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Diffstat (limited to 'gcc/tree-vect-loop.c')
| -rw-r--r-- | gcc/tree-vect-loop.c | 3587 |
1 files changed, 3587 insertions, 0 deletions
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c new file mode 100644 index 0000000..77dcdd6 --- /dev/null +++ b/gcc/tree-vect-loop.c @@ -0,0 +1,3587 @@ +/* Loop Vectorization + Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software + Foundation, Inc. + Contributed by Dorit Naishlos <dorit@il.ibm.com> and + Ira Rosen <irar@il.ibm.com> + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "ggc.h" +#include "tree.h" +#include "basic-block.h" +#include "diagnostic.h" +#include "tree-flow.h" +#include "tree-dump.h" +#include "cfgloop.h" +#include "cfglayout.h" +#include "expr.h" +#include "recog.h" +#include "optabs.h" +#include "params.h" +#include "toplev.h" +#include "tree-chrec.h" +#include "tree-scalar-evolution.h" +#include "tree-vectorizer.h" + +/* Loop Vectorization Pass. + + This pass tries to vectorize loops. + + For example, the vectorizer transforms the following simple loop: + + short a[N]; short b[N]; short c[N]; int i; + + for (i=0; i<N; i++){ + a[i] = b[i] + c[i]; + } + + as if it was manually vectorized by rewriting the source code into: + + typedef int __attribute__((mode(V8HI))) v8hi; + short a[N]; short b[N]; short c[N]; int i; + v8hi *pa = (v8hi*)a, *pb = (v8hi*)b, *pc = (v8hi*)c; + v8hi va, vb, vc; + + for (i=0; i<N/8; i++){ + vb = pb[i]; + vc = pc[i]; + va = vb + vc; + pa[i] = va; + } + + The main entry to this pass is vectorize_loops(), in which + the vectorizer applies a set of analyses on a given set of loops, + followed by the actual vectorization transformation for the loops that + had successfully passed the analysis phase. + Throughout this pass we make a distinction between two types of + data: scalars (which are represented by SSA_NAMES), and memory references + ("data-refs"). These two types of data require different handling both + during analysis and transformation. The types of data-refs that the + vectorizer currently supports are ARRAY_REFS which base is an array DECL + (not a pointer), and INDIRECT_REFS through pointers; both array and pointer + accesses are required to have a simple (consecutive) access pattern. + + Analysis phase: + =============== + The driver for the analysis phase is vect_analyze_loop(). + It applies a set of analyses, some of which rely on the scalar evolution + analyzer (scev) developed by Sebastian Pop. + + During the analysis phase the vectorizer records some information + per stmt in a "stmt_vec_info" struct which is attached to each stmt in the + loop, as well as general information about the loop as a whole, which is + recorded in a "loop_vec_info" struct attached to each loop. + + Transformation phase: + ===================== + The loop transformation phase scans all the stmts in the loop, and + creates a vector stmt (or a sequence of stmts) for each scalar stmt S in + the loop that needs to be vectorized. It inserts the vector code sequence + just before the scalar stmt S, and records a pointer to the vector code + in STMT_VINFO_VEC_STMT (stmt_info) (stmt_info is the stmt_vec_info struct + attached to S). This pointer will be used for the vectorization of following + stmts which use the def of stmt S. Stmt S is removed if it writes to memory; + otherwise, we rely on dead code elimination for removing it. + + For example, say stmt S1 was vectorized into stmt VS1: + + VS1: vb = px[i]; + S1: b = x[i]; STMT_VINFO_VEC_STMT (stmt_info (S1)) = VS1 + S2: a = b; + + To vectorize stmt S2, the vectorizer first finds the stmt that defines + the operand 'b' (S1), and gets the relevant vector def 'vb' from the + vector stmt VS1 pointed to by STMT_VINFO_VEC_STMT (stmt_info (S1)). The + resulting sequence would be: + + VS1: vb = px[i]; + S1: b = x[i]; STMT_VINFO_VEC_STMT (stmt_info (S1)) = VS1 + VS2: va = vb; + S2: a = b; STMT_VINFO_VEC_STMT (stmt_info (S2)) = VS2 + + Operands that are not SSA_NAMEs, are data-refs that appear in + load/store operations (like 'x[i]' in S1), and are handled differently. + + Target modeling: + ================= + Currently the only target specific information that is used is the + size of the vector (in bytes) - "UNITS_PER_SIMD_WORD". Targets that can + support different sizes of vectors, for now will need to specify one value + for "UNITS_PER_SIMD_WORD". More flexibility will be added in the future. + + Since we only vectorize operations which vector form can be + expressed using existing tree codes, to verify that an operation is + supported, the vectorizer checks the relevant optab at the relevant + machine_mode (e.g, optab_handler (add_optab, V8HImode)->insn_code). If + the value found is CODE_FOR_nothing, then there's no target support, and + we can't vectorize the stmt. + + For additional information on this project see: + http://gcc.gnu.org/projects/tree-ssa/vectorization.html +*/ + +/* Function vect_determine_vectorization_factor + + Determine the vectorization factor (VF). VF is the number of data elements + that are operated upon in parallel in a single iteration of the vectorized + loop. For example, when vectorizing a loop that operates on 4byte elements, + on a target with vector size (VS) 16byte, the VF is set to 4, since 4 + elements can fit in a single vector register. + + We currently support vectorization of loops in which all types operated upon + are of the same size. Therefore this function currently sets VF according to + the size of the types operated upon, and fails if there are multiple sizes + in the loop. + + VF is also the factor by which the loop iterations are strip-mined, e.g.: + original loop: + for (i=0; i<N; i++){ + a[i] = b[i] + c[i]; + } + + vectorized loop: + for (i=0; i<N; i+=VF){ + a[i:VF] = b[i:VF] + c[i:VF]; + } +*/ + +static bool +vect_determine_vectorization_factor (loop_vec_info loop_vinfo) +{ + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); + int nbbs = loop->num_nodes; + gimple_stmt_iterator si; + unsigned int vectorization_factor = 0; + tree scalar_type; + gimple phi; + tree vectype; + unsigned int nunits; + stmt_vec_info stmt_info; + int i; + HOST_WIDE_INT dummy; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vect_determine_vectorization_factor ==="); + + for (i = 0; i < nbbs; i++) + { + basic_block bb = bbs[i]; + + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + { + phi = gsi_stmt (si); + stmt_info = vinfo_for_stmt (phi); + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "==> examining phi: "); + print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM); + } + + gcc_assert (stmt_info); + + if (STMT_VINFO_RELEVANT_P (stmt_info)) + { + gcc_assert (!STMT_VINFO_VECTYPE (stmt_info)); + scalar_type = TREE_TYPE (PHI_RESULT (phi)); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "get vectype for scalar type: "); + print_generic_expr (vect_dump, scalar_type, TDF_SLIM); + } + + vectype = get_vectype_for_scalar_type (scalar_type); + if (!vectype) + { + if (vect_print_dump_info (REPORT_UNVECTORIZED_LOOPS)) + { + fprintf (vect_dump, + "not vectorized: unsupported data-type "); + print_generic_expr (vect_dump, scalar_type, TDF_SLIM); + } + return false; + } + STMT_VINFO_VECTYPE (stmt_info) = vectype; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "vectype: "); + print_generic_expr (vect_dump, vectype, TDF_SLIM); + } + + nunits = TYPE_VECTOR_SUBPARTS (vectype); + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "nunits = %d", nunits); + + if (!vectorization_factor + || (nunits > vectorization_factor)) + vectorization_factor = nunits; + } + } + + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple stmt = gsi_stmt (si); + stmt_info = vinfo_for_stmt (stmt); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "==> examining statement: "); + print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM); + } + + gcc_assert (stmt_info); + + /* skip stmts which do not need to be vectorized. */ + if (!STMT_VINFO_RELEVANT_P (stmt_info) + && !STMT_VINFO_LIVE_P (stmt_info)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "skip."); + continue; + } + + if (gimple_get_lhs (stmt) == NULL_TREE) + { + if (vect_print_dump_info (REPORT_UNVECTORIZED_LOOPS)) + { + fprintf (vect_dump, "not vectorized: irregular stmt."); + print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM); + } + return false; + } + + if (VECTOR_MODE_P (TYPE_MODE (gimple_expr_type (stmt)))) + { + if (vect_print_dump_info (REPORT_UNVECTORIZED_LOOPS)) + { + fprintf (vect_dump, "not vectorized: vector stmt in loop:"); + print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM); + } + return false; + } + + if (STMT_VINFO_VECTYPE (stmt_info)) + { + /* The only case when a vectype had been already set is for stmts + that contain a dataref, or for "pattern-stmts" (stmts generated + by the vectorizer to represent/replace a certain idiom). */ + gcc_assert (STMT_VINFO_DATA_REF (stmt_info) + || is_pattern_stmt_p (stmt_info)); + vectype = STMT_VINFO_VECTYPE (stmt_info); + } + else + { + + gcc_assert (! STMT_VINFO_DATA_REF (stmt_info) + && !is_pattern_stmt_p (stmt_info)); + + scalar_type = vect_get_smallest_scalar_type (stmt, &dummy, + &dummy); + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "get vectype for scalar type: "); + print_generic_expr (vect_dump, scalar_type, TDF_SLIM); + } + + vectype = get_vectype_for_scalar_type (scalar_type); + if (!vectype) + { + if (vect_print_dump_info (REPORT_UNVECTORIZED_LOOPS)) + { + fprintf (vect_dump, + "not vectorized: unsupported data-type "); + print_generic_expr (vect_dump, scalar_type, TDF_SLIM); + } + return false; + } + STMT_VINFO_VECTYPE (stmt_info) = vectype; + } + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "vectype: "); + print_generic_expr (vect_dump, vectype, TDF_SLIM); + } + + nunits = TYPE_VECTOR_SUBPARTS (vectype); + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "nunits = %d", nunits); + + if (!vectorization_factor + || (nunits > vectorization_factor)) + vectorization_factor = nunits; + + } + } + + /* TODO: Analyze cost. Decide if worth while to vectorize. */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "vectorization factor = %d", vectorization_factor); + if (vectorization_factor <= 1) + { + if (vect_print_dump_info (REPORT_UNVECTORIZED_LOOPS)) + fprintf (vect_dump, "not vectorized: unsupported data-type"); + return false; + } + LOOP_VINFO_VECT_FACTOR (loop_vinfo) = vectorization_factor; + + return true; +} + + +/* Function vect_is_simple_iv_evolution. + + FORNOW: A simple evolution of an induction variables in the loop is + considered a polynomial evolution with constant step. */ + +static bool +vect_is_simple_iv_evolution (unsigned loop_nb, tree access_fn, tree * init, + tree * step) +{ + tree init_expr; + tree step_expr; + tree evolution_part = evolution_part_in_loop_num (access_fn, loop_nb); + + /* When there is no evolution in this loop, the evolution function + is not "simple". */ + if (evolution_part == NULL_TREE) + return false; + + /* When the evolution is a polynomial of degree >= 2 + the evolution function is not "simple". */ + if (tree_is_chrec (evolution_part)) + return false; + + step_expr = evolution_part; + init_expr = unshare_expr (initial_condition_in_loop_num (access_fn, loop_nb)); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "step: "); + print_generic_expr (vect_dump, step_expr, TDF_SLIM); + fprintf (vect_dump, ", init: "); + print_generic_expr (vect_dump, init_expr, TDF_SLIM); + } + + *init = init_expr; + *step = step_expr; + + if (TREE_CODE (step_expr) != INTEGER_CST) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "step unknown."); + return false; + } + + return true; +} + +/* Function vect_analyze_scalar_cycles_1. + + Examine the cross iteration def-use cycles of scalar variables + in LOOP. LOOP_VINFO represents the loop that is now being + considered for vectorization (can be LOOP, or an outer-loop + enclosing LOOP). */ + +static void +vect_analyze_scalar_cycles_1 (loop_vec_info loop_vinfo, struct loop *loop) +{ + basic_block bb = loop->header; + tree dumy; + VEC(gimple,heap) *worklist = VEC_alloc (gimple, heap, 64); + gimple_stmt_iterator gsi; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vect_analyze_scalar_cycles ==="); + + /* First - identify all inductions. */ + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple phi = gsi_stmt (gsi); + tree access_fn = NULL; + tree def = PHI_RESULT (phi); + stmt_vec_info stmt_vinfo = vinfo_for_stmt (phi); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "Analyze phi: "); + print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM); + } + + /* Skip virtual phi's. The data dependences that are associated with + virtual defs/uses (i.e., memory accesses) are analyzed elsewhere. */ + if (!is_gimple_reg (SSA_NAME_VAR (def))) + continue; + + STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_unknown_def_type; + + /* Analyze the evolution function. */ + access_fn = analyze_scalar_evolution (loop, def); + if (access_fn && vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "Access function of PHI: "); + print_generic_expr (vect_dump, access_fn, TDF_SLIM); + } + + if (!access_fn + || !vect_is_simple_iv_evolution (loop->num, access_fn, &dumy, &dumy)) + { + VEC_safe_push (gimple, heap, worklist, phi); + continue; + } + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Detected induction."); + STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_induction_def; + } + + + /* Second - identify all reductions. */ + while (VEC_length (gimple, worklist) > 0) + { + gimple phi = VEC_pop (gimple, worklist); + tree def = PHI_RESULT (phi); + stmt_vec_info stmt_vinfo = vinfo_for_stmt (phi); + gimple reduc_stmt; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "Analyze phi: "); + print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM); + } + + gcc_assert (is_gimple_reg (SSA_NAME_VAR (def))); + gcc_assert (STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_unknown_def_type); + + reduc_stmt = vect_is_simple_reduction (loop_vinfo, phi); + if (reduc_stmt) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Detected reduction."); + STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_reduction_def; + STMT_VINFO_DEF_TYPE (vinfo_for_stmt (reduc_stmt)) = + vect_reduction_def; + } + else + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Unknown def-use cycle pattern."); + } + + VEC_free (gimple, heap, worklist); + return; +} + + +/* Function vect_analyze_scalar_cycles. + + Examine the cross iteration def-use cycles of scalar variables, by + analyzing the loop-header PHIs of scalar variables; Classify each + cycle as one of the following: invariant, induction, reduction, unknown. + We do that for the loop represented by LOOP_VINFO, and also to its + inner-loop, if exists. + Examples for scalar cycles: + + Example1: reduction: + + loop1: + for (i=0; i<N; i++) + sum += a[i]; + + Example2: induction: + + loop2: + for (i=0; i<N; i++) + a[i] = i; */ + +static void +vect_analyze_scalar_cycles (loop_vec_info loop_vinfo) +{ + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + + vect_analyze_scalar_cycles_1 (loop_vinfo, loop); + + /* When vectorizing an outer-loop, the inner-loop is executed sequentially. + Reductions in such inner-loop therefore have different properties than + the reductions in the nest that gets vectorized: + 1. When vectorized, they are executed in the same order as in the original + scalar loop, so we can't change the order of computation when + vectorizing them. + 2. FIXME: Inner-loop reductions can be used in the inner-loop, so the + current checks are too strict. */ + + if (loop->inner) + vect_analyze_scalar_cycles_1 (loop_vinfo, loop->inner); +} + + +/* Function vect_get_loop_niters. + + Determine how many iterations the loop is executed. + If an expression that represents the number of iterations + can be constructed, place it in NUMBER_OF_ITERATIONS. + Return the loop exit condition. */ + +static gimple +vect_get_loop_niters (struct loop *loop, tree *number_of_iterations) +{ + tree niters; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== get_loop_niters ==="); + + niters = number_of_exit_cond_executions (loop); + + if (niters != NULL_TREE + && niters != chrec_dont_know) + { + *number_of_iterations = niters; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "==> get_loop_niters:" ); + print_generic_expr (vect_dump, *number_of_iterations, TDF_SLIM); + } + } + + return get_loop_exit_condition (loop); +} + + +/* Function bb_in_loop_p + + Used as predicate for dfs order traversal of the loop bbs. */ + +static bool +bb_in_loop_p (const_basic_block bb, const void *data) +{ + const struct loop *const loop = (const struct loop *)data; + if (flow_bb_inside_loop_p (loop, bb)) + return true; + return false; +} + + +/* Function new_loop_vec_info. + + Create and initialize a new loop_vec_info struct for LOOP, as well as + stmt_vec_info structs for all the stmts in LOOP. */ + +static loop_vec_info +new_loop_vec_info (struct loop *loop) +{ + loop_vec_info res; + basic_block *bbs; + gimple_stmt_iterator si; + unsigned int i, nbbs; + + res = (loop_vec_info) xcalloc (1, sizeof (struct _loop_vec_info)); + LOOP_VINFO_LOOP (res) = loop; + + bbs = get_loop_body (loop); + + /* Create/Update stmt_info for all stmts in the loop. */ + for (i = 0; i < loop->num_nodes; i++) + { + basic_block bb = bbs[i]; + + /* BBs in a nested inner-loop will have been already processed (because + we will have called vect_analyze_loop_form for any nested inner-loop). + Therefore, for stmts in an inner-loop we just want to update the + STMT_VINFO_LOOP_VINFO field of their stmt_info to point to the new + loop_info of the outer-loop we are currently considering to vectorize + (instead of the loop_info of the inner-loop). + For stmts in other BBs we need to create a stmt_info from scratch. */ + if (bb->loop_father != loop) + { + /* Inner-loop bb. */ + gcc_assert (loop->inner && bb->loop_father == loop->inner); + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple phi = gsi_stmt (si); + stmt_vec_info stmt_info = vinfo_for_stmt (phi); + loop_vec_info inner_loop_vinfo = + STMT_VINFO_LOOP_VINFO (stmt_info); + gcc_assert (loop->inner == LOOP_VINFO_LOOP (inner_loop_vinfo)); + STMT_VINFO_LOOP_VINFO (stmt_info) = res; + } + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple stmt = gsi_stmt (si); + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + loop_vec_info inner_loop_vinfo = + STMT_VINFO_LOOP_VINFO (stmt_info); + gcc_assert (loop->inner == LOOP_VINFO_LOOP (inner_loop_vinfo)); + STMT_VINFO_LOOP_VINFO (stmt_info) = res; + } + } + else + { + /* bb in current nest. */ + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple phi = gsi_stmt (si); + gimple_set_uid (phi, 0); + set_vinfo_for_stmt (phi, new_stmt_vec_info (phi, res)); + } + + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple stmt = gsi_stmt (si); + gimple_set_uid (stmt, 0); + set_vinfo_for_stmt (stmt, new_stmt_vec_info (stmt, res)); + } + } + } + + /* CHECKME: We want to visit all BBs before their successors (except for + latch blocks, for which this assertion wouldn't hold). In the simple + case of the loop forms we allow, a dfs order of the BBs would the same + as reversed postorder traversal, so we are safe. */ + + free (bbs); + bbs = XCNEWVEC (basic_block, loop->num_nodes); + nbbs = dfs_enumerate_from (loop->header, 0, bb_in_loop_p, + bbs, loop->num_nodes, loop); + gcc_assert (nbbs == loop->num_nodes); + + LOOP_VINFO_BBS (res) = bbs; + LOOP_VINFO_NITERS (res) = NULL; + LOOP_VINFO_NITERS_UNCHANGED (res) = NULL; + LOOP_VINFO_COST_MODEL_MIN_ITERS (res) = 0; + LOOP_VINFO_VECTORIZABLE_P (res) = 0; + LOOP_PEELING_FOR_ALIGNMENT (res) = 0; + LOOP_VINFO_VECT_FACTOR (res) = 0; + LOOP_VINFO_DATAREFS (res) = VEC_alloc (data_reference_p, heap, 10); + LOOP_VINFO_DDRS (res) = VEC_alloc (ddr_p, heap, 10 * 10); + LOOP_VINFO_UNALIGNED_DR (res) = NULL; + LOOP_VINFO_MAY_MISALIGN_STMTS (res) = + VEC_alloc (gimple, heap, + PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIGNMENT_CHECKS)); + LOOP_VINFO_MAY_ALIAS_DDRS (res) = + VEC_alloc (ddr_p, heap, + PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS)); + LOOP_VINFO_STRIDED_STORES (res) = VEC_alloc (gimple, heap, 10); + LOOP_VINFO_SLP_INSTANCES (res) = VEC_alloc (slp_instance, heap, 10); + LOOP_VINFO_SLP_UNROLLING_FACTOR (res) = 1; + + return res; +} + + +/* Function destroy_loop_vec_info. + + Free LOOP_VINFO struct, as well as all the stmt_vec_info structs of all the + stmts in the loop. */ + +void +destroy_loop_vec_info (loop_vec_info loop_vinfo, bool clean_stmts) +{ + struct loop *loop; + basic_block *bbs; + int nbbs; + gimple_stmt_iterator si; + int j; + VEC (slp_instance, heap) *slp_instances; + slp_instance instance; + + if (!loop_vinfo) + return; + + loop = LOOP_VINFO_LOOP (loop_vinfo); + + bbs = LOOP_VINFO_BBS (loop_vinfo); + nbbs = loop->num_nodes; + + if (!clean_stmts) + { + free (LOOP_VINFO_BBS (loop_vinfo)); + free_data_refs (LOOP_VINFO_DATAREFS (loop_vinfo)); + free_dependence_relations (LOOP_VINFO_DDRS (loop_vinfo)); + VEC_free (gimple, heap, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)); + + free (loop_vinfo); + loop->aux = NULL; + return; + } + + for (j = 0; j < nbbs; j++) + { + basic_block bb = bbs[j]; + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + free_stmt_vec_info (gsi_stmt (si)); + + for (si = gsi_start_bb (bb); !gsi_end_p (si); ) + { + gimple stmt = gsi_stmt (si); + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + + if (stmt_info) + { + /* Check if this is a "pattern stmt" (introduced by the + vectorizer during the pattern recognition pass). */ + bool remove_stmt_p = false; + gimple orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info); + if (orig_stmt) + { + stmt_vec_info orig_stmt_info = vinfo_for_stmt (orig_stmt); + if (orig_stmt_info + && STMT_VINFO_IN_PATTERN_P (orig_stmt_info)) + remove_stmt_p = true; + } + + /* Free stmt_vec_info. */ + free_stmt_vec_info (stmt); + + /* Remove dead "pattern stmts". */ + if (remove_stmt_p) + gsi_remove (&si, true); + } + gsi_next (&si); + } + } + + free (LOOP_VINFO_BBS (loop_vinfo)); + free_data_refs (LOOP_VINFO_DATAREFS (loop_vinfo)); + free_dependence_relations (LOOP_VINFO_DDRS (loop_vinfo)); + VEC_free (gimple, heap, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)); + VEC_free (ddr_p, heap, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo)); + slp_instances = LOOP_VINFO_SLP_INSTANCES (loop_vinfo); + for (j = 0; VEC_iterate (slp_instance, slp_instances, j, instance); j++) + vect_free_slp_instance (instance); + + VEC_free (slp_instance, heap, LOOP_VINFO_SLP_INSTANCES (loop_vinfo)); + VEC_free (gimple, heap, LOOP_VINFO_STRIDED_STORES (loop_vinfo)); + + free (loop_vinfo); + loop->aux = NULL; +} + + +/* Function vect_analyze_loop_1. + + Apply a set of analyses on LOOP, and create a loop_vec_info struct + for it. The different analyses will record information in the + loop_vec_info struct. This is a subset of the analyses applied in + vect_analyze_loop, to be applied on an inner-loop nested in the loop + that is now considered for (outer-loop) vectorization. */ + +static loop_vec_info +vect_analyze_loop_1 (struct loop *loop) +{ + loop_vec_info loop_vinfo; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "===== analyze_loop_nest_1 ====="); + + /* Check the CFG characteristics of the loop (nesting, entry/exit, etc. */ + + loop_vinfo = vect_analyze_loop_form (loop); + if (!loop_vinfo) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad inner-loop form."); + return NULL; + } + + return loop_vinfo; +} + + +/* Function vect_analyze_loop_form. + + Verify that certain CFG restrictions hold, including: + - the loop has a pre-header + - the loop has a single entry and exit + - the loop exit condition is simple enough, and the number of iterations + can be analyzed (a countable loop). */ + +loop_vec_info +vect_analyze_loop_form (struct loop *loop) +{ + loop_vec_info loop_vinfo; + gimple loop_cond; + tree number_of_iterations = NULL; + loop_vec_info inner_loop_vinfo = NULL; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vect_analyze_loop_form ==="); + + /* Different restrictions apply when we are considering an inner-most loop, + vs. an outer (nested) loop. + (FORNOW. May want to relax some of these restrictions in the future). */ + + if (!loop->inner) + { + /* Inner-most loop. We currently require that the number of BBs is + exactly 2 (the header and latch). Vectorizable inner-most loops + look like this: + + (pre-header) + | + header <--------+ + | | | + | +--> latch --+ + | + (exit-bb) */ + + if (loop->num_nodes != 2) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: too many BBs in loop."); + return NULL; + } + + if (empty_block_p (loop->header)) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: empty loop."); + return NULL; + } + } + else + { + struct loop *innerloop = loop->inner; + edge backedge, entryedge; + + /* Nested loop. We currently require that the loop is doubly-nested, + contains a single inner loop, and the number of BBs is exactly 5. + Vectorizable outer-loops look like this: + + (pre-header) + | + header <---+ + | | + inner-loop | + | | + tail ------+ + | + (exit-bb) + + The inner-loop has the properties expected of inner-most loops + as described above. */ + + if ((loop->inner)->inner || (loop->inner)->next) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: multiple nested loops."); + return NULL; + } + + /* Analyze the inner-loop. */ + inner_loop_vinfo = vect_analyze_loop_1 (loop->inner); + if (!inner_loop_vinfo) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: Bad inner loop."); + return NULL; + } + + if (!expr_invariant_in_loop_p (loop, + LOOP_VINFO_NITERS (inner_loop_vinfo))) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, + "not vectorized: inner-loop count not invariant."); + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + if (loop->num_nodes != 5) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: too many BBs in loop."); + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + gcc_assert (EDGE_COUNT (innerloop->header->preds) == 2); + backedge = EDGE_PRED (innerloop->header, 1); + entryedge = EDGE_PRED (innerloop->header, 0); + if (EDGE_PRED (innerloop->header, 0)->src == innerloop->latch) + { + backedge = EDGE_PRED (innerloop->header, 0); + entryedge = EDGE_PRED (innerloop->header, 1); + } + + if (entryedge->src != loop->header + || !single_exit (innerloop) + || single_exit (innerloop)->dest != EDGE_PRED (loop->latch, 0)->src) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: unsupported outerloop form."); + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Considering outer-loop vectorization."); + } + + if (!single_exit (loop) + || EDGE_COUNT (loop->header->preds) != 2) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + { + if (!single_exit (loop)) + fprintf (vect_dump, "not vectorized: multiple exits."); + else if (EDGE_COUNT (loop->header->preds) != 2) + fprintf (vect_dump, "not vectorized: too many incoming edges."); + } + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + /* We assume that the loop exit condition is at the end of the loop. i.e, + that the loop is represented as a do-while (with a proper if-guard + before the loop if needed), where the loop header contains all the + executable statements, and the latch is empty. */ + if (!empty_block_p (loop->latch) + || phi_nodes (loop->latch)) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: unexpected loop form."); + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + /* Make sure there exists a single-predecessor exit bb: */ + if (!single_pred_p (single_exit (loop)->dest)) + { + edge e = single_exit (loop); + if (!(e->flags & EDGE_ABNORMAL)) + { + split_loop_exit_edge (e); + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "split exit edge."); + } + else + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: abnormal loop exit edge."); + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + } + + loop_cond = vect_get_loop_niters (loop, &number_of_iterations); + if (!loop_cond) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "not vectorized: complicated exit condition."); + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + if (!number_of_iterations) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, + "not vectorized: number of iterations cannot be computed."); + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + if (chrec_contains_undetermined (number_of_iterations)) + { + if (vect_print_dump_info (REPORT_BAD_FORM_LOOPS)) + fprintf (vect_dump, "Infinite number of iterations."); + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, true); + return NULL; + } + + if (!NITERS_KNOWN_P (number_of_iterations)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "Symbolic number of iterations is "); + print_generic_expr (vect_dump, number_of_iterations, TDF_DETAILS); + } + } + else if (TREE_INT_CST_LOW (number_of_iterations) == 0) + { + if (vect_print_dump_info (REPORT_UNVECTORIZED_LOOPS)) + fprintf (vect_dump, "not vectorized: number of iterations = 0."); + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, false); + return NULL; + } + + loop_vinfo = new_loop_vec_info (loop); + LOOP_VINFO_NITERS (loop_vinfo) = number_of_iterations; + LOOP_VINFO_NITERS_UNCHANGED (loop_vinfo) = number_of_iterations; + + STMT_VINFO_TYPE (vinfo_for_stmt (loop_cond)) = loop_exit_ctrl_vec_info_type; + + /* CHECKME: May want to keep it around it in the future. */ + if (inner_loop_vinfo) + destroy_loop_vec_info (inner_loop_vinfo, false); + + gcc_assert (!loop->aux); + loop->aux = loop_vinfo; + return loop_vinfo; +} + +/* Function vect_analyze_loop. + + Apply a set of analyses on LOOP, and create a loop_vec_info struct + for it. The different analyses will record information in the + loop_vec_info struct. */ +loop_vec_info +vect_analyze_loop (struct loop *loop) +{ + bool ok; + loop_vec_info loop_vinfo; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "===== analyze_loop_nest ====="); + + if (loop_outer (loop) + && loop_vec_info_for_loop (loop_outer (loop)) + && LOOP_VINFO_VECTORIZABLE_P (loop_vec_info_for_loop (loop_outer (loop)))) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "outer-loop already vectorized."); + return NULL; + } + + /* Check the CFG characteristics of the loop (nesting, entry/exit, etc. */ + + loop_vinfo = vect_analyze_loop_form (loop); + if (!loop_vinfo) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad loop form."); + return NULL; + } + + /* Find all data references in the loop (which correspond to vdefs/vuses) + and analyze their evolution in the loop. + + FORNOW: Handle only simple, array references, which + alignment can be forced, and aligned pointer-references. */ + + ok = vect_analyze_data_refs (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad data references."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + /* Classify all cross-iteration scalar data-flow cycles. + Cross-iteration cycles caused by virtual phis are analyzed separately. */ + + vect_analyze_scalar_cycles (loop_vinfo); + + vect_pattern_recog (loop_vinfo); + + /* Data-flow analysis to detect stmts that do not need to be vectorized. */ + + ok = vect_mark_stmts_to_be_vectorized (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "unexpected pattern."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + /* Analyze the alignment of the data-refs in the loop. + Fail if a data reference is found that cannot be vectorized. */ + + ok = vect_analyze_data_refs_alignment (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad data alignment."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + ok = vect_determine_vectorization_factor (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "can't determine vectorization factor."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + /* Analyze data dependences between the data-refs in the loop. + FORNOW: fail at the first data dependence that we encounter. */ + + ok = vect_analyze_data_ref_dependences (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad data dependence."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + /* Analyze the access patterns of the data-refs in the loop (consecutive, + complex, etc.). FORNOW: Only handle consecutive access pattern. */ + + ok = vect_analyze_data_ref_accesses (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad data access."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + /* Prune the list of ddrs to be tested at run-time by versioning for alias. + It is important to call pruning after vect_analyze_data_ref_accesses, + since we use grouping information gathered by interleaving analysis. */ + ok = vect_prune_runtime_alias_test_list (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "too long list of versioning for alias " + "run-time tests."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + /* Check the SLP opportunities in the loop, analyze and build SLP trees. */ + ok = vect_analyze_slp (loop_vinfo); + if (ok) + { + /* Decide which possible SLP instances to SLP. */ + vect_make_slp_decision (loop_vinfo); + + /* Find stmts that need to be both vectorized and SLPed. */ + vect_detect_hybrid_slp (loop_vinfo); + } + + /* This pass will decide on using loop versioning and/or loop peeling in + order to enhance the alignment of data references in the loop. */ + + ok = vect_enhance_data_refs_alignment (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad data alignment."