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Diffstat (limited to 'contrib/gcc/tree-vect-transform.c')
| -rw-r--r-- | contrib/gcc/tree-vect-transform.c | 3138 |
1 files changed, 3138 insertions, 0 deletions
diff --git a/contrib/gcc/tree-vect-transform.c b/contrib/gcc/tree-vect-transform.c new file mode 100644 index 0000000..14d3cc5 --- /dev/null +++ b/contrib/gcc/tree-vect-transform.c @@ -0,0 +1,3138 @@ +/* Transformation Utilities for Loop Vectorization. + Copyright (C) 2003,2004,2005,2006 Free Software Foundation, Inc. + Contributed by Dorit Naishlos <dorit@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 2, 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 COPYING. If not, write to the Free +Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "ggc.h" +#include "tree.h" +#include "target.h" +#include "rtl.h" +#include "basic-block.h" +#include "diagnostic.h" +#include "tree-flow.h" +#include "tree-dump.h" +#include "timevar.h" +#include "cfgloop.h" +#include "expr.h" +#include "optabs.h" +#include "recog.h" +#include "tree-data-ref.h" +#include "tree-chrec.h" +#include "tree-scalar-evolution.h" +#include "tree-vectorizer.h" +#include "langhooks.h" +#include "tree-pass.h" +#include "toplev.h" +#include "real.h" + +/* Utility functions for the code transformation. */ +static bool vect_transform_stmt (tree, block_stmt_iterator *); +static void vect_align_data_ref (tree); +static tree vect_create_destination_var (tree, tree); +static tree vect_create_data_ref_ptr + (tree, block_stmt_iterator *, tree, tree *, bool); +static tree vect_create_addr_base_for_vector_ref (tree, tree *, tree); +static tree vect_get_new_vect_var (tree, enum vect_var_kind, const char *); +static tree vect_get_vec_def_for_operand (tree, tree, tree *); +static tree vect_init_vector (tree, tree); +static void vect_finish_stmt_generation + (tree stmt, tree vec_stmt, block_stmt_iterator *bsi); +static bool vect_is_simple_cond (tree, loop_vec_info); +static void update_vuses_to_preheader (tree, struct loop*); +static void vect_create_epilog_for_reduction (tree, tree, enum tree_code, tree); +static tree get_initial_def_for_reduction (tree, tree, tree *); + +/* Utility function dealing with loop peeling (not peeling itself). */ +static void vect_generate_tmps_on_preheader + (loop_vec_info, tree *, tree *, tree *); +static tree vect_build_loop_niters (loop_vec_info); +static void vect_update_ivs_after_vectorizer (loop_vec_info, tree, edge); +static tree vect_gen_niters_for_prolog_loop (loop_vec_info, tree); +static void vect_update_init_of_dr (struct data_reference *, tree niters); +static void vect_update_inits_of_drs (loop_vec_info, tree); +static void vect_do_peeling_for_alignment (loop_vec_info, struct loops *); +static void vect_do_peeling_for_loop_bound + (loop_vec_info, tree *, struct loops *); +static int vect_min_worthwhile_factor (enum tree_code); + + +/* Function vect_get_new_vect_var. + + Returns a name for a new variable. The current naming scheme appends the + prefix "vect_" or "vect_p" (depending on the value of VAR_KIND) to + the name of vectorizer generated variables, and appends that to NAME if + provided. */ + +static tree +vect_get_new_vect_var (tree type, enum vect_var_kind var_kind, const char *name) +{ + const char *prefix; + tree new_vect_var; + + switch (var_kind) + { + case vect_simple_var: + prefix = "vect_"; + break; + case vect_scalar_var: + prefix = "stmp_"; + break; + case vect_pointer_var: + prefix = "vect_p"; + break; + default: + gcc_unreachable (); + } + + if (name) + new_vect_var = create_tmp_var (type, concat (prefix, name, NULL)); + else + new_vect_var = create_tmp_var (type, prefix); + + return new_vect_var; +} + + +/* Function vect_create_addr_base_for_vector_ref. + + Create an expression that computes the address of the first memory location + that will be accessed for a data reference. + + Input: + STMT: The statement containing the data reference. + NEW_STMT_LIST: Must be initialized to NULL_TREE or a statement list. + OFFSET: Optional. If supplied, it is be added to the initial address. + + Output: + 1. Return an SSA_NAME whose value is the address of the memory location of + the first vector of the data reference. + 2. If new_stmt_list is not NULL_TREE after return then the caller must insert + these statement(s) which define the returned SSA_NAME. + + FORNOW: We are only handling array accesses with step 1. */ + +static tree +vect_create_addr_base_for_vector_ref (tree stmt, + tree *new_stmt_list, + tree offset) +{ + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); + tree data_ref_base = unshare_expr (DR_BASE_ADDRESS (dr)); + tree base_name = build_fold_indirect_ref (data_ref_base); + tree ref = DR_REF (dr); + tree scalar_type = TREE_TYPE (ref); + tree scalar_ptr_type = build_pointer_type (scalar_type); + tree vec_stmt; + tree new_temp; + tree addr_base, addr_expr; + tree dest, new_stmt; + tree base_offset = unshare_expr (DR_OFFSET (dr)); + tree init = unshare_expr (DR_INIT (dr)); + + /* Create base_offset */ + base_offset = size_binop (PLUS_EXPR, base_offset, init); + dest = create_tmp_var (TREE_TYPE (base_offset), "base_off"); + add_referenced_var (dest); + base_offset = force_gimple_operand (base_offset, &new_stmt, false, dest); + append_to_statement_list_force (new_stmt, new_stmt_list); + + if (offset) + { + tree tmp = create_tmp_var (TREE_TYPE (base_offset), "offset"); + add_referenced_var (tmp); + offset = fold_build2 (MULT_EXPR, TREE_TYPE (offset), offset, + DR_STEP (dr)); + base_offset = fold_build2 (PLUS_EXPR, TREE_TYPE (base_offset), + base_offset, offset); + base_offset = force_gimple_operand (base_offset, &new_stmt, false, tmp); + append_to_statement_list_force (new_stmt, new_stmt_list); + } + + /* base + base_offset */ + addr_base = fold_build2 (PLUS_EXPR, TREE_TYPE (data_ref_base), data_ref_base, + base_offset); + + /* addr_expr = addr_base */ + addr_expr = vect_get_new_vect_var (scalar_ptr_type, vect_pointer_var, + get_name (base_name)); + add_referenced_var (addr_expr); + vec_stmt = build2 (MODIFY_EXPR, void_type_node, addr_expr, addr_base); + new_temp = make_ssa_name (addr_expr, vec_stmt); + TREE_OPERAND (vec_stmt, 0) = new_temp; + append_to_statement_list_force (vec_stmt, new_stmt_list); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "created "); + print_generic_expr (vect_dump, vec_stmt, TDF_SLIM); + } + return new_temp; +} + + +/* Function vect_align_data_ref. + + Handle misalignment of a memory accesses. + + FORNOW: Can't handle misaligned accesses. + Make sure that the dataref is aligned. */ + +static void +vect_align_data_ref (tree stmt) +{ + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); + + /* FORNOW: can't handle misaligned accesses; + all accesses expected to be aligned. */ + gcc_assert (aligned_access_p (dr)); +} + + +/* Function vect_create_data_ref_ptr. + + Create a memory reference expression for vector access, to be used in a + vector load/store stmt. The reference is based on a new pointer to vector + type (vp). + + Input: + 1. STMT: a stmt that references memory. Expected to be of the form + MODIFY_EXPR <name, data-ref> or MODIFY_EXPR <data-ref, name>. + 2. BSI: block_stmt_iterator where new stmts can be added. + 3. OFFSET (optional): an offset to be added to the initial address accessed + by the data-ref in STMT. + 4. ONLY_INIT: indicate if vp is to be updated in the loop, or remain + pointing to the initial address. + + Output: + 1. Declare a new ptr to vector_type, and have it point to the base of the + data reference (initial addressed accessed by the data reference). + For example, for vector of type V8HI, the following code is generated: + + v8hi *vp; + vp = (v8hi *)initial_address; + + if OFFSET is not supplied: + initial_address = &a[init]; + if OFFSET is supplied: + initial_address = &a[init + OFFSET]; + + Return the initial_address in INITIAL_ADDRESS. + + 2. If ONLY_INIT is true, return the initial pointer. Otherwise, create + a data-reference in the loop based on the new vector pointer vp. This + new data reference will by some means be updated each iteration of + the loop. Return the pointer vp'. + + FORNOW: handle only aligned and consecutive accesses. */ + +static tree +vect_create_data_ref_ptr (tree stmt, + block_stmt_iterator *bsi ATTRIBUTE_UNUSED, + tree offset, tree *initial_address, bool only_init) +{ + tree base_name; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + tree vect_ptr_type; + tree vect_ptr; + tree tag; + tree new_temp; + tree vec_stmt; + tree new_stmt_list = NULL_TREE; + edge pe = loop_preheader_edge (loop); + basic_block new_bb; + tree vect_ptr_init; + struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); + + base_name = build_fold_indirect_ref (unshare_expr (DR_BASE_ADDRESS (dr))); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + tree data_ref_base = base_name; + fprintf (vect_dump, "create vector-pointer variable to type: "); + print_generic_expr (vect_dump, vectype, TDF_SLIM); + if (TREE_CODE (data_ref_base) == VAR_DECL) + fprintf (vect_dump, " vectorizing a one dimensional array ref: "); + else if (TREE_CODE (data_ref_base) == ARRAY_REF) + fprintf (vect_dump, " vectorizing a multidimensional array ref: "); + else if (TREE_CODE (data_ref_base) == COMPONENT_REF) + fprintf (vect_dump, " vectorizing a record based array ref: "); + else if (TREE_CODE (data_ref_base) == SSA_NAME) + fprintf (vect_dump, " vectorizing a pointer ref: "); + print_generic_expr (vect_dump, base_name, TDF_SLIM); + } + + /** (1) Create the new vector-pointer variable: **/ + + vect_ptr_type = build_pointer_type (vectype); + vect_ptr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var, + get_name (base_name)); + add_referenced_var (vect_ptr); + + + /** (2) Add aliasing information to the new vector-pointer: + (The points-to info (DR_PTR_INFO) may be defined later.) **/ + + tag = DR_MEMTAG (dr); + gcc_assert (tag); + + /* If tag is a variable (and NOT_A_TAG) than a new symbol memory + tag must be created with tag added to its may alias list. */ + if (!MTAG_P (tag)) + new_type_alias (vect_ptr, tag, DR_REF (dr)); + else + var_ann (vect_ptr)->symbol_mem_tag = tag; + + var_ann (vect_ptr)->subvars = DR_SUBVARS (dr); + + /** (3) Calculate the initial address the vector-pointer, and set + the vector-pointer to point to it before the loop: **/ + + /* Create: (&(base[init_val+offset]) in the loop preheader. */ + new_temp = vect_create_addr_base_for_vector_ref (stmt, &new_stmt_list, + offset); + pe = loop_preheader_edge (loop); + new_bb = bsi_insert_on_edge_immediate (pe, new_stmt_list); + gcc_assert (!new_bb); + *initial_address = new_temp; + + /* Create: p = (vectype *) initial_base */ + vec_stmt = fold_convert (vect_ptr_type, new_temp); + vec_stmt = build2 (MODIFY_EXPR, void_type_node, vect_ptr, vec_stmt); + vect_ptr_init = make_ssa_name (vect_ptr, vec_stmt); + TREE_OPERAND (vec_stmt, 0) = vect_ptr_init; + new_bb = bsi_insert_on_edge_immediate (pe, vec_stmt); + gcc_assert (!new_bb); + + + /** (4) Handle the updating of the vector-pointer inside the loop: **/ + + if (only_init) /* No update in loop is required. */ + { + /* Copy the points-to information if it exists. */ + if (DR_PTR_INFO (dr)) + duplicate_ssa_name_ptr_info (vect_ptr_init, DR_PTR_INFO (dr)); + return vect_ptr_init; + } + else + { + block_stmt_iterator incr_bsi; + bool insert_after; + tree indx_before_incr, indx_after_incr; + tree incr; + + standard_iv_increment_position (loop, &incr_bsi, &insert_after); + create_iv (vect_ptr_init, + fold_convert (vect_ptr_type, TYPE_SIZE_UNIT (vectype)), + NULL_TREE, loop, &incr_bsi, insert_after, + &indx_before_incr, &indx_after_incr); + incr = bsi_stmt (incr_bsi); + set_stmt_info (stmt_ann (incr), + new_stmt_vec_info (incr, loop_vinfo)); + + /* Copy the points-to