_prolog = build_one_cst (TREE_TYPE (niters_prolog)); |
| vect_set_loop_condition (prolog, NULL, niters_prolog, |
| step_prolog, NULL_TREE, false); |
| |
| /* Skip the prolog loop. */ |
| if (skip_prolog) |
| { |
| guard_cond = fold_build2 (EQ_EXPR, boolean_type_node, |
| niters_prolog, build_int_cst (type, 0)); |
| guard_bb = loop_preheader_edge (prolog)->src; |
| basic_block bb_after_prolog = loop_preheader_edge (loop)->src; |
| guard_to = split_edge (loop_preheader_edge (loop)); |
| guard_e = slpeel_add_loop_guard (guard_bb, guard_cond, |
| guard_to, guard_bb, |
| prob_prolog.invert (), |
| irred_flag); |
| e = EDGE_PRED (guard_to, 0); |
| e = (e != guard_e ? e : EDGE_PRED (guard_to, 1)); |
| slpeel_update_phi_nodes_for_guard1 (prolog, loop, guard_e, e); |
| |
| scale_bbs_frequencies (&bb_after_prolog, 1, prob_prolog); |
| scale_loop_profile (prolog, prob_prolog, bound_prolog); |
| } |
| |
| /* Update init address of DRs. */ |
| vect_update_inits_of_drs (loop_vinfo, niters_prolog, PLUS_EXPR); |
| /* Update niters for vector loop. */ |
| LOOP_VINFO_NITERS (loop_vinfo) |
| = fold_build2 (MINUS_EXPR, type, niters, niters_prolog); |
| LOOP_VINFO_NITERSM1 (loop_vinfo) |
| = fold_build2 (MINUS_EXPR, type, |
| LOOP_VINFO_NITERSM1 (loop_vinfo), niters_prolog); |
| bool new_var_p = false; |
| niters = vect_build_loop_niters (loop_vinfo, &new_var_p); |
| /* It's guaranteed that vector loop bound before vectorization is at |
| least VF, so set range information for newly generated var. */ |
| if (new_var_p) |
| set_range_info (niters, VR_RANGE, |
| wi::to_wide (build_int_cst (type, vf)), |
| wi::to_wide (TYPE_MAX_VALUE (type))); |
| |
| /* Prolog iterates at most bound_prolog times, latch iterates at |
| most bound_prolog - 1 times. */ |
| record_niter_bound (prolog, bound_prolog - 1, false, true); |
| delete_update_ssa (); |
| adjust_vec_debug_stmts (); |
| scev_reset (); |
| } |
| |
| if (epilog_peeling) |
| { |
| e = single_exit (loop); |
| if (!slpeel_can_duplicate_loop_p (loop, e)) |
| { |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc, |
| "loop can't be duplicated to exit edge.\n"); |
| gcc_unreachable (); |
| } |
| /* Peel epilog and put it on exit edge of loop. If we are vectorizing |
| said epilog then we should use a copy of the main loop as a starting |
| point. This loop may have already had some preliminary transformations |
| to allow for more optimal vectorization, for example if-conversion. |
| If we are not vectorizing the epilog then we should use the scalar loop |
| as the transformations mentioned above make less or no sense when not |
| vectorizing. */ |
| epilog = vect_epilogues ? get_loop_copy (loop) : scalar_loop; |
| if (vop_to_rename) |
| { |
| /* Vectorizing the main loop can sometimes introduce a vdef to |
| a loop that previously didn't have one; see the comment above |
| the definition of VOP_TO_RENAME for details. The definition |
| D that holds on E will then be different from the definition |
| VOP_TO_RENAME that holds during SCALAR_LOOP, so we need to |
| rename VOP_TO_RENAME to D when copying the loop. |
| |
| The virtual operand is in LCSSA form for the main loop, |
| and no stmt between the main loop and E needs a vdef, |