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + /* Scan all the operations in the loop and make sure they are + vectorizable. */ + + ok = vect_analyze_operations (loop_vinfo); + if (!ok) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "bad operation or unsupported loop bound."); + destroy_loop_vec_info (loop_vinfo, true); + return NULL; + } + + LOOP_VINFO_VECTORIZABLE_P (loop_vinfo) = 1; + + return loop_vinfo; +} + + +/* Function reduction_code_for_scalar_code + + Input: + CODE - tree_code of a reduction operations. + + Output: + REDUC_CODE - the corresponding tree-code to be used to reduce the + vector of partial results into a single scalar result (which + will also reside in a vector). + + Return TRUE if a corresponding REDUC_CODE was found, FALSE otherwise. */ + +static bool +reduction_code_for_scalar_code (enum tree_code code, + enum tree_code *reduc_code) +{ + switch (code) + { + case MAX_EXPR: + *reduc_code = REDUC_MAX_EXPR; + return true; + + case MIN_EXPR: + *reduc_code = REDUC_MIN_EXPR; + return true; + + case PLUS_EXPR: + *reduc_code = REDUC_PLUS_EXPR; + return true; + + default: + return false; + } +} + + +/* Error reporting helper for vect_is_simple_reduction below. GIMPLE statement + STMT is printed with a message MSG. */ + +static void +report_vect_op (gimple stmt, const char *msg) +{ + fprintf (vect_dump, "%s", msg); + print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM); +} + + +/* Function vect_is_simple_reduction + + Detect a cross-iteration def-use cycle that represents a simple + reduction computation. We look for the following pattern: + + loop_header: + a1 = phi < a0, a2 > + a3 = ... + a2 = operation (a3, a1) + + such that: + 1. operation is commutative and associative and it is safe to + change the order of the computation. + 2. no uses for a2 in the loop (a2 is used out of the loop) + 3. no uses of a1 in the loop besides the reduction operation. + + Condition 1 is tested here. + Conditions 2,3 are tested in vect_mark_stmts_to_be_vectorized. */ + +gimple +vect_is_simple_reduction (loop_vec_info loop_info, gimple phi) +{ + struct loop *loop = (gimple_bb (phi))->loop_father; + struct loop *vect_loop = LOOP_VINFO_LOOP (loop_info); + edge latch_e = loop_latch_edge (loop); + tree loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e); + gimple def_stmt, def1, def2; + enum tree_code code; + tree op1, op2; + tree type; + int nloop_uses; + tree name; + imm_use_iterator imm_iter; + use_operand_p use_p; + + gcc_assert (loop == vect_loop || flow_loop_nested_p (vect_loop, loop)); + + name = PHI_RESULT (phi); + nloop_uses = 0; + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name) + { + gimple use_stmt = USE_STMT (use_p); + if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)) + && vinfo_for_stmt (use_stmt) + && !is_pattern_stmt_p (vinfo_for_stmt (use_stmt))) + nloop_uses++; + if (nloop_uses > 1) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "reduction used in loop."); + return NULL; + } + } + + if (TREE_CODE (loop_arg) != SSA_NAME) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: not ssa_name: "); + print_generic_expr (vect_dump, loop_arg, TDF_SLIM); + } + return NULL; + } + + def_stmt = SSA_NAME_DEF_STMT (loop_arg); + if (!def_stmt) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "reduction: no def_stmt."); + return NULL; + } + + if (!is_gimple_assign (def_stmt)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + print_gimple_stmt (vect_dump, def_stmt, 0, TDF_SLIM); + return NULL; + } + + name = gimple_assign_lhs (def_stmt); + nloop_uses = 0; + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name) + { + gimple use_stmt = USE_STMT (use_p); + if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt)) + && vinfo_for_stmt (use_stmt) + && !is_pattern_stmt_p (vinfo_for_stmt (use_stmt))) + nloop_uses++; + if (nloop_uses > 1) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "reduction used in loop."); + return NULL; + } + } + + code = gimple_assign_rhs_code (def_stmt); + + if (!commutative_tree_code (code) || !associative_tree_code (code)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "reduction: not commutative/associative: "); + return NULL; + } + + if (get_gimple_rhs_class (code) != GIMPLE_BINARY_RHS) + { + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "reduction: not binary operation: "); + return NULL; + } + + op1 = gimple_assign_rhs1 (def_stmt); + op2 = gimple_assign_rhs2 (def_stmt); + if (TREE_CODE (op1) != SSA_NAME || TREE_CODE (op2) != SSA_NAME) + { + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "reduction: uses not ssa_names: "); + return NULL; + } + + /* Check that it's ok to change the order of the computation. */ + type = TREE_TYPE (gimple_assign_lhs (def_stmt)); + if (TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (TREE_TYPE (op1)) + || TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (TREE_TYPE (op2))) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: multiple types: operation type: "); + print_generic_expr (vect_dump, type, TDF_SLIM); + fprintf (vect_dump, ", operands types: "); + print_generic_expr (vect_dump, TREE_TYPE (op1), TDF_SLIM); + fprintf (vect_dump, ","); + print_generic_expr (vect_dump, TREE_TYPE (op2), TDF_SLIM); + } + return NULL; + } + + /* Generally, when vectorizing a reduction we change the order of the + computation. This may change the behavior of the program in some + cases, so we need to check that this is ok. One exception is when + vectorizing an outer-loop: the inner-loop is executed sequentially, + and therefore vectorizing reductions in the inner-loop during + outer-loop vectorization is safe. */ + + /* CHECKME: check for !flag_finite_math_only too? */ + if (SCALAR_FLOAT_TYPE_P (type) && !flag_associative_math + && !nested_in_vect_loop_p (vect_loop, def_stmt)) + { + /* Changing the order of operations changes the semantics. */ + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "reduction: unsafe fp math optimization: "); + return NULL; + } + else if (INTEGRAL_TYPE_P (type) && TYPE_OVERFLOW_TRAPS (type) + && !nested_in_vect_loop_p (vect_loop, def_stmt)) + { + /* Changing the order of operations changes the semantics. */ + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "reduction: unsafe int math optimization: "); + return NULL; + } + else if (SAT_FIXED_POINT_TYPE_P (type)) + { + /* Changing the order of operations changes the semantics. */ + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, + "reduction: unsafe fixed-point math optimization: "); + return NULL; + } + + /* reduction is safe. we're dealing with one of the following: + 1) integer arithmetic and no trapv + 2) floating point arithmetic, and special flags permit this optimization. + */ + def1 = SSA_NAME_DEF_STMT (op1); + def2 = SSA_NAME_DEF_STMT (op2); + if (!def1 || !def2 || gimple_nop_p (def1) || gimple_nop_p (def2)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "reduction: no defs for operands: "); + return NULL; + } + + + /* Check that one def is the reduction def, defined by PHI, + the other def is either defined in the loop ("vect_loop_def"), + or it's an induction (defined by a loop-header phi-node). */ + + if (def2 == phi + && flow_bb_inside_loop_p (loop, gimple_bb (def1)) + && (is_gimple_assign (def1) + || STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def1)) == vect_induction_def + || (gimple_code (def1) == GIMPLE_PHI + && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def1)) == vect_loop_def + && !is_loop_header_bb_p (gimple_bb (def1))))) + { + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "detected reduction:"); + return def_stmt; + } + else if (def1 == phi + && flow_bb_inside_loop_p (loop, gimple_bb (def2)) + && (is_gimple_assign (def2) + || STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def2)) == vect_induction_def + || (gimple_code (def2) == GIMPLE_PHI + && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def2)) == vect_loop_def + && !is_loop_header_bb_p (gimple_bb (def2))))) + { + /* Swap operands (just for simplicity - so that the rest of the code + can assume that the reduction variable is always the last (second) + argument). */ + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt , + "detected reduction: need to swap operands:"); + swap_tree_operands (def_stmt, gimple_assign_rhs1_ptr (def_stmt), + gimple_assign_rhs2_ptr (def_stmt)); + return def_stmt; + } + else + { + if (vect_print_dump_info (REPORT_DETAILS)) + report_vect_op (def_stmt, "reduction: unknown pattern."); + return NULL; + } +} + + +/* Function vect_estimate_min_profitable_iters + + Return the number of iterations required for the vector version of the + loop to be profitable relative to the cost of the scalar version of the + loop. + + TODO: Take profile info into account before making vectorization + decisions, if available. */ + +int +vect_estimate_min_profitable_iters (loop_vec_info loop_vinfo) +{ + int i; + int min_profitable_iters; + int peel_iters_prologue; + int peel_iters_epilogue; + int vec_inside_cost = 0; + int vec_outside_cost = 0; + int scalar_single_iter_cost = 0; + int scalar_outside_cost = 0; + int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); + int nbbs = loop->num_nodes; + int byte_misalign = LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo); + int peel_guard_costs = 0; + int innerloop_iters = 0, factor; + VEC (slp_instance, heap) *slp_instances; + slp_instance instance; + + /* Cost model disabled. */ + if (!flag_vect_cost_model) + { + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "cost model disabled."); + return 0; + } + + /* Requires loop versioning tests to handle misalignment. */ + if (VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo))) + { + /* FIXME: Make cost depend on complexity of individual check. */ + vec_outside_cost += + VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)); + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "cost model: Adding cost of checks for loop " + "versioning to treat misalignment.\n"); + } + + if (VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo))) + { + /* FIXME: Make cost depend on complexity of individual check. */ + vec_outside_cost += + VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo)); + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "cost model: Adding cost of checks for loop " + "versioning aliasing.