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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/tree-vectorizer.c')
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diff --git a/gcc-4.2.1-5666.3/gcc/tree-vectorizer.c b/gcc-4.2.1-5666.3/gcc/tree-vectorizer.c new file mode 100644 index 000000000..1419dc3bb --- /dev/null +++ b/gcc-4.2.1-5666.3/gcc/tree-vectorizer.c @@ -0,0 +1,2101 @@ +/* Loop Vectorization + Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. + Contributed by Dorit Naishlos <dorit@il.ibm.com> + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to the Free +Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301, USA. */ + +/* Loop Vectorization Pass. + + This pass tries to vectorize loops. This first implementation focuses on + simple inner-most loops, with no conditional control flow, and a set of + simple operations which vector form can be expressed using existing + tree codes (PLUS, MULT etc). + + 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_nest(). + 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 insert 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, add_optab->handlers[(int) 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 +*/ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "ggc.h" +#include "tree.h" +#include "target.h" +#include "rtl.h" +#include "basic-block.h" +#include "diagnostic.h" +#include "tree-flow.h" +#include "tree-dump.h" +#include "timevar.h" +#include "cfgloop.h" +#include "cfglayout.h" +#include "expr.h" +#include "optabs.h" +#include "params.h" +#include "toplev.h" +#include "tree-chrec.h" +#include "tree-data-ref.h" +#include "tree-scalar-evolution.h" +#include "input.h" +/* APPLE LOCAL opt diary */ +#include "debug.h" +#include "tree-vectorizer.h" +#include "tree-pass.h" + +/************************************************************************* + Simple Loop Peeling Utilities + *************************************************************************/ +static struct loop *slpeel_tree_duplicate_loop_to_edge_cfg + (struct loop *, struct loops *, edge); +static void slpeel_update_phis_for_duplicate_loop + (struct loop *, struct loop *, bool after); +static void slpeel_update_phi_nodes_for_guard1 + (edge, struct loop *, bool, basic_block *, bitmap *); +static void slpeel_update_phi_nodes_for_guard2 + (edge, struct loop *, bool, basic_block *); +static edge slpeel_add_loop_guard (basic_block, tree, basic_block, basic_block); + +static void rename_use_op (use_operand_p); +static void rename_variables_in_bb (basic_block); +static void rename_variables_in_loop (struct loop *); + +/************************************************************************* + General Vectorization Utilities + *************************************************************************/ +static void vect_set_dump_settings (void); + +/* vect_dump will be set to stderr or dump_file if exist. */ +FILE *vect_dump; + +/* vect_verbosity_level set to an invalid value + to mark that it's uninitialized. */ +enum verbosity_levels vect_verbosity_level = MAX_VERBOSITY_LEVEL; + +/* Number of loops, at the beginning of vectorization. */ +unsigned int vect_loops_num; + +/* Loop location. */ +static LOC vect_loop_location; + +/* Bitmap of virtual variables to be renamed. */ +bitmap vect_vnames_to_rename; + +/************************************************************************* + Simple Loop Peeling Utilities + + Utilities to support loop peeling for vectorization purposes. + *************************************************************************/ + + +/* Renames the use *OP_P. */ + +static void +rename_use_op (use_operand_p op_p) +{ + tree new_name; + + if (TREE_CODE (USE_FROM_PTR (op_p)) != SSA_NAME) + return; + + new_name = get_current_def (USE_FROM_PTR (op_p)); + + /* Something defined outside of the loop. */ + if (!new_name) + return; + + /* An ordinary ssa name defined in the loop. */ + + SET_USE (op_p, new_name); +} + + +/* Renames the variables in basic block BB. */ + +static void +rename_variables_in_bb (basic_block bb) +{ + tree phi; + block_stmt_iterator bsi; + tree stmt; + use_operand_p use_p; + ssa_op_iter iter; + edge e; + edge_iterator ei; + struct loop *loop = bb->loop_father; + + for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) + { + stmt = bsi_stmt (bsi); + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, + (SSA_OP_ALL_USES | SSA_OP_ALL_KILLS)) + rename_use_op (use_p); + } + + FOR_EACH_EDGE (e, ei, bb->succs) + { + if (!flow_bb_inside_loop_p (loop, e->dest)) + continue; + for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi)) + rename_use_op (PHI_ARG_DEF_PTR_FROM_EDGE (phi, e)); + } +} + + +/* Renames variables in new generated LOOP. */ + +static void +rename_variables_in_loop (struct loop *loop) +{ + unsigned i; + basic_block *bbs; + + bbs = get_loop_body (loop); + + for (i = 0; i < loop->num_nodes; i++) + rename_variables_in_bb (bbs[i]); + + free (bbs); +} + + +/* Update the PHI nodes of NEW_LOOP. + + NEW_LOOP is a duplicate of ORIG_LOOP. + AFTER indicates whether NEW_LOOP executes before or after ORIG_LOOP: + AFTER is true if NEW_LOOP executes after ORIG_LOOP, and false if it + executes before it. */ + +static void +slpeel_update_phis_for_duplicate_loop (struct loop *orig_loop, + struct loop *new_loop, bool after) +{ + tree new_ssa_name; + tree phi_new, phi_orig; + tree def; + edge orig_loop_latch = loop_latch_edge (orig_loop); + edge orig_entry_e = loop_preheader_edge (orig_loop); + edge new_loop_exit_e = new_loop->single_exit; + edge new_loop_entry_e = loop_preheader_edge (new_loop); + edge entry_arg_e = (after ? orig_loop_latch : orig_entry_e); + + /* + step 1. For each loop-header-phi: + Add the first phi argument for the phi in NEW_LOOP + (the one associated with the entry of NEW_LOOP) + + step 2. For each loop-header-phi: + Add the second phi argument for the phi in NEW_LOOP + (the one associated with the latch of NEW_LOOP) + + step 