| so we know that D is provided by a phi rather than by a |
| vdef on a normal gimple stmt. */ |
| basic_block vdef_bb = e->src; |
| gphi *vphi; |
| while (!(vphi = get_virtual_phi (vdef_bb))) |
| vdef_bb = get_immediate_dominator (CDI_DOMINATORS, vdef_bb); |
| gcc_assert (vop_to_rename != gimple_phi_result (vphi)); |
| set_current_def (vop_to_rename, gimple_phi_result (vphi)); |
| } |
| epilog = slpeel_tree_duplicate_loop_to_edge_cfg (loop, epilog, e); |
| if (!epilog) |
| { |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, loop_loc, |
| "slpeel_tree_duplicate_loop_to_edge_cfg failed.\n"); |
| gcc_unreachable (); |
| } |
| epilog->force_vectorize = false; |
| slpeel_update_phi_nodes_for_loops (loop_vinfo, loop, epilog, false); |
| |
| /* Scalar version loop may be preferred. In this case, add guard |
| and skip to epilog. Note this only happens when the number of |
| iterations of loop is unknown at compile time, otherwise this |
| won't be vectorized. */ |
| if (skip_vector) |
| { |
| /* Additional epilogue iteration is peeled if gap exists. */ |
| tree t = vect_gen_scalar_loop_niters (niters_prolog, prolog_peeling, |
| bound_prolog, bound_epilog, |
| th, &bound_scalar, |
| check_profitability); |
| /* Build guard against NITERSM1 since NITERS may overflow. */ |
| guard_cond = fold_build2 (LT_EXPR, boolean_type_node, nitersm1, t); |
| guard_bb = anchor; |
| guard_to = split_edge (loop_preheader_edge (epilog)); |
| guard_e = slpeel_add_loop_guard (guard_bb, guard_cond, |
| guard_to, guard_bb, |
| prob_vector.invert (), |
| irred_flag); |
| skip_e = guard_e; |
| e = EDGE_PRED (guard_to, 0); |
| e = (e != guard_e ? e : EDGE_PRED (guard_to, 1)); |
| slpeel_update_phi_nodes_for_guard1 (first_loop, epilog, guard_e, e); |
| |
| /* Simply propagate profile info from guard_bb to guard_to which is |
| a merge point of control flow. */ |
| guard_to->count = guard_bb->count; |
| |
| /* Scale probability of epilog loop back. |
| FIXME: We should avoid scaling down and back up. Profile may |
| get lost if we scale down to 0. */ |
| basic_block *bbs = get_loop_body (epilog); |
| for (unsigned int i = 0; i < epilog->num_nodes; i++) |
| bbs[i]->count = bbs[i]->count.apply_scale |
| (bbs[i]->count, |
| bbs[i]->count.apply_probability |
| (prob_vector)); |
| free (bbs); |
| } |
| |
| basic_block bb_before_epilog = loop_preheader_edge (epilog)->src; |
| /* If loop is peeled for non-zero constant times, now niters refers to |
| orig_niters - prolog_peeling, it won't overflow even the orig_niters |
| overflows. */ |
| niters_no_overflow |= (prolog_peeling > 0); |
| vect_gen_vector_loop_niters (loop_vinfo, niters, |
| niters_vector, step_vector, |
| niters_no_overflow); |
| if (!integer_onep (*step_vector)) |
| { |
| /* On exit from the loop we will have an easy way of calcalating |
| NITERS_VECTOR / STEP * STEP. Install a dummy definition |
| until then. */ |
| niters_vector_mult_vf = make_ssa_name (TREE_TYPE (*niters_vector)); |
| SSA_NAME_DEF_STMT (niters_vector_mult_vf) = gimple_build_nop (); |
| *niters_vector_mult_vf_var = niters_vector_mult_vf; |
| } |
| else |
| vect_gen_vector_loop_niters_mult_vf (loop_vinfo, *niters_vector, |