\n"); + } + + if (VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)) + || VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo))) + { + vec_outside_cost += TARG_COND_TAKEN_BRANCH_COST; + } + + /* Count statements in scalar loop. Using this as scalar cost for a single + iteration for now. + + TODO: Add outer loop support. + + TODO: Consider assigning different costs to different scalar + statements. */ + + /* FORNOW. */ + if (loop->inner) + innerloop_iters = 50; /* FIXME */ + + for (i = 0; i < nbbs; i++) + { + gimple_stmt_iterator si; + basic_block bb = bbs[i]; + + if (bb->loop_father == loop->inner) + factor = innerloop_iters; + else + factor = 1; + + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple stmt = gsi_stmt (si); + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + /* Skip stmts that are not vectorized inside the loop. */ + if (!STMT_VINFO_RELEVANT_P (stmt_info) + && (!STMT_VINFO_LIVE_P (stmt_info) + || STMT_VINFO_DEF_TYPE (stmt_info) != vect_reduction_def)) + continue; + scalar_single_iter_cost += cost_for_stmt (stmt) * factor; + vec_inside_cost += STMT_VINFO_INSIDE_OF_LOOP_COST (stmt_info) * factor; + /* FIXME: for stmts in the inner-loop in outer-loop vectorization, + some of the "outside" costs are generated inside the outer-loop. */ + vec_outside_cost += STMT_VINFO_OUTSIDE_OF_LOOP_COST (stmt_info); + } + } + + /* Add additional cost for the peeled instructions in prologue and epilogue + loop. + + FORNOW: If we don't know the value of peel_iters for prologue or epilogue + at compile-time - we assume it's vf/2 (the worst would be vf-1). + + TODO: Build an expression that represents peel_iters for prologue and + epilogue to be used in a run-time test. */ + + if (byte_misalign < 0) + { + peel_iters_prologue = vf/2; + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "cost model: " + "prologue peel iters set to vf/2."); + + /* If peeling for alignment is unknown, loop bound of main loop becomes + unknown. */ + peel_iters_epilogue = vf/2; + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "cost model: " + "epilogue peel iters set to vf/2 because " + "peeling for alignment is unknown ."); + + /* If peeled iterations are unknown, count a taken branch and a not taken + branch per peeled loop. Even if scalar loop iterations are known, + vector iterations are not known since peeled prologue iterations are + not known. Hence guards remain the same. */ + peel_guard_costs += 2 * (TARG_COND_TAKEN_BRANCH_COST + + TARG_COND_NOT_TAKEN_BRANCH_COST); + } + else + { + if (byte_misalign) + { + struct data_reference *dr = LOOP_VINFO_UNALIGNED_DR (loop_vinfo); + int element_size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (DR_REF (dr)))); + tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (DR_STMT (dr))); + int nelements = TYPE_VECTOR_SUBPARTS (vectype); + + peel_iters_prologue = nelements - (byte_misalign / element_size); + } + else + peel_iters_prologue = 0; + + if (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)) + { + peel_iters_epilogue = vf/2; + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "cost model: " + "epilogue peel iters set to vf/2 because " + "loop iterations are unknown ."); + + /* If peeled iterations are known but number of scalar loop + iterations are unknown, count a taken branch per peeled loop. */ + peel_guard_costs += 2 * TARG_COND_TAKEN_BRANCH_COST; + + } + else + { + int niters = LOOP_VINFO_INT_NITERS (loop_vinfo); + peel_iters_prologue = niters < peel_iters_prologue ? + niters : peel_iters_prologue; + peel_iters_epilogue = (niters - peel_iters_prologue) % vf; + } + } + + vec_outside_cost += (peel_iters_prologue * scalar_single_iter_cost) + + (peel_iters_epilogue * scalar_single_iter_cost) + + peel_guard_costs; + + /* FORNOW: The scalar outside cost is incremented in one of the + following ways: + + 1. The vectorizer checks for alignment and aliasing and generates + a condition that allows dynamic vectorization. A cost model + check is ANDED with the versioning condition. Hence scalar code + path now has the added cost of the versioning check. + + if (cost > th & versioning_check) + jmp to vector code + + Hence run-time scalar is incremented by not-taken branch cost. + + 2. The vectorizer then checks if a prologue is required. If the + cost model check was not done before during versioning, it has to + be done before the prologue check. + + if (cost <= th) + prologue = scalar_iters + if (prologue == 0) + jmp to vector code + else + execute prologue + if (prologue == num_iters) + go to exit + + Hence the run-time scalar cost is incremented by a taken branch, + plus a not-taken branch, plus a taken branch cost. + + 3. The vectorizer then checks if an epilogue is required. If the + cost model check was not done before during prologue check, it + has to be done with the epilogue check. + + if (prologue == 0) + jmp to vector code + else + execute prologue + if (prologue == num_iters) + go to exit + vector code: + if ((cost <= th) | (scalar_iters-prologue-epilogue == 0)) + jmp to epilogue + + Hence the run-time scalar cost should be incremented by 2 taken + branches. + + TODO: The back end may reorder the BBS's differently and reverse + conditions/branch directions. Change the estimates below to + something more reasonable. */ + + /* If the number of iterations is known and we do not do versioning, we can + decide whether to vectorize at compile time. Hence the scalar version + do not carry cost model guard costs. */ + if (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) + || VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)) + || VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo))) + { + /* Cost model check occurs at versioning. */ + if (VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)) + || VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo))) + scalar_outside_cost += TARG_COND_NOT_TAKEN_BRANCH_COST; + else + { + /* Cost model check occurs at prologue generation. */ + if (LOOP_PEELING_FOR_ALIGNMENT (loop_vinfo) < 0) + scalar_outside_cost += 2 * TARG_COND_TAKEN_BRANCH_COST + + TARG_COND_NOT_TAKEN_BRANCH_COST; + /* Cost model check occurs at epilogue generation. */ + else + scalar_outside_cost += 2 * TARG_COND_TAKEN_BRANCH_COST; + } + } + + /* Add SLP costs. */ + slp_instances = LOOP_VINFO_SLP_INSTANCES (loop_vinfo); + for (i = 0; VEC_iterate (slp_instance, slp_instances, i, instance); i++) + { + vec_outside_cost += SLP_INSTANCE_OUTSIDE_OF_LOOP_COST (instance); + vec_inside_cost += SLP_INSTANCE_INSIDE_OF_LOOP_COST (instance); + } + + /* Calculate number of iterations required to make the vector version + profitable, relative to the loop bodies only. The following condition + must hold true: + SIC * niters + SOC > VIC * ((niters-PL_ITERS-EP_ITERS)/VF) + VOC + where + SIC = scalar iteration cost, VIC = vector iteration cost, + VOC = vector outside cost, VF = vectorization factor, + PL_ITERS = prologue iterations, EP_ITERS= epilogue iterations + SOC = scalar outside cost for run time cost model check. */ + + if ((scalar_single_iter_cost * vf) > vec_inside_cost) + { + if (vec_outside_cost <= 0) + min_profitable_iters = 1; + else + { + min_profitable_iters = ((vec_outside_cost - scalar_outside_cost) * vf + - vec_inside_cost * peel_iters_prologue + - vec_inside_cost * peel_iters_epilogue) + / ((scalar_single_iter_cost * vf) + - vec_inside_cost); + + if ((scalar_single_iter_cost * vf * min_profitable_iters) + <= ((vec_inside_cost * min_profitable_iters) + + ((vec_outside_cost - scalar_outside_cost) * vf))) + min_profitable_iters++; + } + } + /* vector version will never be profitable. */ + else + { + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "cost model: vector iteration cost = %d " + "is divisible by scalar iteration cost = %d by a factor " + "greater than or equal to the vectorization factor = %d .", + vec_inside_cost, scalar_single_iter_cost, vf); + return -1; + } + + if (vect_print_dump_info (REPORT_COST)) + { + fprintf (vect_dump, "Cost model analysis: \n"); + fprintf (vect_dump, " Vector inside of loop cost: %d\n", + vec_inside_cost); + fprintf (vect_dump, " Vector outside of loop cost: %d\n", + vec_outside_cost); + fprintf (vect_dump, " Scalar iteration cost: %d\n", + scalar_single_iter_cost); + fprintf (vect_dump, " Scalar outside cost: %d\n", scalar_outside_cost); + fprintf (vect_dump, " prologue iterations: %d\n", + peel_iters_prologue); + fprintf (vect_dump, " epilogue iterations: %d\n", + peel_iters_epilogue); + fprintf (vect_dump, " Calculated minimum iters for profitability: %d\n", + min_profitable_iters); + } + + min_profitable_iters = + min_profitable_iters < vf ? vf : min_profitable_iters; + + /* Because the condition we create is: + if (niters <= min_profitable_iters) + then skip the vectorized loop. */ + min_profitable_iters--; + + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, " Profitability threshold = %d\n", + min_profitable_iters); + + return min_profitable_iters; +} + + +/* TODO: Close dependency between vect_model_*_cost and vectorizable_* + functions. Design better to avoid maintenance issues. */ + +/* Function vect_model_reduction_cost. + + Models cost for a reduction operation, including the vector ops + generated within the strip-mine loop, the initial definition before + the loop, and the epilogue code that must be generated. */ + +static bool +vect_model_reduction_cost (stmt_vec_info stmt_info, enum tree_code reduc_code, + int ncopies) +{ + int outer_cost = 0; + enum tree_code code; + optab optab; + tree vectype; + gimple stmt, orig_stmt; + tree reduction_op; + enum machine_mode mode; + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + + + /* Cost of reduction op inside loop. */ + STMT_VINFO_INSIDE_OF_LOOP_COST (stmt_info) += ncopies * TARG_VEC_STMT_COST; + + stmt = STMT_VINFO_STMT (stmt_info); + + switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt))) + { + case GIMPLE_SINGLE_RHS: + gcc_assert (TREE_OPERAND_LENGTH (gimple_assign_rhs1 (stmt)) == ternary_op); + reduction_op = TREE_OPERAND (gimple_assign_rhs1 (stmt), 2); + break; + case GIMPLE_UNARY_RHS: + reduction_op = gimple_assign_rhs1 (stmt); + break; + case GIMPLE_BINARY_RHS: + reduction_op = gimple_assign_rhs2 (stmt); + break; + default: + gcc_unreachable (); + } + + vectype = get_vectype_for_scalar_type (TREE_TYPE (reduction_op)); + if (!vectype) + { + if (vect_print_dump_info (REPORT_COST)) + { + fprintf (vect_dump, "unsupported data-type "); + print_generic_expr (vect_dump, TREE_TYPE (reduction_op), TDF_SLIM); + } + return false; + } + + mode = TYPE_MODE (vectype); + orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info); + + if (!orig_stmt) + orig_stmt = STMT_VINFO_STMT (stmt_info); + + code = gimple_assign_rhs_code (orig_stmt); + + /* Add in cost for initial definition. */ + outer_cost += TARG_SCALAR_TO_VEC_COST; + + /* Determine cost of epilogue code. + + We have a reduction operator that will reduce the vector in one statement. + Also requires scalar extract. */ + + if (!nested_in_vect_loop_p (loop, orig_stmt)) + { + if (reduc_code < NUM_TREE_CODES) + outer_cost += TARG_VEC_STMT_COST + TARG_VEC_TO_SCALAR_COST; + else + { + int vec_size_in_bits = tree_low_cst (TYPE_SIZE (vectype), 1); + tree bitsize = + TYPE_SIZE (TREE_TYPE (gimple_assign_lhs (orig_stmt))); + int element_bitsize = tree_low_cst (bitsize, 1); + int nelements = vec_size_in_bits / element_bitsize; + + optab = optab_for_tree_code (code, vectype, optab_default); + + /* We have a whole vector shift available. */ + if (VECTOR_MODE_P (mode) + && optab_handler (optab, mode)->insn_code != CODE_FOR_nothing + && optab_handler (vec_shr_optab, mode)->insn_code != CODE_FOR_nothing) + /* Final reduction via vector shifts and the reduction operator. Also + requires scalar extract. */ + outer_cost += ((exact_log2(nelements) * 2) * TARG_VEC_STMT_COST + + TARG_VEC_TO_SCALAR_COST); + else + /* Use extracts and reduction op for final reduction. For N elements, + we have N extracts and N-1 reduction ops. */ + outer_cost += ((nelements + nelements - 1) * TARG_VEC_STMT_COST); + } + } + + STMT_VINFO_OUTSIDE_OF_LOOP_COST (stmt_info) = outer_cost; + + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "vect_model_reduction_cost: inside_cost = %d, " + "outside_cost = %d .", STMT_VINFO_INSIDE_OF_LOOP_COST (stmt_info), + STMT_VINFO_OUTSIDE_OF_LOOP_COST (stmt_info)); + + return true; +} + + +/* Function vect_model_induction_cost. + + Models cost for induction operations. */ + +static void +vect_model_induction_cost (stmt_vec_info stmt_info, int ncopies) +{ + /* loop cost for vec_loop. */ + STMT_VINFO_INSIDE_OF_LOOP_COST (stmt_info) = ncopies * TARG_VEC_STMT_COST; + /* prologue cost for vec_init and vec_step. */ + STMT_VINFO_OUTSIDE_OF_LOOP_COST (stmt_info) = 2 * TARG_SCALAR_TO_VEC_COST; + + if (vect_print_dump_info (REPORT_COST)) + fprintf (vect_dump, "vect_model_induction_cost: inside_cost = %d, " + "outside_cost = %d .", STMT_VINFO_INSIDE_OF_LOOP_COST (stmt_info), + STMT_VINFO_OUTSIDE_OF_LOOP_COST (stmt_info)); +} + + +/* Function get_initial_def_for_induction + + Input: + STMT - a stmt that performs