information if it exists. */ + if (DR_PTR_INFO (dr)) + { + duplicate_ssa_name_ptr_info (indx_before_incr, DR_PTR_INFO (dr)); + duplicate_ssa_name_ptr_info (indx_after_incr, DR_PTR_INFO (dr)); + } + merge_alias_info (vect_ptr_init, indx_before_incr); + merge_alias_info (vect_ptr_init, indx_after_incr); + + return indx_before_incr; + } +} + + +/* Function vect_create_destination_var. + + Create a new temporary of type VECTYPE. */ + +static tree +vect_create_destination_var (tree scalar_dest, tree vectype) +{ + tree vec_dest; + const char *new_name; + tree type; + enum vect_var_kind kind; + + kind = vectype ? vect_simple_var : vect_scalar_var; + type = vectype ? vectype : TREE_TYPE (scalar_dest); + + gcc_assert (TREE_CODE (scalar_dest) == SSA_NAME); + + new_name = get_name (scalar_dest); + if (!new_name) + new_name = "var_"; + vec_dest = vect_get_new_vect_var (type, vect_simple_var, new_name); + add_referenced_var (vec_dest); + + return vec_dest; +} + + +/* Function vect_init_vector. + + Insert a new stmt (INIT_STMT) that initializes a new vector variable with + the vector elements of VECTOR_VAR. Return the DEF of INIT_STMT. It will be + used in the vectorization of STMT. */ + +static tree +vect_init_vector (tree stmt, tree vector_var) +{ + stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree new_var; + tree init_stmt; + tree vectype = STMT_VINFO_VECTYPE (stmt_vinfo); + tree vec_oprnd; + edge pe; + tree new_temp; + basic_block new_bb; + + new_var = vect_get_new_vect_var (vectype, vect_simple_var, "cst_"); + add_referenced_var (new_var); + + init_stmt = build2 (MODIFY_EXPR, vectype, new_var, vector_var); + new_temp = make_ssa_name (new_var, init_stmt); + TREE_OPERAND (init_stmt, 0) = new_temp; + + pe = loop_preheader_edge (loop); + new_bb = bsi_insert_on_edge_immediate (pe, init_stmt); + gcc_assert (!new_bb); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "created new init_stmt: "); + print_generic_expr (vect_dump, init_stmt, TDF_SLIM); + } + + vec_oprnd = TREE_OPERAND (init_stmt, 0); + return vec_oprnd; +} + + +/* Function vect_get_vec_def_for_operand. + + OP is an operand in STMT. This function returns a (vector) def that will be + used in the vectorized stmt for STMT. + + In the case that OP is an SSA_NAME which is defined in the loop, then + STMT_VINFO_VEC_STMT of the defining stmt holds the relevant def. + + In case OP is an invariant or constant, a new stmt that creates a vector def + needs to be introduced. */ + +static tree +vect_get_vec_def_for_operand (tree op, tree stmt, tree *scalar_def) +{ + tree vec_oprnd; + tree vec_stmt; + tree def_stmt; + stmt_vec_info def_stmt_info = NULL; + stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt); + tree vectype = STMT_VINFO_VECTYPE (stmt_vinfo); + int nunits = TYPE_VECTOR_SUBPARTS (vectype); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree vec_inv; + tree vec_cst; + tree t = NULL_TREE; + tree def; + int i; + enum vect_def_type dt; + bool is_simple_use; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "vect_get_vec_def_for_operand: "); + print_generic_expr (vect_dump, op, TDF_SLIM); + } + + is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt); + gcc_assert (is_simple_use); + if (vect_print_dump_info (REPORT_DETAILS)) + { + if (def) + { + fprintf (vect_dump, "def = "); + print_generic_expr (vect_dump, def, TDF_SLIM); + } + if (def_stmt) + { + fprintf (vect_dump, " def_stmt = "); + print_generic_expr (vect_dump, def_stmt, TDF_SLIM); + } + } + + switch (dt) + { + /* Case 1: operand is a constant. */ + case vect_constant_def: + { + if (scalar_def) + *scalar_def = op; + + /* Create 'vect_cst_ = {cst,cst,...,cst}' */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Create vector_cst. nunits = %d", nunits); + + for (i = nunits - 1; i >= 0; --i) + { + t = tree_cons (NULL_TREE, op, t); + } + vec_cst = build_vector (vectype, t); + return vect_init_vector (stmt, vec_cst); + } + + /* Case 2: operand is defined outside the loop - loop invariant. */ + case vect_invariant_def: + { + if (scalar_def) + *scalar_def = def; + + /* Create 'vec_inv = {inv,inv,..,inv}' */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Create vector_inv."); + + for (i = nunits - 1; i >= 0; --i) + { + t = tree_cons (NULL_TREE, def, t); + } + + /* FIXME: use build_constructor directly. */ + vec_inv = build_constructor_from_list (vectype, t); + return vect_init_vector (stmt, vec_inv); + } + + /* Case 3: operand is defined inside the loop. */ + case vect_loop_def: + { + if (scalar_def) + *scalar_def = def_stmt; + + /* Get the def from the vectorized stmt. */ + def_stmt_info = vinfo_for_stmt (def_stmt); + vec_stmt = STMT_VINFO_VEC_STMT (def_stmt_info); + gcc_assert (vec_stmt); + vec_oprnd = TREE_OPERAND (vec_stmt, 0); + return vec_oprnd; + } + + /* Case 4: operand is defined by a loop header phi - reduction */ + case vect_reduction_def: + { + gcc_assert (TREE_CODE (def_stmt) == PHI_NODE); + + /* Get the def before the loop */ + op = PHI_ARG_DEF_FROM_EDGE (def_stmt, loop_preheader_edge (loop)); + return get_initial_def_for_reduction (stmt, op, scalar_def); + } + + /* Case 5: operand is defined by loop-header phi - induction. */ + case vect_induction_def: + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "induction - unsupported."); + internal_error ("no support for induction"); /* FORNOW */ + } + + default: + gcc_unreachable (); + } +} + + +/* Function vect_finish_stmt_generation. + + Insert a new stmt. */ + +static void +vect_finish_stmt_generation (tree stmt, tree vec_stmt, block_stmt_iterator *bsi) +{ + bsi_insert_before (bsi, vec_stmt, BSI_SAME_STMT); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "add new stmt: "); + print_generic_expr (vect_dump, vec_stmt, TDF_SLIM); + } + + /* Make sure bsi points to the stmt that is being vectorized. */ + gcc_assert (stmt == bsi_stmt (*bsi)); + +#ifdef USE_MAPPED_LOCATION + SET_EXPR_LOCATION (vec_stmt, EXPR_LOCATION (stmt)); +#else + SET_EXPR_LOCUS (vec_stmt, EXPR_LOCUS (stmt)); +#endif +} + + +#define ADJUST_IN_EPILOG 1 + +/* Function get_initial_def_for_reduction + + Input: + STMT - a stmt that performs a reduction operation in the loop. + INIT_VAL - the initial value of the reduction variable + + Output: + SCALAR_DEF - a tree that holds a value to be added to the final result + of the reduction (used for "ADJUST_IN_EPILOG" - see below). + Return a vector variable, initialized according to the operation that STMT + performs. This vector will be used as the initial value of the + vector of partial results. + + Option1 ("ADJUST_IN_EPILOG"): Initialize the vector as follows: + add: [0,0,...,0,0] + mult: [1,1,...,1,1] + min/max: [init_val,init_val,..,init_val,init_val] + bit and/or: [init_val,init_val,..,init_val,init_val] + and when necessary (e.g. add/mult case) let the caller know + that it needs to adjust the result by init_val. + + Option2: Initialize the vector as follows: + add: [0,0,...,0,init_val] + mult: [1,1,...,1,init_val] + min/max: [init_val,init_val,...,init_val] + bit and/or: [init_val,init_val,...,init_val] + and no adjustments are needed. + + For example, for the following code: + + s = init_val; + for (i=0;i<n;i++) + s = s + a[i]; + + STMT is 's = s + a[i]', and the reduction variable is 's'. + For a vector of 4 units, we want to return either [0,0,0,init_val], + or [0,0,0,0] and let the caller know that it needs to adjust + the result at the end by 'init_val'. + + FORNOW: We use the "ADJUST_IN_EPILOG" scheme. + TODO: Use some cost-model to estimate which scheme is more profitable. +*/ + +static tree +get_initial_def_for_reduction (tree stmt, tree init_val, tree *scalar_def) +{ + stmt_vec_info stmt_vinfo = vinfo_for_stmt (stmt); + tree vectype = STMT_VINFO_VECTYPE (stmt_vinfo); + int nunits = GET_MODE_NUNITS (TYPE_MODE (vectype)); + int nelements; + enum tree_code code = TREE_CODE (TREE_OPERAND (stmt, 1)); + tree type = TREE_TYPE (init_val); + tree def; + tree vec, t = NULL_TREE; + bool need_epilog_adjust; + int i; + + gcc_assert (INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type)); + + switch (code) + { + case WIDEN_SUM_EXPR: + case DOT_PROD_EXPR: + case PLUS_EXPR: + if (INTEGRAL_TYPE_P (type)) + def = build_int_cst (type, 0); + else + def = build_real (type, dconst0); + +#ifdef ADJUST_IN_EPILOG + /* All the 'nunits' elements are set to 0. The final result will be + adjusted by 'init_val' at the loop epilog. */ + nelements = nunits; + need_epilog_adjust = true; +#else + /* 'nunits - 1' elements are set to 0; The last element is set to + 'init_val'. No further adjustments at the epilog are needed. */ + nelements = nunits - 1; + need_epilog_adjust = false; +#endif + break; + + case MIN_EXPR: + case MAX_EXPR: + def = init_val; + nelements = nunits; + need_epilog_adjust = false; + break; + + default: + gcc_unreachable (); + } + + for (i = nelements - 1; i >= 0; --i) + t = tree_cons (NULL_TREE, def, t); + + if (nelements == nunits - 1) + { + /* Set the last element of the vector. */ + t = tree_cons (NULL_TREE, init_val, t); + nelements += 1; + } + gcc_assert (nelements == nunits); + + if (TREE_CODE (init_val) == INTEGER_CST || TREE_CODE (init_val) == REAL_CST) + vec = build_vector (vectype, t); + else + vec = build_constructor_from_list (vectype, t); + + if (!need_epilog_adjust) + *scalar_def = NULL_TREE; + else + *scalar_def = init_val; + + return vect_init_vector (stmt, vec); +} + + +/* Function vect_create_epilog_for_reduction + + Create code at the loop-epilog to finalize the result of a reduction + computation. + + VECT_DEF is a vector of partial results. + REDUC_CODE is the tree-code for the epilog reduction. + STMT is the scalar reduction stmt that is being vectorized. + REDUCTION_PHI is the phi-node that carries the reduction computation. + + This function: + 1. Creates the reduction def-use cycle: sets the the arguments for + REDUCTION_PHI: + The loop-entry argument is the vectorized initial-value of the reduction. + The loop-latch argument is VECT_DEF - the vector of partial sums. + 2. "Reduces" the vector of partial results VECT_DEF into a single result, + by applying the operation specified by REDUC_CODE if available, or by + other means (whole-vector shifts or a scalar loop). + The function also creates a new phi node at the loop exit to preserve + loop-closed form, as illustrated below. + + The flow at the entry to this function: + + loop: + vec_def = phi <null, null> # REDUCTION_PHI + VECT_DEF = vector_stmt # vectorized form of STMT + s_loop = scalar_stmt # (scalar) STMT + loop_exit: + s_out0 = phi <s_loop> # (scalar) EXIT_PHI + use <s_out0> + use <s_out0> + + The above is transformed by this function into: + + loop: + vec_def = phi <vec_init, VECT_DEF> # REDUCTION_PHI + VECT_DEF = vector_stmt # vectorized form of STMT + s_loop = scalar_stmt # (scalar) STMT + loop_exit: + s_out0 = phi <s_loop> # (scalar) EXIT_PHI + v_out1 = phi <VECT_DEF> # NEW_EXIT_PHI + v_out2 = reduce <v_out1> + s_out3 = extract_field <v_out2, 0> + s_out4 = adjust_result <s_out3> + use <s_out4> + use <s_out4> +*/ + +static void +vect_create_epilog_for_reduction (tree vect_def, tree stmt, + enum tree_code reduc_code, tree reduction_phi) +{ + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + tree vectype; + enum machine_mode mode; + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + basic_block exit_bb; + tree scalar_dest; + tree scalar_type; + tree new_phi; + block_stmt_iterator exit_bsi; + tree vec_dest; + tree new_temp; + tree new_name; + tree epilog_stmt; + tree new_scalar_dest, exit_phi; + tree bitsize, bitpos, bytesize; + enum tree_code code = TREE_CODE (TREE_OPERAND (stmt, 1)); + tree scalar_initial_def; + tree vec_initial_def; + tree orig_name; + imm_use_iterator imm_iter; + use_operand_p use_p; + bool extract_scalar_result; + tree reduction_op; + tree