| &niters_vector_mult_vf); |
| /* Update IVs of original loop as if they were advanced by |
| niters_vector_mult_vf steps. */ |
| gcc_checking_assert (vect_can_advance_ivs_p (loop_vinfo)); |
| update_e = skip_vector ? e : loop_preheader_edge (epilog); |
| vect_update_ivs_after_vectorizer (loop_vinfo, niters_vector_mult_vf, |
| update_e); |
| |
| if (skip_epilog) |
| { |
| guard_cond = fold_build2 (EQ_EXPR, boolean_type_node, |
| niters, niters_vector_mult_vf); |
| guard_bb = single_exit (loop)->dest; |
| guard_to = split_edge (single_exit (epilog)); |
| guard_e = slpeel_add_loop_guard (guard_bb, guard_cond, guard_to, |
| skip_vector ? anchor : guard_bb, |
| prob_epilog.invert (), |
| irred_flag); |
| if (vect_epilogues) |
| epilogue_vinfo->skip_this_loop_edge = guard_e; |
| slpeel_update_phi_nodes_for_guard2 (loop, epilog, guard_e, |
| single_exit (epilog)); |
| /* Only need to handle basic block before epilog loop if it's not |
| the guard_bb, which is the case when skip_vector is true. */ |
| if (guard_bb != bb_before_epilog) |
| { |
| prob_epilog = prob_vector * prob_epilog + prob_vector.invert (); |
| |
| scale_bbs_frequencies (&bb_before_epilog, 1, prob_epilog); |
| } |
| scale_loop_profile (epilog, prob_epilog, 0); |
| } |
| else |
| slpeel_update_phi_nodes_for_lcssa (epilog); |
| |
| unsigned HOST_WIDE_INT bound; |
| if (bound_scalar.is_constant (&bound)) |
| { |
| gcc_assert (bound != 0); |
| /* -1 to convert loop iterations to latch iterations. */ |
| record_niter_bound (epilog, bound - 1, false, true); |
| } |
| |
| delete_update_ssa (); |
| adjust_vec_debug_stmts (); |
| scev_reset (); |
| } |
| |
| if (vect_epilogues) |
| { |
| epilog->aux = epilogue_vinfo; |
| LOOP_VINFO_LOOP (epilogue_vinfo) = epilog; |
| |
| loop_constraint_clear (epilog, LOOP_C_INFINITE); |
| |
| /* We now must calculate the number of NITERS performed by the previous |
| loop and EPILOGUE_NITERS to be performed by the epilogue. */ |
| tree niters = fold_build2 (PLUS_EXPR, TREE_TYPE (niters_vector_mult_vf), |
| niters_prolog, niters_vector_mult_vf); |
| |
| /* If skip_vector we may skip the previous loop, we insert a phi-node to |
| determine whether we are coming from the previous vectorized loop |
| using the update_e edge or the skip_vector basic block using the |
| skip_e edge. */ |
| if (skip_vector) |
| { |
| gcc_assert (update_e != NULL |
| && skip_e != NULL |
| && !vect_epilogues_updated_niters); |
| gphi *new_phi = create_phi_node (make_ssa_name (TREE_TYPE (niters)), |
| update_e->dest); |
| tree new_ssa = make_ssa_name (TREE_TYPE (niters)); |
| gimple *stmt = gimple_build_assign (new_ssa, niters); |
| gimple_stmt_iterator gsi; |
| if (TREE_CODE (niters_vector_mult_vf) == SSA_NAME |
| && SSA_NAME_DEF_STMT (niters_vector_mult_vf)->bb != NULL) |
| { |
| gsi = gsi_for_stmt (SSA_NAME_DEF_STMT (niters_vector_mult_vf)); |
| gsi_insert_after (&gsi, stmt, GSI_NEW_STMT); |
| } |
| else |
| { |
| gsi = gsi_last_bb (update_e->src); |
| gsi_insert_before (&gsi, stmt, GSI_NEW_STMT); |
| } |
| |
| niters = new_ssa; |
| add_phi_arg (new_phi, niters, update_e, UNKNOWN_LOCATION); |
| add_phi_arg (new_phi, build_zero_cst (TREE_TYPE (niters)), skip_e, |