an induction operation in the loop. + IV_PHI - the initial value of the induction variable + + Output: + Return a vector variable, initialized with the first VF values of + the induction variable. E.g., for an iv with IV_PHI='X' and + evolution S, for a vector of 4 units, we want to return: + [X, X + S, X + 2*S, X + 3*S]. */ + +static tree +get_initial_def_for_induction (gimple iv_phi) +{ + stmt_vec_info stmt_vinfo = vinfo_for_stmt (iv_phi); + loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo); + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + tree scalar_type = TREE_TYPE (gimple_phi_result (iv_phi)); + tree vectype; + int nunits; + edge pe = loop_preheader_edge (loop); + struct loop *iv_loop; + basic_block new_bb; + tree vec, vec_init, vec_step, t; + tree access_fn; + tree new_var; + tree new_name; + gimple init_stmt, induction_phi, new_stmt; + tree induc_def, vec_def, vec_dest; + tree init_expr, step_expr; + int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); + int i; + bool ok; + int ncopies; + tree expr; + stmt_vec_info phi_info = vinfo_for_stmt (iv_phi); + bool nested_in_vect_loop = false; + gimple_seq stmts = NULL; + imm_use_iterator imm_iter; + use_operand_p use_p; + gimple exit_phi; + edge latch_e; + tree loop_arg; + gimple_stmt_iterator si; + basic_block bb = gimple_bb (iv_phi); + + vectype = get_vectype_for_scalar_type (scalar_type); + gcc_assert (vectype); + nunits = TYPE_VECTOR_SUBPARTS (vectype); + ncopies = vf / nunits; + + gcc_assert (phi_info); + gcc_assert (ncopies >= 1); + + /* Find the first insertion point in the BB. */ + si = gsi_after_labels (bb); + + if (INTEGRAL_TYPE_P (scalar_type) || POINTER_TYPE_P (scalar_type)) + step_expr = build_int_cst (scalar_type, 0); + else + step_expr = build_real (scalar_type, dconst0); + + /* Is phi in an inner-loop, while vectorizing an enclosing outer-loop? */ + if (nested_in_vect_loop_p (loop, iv_phi)) + { + nested_in_vect_loop = true; + iv_loop = loop->inner; + } + else + iv_loop = loop; + gcc_assert (iv_loop == (gimple_bb (iv_phi))->loop_father); + + latch_e = loop_latch_edge (iv_loop); + loop_arg = PHI_ARG_DEF_FROM_EDGE (iv_phi, latch_e); + + access_fn = analyze_scalar_evolution (iv_loop, PHI_RESULT (iv_phi)); + gcc_assert (access_fn); + ok = vect_is_simple_iv_evolution (iv_loop->num, access_fn, + &init_expr, &step_expr); + gcc_assert (ok); + pe = loop_preheader_edge (iv_loop); + + /* Create the vector that holds the initial_value of the induction. */ + if (nested_in_vect_loop) + { + /* iv_loop is nested in the loop to be vectorized. init_expr had already + been created during vectorization of previous stmts; We obtain it from + the STMT_VINFO_VEC_STMT of the defining stmt. */ + tree iv_def = PHI_ARG_DEF_FROM_EDGE (iv_phi, loop_preheader_edge (iv_loop)); + vec_init = vect_get_vec_def_for_operand (iv_def, iv_phi, NULL); + } + else + { + /* iv_loop is the loop to be vectorized. Create: + vec_init = [X, X+S, X+2*S, X+3*S] (S = step_expr, X = init_expr) */ + new_var = vect_get_new_vect_var (scalar_type, vect_scalar_var, "var_"); + add_referenced_var (new_var); + + new_name = force_gimple_operand (init_expr, &stmts, false, new_var); + if (stmts) + { + new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts); + gcc_assert (!new_bb); + } + + t = NULL_TREE; + t = tree_cons (NULL_TREE, init_expr, t); + for (i = 1; i < nunits; i++) + { + /* Create: new_name_i = new_name + step_expr */ + enum tree_code code = POINTER_TYPE_P (scalar_type) + ? POINTER_PLUS_EXPR : PLUS_EXPR; + init_stmt = gimple_build_assign_with_ops (code, new_var, + new_name, step_expr); + new_name = make_ssa_name (new_var, init_stmt); + gimple_assign_set_lhs (init_stmt, new_name); + + new_bb = gsi_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_gimple_stmt (vect_dump, init_stmt, 0, TDF_SLIM); + } + t = tree_cons (NULL_TREE, new_name, t); + } + /* Create a vector from [new_name_0, new_name_1, ..., new_name_nunits-1] */ + vec = build_constructor_from_list (vectype, nreverse (t)); + vec_init = vect_init_vector (iv_phi, vec, vectype, NULL); + } + + + /* Create the vector that holds the step of the induction. */ + if (nested_in_vect_loop) + /* iv_loop is nested in the loop to be vectorized. Generate: + vec_step = [S, S, S, S] */ + new_name = step_expr; + else + { + /* iv_loop is the loop to be vectorized. Generate: + vec_step = [VF*S, VF*S, VF*S, VF*S] */ + expr = build_int_cst (scalar_type, vf); + new_name = fold_build2 (MULT_EXPR, scalar_type, expr, step_expr); + } + + t = NULL_TREE; + for (i = 0; i < nunits; i++) + t = tree_cons (NULL_TREE, unshare_expr (new_name), t); + gcc_assert (CONSTANT_CLASS_P (new_name)); + vec = build_vector (vectype, t); + vec_step = vect_init_vector (iv_phi, vec, vectype, NULL); + + + /* Create the following def-use cycle: + loop prolog: + vec_init = ... + vec_step = ... + loop: + vec_iv = PHI <vec_init, vec_loop> + ... + STMT + ... + vec_loop = vec_iv + vec_step; */ + + /* Create the induction-phi that defines the induction-operand. */ + vec_dest = vect_get_new_vect_var (vectype, vect_simple_var, "vec_iv_"); + add_referenced_var (vec_dest); + induction_phi = create_phi_node (vec_dest, iv_loop->header); + set_vinfo_for_stmt (induction_phi, + new_stmt_vec_info (induction_phi, loop_vinfo)); + induc_def = PHI_RESULT (induction_phi); + + /* Create the iv update inside the loop */ + new_stmt = gimple_build_assign_with_ops (PLUS_EXPR, vec_dest, + induc_def, vec_step); + vec_def = make_ssa_name (vec_dest, new_stmt); + gimple_assign_set_lhs (new_stmt, vec_def); + gsi_insert_before (&si, new_stmt, GSI_SAME_STMT); + set_vinfo_for_stmt (new_stmt, new_stmt_vec_info (new_stmt, loop_vinfo)); + + /* Set the arguments of the phi node: */ + add_phi_arg (induction_phi, vec_init, pe); + add_phi_arg (induction_phi, vec_def, loop_latch_edge (iv_loop)); + + + /* In case that vectorization factor (VF) is bigger than the number + of elements that we can fit in a vectype (nunits), we have to generate + more than one vector stmt - i.e - we need to "unroll" the + vector stmt by a factor VF/nunits. For more details see documentation + in vectorizable_operation. */ + + if (ncopies > 1) + { + stmt_vec_info prev_stmt_vinfo; + /* FORNOW. This restriction should be relaxed. */ + gcc_assert (!nested_in_vect_loop); + + /* Create the vector that holds the step of the induction. */ + expr = build_int_cst (scalar_type, nunits); + new_name = fold_build2 (MULT_EXPR, scalar_type, expr, step_expr); + t = NULL_TREE; + for (i = 0; i < nunits; i++) + t = tree_cons (NULL_TREE, unshare_expr (new_name), t); + gcc_assert (CONSTANT_CLASS_P (new_name)); + vec = build_vector (vectype, t); + vec_step = vect_init_vector (iv_phi, vec, vectype, NULL); + + vec_def = induc_def; + prev_stmt_vinfo = vinfo_for_stmt (induction_phi); + for (i = 1; i < ncopies; i++) + { + /* vec_i = vec_prev + vec_step */ + new_stmt = gimple_build_assign_with_ops (PLUS_EXPR, vec_dest, + vec_def, vec_step); + vec_def = make_ssa_name (vec_dest, new_stmt); + gimple_assign_set_lhs (new_stmt, vec_def); + + gsi_insert_before (&si, new_stmt, GSI_SAME_STMT); + set_vinfo_for_stmt (new_stmt, + new_stmt_vec_info (new_stmt, loop_vinfo)); + STMT_VINFO_RELATED_STMT (prev_stmt_vinfo) = new_stmt; + prev_stmt_vinfo = vinfo_for_stmt (new_stmt); + } + } + + if (nested_in_vect_loop) + { + /* Find the loop-closed exit-phi of the induction, and record + the final vector of induction results: */ + exit_phi = NULL; + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, loop_arg) + { + if (!flow_bb_inside_loop_p (iv_loop, gimple_bb (USE_STMT (use_p)))) + { + exit_phi = USE_STMT (use_p); + break; + } + } + if (exit_phi) + { + stmt_vec_info stmt_vinfo = vinfo_for_stmt (exit_phi); + /* FORNOW. Currently not supporting the case that an inner-loop induction + is not used in the outer-loop (i.e. only outside the outer-loop). */ + gcc_assert (STMT_VINFO_RELEVANT_P (stmt_vinfo) + && !STMT_VINFO_LIVE_P (stmt_vinfo)); + + STMT_VINFO_VEC_STMT (stmt_vinfo) = new_stmt; + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "vector of inductions after inner-loop:"); + print_gimple_stmt (vect_dump, new_stmt, 0, TDF_SLIM); + } + } + } + + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "transform induction: created def-use cycle: "); + print_gimple_stmt (vect_dump, induction_phi, 0, TDF_SLIM); + fprintf (vect_dump, "\n"); + print_gimple_stmt (vect_dump, SSA_NAME_DEF_STMT (vec_def), 0, TDF_SLIM); + } + + STMT_VINFO_VEC_STMT (phi_info) = induction_phi; + return induc_def; +} + + +/* 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: + ADJUSTMENT_DEF - a tree that holds a value to be added to the final result + of the reduction (used for adjusting the 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 are using the 'adjust in epilog' scheme, because this way the + initialization vector is simpler (same element in all entries). + A cost model should help decide between these two schemes. */ + +tree +get_initial_def_for_reduction (gimple stmt, tree init_val, tree *adjustment_def) +{ + 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 vectype = STMT_VINFO_VECTYPE (stmt_vinfo); + int nunits = TYPE_VECTOR_SUBPARTS (vectype); + tree scalar_type = TREE_TYPE (vectype); + enum tree_code code = gimple_assign_rhs_code (stmt); + tree type = TREE_TYPE (init_val); + tree vecdef; + tree def_for_init; + tree init_def; + tree t = NULL_TREE; + int i; + bool nested_in_vect_loop = false; + + gcc_assert (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type)); + if (nested_in_vect_loop_p (loop, stmt)) + nested_in_vect_loop = true; + else + gcc_assert (loop == (gimple_bb (stmt))->loop_father); + + vecdef = vect_get_vec_def_for_operand (init_val, stmt, NULL); + + switch (code) + { + case WIDEN_SUM_EXPR: + case DOT_PROD_EXPR: + case PLUS_EXPR: + if (nested_in_vect_loop) + *adjustment_def = vecdef; + else + *adjustment_def = init_val; + /* Create a vector of zeros for init_def. */ + if (SCALAR_FLOAT_TYPE_P (scalar_type)) + def_for_init = build_real (scalar_type, dconst0); + else + def_for_init = build_int_cst (scalar_type, 0); + + for (i = nunits - 1; i >= 0; --i) + t = tree_cons (NULL_TREE, def_for_init, t); + init_def = build_vector (vectype, t); + break; + + case MIN_EXPR: + case MAX_EXPR: + *adjustment_def = NULL_TREE; + init_def = vecdef; + break; + + default: + gcc_unreachable (); + } + + return init_def; +} + + +/* 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. + NCOPIES is > 1 in case the vectorization factor (VF) is bigger than the + number of elements that we can fit in a vectype (nunits). In this case + we have to generate more than one vector stmt - i.e - we need to "unroll" + the vector stmt by a factor VF/nunits. For more details see documentation + in vectorizable_operation. + 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 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, gimple stmt, + int ncopies, + enum tree_code reduc_code, + gimple reduction_phi) +{ + stmt_vec_info stmt_info = vinfo_for_stmt (stmt); + stmt_vec_info prev_phi_info; + 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; + gimple new_phi = NULL, phi; + gimple_stmt_iterator exit_gsi; + tree vec_dest; + tree new_temp = NULL_TREE; + tree new_name; + gimple epilog_stmt = NULL; + tree new_scalar_dest, new_dest; + gimple exit_phi; + tree bitsize, bitpos, bytesize; + enum tree_code code = gimple_assign_rhs_code (stmt); + tree adjustment_def; + tree