orig_stmt; + tree use_stmt; + tree operation = TREE_OPERAND (stmt, 1); + int op_type; + + op_type = TREE_CODE_LENGTH (TREE_CODE (operation)); + reduction_op = TREE_OPERAND (operation, op_type-1); + vectype = get_vectype_for_scalar_type (TREE_TYPE (reduction_op)); + mode = TYPE_MODE (vectype); + + /*** 1. Create the reduction def-use cycle ***/ + + /* 1.1 set the loop-entry arg of the reduction-phi: */ + /* For the case of reduction, vect_get_vec_def_for_operand returns + the scalar def before the loop, that defines the initial value + of the reduction variable. */ + vec_initial_def = vect_get_vec_def_for_operand (reduction_op, stmt, + &scalar_initial_def); + add_phi_arg (reduction_phi, vec_initial_def, loop_preheader_edge (loop)); + + /* 1.2 set the loop-latch arg for the reduction-phi: */ + add_phi_arg (reduction_phi, vect_def, loop_latch_edge (loop)); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "transform reduction: created def-use cycle:"); + print_generic_expr (vect_dump, reduction_phi, TDF_SLIM); + fprintf (vect_dump, "\n"); + print_generic_expr (vect_dump, SSA_NAME_DEF_STMT (vect_def), TDF_SLIM); + } + + + /*** 2. Create epilog code + The reduction epilog code operates across the elements of the vector + of partial results computed by the vectorized loop. + The reduction epilog code consists of: + step 1: compute the scalar result in a vector (v_out2) + step 2: extract the scalar result (s_out3) from the vector (v_out2) + step 3: adjust the scalar result (s_out3) if needed. + + Step 1 can be accomplished using one the following three schemes: + (scheme 1) using reduc_code, if available. + (scheme 2) using whole-vector shifts, if available. + (scheme 3) using a scalar loop. In this case steps 1+2 above are + combined. + + The overall epilog code looks like this: + + s_out0 = phi <s_loop> # original EXIT_PHI + v_out1 = phi <VECT_DEF> # NEW_EXIT_PHI + v_out2 = reduce <v_out1> # step 1 + s_out3 = extract_field <v_out2, 0> # step 2 + s_out4 = adjust_result <s_out3> # step 3 + + (step 3 is optional, and step2 1 and 2 may be combined). + Lastly, the uses of s_out0 are replaced by s_out4. + + ***/ + + /* 2.1 Create new loop-exit-phi to preserve loop-closed form: + v_out1 = phi <v_loop> */ + + exit_bb = loop->single_exit->dest; + new_phi = create_phi_node (SSA_NAME_VAR (vect_def), exit_bb); + SET_PHI_ARG_DEF (new_phi, loop->single_exit->dest_idx, vect_def); + exit_bsi = bsi_start (exit_bb); + + /* 2.2 Get the relevant tree-code to use in the epilog for schemes 2,3 + (i.e. when reduc_code is not available) and in the final adjustment code + (if needed). Also get the original scalar reduction variable as + defined in the loop. In case STMT is a "pattern-stmt" (i.e. - it + represents a reduction pattern), the tree-code and scalar-def are + taken from the original stmt that the pattern-stmt (STMT) replaces. + Otherwise (it is a regular reduction) - the tree-code and scalar-def + are taken from STMT. */ + + orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info); + if (!orig_stmt) + { + /* Regular reduction */ + orig_stmt = stmt; + } + else + { + /* Reduction pattern */ + stmt_vec_info stmt_vinfo = vinfo_for_stmt (orig_stmt); + gcc_assert (STMT_VINFO_IN_PATTERN_P (stmt_vinfo)); + gcc_assert (STMT_VINFO_RELATED_STMT (stmt_vinfo) == stmt); + } + code = TREE_CODE (TREE_OPERAND (orig_stmt, 1)); + scalar_dest = TREE_OPERAND (orig_stmt, 0); + scalar_type = TREE_TYPE (scalar_dest); + new_scalar_dest = vect_create_destination_var (scalar_dest, NULL); + bitsize = TYPE_SIZE (scalar_type); + bytesize = TYPE_SIZE_UNIT (scalar_type); + + /* 2.3 Create the reduction code, using one of the three schemes described + above. */ + + if (reduc_code < NUM_TREE_CODES) + { + /*** Case 1: Create: + v_out2 = reduc_expr <v_out1> */ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Reduce using direct vector reduction."); + + vec_dest = vect_create_destination_var (scalar_dest, vectype); + epilog_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, + build1 (reduc_code, vectype, PHI_RESULT (new_phi))); + new_temp = make_ssa_name (vec_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_temp; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + + extract_scalar_result = true; + } + else + { + enum tree_code shift_code = 0; + bool have_whole_vector_shift = true; + int bit_offset; + int element_bitsize = tree_low_cst (bitsize, 1); + int vec_size_in_bits = tree_low_cst (TYPE_SIZE (vectype), 1); + tree vec_temp; + + if (vec_shr_optab->handlers[mode].insn_code != CODE_FOR_nothing) + shift_code = VEC_RSHIFT_EXPR; + else + have_whole_vector_shift = false; + + /* Regardless of whether we have a whole vector shift, if we're + emulating the operation via tree-vect-generic, we don't want + to use it. Only the first round of the reduction is likely + to still be profitable via emulation. */ + /* ??? It might be better to emit a reduction tree code here, so that + tree-vect-generic can expand the first round via bit tricks. */ + if (!VECTOR_MODE_P (mode)) + have_whole_vector_shift = false; + else + { + optab optab = optab_for_tree_code (code, vectype); + if (optab->handlers[mode].insn_code == CODE_FOR_nothing) + have_whole_vector_shift = false; + } + + if (have_whole_vector_shift) + { + /*** Case 2: Create: + for (offset = VS/2; offset >= element_size; offset/=2) + { + Create: va' = vec_shift <va, offset> + Create: va = vop <va, va'> + } */ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Reduce using vector shifts"); + + vec_dest = vect_create_destination_var (scalar_dest, vectype); + new_temp = PHI_RESULT (new_phi); + + for (bit_offset = vec_size_in_bits/2; + bit_offset >= element_bitsize; + bit_offset /= 2) + { + tree bitpos = size_int (bit_offset); + + epilog_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, + build2 (shift_code, vectype, new_temp, bitpos)); + new_name = make_ssa_name (vec_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_name; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + + epilog_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, + build2 (code, vectype, new_name, new_temp)); + new_temp = make_ssa_name (vec_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_temp; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + } + + extract_scalar_result = true; + } + else + { + tree rhs; + + /*** Case 3: Create: + s = extract_field <v_out2, 0> + for (offset = element_size; + offset < vector_size; + offset += element_size;) + { + Create: s' = extract_field <v_out2, offset> + Create: s = op <s, s'> + } */ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Reduce using scalar code. "); + + vec_temp = PHI_RESULT (new_phi); + vec_size_in_bits = tree_low_cst (TYPE_SIZE (vectype), 1); + rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp, bitsize, + bitsize_zero_node); + BIT_FIELD_REF_UNSIGNED (rhs) = TYPE_UNSIGNED (scalar_type); + epilog_stmt = build2 (MODIFY_EXPR, scalar_type, new_scalar_dest, rhs); + new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_temp; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + + for (bit_offset = element_bitsize; + bit_offset < vec_size_in_bits; + bit_offset += element_bitsize) + { + tree bitpos = bitsize_int (bit_offset); + tree rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp, bitsize, + bitpos); + + BIT_FIELD_REF_UNSIGNED (rhs) = TYPE_UNSIGNED (scalar_type); + epilog_stmt = build2 (MODIFY_EXPR, scalar_type, new_scalar_dest, + rhs); + new_name = make_ssa_name (new_scalar_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_name; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + + epilog_stmt = build2 (MODIFY_EXPR, scalar_type, new_scalar_dest, + build2 (code, scalar_type, new_name, new_temp)); + new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_temp; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + } + + extract_scalar_result = false; + } + } + + /* 2.4 Extract the final scalar result. Create: + s_out3 = extract_field <v_out2, bitpos> */ + + if (extract_scalar_result) + { + tree rhs; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "extract scalar result"); + + if (BYTES_BIG_ENDIAN) + bitpos = size_binop (MULT_EXPR, + bitsize_int (TYPE_VECTOR_SUBPARTS (vectype) - 1), + TYPE_SIZE (scalar_type)); + else + bitpos = bitsize_zero_node; + + rhs = build3 (BIT_FIELD_REF, scalar_type, new_temp, bitsize, bitpos); + BIT_FIELD_REF_UNSIGNED (rhs) = TYPE_UNSIGNED (scalar_type); + epilog_stmt = build2 (MODIFY_EXPR, scalar_type, new_scalar_dest, rhs); + new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_temp; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + } + + /* 2.4 Adjust the final result by the initial value of the reduction + variable. (When such adjustment is not needed, then + 'scalar_initial_def' is zero). + + Create: + s_out4 = scalar_expr <s_out3, scalar_initial_def> */ + + if (scalar_initial_def) + { + epilog_stmt = build2 (MODIFY_EXPR, scalar_type, new_scalar_dest, + build2 (code, scalar_type, new_temp, scalar_initial_def)); + new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); + TREE_OPERAND (epilog_stmt, 0) = new_temp; + bsi_insert_after (&exit_bsi, epilog_stmt, BSI_NEW_STMT); + } + + /* 2.6 Replace uses of s_out0 with uses of s_out3 */ + + /* Find the loop-closed-use at the loop exit of the original scalar result. + (The reduction result is expected to have two immediate uses - one at the + latch block, and one at the loop exit). */ + exit_phi = NULL; + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, scalar_dest) + { + if (!flow_bb_inside_loop_p (loop, bb_for_stmt (USE_STMT (use_p)))) + { + exit_phi = USE_STMT (use_p); + break; + } + } + /* We expect to have found an exit_phi because of loop-closed-ssa form. */ + gcc_assert (exit_phi); + /* Replace the uses: */ + orig_name = PHI_RESULT (exit_phi); + FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, orig_name) + FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) + SET_USE (use_p, new_temp); +} + + +/* Function vectorizable_reduction. + + Check if STMT performs a reduction operation that can be vectorized. + If VEC_STMT is also passed, vectorize the STMT: create a vectorized + stmt to replace it, put it in VEC_STMT, and insert it at BSI. + Return FALSE if not a vectorizable STMT, TRUE otherwise. + + This function also handles reduction idioms (patterns) that have been + recognized in advance during vect_pattern_recog. In this case, STMT may be + of this form: + X = pattern_expr (arg0, arg1, ..., X) + and it's STMT_VINFO_RELATED_STMT points to the last stmt in the original + sequence that had been detected and replaced by the pattern-stmt (STMT). + + In some cases of reduction patterns, the type of the reduction variable X is + different than the type of the other arguments of STMT. + In such cases, the vectype that is used when transforming STMT into a vector + stmt is different than the vectype that is used to determine the + vectorization factor, because it consists of a different number of elements + than the actual number of elements that are being operated upon in parallel. + + For example, consider an accumulation of shorts into an int accumulator. + On some targets it's possible to vectorize this pattern operating on 8 + shorts at a time (hence, the vectype for purposes of determining the + vectorization factor should be V8HI); on the other hand, the vectype that + is used to create the vector form is actually V4SI (the type of the result). + + Upon entry to this function, STMT_VINFO_VECTYPE records the vectype that + indicates what is the actual level of parallelism (V8HI in the example), so + that the right vectorization factor would be derived. This vectype + corresponds to the type of arguments to the reduction stmt, and should *NOT* + be used to create the vectorized stmt. The