| UNKNOWN_LOCATION); |
| niters = PHI_RESULT (new_phi); |
| epilogue_vinfo->main_loop_edge = update_e; |
| epilogue_vinfo->skip_main_loop_edge = skip_e; |
| } |
| |
| /* Set ADVANCE to the number of iterations performed by the previous |
| loop and its prologue. */ |
| *advance = niters; |
| |
| if (!vect_epilogues_updated_niters) |
| { |
| /* Subtract the number of iterations performed by the vectorized loop |
| from the number of total iterations. */ |
| tree epilogue_niters = fold_build2 (MINUS_EXPR, TREE_TYPE (niters), |
| before_loop_niters, |
| niters); |
| |
| LOOP_VINFO_NITERS (epilogue_vinfo) = epilogue_niters; |
| LOOP_VINFO_NITERSM1 (epilogue_vinfo) |
| = fold_build2 (MINUS_EXPR, TREE_TYPE (epilogue_niters), |
| epilogue_niters, |
| build_one_cst (TREE_TYPE (epilogue_niters))); |
| |
| /* Decide what to do if the number of epilogue iterations is not |
| a multiple of the epilogue loop's vectorization factor. |
| We should have rejected the loop during the analysis phase |
| if this fails. */ |
| if (!vect_determine_partial_vectors_and_peeling (epilogue_vinfo, |
| true)) |
| gcc_unreachable (); |
| } |
| } |
| |
| adjust_vec.release (); |
| free_original_copy_tables (); |
| |
| return vect_epilogues ? epilog : NULL; |
| } |
| |
| /* Function vect_create_cond_for_niters_checks. |
| |
| Create a conditional expression that represents the run-time checks for |
| loop's niter. The loop is guaranteed to terminate if the run-time |
| checks hold. |
| |
| Input: |
| COND_EXPR - input conditional expression. New conditions will be chained |
| with logical AND operation. If it is NULL, then the function |
| is used to return the number of alias checks. |
| LOOP_VINFO - field LOOP_VINFO_MAY_ALIAS_STMTS contains the list of ddrs |
| to be checked. |
| |
| Output: |
| COND_EXPR - conditional expression. |
| |
| The returned COND_EXPR is the conditional expression to be used in the |
| if statement that controls which version of the loop gets executed at |
| runtime. */ |
| |
| static void |
| vect_create_cond_for_niters_checks (loop_vec_info loop_vinfo, tree *cond_expr) |
| { |
| tree part_cond_expr = LOOP_VINFO_NITERS_ASSUMPTIONS (loop_vinfo); |
| |
| if (*cond_expr) |
| *cond_expr = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, |
| *cond_expr, part_cond_expr); |
| else |
| *cond_expr = part_cond_expr; |
| } |
| |
| /* Set *COND_EXPR to a tree that is true when both the original *COND_EXPR |
| and PART_COND_EXPR are true. Treat a null *COND_EXPR as "true". */ |
| |
| static void |
| chain_cond_expr (tree *cond_expr, tree part_cond_expr) |
| { |
| if (*cond_expr) |
| *cond_expr = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, |
| *cond_expr, part_cond_expr); |
| else |
| *cond_expr = part_cond_expr; |
| } |
| |
| /* Function vect_create_cond_for_align_checks. |
| |
| Create a conditional expression that represents the alignment checks for |
| all of data references (array element references) whose alignment must be |
| checked at runtime. |
| |
| Input: |
| COND_EXPR - input conditional expression. New conditions will be chained |
| with logical AND operation. |
| LOOP_VINFO - two fields of the loop information are used. |