vec_initial_def, def; + tree orig_name; + imm_use_iterator imm_iter; + use_operand_p use_p; + bool extract_scalar_result = false; + tree reduction_op, expr; + gimple orig_stmt; + gimple use_stmt; + bool nested_in_vect_loop = false; + VEC(gimple,heap) *phis = NULL; + enum vect_def_type dt = vect_unknown_def_type; + int j, i; + + if (nested_in_vect_loop_p (loop, stmt)) + { + loop = loop->inner; + nested_in_vect_loop = true; + } + + switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt))) + { + case GIMPLE_SINGLE_RHS: + gcc_assert (TREE_OPERAND_LENGTH (gimple_assign_rhs1 (stmt)) == ternary_op); + reduction_op = TREE_OPERAND (gimple_assign_rhs1 (stmt), 2); + break; + case GIMPLE_UNARY_RHS: + reduction_op = gimple_assign_rhs1 (stmt); + break; + case GIMPLE_BINARY_RHS: + reduction_op = gimple_assign_rhs2 (stmt); + break; + default: + gcc_unreachable (); + } + + vectype = get_vectype_for_scalar_type (TREE_TYPE (reduction_op)); + gcc_assert (vectype); + mode = TYPE_MODE (vectype); + + /*** 1. Create the reduction def-use cycle ***/ + + /* 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, + &adjustment_def); + + phi = reduction_phi; + def = vect_def; + for (j = 0; j < ncopies; j++) + { + /* 1.1 set the loop-entry arg of the reduction-phi: */ + add_phi_arg (phi, vec_initial_def, loop_preheader_edge (loop)); + + /* 1.2 set the loop-latch arg for the reduction-phi: */ + if (j > 0) + def = vect_get_vec_def_for_stmt_copy (dt, def); + add_phi_arg (phi, def, loop_latch_edge (loop)); + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "transform reduction: created def-use cycle: "); + print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM); + fprintf (vect_dump, "\n"); + print_gimple_stmt (vect_dump, SSA_NAME_DEF_STMT (def), 0, TDF_SLIM); + } + + phi = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (phi)); + } + + /*** 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 steps 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 = single_exit (loop)->dest; + def = vect_def; + prev_phi_info = NULL; + for (j = 0; j < ncopies; j++) + { + phi = create_phi_node (SSA_NAME_VAR (vect_def), exit_bb); + set_vinfo_for_stmt (phi, new_stmt_vec_info (phi, loop_vinfo)); + if (j == 0) + new_phi = phi; + else + { + def = vect_get_vec_def_for_stmt_copy (dt, def); + STMT_VINFO_RELATED_STMT (prev_phi_info) = phi; + } + SET_PHI_ARG_DEF (phi, single_exit (loop)->dest_idx, def); + prev_phi_info = vinfo_for_stmt (phi); + } + exit_gsi = gsi_after_labels (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 = gimple_assign_rhs_code (orig_stmt); + scalar_dest = gimple_assign_lhs (orig_stmt); + 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); + + + /* In case this is a reduction in an inner-loop while vectorizing an outer + loop - we don't need to extract a single scalar result at the end of the + inner-loop. The final vector of partial results will be used in the + vectorized outer-loop, or reduced to a scalar result at the end of the + outer-loop. */ + if (nested_in_vect_loop) + goto vect_finalize_reduction; + + /* FORNOW */ + gcc_assert (ncopies == 1); + + /* 2.3 Create the reduction code, using one of the three schemes described + above. */ + + if (reduc_code < NUM_TREE_CODES) + { + tree tmp; + + /*** 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); + tmp = build1 (reduc_code, vectype, PHI_RESULT (new_phi)); + epilog_stmt = gimple_build_assign (vec_dest, tmp); + new_temp = make_ssa_name (vec_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_temp); + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_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 (optab_handler (vec_shr_optab, 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, optab_default); + if (optab_handler (optab, 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 = gimple_build_assign_with_ops (shift_code, vec_dest, + new_temp, bitpos); + new_name = make_ssa_name (vec_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_name); + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); + + epilog_stmt = gimple_build_assign_with_ops (code, vec_dest, + new_name, new_temp); + new_temp = make_ssa_name (vec_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_temp); + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_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); + epilog_stmt = gimple_build_assign (new_scalar_dest, rhs); + new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_temp); + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_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); + + epilog_stmt = gimple_build_assign (new_scalar_dest, rhs); + new_name = make_ssa_name (new_scalar_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_name); + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); + + epilog_stmt = gimple_build_assign_with_ops (code, + new_scalar_dest, + new_name, new_temp); + new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_temp); + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_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; + + gcc_assert (!nested_in_vect_loop); + 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); + epilog_stmt = gimple_build_assign (new_scalar_dest, rhs); + new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_temp); + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); + } + +vect_finalize_reduction: + + /* 2.5 Adjust the final result by the initial value of the reduction + variable. (When such adjustment is not needed, then + 'adjustment_def' is zero). For example, if code is PLUS we create: + new_temp = loop_exit_def + adjustment_def */ + + if (adjustment_def) + { + if (nested_in_vect_loop) + { + gcc_assert (TREE_CODE (TREE_TYPE (adjustment_def)) == VECTOR_TYPE); + expr = build2 (code, vectype, PHI_RESULT (new_phi), adjustment_def); + new_dest = vect_create_destination_var (scalar_dest, vectype); + } + else + { + gcc_assert (TREE_CODE (TREE_TYPE (adjustment_def)) != VECTOR_TYPE); + expr = build2 (code, scalar_type, new_temp, adjustment_def); + new_dest = vect_create_destination_var (scalar_dest, scalar_type); + } + epilog_stmt = gimple_build_assign (new_dest, expr); + new_temp = make_ssa_name (new_dest, epilog_stmt); + gimple_assign_set_lhs (epilog_stmt, new_temp); + SSA_NAME_DEF_STMT (new_temp) = epilog_stmt; + gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); + } + + + /* 2.6 Handle the loop-exit phi */ + + /* 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). */ + phis = VEC_alloc (gimple, heap, 10); + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, scalar_dest) + { + if (!flow_bb_inside_loop_p (loop, gimple_bb (USE_STMT (use_p)))) + { + exit_phi = USE_STMT (use_p); + VEC_quick_push (gimple, phis, exit_phi); + } + } + /* We expect to have found an exit_phi because of loop-closed-ssa form. */ + gcc_assert (!VEC_empty (gimple, phis)); + + for (i = 0; VEC_iterate (gimple, phis, i, exit_phi); i++) + { + if (nested_in_vect_loop) + { + stmt_vec_info stmt_vinfo = vinfo_for_stmt (exit_phi); + + /* FORNOW. Currently not supporting the case that an inner-loop + reduction is not used in the outer-loop (but only outside the + outer-loop). */ + gcc_assert (STMT_VINFO_RELEVANT_P (stmt_vinfo) + && !STMT_VINFO_LIVE_P (stmt_vinfo)); + + epilog_stmt = adjustment_def ? epilog_stmt : new_phi; + STMT_VINFO_VEC_STMT (stmt_vinfo) = epilog_stmt; + set_vinfo_for_stmt (epilog_stmt, + new_stmt_vec_info (epilog_stmt, loop_vinfo)); + if (adjustment_def) + STMT_VINFO_RELATED_STMT (vinfo_for_stmt (epilog_stmt)) = + STMT_VINFO_RELATED_STMT (vinfo_for_stmt (new_phi)); + continue; + } + + /* 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); + } + VEC_free (gimple, heap, phis); +} + + +/* 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 (gimple stmt, gimple_stmt_iterator *gsi, + gimple *vec_stmt) +{ + tree vec_dest; + tree scalar_dest; + tree loop_vec_def0 = NULL_TREE, loop_vec_def1 = NULL_TREE; + 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); + 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 = NULL_TREE; + tree def; + gimple def_stmt; + enum vect_def_type dt; + gimple new_phi = NULL; + tree scalar_type; + bool is_simple_use; + gimple orig_stmt; + stmt_vec_info orig_stmt_info; + tree expr = NULL_TREE; + int i; + int nunits = TYPE_VECTOR_SUBPARTS (vectype); + int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits; + int epilog_copies; + stmt_vec_info prev_stmt_info, prev_phi_info; + gimple first_phi = NULL; + bool single_defuse_cycle = false; + tree reduc_def; + gimple new_stmt = NULL; + int j; + tree ops[3]; + + if (nested_in_vect_loop_p (loop, stmt)) + loop = loop->inner; + + gcc_assert (ncopies >= 1); + + /* FORNOW: SLP not supported. */ + if (STMT_SLP_TYPE (stmt_info)) + return false; + + /* 1. Is vectorizable reduction? */ + + /* Not supportable if the reduction variable is used in the loop. */ + if (STMT_VINFO_RELEVANT (stmt_info) > vect_used_in_outer) + return false; + + /* Reductions that are not used even in an enclosing outer-loop, + are expected to be "live" (used out of the loop). */ + if (STMT_VINFO_RELEVANT (stmt_info) == vect_unused_in_loop + && !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 (is_gimple_assign (stmt)); + + /* Flatten RHS */ + switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt))) + { + case GIMPLE_SINGLE_RHS: + op_type = TREE_OPERAND_LENGTH (gimple_assign_rhs1 (stmt)); + if (op_type == ternary_op) + { + tree rhs = gimple_assign_rhs1 (stmt); + ops[0] = TREE_OPERAND (rhs, 0); + ops[1] = TREE_OPERAND (rhs, 1); + ops[2] = TREE_OPERAND (rhs, 2); + code = TREE_CODE (rhs); + } + else + return false; + break; + + case GIMPLE_BINARY_RHS: + code = gimple_assign_rhs_code (stmt); + op_type = TREE_CODE_LENGTH (code); + gcc_assert (op_type == binary_op); + ops[0] = gimple_assign_rhs1 (stmt); + ops[1] = gimple_assign_rhs2 (stmt); + break; + + case GIMPLE_UNARY_RHS: + return false; + + default: + gcc_unreachable (); + } + + scalar_dest = gimple_assign_lhs (stmt); + scalar_type = TREE_TYPE (scalar_dest); + if (!POINTER_TYPE_P (scalar_type) && !INTEGRAL_TYPE_P (scalar_type) + && !SCALAR_FLOAT_TYPE_P (scalar_type)) + return false; + + /* 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++) + { + is_simple_use = vect_is_simple_use (ops[i], loop_vinfo, &def_stmt, + &def, &dt); + gcc_assert (is_simple_use); + if (dt != vect_loop_def + && dt != vect_invariant_def + && dt != vect_constant_def + && dt != vect_induction_def) + return false; + } + + is_simple_use = vect_is_simple_use (ops[i], loop_vinfo, &def_stmt, &def, &dt); + gcc_assert (is_simple_use); + gcc_assert (dt == vect_reduction_def); + gcc_assert (gimple_code (def_stmt) == GIMPLE_PHI); + if (orig_stmt) + gcc_assert (orig_stmt == vect_is_simple_reduction (loop_vinfo, def_stmt)); + else + gcc_assert (stmt == vect_is_simple_reduction (loop_vinfo, 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, optab_default); + if (!optab) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "no optab."); + return false; + } + vec_mode = TYPE_MODE (vectype); + if (optab_handler (optab, 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 = gimple_assign_rhs_code (orig_stmt); + vectype = get_vectype_for_scalar_type (TREE_TYPE (def)); + if (!vectype) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "unsupported data-type "); + print_generic_expr (vect_dump, TREE_TYPE (def), TDF_SLIM); + } + return false; + } + + 