3. Update the phis in the successor block of NEW_LOOP. + + case 1: NEW_LOOP was placed before ORIG_LOOP: + The successor block of NEW_LOOP is the header of ORIG_LOOP. + Updating the phis in the successor block can therefore be done + along with the scanning of the loop header phis, because the + header blocks of ORIG_LOOP and NEW_LOOP have exactly the same + phi nodes, organized in the same order. + + case 2: NEW_LOOP was placed after ORIG_LOOP: + The successor block of NEW_LOOP is the original exit block of + ORIG_LOOP - the phis to be updated are the loop-closed-ssa phis. + We postpone updating these phis to a later stage (when + loop guards are added). + */ + + + /* Scan the phis in the headers of the old and new loops + (they are organized in exactly the same order). */ + + for (phi_new = phi_nodes (new_loop->header), + phi_orig = phi_nodes (orig_loop->header); + phi_new && phi_orig; + phi_new = PHI_CHAIN (phi_new), phi_orig = PHI_CHAIN (phi_orig)) + { + /* step 1. */ + def = PHI_ARG_DEF_FROM_EDGE (phi_orig, entry_arg_e); + add_phi_arg (phi_new, def, new_loop_entry_e); + + /* step 2. */ + def = PHI_ARG_DEF_FROM_EDGE (phi_orig, orig_loop_latch); + if (TREE_CODE (def) != SSA_NAME) + continue; + + new_ssa_name = get_current_def (def); + if (!new_ssa_name) + { + /* This only happens if there are no definitions + inside the loop. use the phi_result in this case. */ + new_ssa_name = PHI_RESULT (phi_new); + } + + /* An ordinary ssa name defined in the loop. */ + add_phi_arg (phi_new, new_ssa_name, loop_latch_edge (new_loop)); + + /* step 3 (case 1). */ + if (!after) + { + gcc_assert (new_loop_exit_e == orig_entry_e); + SET_PHI_ARG_DEF (phi_orig, + new_loop_exit_e->dest_idx, + new_ssa_name); + } + } +} + + +/* Update PHI nodes for a guard of the LOOP. + + Input: + - LOOP, GUARD_EDGE: LOOP is a loop for which we added guard code that + controls whether LOOP is to be executed. GUARD_EDGE is the edge that + originates from the guard-bb, skips LOOP and reaches the (unique) exit + bb of LOOP. This loop-exit-bb is an empty bb with one successor. + We denote this bb NEW_MERGE_BB because before the guard code was added + it had a single predecessor (the LOOP header), and now it became a merge + point of two paths - the path that ends with the LOOP exit-edge, and + the path that ends with GUARD_EDGE. + - NEW_EXIT_BB: New basic block that is added by this function between LOOP + and NEW_MERGE_BB. It is used to place loop-closed-ssa-form exit-phis. + + ===> The CFG before the guard-code was added: + LOOP_header_bb: + loop_body + if (exit_loop) goto update_bb + else goto LOOP_header_bb + update_bb: + + ==> The CFG after the guard-code was added: + guard_bb: + if (LOOP_guard_condition) goto new_merge_bb + else goto LOOP_header_bb + LOOP_header_bb: + loop_body + if (exit_loop_condition) goto new_merge_bb + else goto LOOP_header_bb + new_merge_bb: + goto update_bb + update_bb: + + ==> The CFG after this function: + guard_bb: + if (LOOP_guard_condition) goto new_merge_bb + else goto LOOP_header_bb + LOOP_header_bb: + loop_body + if (exit_loop_condition) goto new_exit_bb + else goto LOOP_header_bb + new_exit_bb: + new_merge_bb: + goto update_bb + update_bb: + + This function: + 1. creates and updates the relevant phi nodes to account for the new + incoming edge (GUARD_EDGE) into NEW_MERGE_BB. This involves: + 1.1. Create phi nodes at NEW_MERGE_BB. + 1.2. Update the phi nodes at the successor of NEW_MERGE_BB (denoted + UPDATE_BB). UPDATE_BB was the exit-bb of LOOP before NEW_MERGE_BB + 2. preserves loop-closed-ssa-form by creating the required phi nodes + at the exit of LOOP (i.e, in NEW_EXIT_BB). + + There are two flavors to this function: + + slpeel_update_phi_nodes_for_guard1: + Here the guard controls whether we enter or skip LOOP, where LOOP is a + prolog_loop (loop1 below), and the new phis created in NEW_MERGE_BB are + for variables that have phis in the loop header. + + slpeel_update_phi_nodes_for_guard2: + Here the guard controls whether we enter or skip LOOP, where LOOP is an + epilog_loop (loop2 below), and the new phis created in NEW_MERGE_BB are + for variables that have phis in the loop exit. + + I.E., the overall structure is: + + loop1_preheader_bb: + guard1 (goto loop1/merg1_bb) + loop1 + loop1_exit_bb: + guard2 (goto merge1_bb/merge2_bb) + merge1_bb + loop2 + loop2_exit_bb + merge2_bb + next_bb + + slpeel_update_phi_nodes_for_guard1 takes care of creating phis in + loop1_exit_bb and merge1_bb. These are entry phis (phis for the vars + that have phis in loop1->header). + + slpeel_update_phi_nodes_for_guard2 takes care of creating phis in + loop2_exit_bb and merge2_bb. These are exit phis (phis for the vars + that have phis in next_bb). It also adds some of these phis to + loop1_exit_bb. + + slpeel_update_phi_nodes_for_guard1 is always called before + slpeel_update_phi_nodes_for_guard2. They are both needed in order + to create correct data-flow and loop-closed-ssa-form. + + Generally slpeel_update_phi_nodes_for_guard1 creates phis for variables + that change between iterations of a loop (and therefore have a phi-node + at the loop entry), whereas slpeel_update_phi_nodes_for_guard2 creates + phis for variables that are used out of the loop (and therefore have + loop-closed exit phis). Some variables may be both updated between + iterations and used after the loop. This is why in loop1_exit_bb we + may need both entry_phis (created by slpeel_update_phi_nodes_for_guard1) + and exit phis (created by slpeel_update_phi_nodes_for_guard2). + + - IS_NEW_LOOP: if IS_NEW_LOOP is true, then LOOP is a newly created copy of + an original loop. i.e., we have: + + orig_loop + guard_bb (goto LOOP/new_merge) + new_loop <-- LOOP + new_exit + new_merge + next_bb + + If IS_NEW_LOOP is false, then LOOP is an original loop, in which case we + have: + + new_loop + guard_bb (goto LOOP/new_merge) + orig_loop <-- LOOP + new_exit + new_merge + next_bb + + The SSA