right vectype for the vectorized + stmt is obtained from the type of the result X: + get_vectype_for_scalar_type (TREE_TYPE (X)) + + This means that, contrary to "regular" reductions (or "regular" stmts in + general), the following equation: + STMT_VINFO_VECTYPE == get_vectype_for_scalar_type (TREE_TYPE (X)) + does *NOT* necessarily hold for reduction patterns. */ + +bool +vectorizable_reduction (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt) +{ + tree vec_dest; + tree scalar_dest; + tree op; + tree loop_vec_def0, loop_vec_def1; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree operation; + enum tree_code code, orig_code, epilog_reduc_code = 0; + enum machine_mode vec_mode; + int op_type; + optab optab, reduc_optab; + tree new_temp; + tree def, def_stmt; + enum vect_def_type dt; + tree new_phi; + tree scalar_type; + bool is_simple_use; + tree orig_stmt; + stmt_vec_info orig_stmt_info; + tree expr = NULL_TREE; + int i; + + /* 1. Is vectorizable reduction? */ + + /* Not supportable if the reduction variable is used in the loop. */ + if (STMT_VINFO_RELEVANT_P (stmt_info)) + return false; + + if (!STMT_VINFO_LIVE_P (stmt_info)) + return false; + + /* Make sure it was already recognized as a reduction computation. */ + if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_reduction_def) + return false; + + /* 2. Has this been recognized as a reduction pattern? + + Check if STMT represents a pattern that has been recognized + in earlier analysis stages. For stmts that represent a pattern, + the STMT_VINFO_RELATED_STMT field records the last stmt in + the original sequence that constitutes the pattern. */ + + orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info); + if (orig_stmt) + { + orig_stmt_info = vinfo_for_stmt (orig_stmt); + gcc_assert (STMT_VINFO_RELATED_STMT (orig_stmt_info) == stmt); + gcc_assert (STMT_VINFO_IN_PATTERN_P (orig_stmt_info)); + gcc_assert (!STMT_VINFO_IN_PATTERN_P (stmt_info)); + } + + /* 3. Check the operands of the operation. The first operands are defined + inside the loop body. The last operand is the reduction variable, + which is defined by the loop-header-phi. */ + + gcc_assert (TREE_CODE (stmt) == MODIFY_EXPR); + + operation = TREE_OPERAND (stmt, 1); + code = TREE_CODE (operation); + op_type = TREE_CODE_LENGTH (code); + + if (op_type != binary_op && op_type != ternary_op) + return false; + scalar_dest = TREE_OPERAND (stmt, 0); + scalar_type = TREE_TYPE (scalar_dest); + + /* All uses but the last are expected to be defined in the loop. + The last use is the reduction variable. */ + for (i = 0; i < op_type-1; i++) + { + op = TREE_OPERAND (operation, i); + is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt); + gcc_assert (is_simple_use); + gcc_assert (dt == vect_loop_def || dt == vect_invariant_def || + dt == vect_constant_def); + } + + op = TREE_OPERAND (operation, i); + is_simple_use = vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt); + gcc_assert (is_simple_use); + gcc_assert (dt == vect_reduction_def); + gcc_assert (TREE_CODE (def_stmt) == PHI_NODE); + if (orig_stmt) + gcc_assert (orig_stmt == vect_is_simple_reduction (loop, def_stmt)); + else + gcc_assert (stmt == vect_is_simple_reduction (loop, def_stmt)); + + if (STMT_VINFO_LIVE_P (vinfo_for_stmt (def_stmt))) + return false; + + /* 4. Supportable by target? */ + + /* 4.1. check support for the operation in the loop */ + optab = optab_for_tree_code (code, vectype); + if (!optab) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "no optab."); + return false; + } + vec_mode = TYPE_MODE (vectype); + if (optab->handlers[(int) vec_mode].insn_code == CODE_FOR_nothing) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "op not supported by target."); + if (GET_MODE_SIZE (vec_mode) != UNITS_PER_WORD + || LOOP_VINFO_VECT_FACTOR (loop_vinfo) + < vect_min_worthwhile_factor (code)) + return false; + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "proceeding using word mode."); + } + + /* Worthwhile without SIMD support? */ + if (!VECTOR_MODE_P (TYPE_MODE (vectype)) + && LOOP_VINFO_VECT_FACTOR (loop_vinfo) + < vect_min_worthwhile_factor (code)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "not worthwhile without SIMD support."); + return false; + } + + /* 4.2. Check support for the epilog operation. + + If STMT represents a reduction pattern, then the type of the + reduction variable may be different than the type of the rest + of the arguments. For example, consider the case of accumulation + of shorts into an int accumulator; The original code: + S1: int_a = (int) short_a; + orig_stmt-> S2: int_acc = plus <int_a ,int_acc>; + + was replaced with: + STMT: int_acc = widen_sum <short_a, int_acc> + + This means that: + 1. The tree-code that is used to create the vector operation in the + epilog code (that reduces the partial results) is not the + tree-code of STMT, but is rather the tree-code of the original + stmt from the pattern that STMT is replacing. I.e, in the example + above we want to use 'widen_sum' in the loop, but 'plus' in the + epilog. + 2. The type (mode) we use to check available target support + for the vector operation to be created in the *epilog*, is + determined by the type of the reduction variable (in the example + above we'd check this: plus_optab[vect_int_mode]). + However the type (mode) we use to check available target support + for the vector operation to be created *inside the loop*, is + determined by the type of the other arguments to STMT (in the + example we'd check this: widen_sum_optab[vect_short_mode]). + + This is contrary to "regular" reductions, in which the types of all + the arguments are the same as the type of the reduction variable. + For "regular" reductions we can therefore use the same vector type + (and also the same tree-code) when generating the epilog code and + when generating the code inside the loop. */ + + if (orig_stmt) + { + /* This is a reduction pattern: get the vectype from the type of the + reduction variable, and get the tree-code from orig_stmt. */ + orig_code = TREE_CODE (TREE_OPERAND (orig_stmt, 1)); + vectype = get_vectype_for_scalar_type (TREE_TYPE (def)); + vec_mode = TYPE_MODE (vectype); + } + else + { + /* Regular reduction: use the same vectype and tree-code as used for + the vector code inside the loop can be used for the epilog code. */ + orig_code = code; + } + + if (!reduction_code_for_scalar_code (orig_code, &epilog_reduc_code)) + return false; + reduc_optab = optab_for_tree_code (epilog_reduc_code, vectype); + if (!reduc_optab) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "no optab for reduction."); + epilog_reduc_code = NUM_TREE_CODES; + } + if (reduc_optab->handlers[(int) vec_mode].insn_code == CODE_FOR_nothing) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "reduc op not supported by target."); + epilog_reduc_code = NUM_TREE_CODES; + } + + if (!vec_stmt) /* transformation not required. */ + { + STMT_VINFO_TYPE (stmt_info) = reduc_vec_info_type; + return true; + } + + /** Transform. **/ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform reduction."); + + /* Create the destination vector */ + vec_dest = vect_create_destination_var (scalar_dest, vectype); + + /* Create the reduction-phi that defines the reduction-operand. */ + new_phi = create_phi_node (vec_dest, loop->header); + + /* Prepare the operand that is defined inside the loop body */ + op = TREE_OPERAND (operation, 0); + loop_vec_def0 = vect_get_vec_def_for_operand (op, stmt, NULL); + if (op_type == binary_op) + expr = build2 (code, vectype, loop_vec_def0, PHI_RESULT (new_phi)); + else if (op_type == ternary_op) + { + op = TREE_OPERAND (operation, 1); + loop_vec_def1 = vect_get_vec_def_for_operand (op, stmt, NULL); + expr = build3 (code, vectype, loop_vec_def0, loop_vec_def1, + PHI_RESULT (new_phi)); + } + + /* Create the vectorized operation that computes the partial results */ + *vec_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, expr); + new_temp = make_ssa_name (vec_dest, *vec_stmt); + TREE_OPERAND (*vec_stmt, 0) = new_temp; + vect_finish_stmt_generation (stmt, *vec_stmt, bsi); + + /* Finalize the reduction-phi (set it's arguments) and create the + epilog reduction code. */ + vect_create_epilog_for_reduction (new_temp, stmt, epilog_reduc_code, new_phi); + return true; +} + + +/* Function vectorizable_assignment. + + Check if STMT performs an assignment (copy) that can be vectorized. + If VEC_STMT is also passed, vectorize the STMT: create a vectorized + stmt to replace it, put it in VEC_STMT, and insert it at BSI. + Return FALSE if not a vectorizable STMT, TRUE otherwise. */ + +bool +vectorizable_assignment (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt) +{ + tree vec_dest; + tree scalar_dest; + tree op; + tree vec_oprnd; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + tree new_temp; + tree def, def_stmt; + enum vect_def_type dt; + + /* Is vectorizable assignment? */ + if (!STMT_VINFO_RELEVANT_P (stmt_info)) + return false; + + gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def); + + if (TREE_CODE (stmt) != MODIFY_EXPR) + return false; + + scalar_dest = TREE_OPERAND (stmt, 0); + if (TREE_CODE (scalar_dest) != SSA_NAME) + return false; + + op = TREE_OPERAND (stmt, 1); + if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "use not simple."); + return false; + } + + if (!vec_stmt) /* transformation not required. */ + { + STMT_VINFO_TYPE (stmt_info) = assignment_vec_info_type; + return true; + } + + /** Transform. **/ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform assignment."); + + /* Handle def. */ + vec_dest = vect_create_destination_var (scalar_dest, vectype); + + /* Handle use. */ + op = TREE_OPERAND (stmt, 1); + vec_oprnd = vect_get_vec_def_for_operand (op, stmt, NULL); + + /* Arguments are ready. create the new vector stmt. */ + *vec_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, vec_oprnd); + new_temp = make_ssa_name (vec_dest, *vec_stmt); + TREE_OPERAND (*vec_stmt, 0) = new_temp; + vect_finish_stmt_generation (stmt, *vec_stmt, bsi); + + return true; +} + + +/* Function vect_min_worthwhile_factor. + + For a loop where we could vectorize the operation indicated by CODE, + return the minimum vectorization factor that makes it worthwhile + to use generic vectors. */ +static int +vect_min_worthwhile_factor (enum tree_code code) +{ + switch (code) + { + case PLUS_EXPR: + case MINUS_EXPR: + case NEGATE_EXPR: + return 4; + + case BIT_AND_EXPR: + case BIT_IOR_EXPR: + case BIT_XOR_EXPR: + case BIT_NOT_EXPR: + return 2; + + default: + return INT_MAX; + } +} + + +/* Function vectorizable_operation. + + Check if STMT performs a binary or unary operation that can be vectorized. + If VEC_STMT is also passed, vectorize the STMT: create a vectorized + stmt to replace it, put it in VEC_STMT, and insert it at BSI. + Return FALSE if not a vectorizable STMT, TRUE otherwise. */ + +bool +vectorizable_operation (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt) +{ + tree vec_dest; + tree scalar_dest; + tree operation; + tree op0, op1 = NULL; + tree vec_oprnd0, vec_oprnd1=NULL; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + int i; + enum tree_code code; + enum machine_mode vec_mode; + tree new_temp; + int op_type; + tree op; + optab optab; + int icode; + enum machine_mode optab_op2_mode; + tree def, def_stmt; + enum vect_def_type dt; + + /* Is STMT a vectorizable binary/unary operation? */ + if (!STMT_VINFO_RELEVANT_P (stmt_info)) + return false; + + gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def); + + if (STMT_VINFO_LIVE_P (stmt_info)) + { + /* FORNOW: not yet supported. */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "value used after loop."); + return false; + } + + if (TREE_CODE (stmt) != MODIFY_EXPR) + return false; + + if (TREE_CODE (TREE_OPERAND (stmt, 0)) != SSA_NAME) + return false; + + operation = TREE_OPERAND (stmt, 1); + code = TREE_CODE (operation); + optab = optab_for_tree_code (code, vectype); + + /* Support only unary or binary operations. */ + op_type = TREE_CODE_LENGTH (code); + if (op_type != unary_op && op_type != binary_op) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "num. args = %d (not unary/binary op).", op_type); + return false; + } + + for (i = 0; i < op_type; i++) + { + op = TREE_OPERAND (operation, i); + if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "use not simple."); + return false; + } + } + + /* Supportable by target? */ + if (!optab) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "no optab."); + return false; + } + vec_mode = TYPE_MODE (vectype); + icode = (int) optab->handlers[(int) vec_mode].insn_code; + if (icode == CODE_FOR_nothing) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "op not supported by target."); + if (GET_MODE_SIZE (vec_mode) != UNITS_PER_WORD + || LOOP_VINFO_VECT_FACTOR (loop_vinfo) + < vect_min_worthwhile_factor (code)) + return false; + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "proceeding using word mode."); + } + + /* Worthwhile without SIMD support? */ + if (!VECTOR_MODE_P (TYPE_MODE (vectype)) + && LOOP_VINFO_VECT_FACTOR (loop_vinfo) + < vect_min_worthwhile_factor (code)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "not worthwhile without SIMD support."); + return false; + } + + if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) + { + /* FORNOW: not yet supported. */ + if (!VECTOR_MODE_P (vec_mode)) + return false; + + /* Invariant argument is needed for a vector shift + by a scalar shift operand. */ + optab_op2_mode = insn_data[icode].operand[2].mode; + if (! (VECTOR_MODE_P (optab_op2_mode) + || dt == vect_constant_def + || dt == vect_invariant_def)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "operand mode requires invariant argument."); + return false; + } + } + + if (!vec_stmt) /* transformation not required. */ + { + STMT_VINFO_TYPE (stmt_info) = op_vec_info_type; + return true; + } + + /** Transform. **/ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform binary/unary operation."); + + /* Handle def. */ + scalar_dest = TREE_OPERAND (stmt, 0); + vec_dest = vect_create_destination_var (scalar_dest, vectype); + + /* Handle uses. */ + op0 = TREE_OPERAND (operation, 0); + vec_oprnd0 = vect_get_vec_def_for_operand (op0, stmt, NULL); + + if (op_type == binary_op) + { + op1 = TREE_OPERAND (operation, 1); + + if (code == LSHIFT_EXPR || code == RSHIFT_EXPR) + { + /* Vector shl and shr insn patterns can be defined with + scalar operand 2 (shift operand). In this case, use + constant or loop invariant op1 directly, without + extending it to vector mode first. */ + + optab_op2_mode = insn_data[icode].operand[2].mode; + if (!VECTOR_MODE_P (optab_op2_mode)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "operand 1 using scalar mode."); + vec_oprnd1 = op1; + } + } + + if (!vec_oprnd1) + vec_oprnd1 = vect_get_vec_def_for_operand (op1, stmt, NULL); + } + + /* Arguments are ready. create the new vector stmt. */ + + if (op_type == binary_op) + *vec_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, + build2 (code, vectype, vec_oprnd0, vec_oprnd1)); + else + *vec_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, + build1 (code, vectype, vec_oprnd0)); + new_temp = make_ssa_name (vec_dest, *vec_stmt); + TREE_OPERAND (*vec_stmt, 0) = new_temp; + vect_finish_stmt_generation (stmt, *vec_stmt, bsi); + + return true; +} + + +/* Function vectorizable_store. + + Check if STMT defines a non scalar data-ref (array/pointer/structure) that + can be vectorized. + If VEC_STMT is also passed, vectorize the STMT: create a vectorized + stmt to replace it, put it in VEC_STMT, and insert it at BSI. + Return FALSE if not a vectorizable STMT, TRUE otherwise. */ + +bool +vectorizable_store (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt) +{ + tree scalar_dest; + tree data_ref; + tree op; + tree vec_oprnd1; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + enum machine_mode vec_mode; + tree dummy; + enum dr_alignment_support alignment_support_cheme; + ssa_op_iter iter; + tree def, def_stmt; + enum vect_def_type dt; + + /* Is vectorizable store? */ + + if (TREE_CODE (stmt) != MODIFY_EXPR) + return false; + + scalar_dest = TREE_OPERAND (stmt, 0); + if (TREE_CODE (scalar_dest) != ARRAY_REF + && TREE_CODE (scalar_dest) != INDIRECT_REF) + return false; + + op = TREE_OPERAND (stmt, 1); + if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "use not simple."); + return false; + } + + vec_mode = TYPE_MODE (vectype); + /* FORNOW. In some cases can vectorize even if data-type not supported + (e.g. - array initialization with 0). */ + if (mov_optab->handlers[(int)vec_mode].insn_code == CODE_FOR_nothing) + return false; + + if (!STMT_VINFO_DATA_REF (stmt_info)) + return false; + + + if (!vec_stmt) /* transformation not required. */ + { + STMT_VINFO_TYPE (stmt_info) = store_vec_info_type; + return true; + } + + /** Transform. **/ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform store"); + + alignment_support_cheme = vect_supportable_dr_alignment (dr); + gcc_assert (alignment_support_cheme); + gcc_assert (alignment_support_cheme == dr_aligned); /* FORNOW */ + + /* Handle use - get the vectorized def from the defining stmt. */ + vec_oprnd1 = vect_get_vec_def_for_operand (op, stmt, NULL); + + /* Handle def. */ + /* FORNOW: make sure the data reference is aligned. */ + vect_align_data_ref (stmt); + data_ref = vect_create_data_ref_ptr (stmt, bsi, NULL_TREE, &dummy, false); + data_ref = build_fold_indirect_ref (data_ref); + + /* Arguments are ready. create the new vector stmt. */ + *vec_stmt = build2 (MODIFY_EXPR, vectype, data_ref, vec_oprnd1); + vect_finish_stmt_generation (stmt, *vec_stmt, bsi); + + /* Copy the V_MAY_DEFS representing the aliasing of the original array + element's definition to the vector's definition then update the + defining statement. The original is being deleted so the same + SSA_NAMEs can be used. */ + copy_virtual_operands (*vec_stmt, stmt); + + FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_VMAYDEF) + { + SSA_NAME_DEF_STMT (def) = *vec_stmt; + + /* If this virtual def has a use outside the loop and a loop peel is + performed then the def may be renamed by the peel. Mark it for + renaming so the later use will also be renamed. */ + mark_sym_for_renaming (SSA_NAME_VAR (def)); + } + + return true; +} + + +/* vectorizable_load. + + Check if STMT reads a non scalar data-ref (array/pointer/structure) that + can be vectorized. + If VEC_STMT is also passed, vectorize the STMT: create a vectorized + stmt to replace it, put it in VEC_STMT, and insert it at BSI. + Return FALSE if not a vectorizable STMT, TRUE otherwise. */ + +bool +vectorizable_load (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt) +{ + tree scalar_dest; + tree vec_dest = NULL; + tree data_ref = NULL; + tree op; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + struct data_reference *dr = STMT_VINFO_DATA_REF (stmt_info); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + tree new_temp; + int mode; + tree init_addr; + tree new_stmt; + tree dummy; + basic_block new_bb; + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + edge pe = loop_preheader_edge (loop); + enum dr_alignment_support alignment_support_cheme; + + /* Is vectorizable load? */ + if (!STMT_VINFO_RELEVANT_P (stmt_info)) + return false; + + gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def); + + if (STMT_VINFO_LIVE_P (stmt_info)) + { + /* FORNOW: not yet supported. */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "value used after loop."); + return false; + } + + if (TREE_CODE (stmt) != MODIFY_EXPR) + return false; + + scalar_dest = TREE_OPERAND (stmt, 0); + if (TREE_CODE (scalar_dest) != SSA_NAME) + return false; + + op = TREE_OPERAND (stmt, 1); + if (TREE_CODE (op) != ARRAY_REF && TREE_CODE (op) != INDIRECT_REF) + return false; + + if (!STMT_VINFO_DATA_REF (stmt_info)) + return false; + + mode = (int) TYPE_MODE (vectype); + + /* FORNOW. In some cases can vectorize even if data-type not supported + (e.g. - data copies). */ + if (mov_optab->handlers[mode].insn_code == CODE_FOR_nothing) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Aligned load, but unsupported type."); + return false; + } + + if (!vec_stmt) /* transformation not required. */ + { + STMT_VINFO_TYPE (stmt_info) = load_vec_info_type; + return true; + } + + /** Transform. **/ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform load."); + + alignment_support_cheme = vect_supportable_dr_alignment (dr); + gcc_assert (alignment_support_cheme); + + if (alignment_support_cheme == dr_aligned + || alignment_support_cheme == dr_unaligned_supported) + { + /* Create: + p = initial_addr; + indx = 0; + loop { + vec_dest = *(p); + indx = indx + 1; + } + */ + + vec_dest = vect_create_destination_var (scalar_dest, vectype); + data_ref = vect_create_data_ref_ptr (stmt, bsi, NULL_TREE, &dummy, false); + if (aligned_access_p (dr)) + data_ref = build_fold_indirect_ref (data_ref); + else + { + int mis = DR_MISALIGNMENT (dr); + tree tmis = (mis == -1 ? size_zero_node : size_int (mis)); + tmis = size_binop (MULT_EXPR, tmis, size_int(BITS_PER_UNIT)); + data_ref = build2 (MISALIGNED_INDIRECT_REF, vectype, data_ref, tmis); + } + new_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, data_ref); + new_temp = make_ssa_name (vec_dest, new_stmt); + TREE_OPERAND (new_stmt, 0) = new_temp; + vect_finish_stmt_generation (stmt, new_stmt, bsi); + copy_virtual_operands (new_stmt, stmt); + } + else if (alignment_support_cheme == dr_unaligned_software_pipeline) + { + /* Create: + p1 = initial_addr; + msq_init = *(floor(p1)) + p2 = initial_addr + VS - 1; + magic = have_builtin ? builtin_result : initial_address; + indx = 0; + loop { + p2' = p2 + indx * vectype_size + lsq = *(floor(p2')) + vec_dest = realign_load (msq, lsq, magic) + indx = indx + 1; + msq = lsq; + } + */ + + tree offset; + tree magic; + tree phi_stmt; + tree msq_init; + tree msq, lsq; + tree dataref_ptr; + tree params; + + /* <1> Create msq_init = *(floor(p1)) in the loop preheader */ + vec_dest = vect_create_destination_var (scalar_dest, vectype); + data_ref = vect_create_data_ref_ptr (stmt, bsi, NULL_TREE, + &init_addr, true); + data_ref = build1 (ALIGN_INDIRECT_REF, vectype, data_ref); + new_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, data_ref); + new_temp = make_ssa_name (vec_dest, new_stmt); + TREE_OPERAND (new_stmt, 0) = new_temp; + new_bb = bsi_insert_on_edge_immediate (pe, new_stmt); + gcc_assert (!new_bb); + msq_init = TREE_OPERAND (new_stmt, 0); + copy_virtual_operands (new_stmt, stmt); + update_vuses_to_preheader (new_stmt, loop); + + + /* <2> Create lsq = *(floor(p2')) in the loop */ + offset = size_int (TYPE_VECTOR_SUBPARTS (vectype) - 1); + vec_dest = vect_create_destination_var (scalar_dest, vectype); + dataref_ptr = vect_create_data_ref_ptr (stmt, bsi, offset, &dummy, false); + data_ref = build1 (ALIGN_INDIRECT_REF, vectype, dataref_ptr); + new_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, data_ref); + new_temp = make_ssa_name (vec_dest, new_stmt); + TREE_OPERAND (new_stmt, 0) = new_temp; + vect_finish_stmt_generation (stmt, new_stmt, bsi); + lsq = TREE_OPERAND (new_stmt, 0); + copy_virtual_operands (new_stmt, stmt); + + + /* <3> */ + if (targetm.vectorize.builtin_mask_for_load) + { + /* Create permutation mask, if required, in loop preheader. */ + tree builtin_decl; + params = build_tree_list (NULL_TREE, init_addr); + vec_dest = vect_create_destination_var (scalar_dest, vectype); + builtin_decl = targetm.vectorize.builtin_mask_for_load (); + new_stmt = build_function_call_expr (builtin_decl, params); + new_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, new_stmt); + new_temp = make_ssa_name (vec_dest, new_stmt); + TREE_OPERAND (new_stmt, 0) = new_temp; + new_bb = bsi_insert_on_edge_immediate (pe, new_stmt); + gcc_assert (!new_bb); + magic = TREE_OPERAND (new_stmt, 0); + + /* The result of the CALL_EXPR to this builtin is determined from + the value of the parameter and no global variables are touched + which makes the builtin a "const" function. Requiring the + builtin to have the "const" attribute makes it unnecessary + to call mark_call_clobbered. */ + gcc_assert (TREE_READONLY (builtin_decl)); + } + else + { + /* Use current address instead of init_addr for reduced reg pressure. + */ + magic = dataref_ptr; + } + + + /* <4> Create msq = phi <msq_init, lsq> in loop */ + vec_dest = vect_create_destination_var (scalar_dest, vectype); + msq = make_ssa_name (vec_dest, NULL_TREE); + phi_stmt = create_phi_node (msq, loop->header); /* CHECKME */ + SSA_NAME_DEF_STMT (msq) = phi_stmt; + add_phi_arg (phi_stmt, msq_init, loop_preheader_edge (loop)); + add_phi_arg (phi_stmt, lsq, loop_latch_edge (loop)); + + + /* <5> Create <vec_dest = realign_load (msq, lsq, magic)> in loop */ + vec_dest = vect_create_destination_var (scalar_dest, vectype); + new_stmt = build3 (REALIGN_LOAD_EXPR, vectype, msq, lsq, magic); + new_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, new_stmt); + new_temp = make_ssa_name (vec_dest, new_stmt); + TREE_OPERAND (new_stmt, 0) = new_temp; + vect_finish_stmt_generation (stmt, new_stmt, bsi); + } + else + gcc_unreachable (); + + *vec_stmt = new_stmt; + return true; +} + + +/* Function vectorizable_live_operation. + + STMT computes a value that is used outside the loop. Check if + it can be supported. */ + +bool +vectorizable_live_operation (tree stmt, + block_stmt_iterator *bsi ATTRIBUTE_UNUSED, + tree *vec_stmt ATTRIBUTE_UNUSED) +{ + tree operation; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + int i; + enum tree_code code; + int op_type; + tree op; + tree def, def_stmt; + enum vect_def_type dt; + + if (!STMT_VINFO_LIVE_P (stmt_info)) + return false; + + if (TREE_CODE (stmt) != MODIFY_EXPR) + return false; + + if (TREE_CODE (TREE_OPERAND (stmt, 0)) != SSA_NAME) + return false; + + operation = TREE_OPERAND (stmt, 1); + code = TREE_CODE (operation); + + op_type = TREE_CODE_LENGTH (code); + + /* FORNOW: support only if all uses are invariant. This means + that the scalar operations can remain in place, unvectorized. + The original last scalar value that they compute will be used. */ + + for (i = 0; i < op_type; i++) + { + op = TREE_OPERAND (operation, i); + if (!vect_is_simple_use (op, loop_vinfo, &def_stmt, &def, &dt)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "use not simple."); + return false; + } + + if (dt != vect_invariant_def && dt != vect_constant_def) + return false; + } + + /* No transformation is required for the cases we currently support. */ + return true; +} + + +/* Function vect_is_simple_cond. + + Input: + LOOP - the loop that is being vectorized. + COND - Condition that is checked for simple use. + + Returns whether a COND can be vectorized. Checks whether + condition operands are supportable using vec_is_simple_use. */ + +static bool +vect_is_simple_cond (tree cond, loop_vec_info loop_vinfo) +{ + tree lhs, rhs; + tree def; + enum vect_def_type dt; + + if (!COMPARISON_CLASS_P (cond)) + return false; + + lhs = TREE_OPERAND (cond, 0); + rhs = TREE_OPERAND (cond, 1); + + if (TREE_CODE (lhs) == SSA_NAME) + { + tree lhs_def_stmt = SSA_NAME_DEF_STMT (lhs); + if (!vect_is_simple_use (lhs, loop_vinfo, &lhs_def_stmt, &def, &dt)) + return false; + } + else if (TREE_CODE (lhs) != INTEGER_CST && TREE_CODE (lhs) != REAL_CST) + return false; + + if (TREE_CODE (rhs) == SSA_NAME) + { + tree rhs_def_stmt = SSA_NAME_DEF_STMT (rhs); + if (!vect_is_simple_use (rhs, loop_vinfo, &rhs_def_stmt, &def, &dt)) + return false; + } + else if (TREE_CODE (rhs) != INTEGER_CST && TREE_CODE (rhs) != REAL_CST) + return false; + + return true; +} + +/* vectorizable_condition. + + Check if STMT is conditional modify expression that can be vectorized. + If VEC_STMT is also passed, vectorize the STMT: create a vectorized + stmt using VEC_COND_EXPR to replace it, put it in VEC_STMT, and insert it + at BSI. + + Return FALSE if not a vectorizable STMT, TRUE otherwise. */ + +bool +vectorizable_condition (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt) +{ + tree scalar_dest = NULL_TREE; + tree vec_dest = NULL_TREE; + tree op = NULL_TREE; + tree cond_expr, then_clause, else_clause; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + tree vec_cond_lhs, vec_cond_rhs, vec_then_clause, vec_else_clause; + tree vec_compare, vec_cond_expr; + tree new_temp; + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + enum machine_mode vec_mode; + tree def; + enum vect_def_type dt; + + if (!STMT_VINFO_RELEVANT_P (stmt_info)) + return false; + + gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_loop_def); + + if (STMT_VINFO_LIVE_P (stmt_info)) + { + /* FORNOW: not yet supported. */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "value used after loop."); + return false; + } + + if (TREE_CODE (stmt) != MODIFY_EXPR) + return false; + + op = TREE_OPERAND (stmt, 1); + + if (TREE_CODE (op) != COND_EXPR) + return false; + + cond_expr = TREE_OPERAND (op, 0); + then_clause = TREE_OPERAND (op, 1); + else_clause = TREE_OPERAND (op, 2); + + if (!vect_is_simple_cond (cond_expr, loop_vinfo)) + return false; + + /* We do not handle two different vector types for the condition + and the values. */ + if (TREE_TYPE (TREE_OPERAND (cond_expr, 0)) != TREE_TYPE (vectype)) + return false; + + if (TREE_CODE (then_clause) == SSA_NAME) + { + tree then_def_stmt = SSA_NAME_DEF_STMT (then_clause); + if (!vect_is_simple_use (then_clause, loop_vinfo, + &then_def_stmt, &def, &dt)) + return false; + } + else if (TREE_CODE (then_clause) != INTEGER_CST + && TREE_CODE (then_clause) != REAL_CST) + return false; + + if (TREE_CODE (else_clause) == SSA_NAME) + { + tree else_def_stmt = SSA_NAME_DEF_STMT (else_clause); + if (!vect_is_simple_use (else_clause, loop_vinfo, + &else_def_stmt, &def, &dt)) + return false; + } + else if (TREE_CODE (else_clause) != INTEGER_CST + && TREE_CODE (else_clause) != REAL_CST) + return false; + + + vec_mode = TYPE_MODE (vectype); + + if (!vec_stmt) + { + STMT_VINFO_TYPE (stmt_info) = condition_vec_info_type; + return expand_vec_cond_expr_p (op, vec_mode); + } + + /* Transform */ + + /* Handle def. */ + scalar_dest = TREE_OPERAND (stmt, 0); + vec_dest = vect_create_destination_var (scalar_dest, vectype); + + /* Handle cond expr. */ + vec_cond_lhs = + vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 0), stmt, NULL); + vec_cond_rhs = + vect_get_vec_def_for_operand (TREE_OPERAND (cond_expr, 1), stmt, NULL); + vec_then_clause = vect_get_vec_def_for_operand (then_clause, stmt, NULL); + vec_else_clause = vect_get_vec_def_for_operand (else_clause, stmt, NULL); + + /* Arguments are ready. create the new vector stmt. */ + vec_compare = build2 (TREE_CODE (cond_expr), vectype, + vec_cond_lhs, vec_cond_rhs); + vec_cond_expr = build3 (VEC_COND_EXPR, vectype, + vec_compare, vec_then_clause, vec_else_clause); + + *vec_stmt = build2 (MODIFY_EXPR, vectype, vec_dest, vec_cond_expr); + new_temp = make_ssa_name (vec_dest, *vec_stmt); + TREE_OPERAND (*vec_stmt, 0) = new_temp; + vect_finish_stmt_generation (stmt, *vec_stmt, bsi); + + return true; +} + +/* Function vect_transform_stmt. + + Create a vectorized stmt to replace STMT, and insert it at BSI. */ + +bool +vect_transform_stmt (tree stmt, block_stmt_iterator *bsi) +{ + bool is_store = false; + tree vec_stmt = NULL_TREE; + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + tree orig_stmt_in_pattern; + bool done; + + if (STMT_VINFO_RELEVANT_P (stmt_info)) + { + switch (STMT_VINFO_TYPE (stmt_info)) + { + case op_vec_info_type: + done = vectorizable_operation (stmt, bsi, &vec_stmt); + gcc_assert (done); + break; + + case assignment_vec_info_type: + done = vectorizable_assignment (stmt, bsi, &vec_stmt); + gcc_assert (done); + break; + + case load_vec_info_type: + done = vectorizable_load (stmt, bsi, &vec_stmt); + gcc_assert (done); + break; + + case store_vec_info_type: + done = vectorizable_store (stmt, bsi, &vec_stmt); + gcc_assert (done); + is_store = true; + break; + + case condition_vec_info_type: + done = vectorizable_condition (stmt, bsi, &vec_stmt); + gcc_assert (done); + break; + + default: + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "stmt not supported."); + gcc_unreachable (); + } + + gcc_assert (vec_stmt); + STMT_VINFO_VEC_STMT (stmt_info) = vec_stmt; + orig_stmt_in_pattern = STMT_VINFO_RELATED_STMT (stmt_info); + if (orig_stmt_in_pattern) + { + stmt_vec_info stmt_vinfo = vinfo_for_stmt (orig_stmt_in_pattern); + if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo)) + { + gcc_assert (STMT_VINFO_RELATED_STMT (stmt_vinfo) == stmt); + + /* STMT was inserted by the vectorizer to replace a computation + idiom. ORIG_STMT_IN_PATTERN is a stmt in the original + sequence that computed this idiom. We need to record a pointer + to VEC_STMT in the stmt_info of ORIG_STMT_IN_PATTERN. See more + detail in the documentation of vect_pattern_recog. */ + + STMT_VINFO_VEC_STMT (stmt_vinfo) = vec_stmt; + } + } + } + + if (STMT_VINFO_LIVE_P (stmt_info)) + { + switch (STMT_VINFO_TYPE (stmt_info)) + { + case reduc_vec_info_type: + done = vectorizable_reduction (stmt, bsi, &vec_stmt); + gcc_assert (done); + break; + + default: + done = vectorizable_live_operation (stmt, bsi, &vec_stmt); + gcc_assert (done); + } + + if (vec_stmt) + { + gcc_assert (!STMT_VINFO_VEC_STMT (stmt_info)); + STMT_VINFO_VEC_STMT (stmt_info) = vec_stmt; + } + } + + return is_store; +} + + +/* This function builds ni_name = number of iterations loop executes + on the loop preheader. */ + +static tree +vect_build_loop_niters (loop_vec_info loop_vinfo) +{ + tree ni_name, stmt, var; + edge pe; + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree ni = unshare_expr (LOOP_VINFO_NITERS (loop_vinfo)); + + var = create_tmp_var (TREE_TYPE (ni), "niters"); + add_referenced_var (var); + ni_name = force_gimple_operand (ni, &stmt, false, var); + + pe = loop_preheader_edge (loop); + if (stmt) + { + basic_block new_bb = bsi_insert_on_edge_immediate (pe, stmt); + gcc_assert (!new_bb); + } + + return ni_name; +} + + +/* This function generates the following statements: + + ni_name = number of iterations loop executes + ratio = ni_name / vf + ratio_mult_vf_name = ratio * vf + + and places them at the loop preheader edge. */ + +static void +vect_generate_tmps_on_preheader (loop_vec_info loop_vinfo, + tree *ni_name_ptr, + tree *ratio_mult_vf_name_ptr, + tree *ratio_name_ptr) +{ + + edge pe; + basic_block new_bb; + tree stmt, ni_name; + tree var; + tree ratio_name; + tree ratio_mult_vf_name; + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree ni = LOOP_VINFO_NITERS (loop_vinfo); + int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); + tree log_vf; + + pe = loop_preheader_edge (loop); + + /* Generate temporary variable that contains + number of iterations loop executes. */ + + ni_name = vect_build_loop_niters (loop_vinfo); + log_vf = build_int_cst (TREE_TYPE (ni), exact_log2 (vf)); + + /* Create: ratio = ni >> log2(vf) */ + + var = create_tmp_var (TREE_TYPE (ni), "bnd"); + add_referenced_var (var); + ratio_name = make_ssa_name (var, NULL_TREE); + stmt = build2 (MODIFY_EXPR, void_type_node, ratio_name, + build2 (RSHIFT_EXPR, TREE_TYPE (ni_name), ni_name, log_vf)); + SSA_NAME_DEF_STMT (ratio_name) = stmt; + + pe = loop_preheader_edge (loop); + new_bb = bsi_insert_on_edge_immediate (pe, stmt); + gcc_assert (!new_bb); + + /* Create: ratio_mult_vf = ratio << log2 (vf). */ + + var = create_tmp_var (TREE_TYPE (ni), "ratio_mult_vf"); + add_referenced_var (var); + ratio_mult_vf_name = make_ssa_name (var, NULL_TREE); + stmt = build2 (MODIFY_EXPR, void_type_node, ratio_mult_vf_name, + build2 (LSHIFT_EXPR, TREE_TYPE (ratio_name), ratio_name, log_vf)); + SSA_NAME_DEF_STMT (ratio_mult_vf_name) = stmt; + + pe = loop_preheader_edge (loop); + new_bb = bsi_insert_on_edge_immediate (pe, stmt); + gcc_assert (!new_bb); + + *ni_name_ptr = ni_name; + *ratio_mult_vf_name_ptr = ratio_mult_vf_name; + *ratio_name_ptr = ratio_name; + + return; +} + + +/* Function update_vuses_to_preheader. + + Input: + STMT - a statement with potential VUSEs. + LOOP - the loop whose preheader will contain STMT. + + It's possible to vectorize a loop even though an SSA_NAME from a VUSE + appears to be defined in a V_MAY_DEF in another statement in a loop. + One such case is when the VUSE is at the dereference of a __restricted__ + pointer in a load and the V_MAY_DEF is at the dereference of a different + __restricted__ pointer in a store. Vectorization may result in + copy_virtual_uses being called to copy the problematic VUSE to a new + statement that is being inserted in the loop preheader. This procedure + is called to change the SSA_NAME in the new statement's VUSE from the + SSA_NAME updated in the loop to the related SSA_NAME available on the + path entering the loop. + + When this function is called, we have the following situation: + + # vuse <name1> + S1: vload + do { + # name1 = phi < name0 , name2> + + # vuse <name1> + S2: vload + + # name2 = vdef <name1> + S3: vstore + + }while... + + Stmt S1 was created in the loop preheader block as part of misaligned-load + handling. This function fixes the name of the vuse of S1 from 'name1' to + 'name0'. */ + +static void +update_vuses_to_preheader (tree stmt, struct loop *loop) +{ + basic_block header_bb = loop->header; + edge preheader_e = loop_preheader_edge (loop); + ssa_op_iter iter; + use_operand_p use_p; + + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_VUSE) + { + tree ssa_name = USE_FROM_PTR (use_p); + tree def_stmt = SSA_NAME_DEF_STMT (ssa_name); + tree name_var = SSA_NAME_VAR (ssa_name); + basic_block bb = bb_for_stmt (def_stmt); + + /* For a use before any definitions, def_stmt is a NOP_EXPR. */ + if (!IS_EMPTY_STMT (def_stmt) + && flow_bb_inside_loop_p (loop, bb)) + { + /* If the block containing the statement defining the SSA_NAME + is in the loop then it's necessary to find the definition + outside the loop using the PHI nodes of the header. */ + tree phi; + bool updated = false; + + for (phi = phi_nodes (header_bb); phi; phi = TREE_CHAIN (phi)) + { + if (SSA_NAME_VAR (PHI_RESULT (phi)) == name_var) + { + SET_USE (use_p, PHI_ARG_DEF (phi, preheader_e->dest_idx)); + updated = true; + break; + } + } + gcc_assert (updated); + } + } +} + + +/* 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) +{ + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + basic_block exit_bb = loop->single_exit->dest; + tree phi, phi1; + basic_block update_bb = update_e->dest; + + /* gcc_assert (vect_can_advance_ivs_p (loop_vinfo)); */ + + /* Make sure there exists a single-predecessor exit bb: */ + gcc_assert (single_pred_p (exit_bb)); + + for (phi = phi_nodes (loop->header), phi1 = phi_nodes (update_bb); + phi && phi1; + phi = PHI_CHAIN (phi), phi1 = PHI_CHAIN (phi1)) + { + tree access_fn = NULL; + tree evolution_part; + tree init_expr; + tree step_expr; + tree var, stmt, ni, ni_name; + block_stmt_iterator last_bsi; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "vect_update_ivs_after_vectorizer: phi: "); + print_generic_expr (vect_dump, phi, TDF_SLIM); + } + + /* Skip virtual phi's. */ + if (!is_gimple_reg (SSA_NAME_VAR (PHI_RESULT (phi)))) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "virtual phi. skip."); + continue; + } + + /* Skip reduction phis. */ + if (STMT_VINFO_DEF_TYPE (vinfo_for_stmt (phi)) == vect_reduction_def) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "reduc phi. skip."); + continue; + } + + access_fn = analyze_scalar_evolution (loop, PHI_RESULT (phi)); + gcc_assert (access_fn); + evolution_part = + unshare_expr (evolution_part_in_loop_num (access_fn, loop->num)); + gcc_assert (evolution_part != NULL_TREE); + + /* FORNOW: We do not support IVs whose evolution function is a polynomial + of degree >= 2 or exponential. */ + gcc_assert (!tree_is_chrec (evolution_part)); + + step_expr = evolution_part; + init_expr = unshare_expr (initial_condition_in_loop_num (access_fn, + loop->num)); + + ni = build2 (PLUS_EXPR, TREE_TYPE (init_expr), + build2 (MULT_EXPR, TREE_TYPE (niters), + niters, step_expr), init_expr); + + var = create_tmp_var (TREE_TYPE (init_expr), "tmp"); + add_referenced_var (var); + + ni_name = force_gimple_operand (ni, &stmt, false, var); + + /* Insert stmt into exit_bb. */ + last_bsi = bsi_last (exit_bb); + if (stmt) + bsi_insert_before (&last_bsi, stmt, BSI_SAME_STMT); + + /* Fix phi expressions in the successor bb. */ + SET_PHI_ARG_DEF (phi1, update_e->dest_idx, ni_name); + } +} + + +/* Function vect_do_peeling_for_loop_bound + + Peel the last iterations of the loop represented by LOOP_VINFO. + The peeled iterations form a new epilog loop. Given that the loop now + iterates NITERS times, the new epilog loop iterates + NITERS % VECTORIZATION_FACTOR times. + + The original loop will later be made to iterate + NITERS / VECTORIZATION_FACTOR times (this value is placed into RATIO). */ + +static void +vect_do_peeling_for_loop_bound (loop_vec_info loop_vinfo, tree *ratio, + struct loops *loops) +{ + tree ni_name, ratio_mult_vf_name; + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + struct loop *new_loop; + edge update_e; + basic_block preheader; + int loop_num; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vect_do_peeling_for_loop_bound ==="); + + initialize_original_copy_tables (); + + /* Generate the following variables on the preheader of original loop: + + ni_name = number of iteration the original loop executes + ratio = ni_name / vf + ratio_mult_vf_name = ratio * vf */ + vect_generate_tmps_on_preheader (loop_vinfo, &ni_name, + &ratio_mult_vf_name, ratio); + + loop_num = loop->num; + new_loop = slpeel_tree_peel_loop_to_edge (loop, loops, loop->single_exit, + ratio_mult_vf_name, ni_name, false); + gcc_assert (new_loop); + gcc_assert (loop_num == loop->num); +#ifdef ENABLE_CHECKING + slpeel_verify_cfg_after_peeling (loop, new_loop); +#endif + + /* A guard that controls whether the new_loop is to be executed or skipped + is placed in LOOP->exit. LOOP->exit therefore has two successors - one + is the preheader of NEW_LOOP, where the IVs from LOOP are used. The other + is a bb after NEW_LOOP, where these IVs are not used. Find the edge that + is on the path where the LOOP IVs are used and need to be updated. */ + + preheader = loop_preheader_edge (new_loop)->src; + if (EDGE_PRED (preheader, 0)->src == loop->single_exit->dest) + update_e = EDGE_PRED (preheader, 0); + else + update_e = EDGE_PRED (preheader, 1); + + /* Update IVs of original loop as if they were advanced + by ratio_mult_vf_name steps. */ + vect_update_ivs_after_vectorizer (loop_vinfo, ratio_mult_vf_name, update_e); + + /* After peeling we have to reset scalar evolution analyzer. */ + scev_reset (); + + free_original_copy_tables (); +} + + +/* Function vect_gen_niters_for_prolog_loop + + Set the number of iterations for the loop represented by LOOP_VINFO + to the minimum between LOOP_NITERS (the original iteration count of the loop) + and 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 & (vectype_size - 1) + + prolog_niters = min ( LOOP_NITERS , (VF - addr_mis/elem_size)&(VF-1) ) + + (elem_size = element type size; an element is the scalar element + whose type is the inner type of the vectype) */ + +static tree +vect_gen_niters_for_prolog_loop (loop_vec_info loop_vinfo, tree loop_niters) +{ + struct data_reference *dr = LOOP_VINFO_UNALIGNED_DR (loop_vinfo); + int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree var, stmt; + tree iters, iters_name; + edge pe; + basic_block new_bb; + tree dr_stmt = DR_STMT (dr); + stmt_vec_info stmt_info = vinfo_for_stmt (dr_stmt); + tree vectype = STMT_VINFO_VECTYPE (stmt_info); + int vectype_align = TYPE_ALIGN (vectype) / BITS_PER_UNIT; + tree niters_type = TREE_TYPE (loop_niters); + + pe = loop_preheader_edge (loop); + + if (LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) > 0) + { + int byte_misalign = LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo); + int element_size = vectype_align/vf; + int elem_misalign = byte_misalign / element_size; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "known alignment = %d.", byte_misalign); + iters = build_int_cst (niters_type, (vf - elem_misalign)&(vf-1)); + } + else + { + tree new_stmts = NULL_TREE; + tree start_addr = + vect_create_addr_base_for_vector_ref (dr_stmt, &new_stmts, NULL_TREE); + tree ptr_type = TREE_TYPE (start_addr); + tree size = TYPE_SIZE (ptr_type); + tree type = lang_hooks.types.type_for_size (tree_low_cst (size, 1), 1); + tree vectype_size_minus_1 = build_int_cst (type, vectype_align - 1); + tree elem_size_log = + build_int_cst (type, exact_log2 (vectype_align/vf)); + tree vf_minus_1 = build_int_cst (type, vf - 1); + tree vf_tree = build_int_cst (type, vf); + tree byte_misalign; + tree elem_misalign; + + new_bb = bsi_insert_on_edge_immediate (pe, new_stmts); + gcc_assert (!new_bb); + + /* Create: byte_misalign = addr & (vectype_size - 1) */ + byte_misalign = + build2 (BIT_AND_EXPR, type, start_addr, vectype_size_minus_1); + + /* Create: elem_misalign = byte_misalign / element_size */ + elem_misalign = + build2 (RSHIFT_EXPR, type, byte_misalign, elem_size_log); + + /* Create: (niters_type) (VF - elem_misalign)&(VF - 1) */ + iters = build2 (MINUS_EXPR, type, vf_tree, elem_misalign); + iters = build2 (BIT_AND_EXPR, type, iters, vf_minus_1); + iters = fold_convert (niters_type, iters); + } + + /* Create: prolog_loop_niters = min (iters, loop_niters) */ + /* If the loop bound is known at compile time we already verified that it is + greater than vf; since the misalignment ('iters') is at most vf, there's + no need to generate the MIN_EXPR in this case. */ + if (TREE_CODE (loop_niters) != INTEGER_CST) + iters = build2 (MIN_EXPR, niters_type, iters, loop_niters); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "niters for prolog loop: "); + print_generic_expr (vect_dump, iters, TDF_SLIM); + } + + var = create_tmp_var (niters_type, "prolog_loop_niters"); + add_referenced_var (var); + iters_name = force_gimple_operand (iters, &stmt, false, var); + + /* Insert stmt on loop preheader edge. */ + if (stmt) + { + basic_block new_bb = bsi_insert_on_edge_immediate (pe, stmt); + gcc_assert (!new_bb); + } + + return iters_name; +} + + +/* Function vect_update_init_of_dr + + NITERS iterations were peeled from LOOP. DR represents a data reference + in LOOP. This function updates the information recorded in DR to + account for the fact that the first NITERS iterations had already been + executed. Specifically, it updates the OFFSET field of DR. */ + +static void +vect_update_init_of_dr (struct data_reference *dr, tree niters) +{ + tree offset = DR_OFFSET (dr); + + niters = fold_build2 (MULT_EXPR, TREE_TYPE (niters), niters, DR_STEP (dr)); + offset = fold_build2 (PLUS_EXPR, TREE_TYPE (offset), offset, niters); + DR_OFFSET (dr) = offset; +} + + +/* Function vect_update_inits_of_drs + + NITERS iterations were peeled from the loop represented by LOOP_VINFO. + This function updates the information recorded for the data references in + the loop to account for the fact that the first NITERS iterations had + already been