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, optab_default); + if (!reduc_optab) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "no optab for reduction."); + epilog_reduc_code = NUM_TREE_CODES; + } + if (optab_handler (reduc_optab, 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; + if (!vect_model_reduction_cost (stmt_info, epilog_reduc_code, ncopies)) + return false; + 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); + + /* In case the vectorization factor (VF) is bigger than the number + of elements that we can fit in a vectype (nunits), we have to generate + more than one vector stmt - i.e - we need to "unroll" the + vector stmt by a factor VF/nunits. For more details see documentation + in vectorizable_operation. */ + + /* If the reduction is used in an outer loop we need to generate + VF intermediate results, like so (e.g. for ncopies=2): + r0 = phi (init, r0) + r1 = phi (init, r1) + r0 = x0 + r0; + r1 = x1 + r1; + (i.e. we generate VF results in 2 registers). + In this case we have a separate def-use cycle for each copy, and therefore + for each copy we get the vector def for the reduction variable from the + respective phi node created for this copy. + + Otherwise (the reduction is unused in the loop nest), we can combine + together intermediate results, like so (e.g. for ncopies=2): + r = phi (init, r) + r = x0 + r; + r = x1 + r; + (i.e. we generate VF/2 results in a single register). + In this case for each copy we get the vector def for the reduction variable + from the vectorized reduction operation generated in the previous iteration. + */ + + if (STMT_VINFO_RELEVANT (stmt_info) == vect_unused_in_loop) + { + single_defuse_cycle = true; + epilog_copies = 1; + } + else + epilog_copies = ncopies; + + prev_stmt_info = NULL; + prev_phi_info = NULL; + for (j = 0; j < ncopies; j++) + { + if (j == 0 || !single_defuse_cycle) + { + /* Create the reduction-phi that defines the reduction-operand. */ + new_phi = create_phi_node (vec_dest, loop->header); + set_vinfo_for_stmt (new_phi, new_stmt_vec_info (new_phi, loop_vinfo)); + } + + /* Handle uses. */ + if (j == 0) + { + loop_vec_def0 = vect_get_vec_def_for_operand (ops[0], stmt, NULL); + if (op_type == ternary_op) + { + loop_vec_def1 = vect_get_vec_def_for_operand (ops[1], stmt, NULL); + } + + /* Get the vector def for the reduction variable from the phi node */ + reduc_def = PHI_RESULT (new_phi); + first_phi = new_phi; + } + else + { + enum vect_def_type dt = vect_unknown_def_type; /* Dummy */ + loop_vec_def0 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def0); + if (op_type == ternary_op) + loop_vec_def1 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def1); + + if (single_defuse_cycle) + reduc_def = gimple_assign_lhs (new_stmt); + else + reduc_def = PHI_RESULT (new_phi); + + STMT_VINFO_RELATED_STMT (prev_phi_info) = new_phi; + } + + /* Arguments are ready. create the new vector stmt. */ + if (op_type == binary_op) + expr = build2 (code, vectype, loop_vec_def0, reduc_def); + else + expr = build3 (code, vectype, loop_vec_def0, loop_vec_def1, + reduc_def); + new_stmt = gimple_build_assign (vec_dest, expr); + new_temp = make_ssa_name (vec_dest, new_stmt); + gimple_assign_set_lhs (new_stmt, new_temp); + vect_finish_stmt_generation (stmt, new_stmt, gsi); + + if (j == 0) + STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt; + else + STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt; + prev_stmt_info = vinfo_for_stmt (new_stmt); + prev_phi_info = vinfo_for_stmt (new_phi); + } + + /* Finalize the reduction-phi (set its arguments) and create the + epilog reduction code. */ + if (!single_defuse_cycle) + new_temp = gimple_assign_lhs (*vec_stmt); + vect_create_epilog_for_reduction (new_temp, stmt, epilog_copies, + epilog_reduc_code, first_phi); + 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. */ +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_induction + + Check if PHI performs an induction computation that can be vectorized. + If VEC_STMT is also passed, vectorize the induction PHI: create a vectorized + phi to replace it, put it in VEC_STMT, and add it to the same basic block. + Return FALSE if not a vectorizable STMT, TRUE otherwise. */ + +bool +vectorizable_induction (gimple phi, gimple_stmt_iterator *gsi ATTRIBUTE_UNUSED, + gimple *vec_stmt) +{ + stmt_vec_info stmt_info = vinfo_for_stmt (phi); + 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); + int nunits = TYPE_VECTOR_SUBPARTS (vectype); + int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits; + tree vec_def; + + gcc_assert (ncopies >= 1); + /* FORNOW. This restriction should be relaxed. */ + if (nested_in_vect_loop_p (loop, phi) && ncopies > 1) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "multiple types in nested loop."); + return false; + } + + if (!STMT_VINFO_RELEVANT_P (stmt_info)) + return false; + + /* FORNOW: SLP not supported. */ + if (STMT_SLP_TYPE (stmt_info)) + return false; + + gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_induction_def); + + if (gimple_code (phi) != GIMPLE_PHI) + return false; + + if (!vec_stmt) /* transformation not required. */ + { + STMT_VINFO_TYPE (stmt_info) = induc_vec_info_type; + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vectorizable_induction ==="); + vect_model_induction_cost (stmt_info, ncopies); + return true; + } + + /** Transform. **/ + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform induction phi."); + + vec_def = get_initial_def_for_induction (phi); + *vec_stmt = SSA_NAME_DEF_STMT (vec_def); + 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 (gimple stmt, + gimple_stmt_iterator *gsi ATTRIBUTE_UNUSED, + gimple *vec_stmt ATTRIBUTE_UNUSED) +{ + 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); + int i; + int op_type; + tree op; + tree def; + gimple def_stmt; + enum vect_def_type dt; + enum tree_code code; + enum gimple_rhs_class rhs_class; + + gcc_assert (STMT_VINFO_LIVE_P (stmt_info)); + + if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def) + return false; + + if (!is_gimple_assign (stmt)) + return false; + + if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME) + return false; + + /* FORNOW. CHECKME. */ + if (nested_in_vect_loop_p (loop, stmt)) + return false; + + code = gimple_assign_rhs_code (stmt); + op_type = TREE_CODE_LENGTH (code); + rhs_class = get_gimple_rhs_class (code); + gcc_assert (rhs_class != GIMPLE_UNARY_RHS || op_type == unary_op); + gcc_assert (rhs_class != GIMPLE_BINARY_RHS || op_type == binary_op); + + /* 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++) + { + if (rhs_class == GIMPLE_SINGLE_RHS) + op = TREE_OPERAND (gimple_op (stmt, 1), i); + else + op = gimple_op (stmt, i + 1); + if (op && !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_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 loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); + int nbbs = loop->num_nodes; + gimple_stmt_iterator si; + int i; + tree ratio = NULL; + int vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo); + bool strided_store; + bool slp_scheduled = false; + unsigned int nunits; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== vec_transform_loop ==="); + + if (VEC_length (gimple, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)) + || VEC_length (ddr_p, LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo))) + vect_loop_versioning (loop_vinfo); + + /* CHECKME: we wouldn't need this if we called update_ssa once + for all loops. */ + bitmap_zero (vect_memsyms_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); + + /* 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); + 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); + + split_edge (loop_preheader_edge (loop)); + + /* 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]; + stmt_vec_info stmt_info; + gimple phi; + + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + { + phi = gsi_stmt (si); + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "------>vectorizing phi: "); + print_gimple_stmt (vect_dump, phi, 0, TDF_SLIM); + } + stmt_info = vinfo_for_stmt (phi); + if (!stmt_info) + continue; + + if (!STMT_VINFO_RELEVANT_P (stmt_info) + && !STMT_VINFO_LIVE_P (stmt_info)) + continue; + + if ((TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info)) + != (unsigned HOST_WIDE_INT) vectorization_factor) + && vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "multiple-types."); + + if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_induction_def) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform phi."); + vect_transform_stmt (phi, NULL, NULL, NULL, NULL); + } + } + + for (si = gsi_start_bb (bb); !gsi_end_p (si);) + { + gimple stmt = gsi_stmt (si); + bool is_store; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "------>vectorizing statement: "); + print_gimple_stmt (vect_dump, stmt, 0, TDF_SLIM); + } + + stmt_info = vinfo_for_stmt (stmt); + + /* vector stmts created in the outer-loop during vectorization of + stmts in an inner-loop may not have a stmt_info, and do not + need to be vectorized. */ + if (!stmt_info) + { + gsi_next (&si); + continue; + } + + if (!STMT_VINFO_RELEVANT_P (stmt_info) + && !STMT_VINFO_LIVE_P (stmt_info)) + { + gsi_next (&si); + continue; + } + + gcc_assert (STMT_VINFO_VECTYPE (stmt_info)); + nunits = + (unsigned int) TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info)); + if (!STMT_SLP_TYPE (stmt_info) + && nunits != (unsigned int) vectorization_factor + && vect_print_dump_info (REPORT_DETAILS)) + /* For SLP VF is set according to unrolling factor, and not to + vector size, hence for SLP this print is not valid. */ + fprintf (vect_dump, "multiple-types."); + + /* SLP. Schedule all the SLP instances when the first SLP stmt is + reached. */ + if (STMT_SLP_TYPE (stmt_info)) + { + if (!slp_scheduled) + { + slp_scheduled = true; + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "=== scheduling SLP instances ==="); + + is_store = vect_schedule_slp (loop_vinfo); + + /* IS_STORE is true if STMT is a store. Stores cannot be of + hybrid SLP type. They are removed in + vect_schedule_slp_instance and their vinfo is destroyed. */ + if (is_store) + { + gsi_next (&si); + continue; + } + } + + /* Hybrid SLP stmts must be vectorized in addition to SLP. */ + if (PURE_SLP_STMT (stmt_info)) + { + gsi_next (&si); + continue; + } + } + + /* -------- vectorize statement ------------ */ + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "transform statement."); + + strided_store = false; + is_store = vect_transform_stmt (stmt, &si, &strided_store, NULL, NULL); + if (is_store) + { + if (STMT_VINFO_STRIDED_ACCESS (stmt_info)) + { + /* Interleaving. If IS_STORE is TRUE, the vectorization of the + interleaving chain was completed - free all the stores in + the chain. */ + vect_remove_stores (DR_GROUP_FIRST_DR (stmt_info)); + gsi_remove (&si, true); + continue; + } + else + { + /* Free the attached stmt_vec_info and remove the stmt. */ + free_stmt_vec_info (stmt); + gsi_remove (&si, true); + continue; + } + } + gsi_next (&si); + } /* stmts in BB */ + } /* BBs in loop */ + + slpeel_make_loop_iterate_ntimes (loop, ratio); + + mark_set_for_renaming (vect_memsyms_to_rename); + + /* 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."); + if (loop->inner && vect_print_dump_info (REPORT_VECTORIZED_LOOPS)) + fprintf (vect_dump, "OUTER LOOP VECTORIZED."); +} + + + |