names defined in the original loop have a current + reaching definition that that records the corresponding new + ssa-name used in the new duplicated loop copy. + */ + +/* Function slpeel_update_phi_nodes_for_guard1 + + Input: + - GUARD_EDGE, LOOP, IS_NEW_LOOP, NEW_EXIT_BB - as explained above. + - DEFS - a bitmap of ssa names to mark new names for which we recorded + information. + + In the context of the overall structure, we have: + + loop1_preheader_bb: + guard1 (goto loop1/merg1_bb) +LOOP-> loop1 + loop1_exit_bb: + guard2 (goto merge1_bb/merge2_bb) + merge1_bb + loop2 + loop2_exit_bb + merge2_bb + next_bb + + For each name updated between loop iterations (i.e - for each name that has + an entry (loop-header) phi in LOOP) we create a new phi in: + 1. merge1_bb (to account for the edge from guard1) + 2. loop1_exit_bb (an exit-phi to keep LOOP in loop-closed form) +*/ + +static void +slpeel_update_phi_nodes_for_guard1 (edge guard_edge, struct loop *loop, + bool is_new_loop, basic_block *new_exit_bb, + bitmap *defs) +{ + tree orig_phi, new_phi; + tree update_phi, update_phi2; + tree guard_arg, loop_arg; + basic_block new_merge_bb = guard_edge->dest; + edge e = EDGE_SUCC (new_merge_bb, 0); + basic_block update_bb = e->dest; + basic_block orig_bb = loop->header; + edge new_exit_e; + tree current_new_name; + tree name; + + /* Create new bb between loop and new_merge_bb. */ + *new_exit_bb = split_edge (loop->single_exit); + add_bb_to_loop (*new_exit_bb, loop->outer); + + new_exit_e = EDGE_SUCC (*new_exit_bb, 0); + + for (orig_phi = phi_nodes (orig_bb), update_phi = phi_nodes (update_bb); + orig_phi && update_phi; + orig_phi = PHI_CHAIN (orig_phi), update_phi = PHI_CHAIN (update_phi)) + { + /* Virtual phi; Mark it for renaming. We actually want to call + mar_sym_for_renaming, but since all ssa renaming datastructures + are going to be freed before we get to call ssa_upate, we just + record this name for now in a bitmap, and will mark it for + renaming later. */ + name = PHI_RESULT (orig_phi); + if (!is_gimple_reg (SSA_NAME_VAR (name))) + bitmap_set_bit (vect_vnames_to_rename, SSA_NAME_VERSION (name)); + + /** 1. Handle new-merge-point phis **/ + + /* 1.1. Generate new phi node in NEW_MERGE_BB: */ + new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)), + new_merge_bb); + + /* 1.2. NEW_MERGE_BB has two incoming edges: GUARD_EDGE and the exit-edge + of LOOP. Set the two phi args in NEW_PHI for these edges: */ + loop_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, EDGE_SUCC (loop->latch, 0)); + guard_arg = PHI_ARG_DEF_FROM_EDGE (orig_phi, loop_preheader_edge (loop)); + + add_phi_arg (new_phi, loop_arg, new_exit_e); + add_phi_arg (new_phi, guard_arg, guard_edge); + + /* 1.3. Update phi in successor block. */ + gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi, e) == loop_arg + || PHI_ARG_DEF_FROM_EDGE (update_phi, e) == guard_arg); + SET_PHI_ARG_DEF (update_phi, e->dest_idx, PHI_RESULT (new_phi)); + update_phi2 = new_phi; + + + /** 2. Handle loop-closed-ssa-form phis **/ + + /* 2.1. Generate new phi node in NEW_EXIT_BB: */ + new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)), + *new_exit_bb); + + /* 2.2. NEW_EXIT_BB has one incoming edge: the exit-edge of the loop. */ + add_phi_arg (new_phi, loop_arg, loop->single_exit); + + /* 2.3. Update phi in successor of NEW_EXIT_BB: */ + gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi2, new_exit_e) == loop_arg); + SET_PHI_ARG_DEF (update_phi2, new_exit_e->dest_idx, PHI_RESULT (new_phi)); + + /* 2.4. Record the newly created name with set_current_def. + We want to find a name such that + name = get_current_def (orig_loop_name) + and to set its current definition as follows: + set_current_def (name, new_phi_name) + + If LOOP is a new loop then loop_arg is already the name we're + looking for. If LOOP is the original loop, then loop_arg is + the orig_loop_name and the relevant name is recorded in its + current reaching definition. */ + if (is_new_loop) + current_new_name = loop_arg; + else + { + current_new_name = get_current_def (loop_arg); + /* current_def is not available only if the variable does not + change inside the loop, in which case we also don't care + about recording a current_def for it because we won't be + trying to create loop-exit-phis for it. */ + if (!current_new_name) + continue; + } + gcc_assert (get_current_def (current_new_name) == NULL_TREE); + + set_current_def (current_new_name, PHI_RESULT (new_phi)); + bitmap_set_bit (*defs, SSA_NAME_VERSION (current_new_name)); + } + + set_phi_nodes (new_merge_bb, phi_reverse (phi_nodes (new_merge_bb))); +} + + +/* Function slpeel_update_phi_nodes_for_guard2 + + Input: + - GUARD_EDGE, LOOP, IS_NEW_LOOP, NEW_EXIT_BB - as explained above. + + In the context of the overall structure, we have: + + loop1_preheader_bb: + guard1 (goto loop1/merg1_bb) + loop1 + loop1_exit_bb: + guard2 (goto merge1_bb/merge2_bb) + merge1_bb +LOOP-> loop2 + loop2_exit_bb + merge2_bb + next_bb + + For each name used out side the loop (i.e - for each name that has an exit + phi in next_bb) we create a new phi in: + 1. merge2_bb (to account for the edge from guard_bb) + 2. loop2_exit_bb (an exit-phi to keep LOOP in loop-closed form) + 3. guard2 bb (an exit phi to keep the preceding loop in loop-closed form), + if needed (if it wasn't handled by slpeel_update_phis_nodes_for_phi1). +*/ + +static void +slpeel_update_phi_nodes_for_guard2 (edge guard_edge, struct loop *loop, + bool is_new_loop, basic_block *new_exit_bb) +{ + tree orig_phi, new_phi; + tree update_phi, update_phi2; + tree guard_arg, loop_arg; + basic_block new_merge_bb = guard_edge->dest; + edge e = EDGE_SUCC (new_merge_bb, 0); + basic_block update_bb = e->dest; + edge new_exit_e; + tree orig_def, orig_def_new_name; + tree new_name, new_name2; + tree arg; + + /* Create new bb between loop and new_merge_bb. */ + *new_exit_bb = split_edge (loop->single_exit); + add_bb_to_loop (*new_exit_bb, loop->outer); + + new_exit_e = EDGE_SUCC (*new_exit_bb, 0); + + for (update_phi = phi_nodes (update_bb); update_phi; + update_phi = PHI_CHAIN (update_phi)) + { + orig_phi = update_phi; + orig_def = PHI_ARG_DEF_FROM_EDGE (orig_phi, e); + /* This loop-closed-phi actually doesn't represent a use + out of the loop - the phi arg is a constant. */ + if (TREE_CODE (orig_def) != SSA_NAME) + continue; + orig_def_new_name = get_current_def (orig_def); + arg = NULL_TREE; + + /** 1. Handle new-merge-point phis **/ + + /* 1.1. Generate new phi node in NEW_MERGE_BB: */ + new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)), + new_merge_bb); + + /* 1.2. NEW_MERGE_BB has two incoming edges: GUARD_EDGE and the exit-edge + of LOOP. Set the two PHI args in NEW_PHI for these edges: */ + new_name = orig_def; + new_name2 = NULL_TREE; + if (orig_def_new_name) + { + new_name = orig_def_new_name; + /* Some variables have both loop-entry-phis and loop-exit-phis. + Such variables were given yet newer names by phis placed in + guard_bb by slpeel_update_phi_nodes_for_guard1. I.e: + new_name2 = get_current_def (get_current_def (orig_name)). */ + new_name2 = get_current_def (new_name); + } + + if (is_new_loop) + { + guard_arg = orig_def; + loop_arg = new_name; + } + else + { + guard_arg = new_name; + loop_arg = orig_def; + } + if (new_name2) + guard_arg = new_name2; + + add_phi_arg (new_phi, loop_arg, new_exit_e); + add_phi_arg (new_phi, guard_arg, guard_edge); + + /* 1.3. Update phi in successor block. */ + gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi, e) == orig_def); + SET_PHI_ARG_DEF (update_phi, e->dest_idx, PHI_RESULT (new_phi)); + update_phi2 = new_phi; + + + /** 2. Handle loop-closed-ssa-form phis **/ + + /* 2.1. Generate new phi node in NEW_EXIT_BB: */ + new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)), + *new_exit_bb); + + /* 2.2. NEW_EXIT_BB has one incoming edge: the exit-edge of the loop. */ + add_phi_arg (new_phi, loop_arg, loop->single_exit); + + /* 2.3. Update phi in successor of NEW_EXIT_BB: */ + gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi2, new_exit_e) == loop_arg); + SET_PHI_ARG_DEF (update_phi2, new_exit_e->dest_idx, PHI_RESULT (new_phi)); + + + /** 3. Handle loop-closed-ssa-form phis for first loop **/ + + /* 3.1. Find the relevant names that need an exit-phi in + GUARD_BB, i.e. names for which + slpeel_update_phi_nodes_for_guard1 had not already created a + phi node. This is the case for names that are used outside + the loop (and therefore need an exit phi) but are not updated + across loop iterations (and therefore don't have a + loop-header-phi). + + slpeel_update_phi_nodes_for_guard1 is responsible for + creating loop-exit phis in GUARD_BB for names that have a + loop-header-phi. When such a phi is created we also record + the new name in its current definition. If this new name + exists, then guard_arg was set to this new name (see 1.2 + above). Therefore, if guard_arg is not this new name, this + is an indication that an exit-phi in GUARD_BB was not yet + created, so we take care of it here. */ + if (guard_arg == new_name2) + continue; + arg = guard_arg; + + /* 3.2. Generate new phi node in GUARD_BB: */ + new_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (orig_phi)), + guard_edge->src); + + /* 3.3. GUARD_BB has one incoming edge: */ + gcc_assert (EDGE_COUNT (guard_edge->src->preds) == 1); + add_phi_arg (new_phi, arg, EDGE_PRED (guard_edge->src, 0)); + + /* 3.4. Update phi in successor of GUARD_BB: */ + gcc_assert (PHI_ARG_DEF_FROM_EDGE (update_phi2, guard_edge) + == guard_arg); + SET_PHI_ARG_DEF (update_phi2, guard_edge->dest_idx, PHI_RESULT (new_phi)); + } + + set_phi_nodes (new_merge_bb, phi_reverse (phi_nodes (new_merge_bb))); +} + + +/* Make the LOOP iterate NITERS times. This is done by adding a new IV + that starts at zero, increases by one and its limit is NITERS. + + Assumption: the exit-condition of LOOP is the last stmt in the loop. */ + +void +slpeel_make_loop_iterate_ntimes (struct loop *loop, tree niters) +{ + tree indx_before_incr, indx_after_incr, cond_stmt, cond; + tree orig_cond; + edge exit_edge = loop->single_exit; + block_stmt_iterator loop_cond_bsi; + block_stmt_iterator incr_bsi; + bool insert_after; + tree begin_label = tree_block_label (loop->latch); + tree exit_label = tree_block_label (loop->single_exit->dest); + tree init = build_int_cst (TREE_TYPE (niters), 0); + tree step = build_int_cst (TREE_TYPE (niters), 1); + tree then_label; + tree else_label; + LOC loop_loc; + + orig_cond = get_loop_exit_condition (loop); + gcc_assert (orig_cond); + loop_cond_bsi = bsi_for_stmt (orig_cond); + + standard_iv_increment_position (loop, &incr_bsi, &insert_after); + create_iv (init, step, NULL_TREE, loop, + &incr_bsi, insert_after, &indx_before_incr, &indx_after_incr); + + if (exit_edge->flags & EDGE_TRUE_VALUE) /* 'then' edge exits the loop. */ + { + cond = build2 (GE_EXPR, boolean_type_node, indx_after_incr, niters); + then_label = build1 (GOTO_EXPR, void_type_node, exit_label); + else_label = build1 (GOTO_EXPR, void_type_node, begin_label); + } + else /* 'then' edge loops back. */ + { + cond = build2 (LT_EXPR, boolean_type_node, indx_after_incr, niters); + then_label = build1 (GOTO_EXPR, void_type_node, begin_label); + else_label = build1 (GOTO_EXPR, void_type_node, exit_label); + } + + cond_stmt = build3 (COND_EXPR, TREE_TYPE (orig_cond), cond, + then_label, else_label); + bsi_insert_before (&loop_cond_bsi, cond_stmt, BSI_SAME_STMT); + + /* Remove old loop exit test: */ + bsi_remove (&loop_cond_bsi, true); + + loop_loc = find_loop_location (loop); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + if (loop_loc != UNKNOWN_LOC) + fprintf (dump_file, "\nloop at %s:%d: ", + LOC_FILE (loop_loc), LOC_LINE (loop_loc)); + print_generic_expr (dump_file, cond_stmt, TDF_SLIM); + } + + loop->nb_iterations = niters; +} + + +/* Given LOOP this function generates a new copy