| LOOP_VINFO_PTR_MASK is the mask used to check the alignment. |
| LOOP_VINFO_MAY_MISALIGN_STMTS contains the refs to be checked. |
| |
| Output: |
| COND_EXPR_STMT_LIST - statements needed to construct the conditional |
| expression. |
| The returned value is the conditional expression to be used in the if |
| statement that controls which version of the loop gets executed at runtime. |
| |
| The algorithm makes two assumptions: |
| 1) The number of bytes "n" in a vector is a power of 2. |
| 2) An address "a" is aligned if a%n is zero and that this |
| test can be done as a&(n-1) == 0. For example, for 16 |
| byte vectors the test is a&0xf == 0. */ |
| |
| static void |
| vect_create_cond_for_align_checks (loop_vec_info loop_vinfo, |
| tree *cond_expr, |
| gimple_seq *cond_expr_stmt_list) |
| { |
| const vec<stmt_vec_info> &may_misalign_stmts |
| = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo); |
| stmt_vec_info stmt_info; |
| int mask = LOOP_VINFO_PTR_MASK (loop_vinfo); |
| tree mask_cst; |
| unsigned int i; |
| tree int_ptrsize_type; |
| char tmp_name[20]; |
| tree or_tmp_name = NULL_TREE; |
| tree and_tmp_name; |
| gimple *and_stmt; |
| tree ptrsize_zero; |
| tree part_cond_expr; |
| |
| /* Check that mask is one less than a power of 2, i.e., mask is |
| all zeros followed by all ones. */ |
| gcc_assert ((mask != 0) && ((mask & (mask+1)) == 0)); |
| |
| int_ptrsize_type = signed_type_for (ptr_type_node); |
| |
| /* Create expression (mask & (dr_1 || ... || dr_n)) where dr_i is the address |
| of the first vector of the i'th data reference. */ |
| |
| FOR_EACH_VEC_ELT (may_misalign_stmts, i, stmt_info) |
| { |
| gimple_seq new_stmt_list = NULL; |
| tree addr_base; |
| tree addr_tmp_name; |
| tree new_or_tmp_name; |
| gimple *addr_stmt, *or_stmt; |
| tree vectype = STMT_VINFO_VECTYPE (stmt_info); |
| bool negative = tree_int_cst_compare |
| (DR_STEP (STMT_VINFO_DATA_REF (stmt_info)), size_zero_node) < 0; |
| tree offset = negative |
| ? size_int ((-TYPE_VECTOR_SUBPARTS (vectype) + 1) |
| * TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (vectype)))) |
| : size_zero_node; |
| |
| /* create: addr_tmp = (int)(address_of_first_vector) */ |
| addr_base = |
| vect_create_addr_base_for_vector_ref (loop_vinfo, |
| stmt_info, &new_stmt_list, |
| offset); |
| if (new_stmt_list != NULL) |
| gimple_seq_add_seq (cond_expr_stmt_list, new_stmt_list); |
| |
| sprintf (tmp_name, "addr2int%d", i); |
| addr_tmp_name = make_temp_ssa_name (int_ptrsize_type, NULL, tmp_name); |
| addr_stmt = gimple_build_assign (addr_tmp_name, NOP_EXPR, addr_base); |
| gimple_seq_add_stmt (cond_expr_stmt_list, addr_stmt); |
| |
| /* The addresses are OR together. */ |
| |
| if (or_tmp_name != NULL_TREE) |
| { |
| /* create: or_tmp = or_tmp | addr_tmp */ |
| sprintf (tmp_name, "orptrs%d", i); |
| new_or_tmp_name = make_temp_ssa_name (int_ptrsize_type, NULL, tmp_name); |
| or_stmt = gimple_build_assign (new_or_tmp_name, BIT_IOR_EXPR, |
| or_tmp_name, addr_tmp_name); |
| gimple_seq_add_stmt (cond_expr_stmt_list, or_stmt); |
| or_tmp_name = new_or_tmp_name; |
| } |
| else |
| or_tmp_name = addr_tmp_name; |
| |
| } /* end for i */ |
| |
| |