executed. Specifically, it updates the initial_condition of the + access_function of all the data_references in the loop. */ + +static void +vect_update_inits_of_drs (loop_vec_info loop_vinfo, tree niters) +{ + unsigned int i; + VEC (data_reference_p, heap) *datarefs = LOOP_VINFO_DATAREFS (loop_vinfo); + struct data_reference *dr; + + if (vect_dump && (dump_flags & TDF_DETAILS)) + fprintf (vect_dump, "=== vect_update_inits_of_dr ==="); + + for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++) + vect_update_init_of_dr (dr, niters); +} + + +/* Function vect_do_peeling_for_alignment + + Peel the first 'niters' iterations of the loop represented by LOOP_VINFO. + 'niters' is set to the misalignment of one of the data references in the + loop, thereby forcing it to refer to an aligned location at the beginning + of the execution of this loop. The data reference for which we are + peeling is recorded in LOOP_VINFO_UNALIGNED_DR. */ + +static void +vect_do_peeling_for_alignment (loop_vec_info loop_vinfo, struct loops *loops) +{ + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree niters_of_prolog_loop, ni_name; + tree n_iters; + struct loop *new_loop; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vect_do_peeling_for_alignment ==="); + + initialize_original_copy_tables (); + + ni_name = vect_build_loop_niters (loop_vinfo); + niters_of_prolog_loop = vect_gen_niters_for_prolog_loop (loop_vinfo, ni_name); + + /* Peel the prolog loop and iterate it niters_of_prolog_loop. */ + new_loop = + slpeel_tree_peel_loop_to_edge (loop, loops, loop_preheader_edge (loop), + niters_of_prolog_loop, ni_name, true); + gcc_assert (new_loop); +#ifdef ENABLE_CHECKING + slpeel_verify_cfg_after_peeling (new_loop, loop); +#endif + + /* Update number of times loop executes. */ + n_iters = LOOP_VINFO_NITERS (loop_vinfo); + LOOP_VINFO_NITERS (loop_vinfo) = fold_build2 (MINUS_EXPR, + TREE_TYPE (n_iters), n_iters, niters_of_prolog_loop); + + /* Update the init conditions of the access functions of all data refs. */ + vect_update_inits_of_drs (loop_vinfo, niters_of_prolog_loop); + + /* After peeling we have to reset scalar evolution analyzer. */ + scev_reset (); + + free_original_copy_tables (); +} + + +/* 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: + 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 tree +vect_create_cond_for_align_checks (loop_vec_info loop_vinfo, + tree *cond_expr_stmt_list) +{ + VEC(tree,heap) *may_misalign_stmts + = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo); + tree ref_stmt; + int mask = LOOP_VINFO_PTR_MASK (loop_vinfo); + tree mask_cst; + unsigned int i; + tree psize; + tree int_ptrsize_type; + char tmp_name[20]; + tree or_tmp_name = NULL_TREE; + tree and_tmp, and_tmp_name, and_stmt; + tree ptrsize_zero; + + /* 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)); + + /* CHECKME: what is the best integer or unsigned type to use to hold a + cast from a pointer value? */ + psize = TYPE_SIZE (ptr_type_node); + int_ptrsize_type + = lang_hooks.types.type_for_size (tree_low_cst (psize, 1), 0); + + /* Create expression (mask & (dr_1 || ... || dr_n)) where dr_i is the address + of the first vector of the i'th data reference. */ + + for (i = 0; VEC_iterate (tree, may_misalign_stmts, i, ref_stmt); i++) + { + tree new_stmt_list = NULL_TREE; + tree addr_base; + tree addr_tmp, addr_tmp_name, addr_stmt; + tree or_tmp, new_or_tmp_name, or_stmt; + + /* create: addr_tmp = (int)(address_of_first_vector) */ + addr_base = vect_create_addr_base_for_vector_ref (ref_stmt, + &new_stmt_list, + NULL_TREE); + + if (new_stmt_list != NULL_TREE) + append_to_statement_list_force (new_stmt_list, cond_expr_stmt_list); + + sprintf (tmp_name, "%s%d", "addr2int", i); + addr_tmp = create_tmp_var (int_ptrsize_type, tmp_name); + add_referenced_var (addr_tmp); + addr_tmp_name = make_ssa_name (addr_tmp, NULL_TREE); + addr_stmt = fold_convert (int_ptrsize_type, addr_base); + addr_stmt = build2 (MODIFY_EXPR, void_type_node, + addr_tmp_name, addr_stmt); + SSA_NAME_DEF_STMT (addr_tmp_name) = addr_stmt; + append_to_statement_list_force (addr_stmt, cond_expr_stmt_list); + + /* The addresses are OR together. */ + + if (or_tmp_name != NULL_TREE) + { + /* create: or_tmp = or_tmp | addr_tmp */ + sprintf (tmp_name, "%s%d", "orptrs", i); + or_tmp = create_tmp_var (int_ptrsize_type, tmp_name); + add_referenced_var (or_tmp); + new_or_tmp_name = make_ssa_name (or_tmp, NULL_TREE); + or_stmt = build2 (MODIFY_EXPR, void_type_node, new_or_tmp_name, + build2 (BIT_IOR_EXPR, int_ptrsize_type, + or_tmp_name, + addr_tmp_name)); + SSA_NAME_DEF_STMT (new_or_tmp_name) = or_stmt; + append_to_statement_list_force (or_stmt, cond_expr_stmt_list); + or_tmp_name = new_or_tmp_name; + } + else + or_tmp_name = addr_tmp_name; + + } /* end for i */ + + mask_cst = build_int_cst (int_ptrsize_type, mask); + + /* create: and_tmp = or_tmp & mask */ + and_tmp = create_tmp_var (int_ptrsize_type, "andmask" ); + add_referenced_var (and_tmp); + and_tmp_name = make_ssa_name (and_tmp, NULL_TREE); + + and_stmt = build2 (MODIFY_EXPR, void_type_node, + and_tmp_name, + build2 (BIT_AND_EXPR, int_ptrsize_type, + or_tmp_name, mask_cst)); + SSA_NAME_DEF_STMT (and_tmp_name) = and_stmt; + append_to_statement_list_force (and_stmt, cond_expr_stmt_list); + + /* Make and_tmp the left operand of the conditional test against zero. + if and_tmp has a nonzero bit then some address is unaligned. */ + ptrsize_zero = build_int_cst (int_ptrsize_type, 0); + return build2 (EQ_EXPR, boolean_type_node, + and_tmp_name, ptrsize_zero); +} + + +/* Function vect_transform_loop. + + The analysis phase has determined that the loop is vectorizable. + Vectorize the loop - created vectorized stmts to replace the scalar + stmts in the loop, and update the loop exit condition. */ + +void +vect_transform_loop (loop_vec_info loop_vinfo, + struct loops *loops ATTRIBUTE_UNUSED) +{ + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); + int nbbs = loop->num_nodes; + block_stmt_iterator si; + int i; + tree ratio = NULL; + int vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo); + bitmap_iterator bi; + unsigned int j; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vec_transform_loop ==="); + + /* If the loop has data references that may or may not be aligned then + two versions of the loop need to be generated, one which is vectorized + and one which isn't. A test is then generated to control which of the + loops is executed. The test checks for the alignment of all of the + data references that may or may not be aligned. */ + + if (VEC_length (tree, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo))) + { + struct loop *nloop; + tree cond_expr; + tree cond_expr_stmt_list = NULL_TREE; + basic_block condition_bb; + block_stmt_iterator cond_exp_bsi; + basic_block merge_bb; + basic_block new_exit_bb; + edge new_exit_e, e; + tree orig_phi, new_phi, arg; + + cond_expr = vect_create_cond_for_align_checks (loop_vinfo, + &cond_expr_stmt_list); + initialize_original_copy_tables (); + nloop = loop_version (loops, loop, cond_expr, &condition_bb, true); + free_original_copy_tables(); + + /** Loop versioning violates an assumption we try to maintain during + vectorization - that the loop exit block has a single predecessor. + After versioning, the exit block of both loop versions is the same + basic block (i.e. it has two predecessors). Just in order to simplify + following transformations in the vectorizer, we fix this situation + here by adding a new (empty) block on the exit-edge of the loop, + with the proper loop-exit phis to maintain loop-closed-form. **/ + + merge_bb = loop->single_exit->dest; + gcc_assert (EDGE_COUNT (merge_bb->preds) == 2); + new_exit_bb = split_edge (loop->single_exit); + add_bb_to_loop (new_exit_bb, loop->outer); + new_exit_e = loop->single_exit; + e = EDGE_SUCC (new_exit_bb, 0); + + for (orig_phi = phi_nodes (merge_bb); orig_phi; + orig_phi = PHI_CHAIN (orig_phi)) + { + new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)), + new_exit_bb); + arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, e); + add_phi_arg (new_phi, arg, new_exit_e); + SET_PHI_ARG_DEF (orig_phi, e->dest_idx, PHI_RESULT (new_phi)); + } + + /** end loop-exit-fixes after versioning **/ + + update_ssa (TODO_update_ssa); + cond_exp_bsi = bsi_last (condition_bb); + bsi_insert_before (&cond_exp_bsi, cond_expr_stmt_list, BSI_SAME_STMT); + } + + /* CHECKME: we wouldn't need this if we called update_ssa once + for all loops. */ + bitmap_zero (vect_vnames_to_rename); + + /* Peel the loop if there are data refs with unknown alignment. + Only one data ref with unknown store is allowed. */ + + if (LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo)) + vect_do_peeling_for_alignment (loop_vinfo, loops); + + /* If the loop has a symbolic number of iterations 'n' (i.e. it's not a + compile time constant), or it is a constant that doesn't divide by the + vectorization factor, then an epilog loop needs to be created. + We therefore duplicate the loop: the original loop will be vectorized, + and will compute the first (n/VF) iterations. The second copy of the loop + will remain scalar and will compute the remaining (n%VF) iterations. + (VF is the vectorization factor). */ + + if (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) + || (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) + && LOOP_VINFO_INT_NITERS (loop_vinfo) % vectorization_factor != 0)) + vect_do_peeling_for_loop_bound (loop_vinfo, &ratio, loops); + else + ratio = build_int_cst (TREE_TYPE (LOOP_VINFO_NITERS (loop_vinfo)), + LOOP_VINFO_INT_NITERS (loop_vinfo) / vectorization_factor); + + /* 1) Make sure the loop header has exactly two entries + 2) Make sure we have a preheader basic block. */ + + gcc_assert (EDGE_COUNT (loop->header->preds) == 2); + + loop_split_edge_with (loop_preheader_edge (loop), NULL); + + + /* FORNOW: the vectorizer supports only loops which body consist + of one basic block (header + empty latch). When the vectorizer will + support more involved loop forms, the order by which the BBs are + traversed need to be reconsidered. */ + + for (i = 0; i < nbbs; i++) + { + basic_block bb = bbs[i]; + + for (si = bsi_start (bb); !bsi_end_p (si);) + { + tree stmt = bsi_stmt (si); + stmt_vec_info stmt_info; + bool is_store; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "------>vectorizing statement: "); + print_generic_expr (vect_dump, stmt, TDF_SLIM); + } + stmt_info = vinfo_for_stmt (stmt); + gcc_assert (stmt_info); + if (!STMT_VINFO_RELEVANT_P (stmt_info) + && !STMT_VINFO_LIVE_P (stmt_info)) + { + bsi_next (&si); + continue; + } + /* FORNOW: Verify that all stmts operate on the same number of + units and no inner unrolling is necessary. */ + gcc_assert + (TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info)) + == (unsigned HOST_WIDE_INT) vectorization_factor); + + /* -------- vectorize statement ------------ */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform statement."); + + is_store = vect_transform_stmt (stmt, &si); + if (is_store) + { + /* Free the attached stmt_vec_info and remove the stmt. */ + stmt_ann_t ann = stmt_ann (stmt); + free (stmt_info); + set_stmt_info (ann, NULL); + bsi_remove (&si, true); + continue; + } + + bsi_next (&si); + } /* stmts in BB */ + } /* BBs in loop */ + + slpeel_make_loop_iterate_ntimes (loop, ratio); + + EXECUTE_IF_SET_IN_BITMAP (vect_vnames_to_rename, 0, j, bi) + mark_sym_for_renaming (SSA_NAME_VAR (ssa_name (j))); + + /* The memory tags and pointers in vectorized statements need to + have their SSA forms updated. FIXME, why can't this be delayed + until all the loops have been transformed? */ + update_ssa (TODO_update_ssa); + + if (vect_print_dump_info (REPORT_VECTORIZED_LOOPS)) + fprintf (vect_dump, "LOOP VECTORIZED."); +} |