of it and puts it + on E which is either the entry or exit of LOOP. */ + +static struct loop * +slpeel_tree_duplicate_loop_to_edge_cfg (struct loop *loop, struct loops *loops, + edge e) +{ + struct loop *new_loop; + basic_block *new_bbs, *bbs; + bool at_exit; + bool was_imm_dom; + basic_block exit_dest; + tree phi, phi_arg; + + at_exit = (e == loop->single_exit); + if (!at_exit && e != loop_preheader_edge (loop)) + return NULL; + + bbs = get_loop_body (loop); + + /* Check whether duplication is possible. */ + if (!can_copy_bbs_p (bbs, loop->num_nodes)) + { + free (bbs); + return NULL; + } + + /* Generate new loop structure. */ + new_loop = duplicate_loop (loops, loop, loop->outer); + if (!new_loop) + { + free (bbs); + return NULL; + } + + exit_dest = loop->single_exit->dest; + was_imm_dom = (get_immediate_dominator (CDI_DOMINATORS, + exit_dest) == loop->header ? + true : false); + + new_bbs = XNEWVEC (basic_block, loop->num_nodes); + + copy_bbs (bbs, loop->num_nodes, new_bbs, + &loop->single_exit, 1, &new_loop->single_exit, NULL, + e->src); + + /* Duplicating phi args at exit bbs as coming + also from exit of duplicated loop. */ + for (phi = phi_nodes (exit_dest); phi; phi = PHI_CHAIN (phi)) + { + phi_arg = PHI_ARG_DEF_FROM_EDGE (phi, loop->single_exit); + if (phi_arg) + { + edge new_loop_exit_edge; + + if (EDGE_SUCC (new_loop->header, 0)->dest == new_loop->latch) + new_loop_exit_edge = EDGE_SUCC (new_loop->header, 1); + else + new_loop_exit_edge = EDGE_SUCC (new_loop->header, 0); + + add_phi_arg (phi, phi_arg, new_loop_exit_edge); + } + } + + if (at_exit) /* Add the loop copy at exit. */ + { + redirect_edge_and_branch_force (e, new_loop->header); + set_immediate_dominator (CDI_DOMINATORS, new_loop->header, e->src); + if (was_imm_dom) + set_immediate_dominator (CDI_DOMINATORS, exit_dest, new_loop->header); + } + else /* Add the copy at entry. */ + { + edge new_exit_e; + edge entry_e = loop_preheader_edge (loop); + basic_block preheader = entry_e->src; + + if (!flow_bb_inside_loop_p (new_loop, + EDGE_SUCC (new_loop->header, 0)->dest)) + new_exit_e = EDGE_SUCC (new_loop->header, 0); + else + new_exit_e = EDGE_SUCC (new_loop->header, 1); + + redirect_edge_and_branch_force (new_exit_e, loop->header); + set_immediate_dominator (CDI_DOMINATORS, loop->header, + new_exit_e->src); + + /* We have to add phi args to the loop->header here as coming + from new_exit_e edge. */ + for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi)) + { + phi_arg = PHI_ARG_DEF_FROM_EDGE (phi, entry_e); + if (phi_arg) + add_phi_arg (phi, phi_arg, new_exit_e); + } + + redirect_edge_and_branch_force (entry_e, new_loop->header); + set_immediate_dominator (CDI_DOMINATORS, new_loop->header, preheader); + } + + free (new_bbs); + free (bbs); + + return new_loop; +} + + +/* Given the condition statement COND, put it as the last statement + of GUARD_BB; EXIT_BB is the basic block to skip the loop; + Assumes that this is the single exit of the guarded loop. + Returns the skip edge. */ + +static edge +slpeel_add_loop_guard (basic_block guard_bb, tree cond, basic_block exit_bb, + basic_block dom_bb) +{ + block_stmt_iterator bsi; + edge new_e, enter_e; + tree cond_stmt, then_label, else_label; + + enter_e = EDGE_SUCC (guard_bb, 0); + enter_e->flags &= ~EDGE_FALLTHRU; + enter_e->flags |= EDGE_FALSE_VALUE; + bsi = bsi_last (guard_bb); + + then_label = build1 (GOTO_EXPR, void_type_node, + tree_block_label (exit_bb)); + else_label = build1 (GOTO_EXPR, void_type_node, + tree_block_label (enter_e->dest)); + cond_stmt = build3 (COND_EXPR, void_type_node, cond, + then_label, else_label); + bsi_insert_after (&bsi, cond_stmt, BSI_NEW_STMT); + /* Add new edge to connect guard block to the merge/loop-exit block. */ + new_e = make_edge (guard_bb, exit_bb, EDGE_TRUE_VALUE); + set_immediate_dominator (CDI_DOMINATORS, exit_bb, dom_bb); + return new_e; +} + + +/* This function verifies that the following restrictions apply to LOOP: + (1) it is innermost + (2) it consists of exactly 2 basic blocks - header, and an empty latch. + (3) it is single entry, single exit + (4) its exit condition is the last stmt in the header + (5) E is the entry/exit edge of LOOP. + */ + +bool +slpeel_can_duplicate_loop_p (struct loop *loop, edge e) +{ + edge exit_e = loop->single_exit; + edge entry_e = loop_preheader_edge (loop); + tree orig_cond = get_loop_exit_condition (loop); + block_stmt_iterator loop_exit_bsi = bsi_last (exit_e->src); + + if (need_ssa_update_p ()) + return false; + + if (loop->inner + /* All loops have an outer scope; the only case loop->outer is NULL is for + the function itself. */ + || !loop->outer + || loop->num_nodes != 2 + || !empty_block_p (loop->latch) + || !loop->single_exit + /* Verify that new loop exit condition can be trivially modified. */ + || (!orig_cond || orig_cond != bsi_stmt (loop_exit_bsi)) + || (e != exit_e && e != entry_e)) + return false; + + return true; +} + +#ifdef ENABLE_CHECKING +void +slpeel_verify_cfg_after_peeling (struct loop *first_loop, + struct loop *second_loop) +{ + basic_block loop1_exit_bb = first_loop->single_exit->dest; + basic_block loop2_entry_bb = loop_preheader_edge (second_loop)->src; + basic_block loop1_entry_bb = loop_preheader_edge (first_loop)->src; + + /* A guard that controls whether the second_loop is to be executed or skipped + is placed in first_loop->exit. first_loopt->exit therefore has two + successors - one is the preheader of second_loop, and the other is a bb + after second_loop. + */ + gcc_assert (EDGE_COUNT (loop1_exit_bb->succs) == 2); + + /* 1. Verify that one of the successors of first_loopt->exit is the preheader + of second_loop. */ + + /* The preheader of new_loop is expected to have two predecessors: + first_loop->exit and the block that precedes first_loop. */ + + gcc_assert (EDGE_COUNT (loop2_entry_bb->preds) == 2 + && ((EDGE_PRED (loop2_entry_bb, 0)->src == loop1_exit_bb + && EDGE_PRED (loop2_entry_bb, 1)->src == loop1_entry_bb) + || (EDGE_PRED (loop2_entry_bb, 1)->src == loop1_exit_bb + && EDGE_PRED (loop2_entry_bb, 0)->src == loop1_entry_bb))); + + /* Verify that the other successor of first_loopt->exit is after the + second_loop. */ + /* TODO */ +} +#endif + +/* Function slpeel_tree_peel_loop_to_edge. + + Peel the first (last) iterations of LOOP into a new prolog (epilog) loop + that is placed on the entry (exit) edge E of LOOP. After this transformation + we have two loops one after the other - first-loop iterates FIRST_NITERS + times, and second-loop iterates the remainder NITERS - FIRST_NITERS times. + + Input: + - LOOP: the loop to be peeled. + - E: the exit or entry edge of LOOP. + If it is the entry edge, we peel the first iterations of LOOP. In this + case first-loop is LOOP, and second-loop is the newly created loop. + If it is the exit edge, we peel the last iterations of LOOP. In this + case, first-loop is the newly created loop, and second-loop is LOOP. + - NITERS: the number of iterations that LOOP iterates. + - FIRST_NITERS: the number of iterations that the first-loop should iterate. + - UPDATE_FIRST_LOOP_COUNT: specified whether this function is responsible + for updating the loop bound of the first-loop to FIRST_NITERS. If it + is false, the caller of this function may want to take care of this + (this can be useful if we don't want new stmts added to first-loop). + + Output: + The function returns a pointer to the new loop-copy, or NULL if it failed + to perform the transformation. + + The function generates two if-then-else guards: one before the first loop, + and the other before the second loop: + The first guard is: + if (FIRST_NITERS == 0) then skip the first loop, + and go directly to the second loop. + The second guard is: + if (FIRST_NITERS == NITERS) then skip the second loop. + + FORNOW only simple loops are supported (see slpeel_can_duplicate_loop_p). + FORNOW the resulting code will not be in loop-closed-ssa form. +*/ + +struct loop* +slpeel_tree_peel_loop_to_edge (struct loop *loop, struct loops *loops, + edge e, tree first_niters, + tree niters, bool update_first_loop_count) +{ + struct loop *new_loop = NULL, *first_loop, *second_loop; + edge skip_e; + tree pre_condition; + bitmap definitions; + basic_block bb_before_second_loop, bb_after_second_loop; + basic_block bb_before_first_loop; + basic_block bb_between_loops; + basic_block new_exit_bb; + edge exit_e = loop->single_exit; + LOC loop_loc; + + if (!slpeel_can_duplicate_loop_p (loop, e)) + return NULL; + + /* We have to initialize cfg_hooks. Then, when calling + cfg_hooks->split_edge, the function tree_split_edge + is actually called and, when calling cfg_hooks->duplicate_block, + the function tree_duplicate_bb is called. */ + tree_register_cfg_hooks (); + + + /* 1. Generate a copy of LOOP and put it on E (E is the entry/exit of LOOP). + Resulting CFG would be: + + first_loop: + do { + } while ... + + second_loop: + do { + } while ... + + orig_exit_bb: + */ + + if (!(new_loop = slpeel_tree_duplicate_loop_to_edge_cfg (loop, loops, e))) + { + loop_loc = find_loop_location (loop); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + if (loop_loc != UNKNOWN_LOC) + fprintf (dump_file, "\n%s:%d: note: ", + LOC_FILE (loop_loc), LOC_LINE (loop_loc)); + fprintf (dump_file, "tree_duplicate_loop_to_edge_cfg failed.\n"); + } + return NULL; + } + + if (e == exit_e) + { + /* NEW_LOOP was placed after LOOP. */ + first_loop = loop; + second_loop = new_loop; + } + else + { + /* NEW_LOOP was placed before LOOP. */ + first_loop = new_loop; + second_loop = loop; + } + + definitions = ssa_names_to_replace (); + slpeel_update_phis_for_duplicate_loop (loop, new_loop, e == exit_e); + rename_variables_in_loop (new_loop); + + + /* 2. Add the guard that controls whether the first loop is executed. + Resulting CFG would be: + + bb_before_first_loop: + if (FIRST_NITERS == 0) GOTO bb_before_second_loop + GOTO first-loop + + first_loop: + do { + } while ... + + bb_before_second_loop: + + second_loop: + do { + } while ... + + orig_exit_bb: + */ + + bb_before_first_loop = split_edge (loop_preheader_edge (first_loop)); + add_bb_to_loop (bb_before_first_loop, first_loop->outer); + bb_before_second_loop = split_edge (first_loop->single_exit); + add_bb_to_loop (bb_before_second_loop, first_loop->outer); + + pre_condition = + fold_build2 (LE_EXPR, boolean_type_node, first_niters, + build_int_cst (TREE_TYPE (first_niters), 0)); + skip_e = slpeel_add_loop_guard (bb_before_first_loop, pre_condition, + bb_before_second_loop, bb_before_first_loop); + slpeel_update_phi_nodes_for_guard1 (skip_e, first_loop, + first_loop == new_loop, + &new_exit_bb, &definitions); + + + /* 3. Add the guard that controls whether the second loop is executed. + Resulting CFG would be: + + bb_before_first_loop: + if (FIRST_NITERS == 0) GOTO bb_before_second_loop (skip first loop) + GOTO first-loop + + first_loop: + do { + } while ... + + bb_between_loops: + if (FIRST_NITERS == NITERS) GOTO bb_after_second_loop (skip second loop) + GOTO bb_before_second_loop + + bb_before_second_loop: + + second_loop: + do { + } while ... + + bb_after_second_loop: + + orig_exit_bb: + */ + + bb_between_loops = new_exit_bb; + bb_after_second_loop = split_edge (second_loop->single_exit); + add_bb_to_loop (bb_after_second_loop, second_loop->outer); + + pre_condition = + fold_build2 (EQ_EXPR, boolean_type_node, first_niters, niters); + skip_e = slpeel_add_loop_guard (bb_between_loops, pre_condition, + bb_after_second_loop, bb_before_first_loop); + slpeel_update_phi_nodes_for_guard2 (skip_e, second_loop, + second_loop == new_loop, &new_exit_bb); + + /* 4. Make first-loop iterate FIRST_NITERS times, if requested. + */ + if (update_first_loop_count) + slpeel_make_loop_iterate_ntimes (first_loop, first_niters); + + BITMAP_FREE (definitions); + delete_update_ssa (); + + return new_loop; +} + +/* Function vect_get_loop_location. + + Extract the location of the loop in the source code. + If the loop is not well formed for vectorization, an estimated + location is calculated. + Return the loop location if succeed and NULL if not. */ + +LOC +find_loop_location (struct loop *loop) +{ + tree node = NULL_TREE; + basic_block bb; + block_stmt_iterator si; + + if (!loop) + return UNKNOWN_LOC; + + node = get_loop_exit_condition (loop); + + if (node && EXPR_P (node) && EXPR_HAS_LOCATION (node) + && EXPR_FILENAME (node) && EXPR_LINENO (node)) + return EXPR_LOC (node); + + /* If we got here the loop is probably not "well formed", + try to estimate the loop location */ + + if (!loop->header) + return UNKNOWN_LOC; + + bb = loop->header; + + for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si)) + { + node = bsi_stmt (si); + if (node && EXPR_P (node) && EXPR_HAS_LOCATION (node)) + return EXPR_LOC (node); + } + + return UNKNOWN_LOC; +} + + +/************************************************************************* + Vectorization Debug Information. + *************************************************************************/ + +/* Function vect_set_verbosity_level. + + Called from toplev.c upon detection of the + -ftree-vectorizer-verbose=N option. */ + +void +vect_set_verbosity_level (const char *val) +{ + unsigned int vl; + + vl = atoi (val); + if (vl < MAX_VERBOSITY_LEVEL) + vect_verbosity_level = vl; + else + vect_verbosity_level = MAX_VERBOSITY_LEVEL - 1; +} + + +/* Function vect_set_dump_settings. + + Fix the verbosity level of the vectorizer if the + requested level was not set explicitly using the flag + -ftree-vectorizer-verbose=N. + Decide where to print the debugging information (dump_file/stderr). + If the user defined the verbosity level, but there is no dump file, + print to stderr, otherwise print to the dump file. */ + +static void +vect_set_dump_settings (void) +{ + vect_dump = dump_file; + + /* Check if the verbosity level was defined by the user: */ + if (vect_verbosity_level != MAX_VERBOSITY_LEVEL) + { + /* If there is no dump file, print to stderr. */ + if (!dump_file) + vect_dump = stderr; + return; + } + + /* User didn't specify verbosity level: */ + if (dump_file && (dump_flags & TDF_DETAILS)) + vect_verbosity_level = REPORT_DETAILS; + else if (dump_file && (dump_flags & TDF_STATS)) + vect_verbosity_level = REPORT_UNVECTORIZED_LOOPS; + else + vect_verbosity_level = REPORT_NONE; + + gcc_assert (dump_file || vect_verbosity_level == REPORT_NONE); +} + + +/* Function debug_loop_details. + + For vectorization debug dumps. */ + +bool +vect_print_dump_info (enum verbosity_levels vl) +{ + if (vl > vect_verbosity_level) + return false; + + if (!current_function_decl || !vect_dump) + return false; + + if (vect_loop_location == UNKNOWN_LOC) + fprintf (vect_dump, "\n%s:%d: note: ", + DECL_SOURCE_FILE (current_function_decl), + DECL_SOURCE_LINE (current_function_decl)); + else + fprintf (vect_dump, "\n%s:%d: note: ", + LOC_FILE (vect_loop_location), LOC_LINE (vect_loop_location)); + + return true; +} + + +/************************************************************************* + Vectorization Utilities. + *************************************************************************/ + +/* Function new_stmt_vec_info. + + Create and initialize a new stmt_vec_info struct for STMT. */ + +stmt_vec_info +new_stmt_vec_info (tree stmt, loop_vec_info loop_vinfo) +{ + stmt_vec_info res; + res = (stmt_vec_info) xcalloc (1, sizeof (struct _stmt_vec_info)); + + STMT_VINFO_TYPE (res) = undef_vec_info_type; + STMT_VINFO_STMT (res) = stmt; + STMT_VINFO_LOOP_VINFO (res) = loop_vinfo; + STMT_VINFO_RELEVANT_P (res) = 0; + STMT_VINFO_LIVE_P (res) = 0; + STMT_VINFO_VECTYPE (res) = NULL; + STMT_VINFO_VEC_STMT (res) = NULL; + STMT_VINFO_IN_PATTERN_P (res) = false; + STMT_VINFO_RELATED_STMT (res) = NULL; + STMT_VINFO_DATA_REF (res) = NULL; + if (TREE_CODE (stmt) == PHI_NODE) + STMT_VINFO_DEF_TYPE (res) = vect_unknown_def_type; + else + STMT_VINFO_DEF_TYPE (res) = vect_loop_def; + STMT_VINFO_SAME_ALIGN_REFS (res) = VEC_alloc (dr_p, heap, 5); + + return res; +} + + +/* 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. */ + +loop_vec_info +new_loop_vec_info (struct loop *loop) +{ + loop_vec_info res; + basic_block *bbs; + block_stmt_iterator si; + unsigned int i; + + res = (loop_vec_info) xcalloc (1, sizeof (struct _loop_vec_info)); + + bbs = get_loop_body (loop); + + /* Create stmt_info for all stmts in the loop. */ + for (i = 0; i < loop->num_nodes; i++) + { + basic_block bb = bbs[i]; + tree phi; + + for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) + { + stmt_ann_t ann = get_stmt_ann (phi); + set_stmt_info (ann, new_stmt_vec_info (phi, res)); + } + + for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si)) + { + tree stmt = bsi_stmt (si); + stmt_ann_t ann; + + ann = stmt_ann (stmt); + set_stmt_info (ann, new_stmt_vec_info (stmt, res)); + } + } + + LOOP_VINFO_LOOP (res) = loop; + LOOP_VINFO_BBS (res) = bbs; + LOOP_VINFO_EXIT_COND (res) = NULL; + LOOP_VINFO_NITERS (res) = NULL; + 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 (tree, heap, PARAM_VALUE (PARAM_VECT_MAX_VERSION_CHECKS)); + + 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) +{ + struct loop *loop; + basic_block *bbs; + int nbbs; + block_stmt_iterator si; + int j; + + if (!loop_vinfo) + return; + + loop = LOOP_VINFO_LOOP (loop_vinfo); + + bbs = LOOP_VINFO_BBS (loop_vinfo); + nbbs = loop->num_nodes; + + for (j = 0; j < nbbs; j++) + { + basic_block bb = bbs[j]; + tree phi; + stmt_vec_info stmt_info; + + for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) + { + stmt_ann_t ann = stmt_ann (phi); + + stmt_info = vinfo_for_stmt (phi); + free (stmt_info); + set_stmt_info (ann, NULL); + } + + for (si = bsi_start (bb); !bsi_end_p (si); ) + { + tree stmt = bsi_stmt (si); + stmt_ann_t ann = stmt_ann (stmt); + 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; + tree 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. */ + VEC_free (dr_p, heap, STMT_VINFO_SAME_ALIGN_REFS (stmt_info)); + free (stmt_info); + set_stmt_info (ann, NULL); + + /* Remove dead "pattern stmts". */ + if (remove_stmt_p) + bsi_remove (&si, true); + } + bsi_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 (tree, heap, LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo)); + + free (loop_vinfo); +} + + +/* Function vect_force_dr_alignment_p. + + Returns whether the alignment of a DECL can be forced to be aligned + on ALIGNMENT bit boundary. */ + +bool +vect_can_force_dr_alignment_p (tree decl, unsigned int alignment) +{ + if (TREE_CODE (decl) != VAR_DECL) + return false; + + if (DECL_EXTERNAL (decl)) + return false; + + if (TREE_ASM_WRITTEN (decl)) + return false; + + if (TREE_STATIC (decl)) + return (alignment <= MAX_OFILE_ALIGNMENT); + else + /* This is not 100% correct. The absolute correct stack alignment + is STACK_BOUNDARY. We're supposed to hope, but not assume, that + PREFERRED_STACK_BOUNDARY is honored by all translation units. + However, until someone implements forced stack alignment, SSE + isn't really usable without this. */ + return (alignment <= PREFERRED_STACK_BOUNDARY); +} + + +/* Function get_vectype_for_scalar_type. + + Returns the vector type corresponding to SCALAR_TYPE as supported + by the target. */ + +tree +get_vectype_for_scalar_type (tree scalar_type) +{ + enum machine_mode inner_mode = TYPE_MODE (scalar_type); + int nbytes = GET_MODE_SIZE (inner_mode); + int nunits; + tree vectype; + + if (nbytes == 0 || nbytes >= UNITS_PER_SIMD_WORD) + return NULL_TREE; + + /* FORNOW: Only a single vector size per target (UNITS_PER_SIMD_WORD) + is expected. */ + nunits = UNITS_PER_SIMD_WORD / nbytes; + + vectype = build_vector_type (scalar_type, nunits); + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "get vectype with %d units of type ", nunits); + print_generic_expr (vect_dump, scalar_type, TDF_SLIM); + } + + if (!vectype) + return NULL_TREE; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "vectype: "); + print_generic_expr (vect_dump, vectype, TDF_SLIM); + } + + if (!VECTOR_MODE_P (TYPE_MODE (vectype)) + && !INTEGRAL_MODE_P (TYPE_MODE (vectype))) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "mode not supported by target."); + return NULL_TREE; + } + + return vectype; +} + + +/* Function vect_supportable_dr_alignment + + Return whether the data reference DR is supported with respect to its + alignment. */ + +enum dr_alignment_support +vect_supportable_dr_alignment (struct data_reference *dr) +{ + tree vectype = STMT_VINFO_VECTYPE (vinfo_for_stmt (DR_STMT (dr))); + enum machine_mode mode = (int) TYPE_MODE (vectype); + + if (aligned_access_p (dr)) + return dr_aligned; + + /* Possibly unaligned access. */ + + if (DR_IS_READ (dr)) + { + if (vec_realign_load_optab->handlers[mode].insn_code != CODE_FOR_nothing + && (!targetm.vectorize.builtin_mask_for_load + || targetm.vectorize.builtin_mask_for_load ())) + return dr_unaligned_software_pipeline; + + if (movmisalign_optab->handlers[mode].insn_code != CODE_FOR_nothing) + /* Can't software pipeline the loads, but can at least do them. */ + return dr_unaligned_supported; + } + + /* Unsupported. */ + return dr_unaligned_unsupported; +} + + +/* Function vect_is_simple_use. + + Input: + LOOP - the loop that is being vectorized. + OPERAND - operand of a stmt in LOOP. + DEF - the defining stmt in case OPERAND is an SSA_NAME. + + Returns whether a stmt with OPERAND can be vectorized. + Supportable operands are constants, loop invariants, and operands that are + defined by the current iteration of the loop. Unsupportable operands are + those that are defined by a previous iteration of the loop (as is the case + in reduction/induction computations). */ + +bool +vect_is_simple_use (tree operand, loop_vec_info loop_vinfo, tree *def_stmt, + tree *def, enum vect_def_type *dt) +{ + basic_block bb; + stmt_vec_info stmt_vinfo; + struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); + + *def_stmt = NULL_TREE; + *def = NULL_TREE; + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "vect_is_simple_use: operand "); + print_generic_expr (vect_dump, operand, TDF_SLIM); + } + + if (TREE_CODE (operand) == INTEGER_CST || TREE_CODE (operand) == REAL_CST) + { + *dt = vect_constant_def; + return true; + } + + if (TREE_CODE (operand) != SSA_NAME) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "not ssa-name."); + return false; + } + + *def_stmt = SSA_NAME_DEF_STMT (operand); + if (*def_stmt == NULL_TREE ) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "no def_stmt."); + return false; + } + + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "def_stmt: "); + print_generic_expr (vect_dump, *def_stmt, TDF_SLIM); + } + + /* empty stmt is expected only in case of a function argument. + (Otherwise - we expect a phi_node or a modify_expr). */ + if (IS_EMPTY_STMT (*def_stmt)) + { + tree arg = TREE_OPERAND (*def_stmt, 0); + if (TREE_CODE (arg) == INTEGER_CST || TREE_CODE (arg) == REAL_CST) + { + *def = operand; + *dt = vect_invariant_def; + return true; + } + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Unexpected empty stmt."); + return false; + } + + bb = bb_for_stmt (*def_stmt); + if (!flow_bb_inside_loop_p (loop, bb)) + *dt = vect_invariant_def; + else + { + stmt_vinfo = vinfo_for_stmt (*def_stmt); + *dt = STMT_VINFO_DEF_TYPE (stmt_vinfo); + } + + if (*dt == vect_unknown_def_type) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "Unsupported pattern."); + return false; + } + + /* stmts inside the loop that have been identified as performing + a reduction operation cannot have uses in the loop. */ + if (*dt == vect_reduction_def && TREE_CODE (*def_stmt) != PHI_NODE) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "reduction used in loop."); + return false; + } + + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "type of def: %d.",*dt); + + switch (TREE_CODE (*def_stmt)) + { + case PHI_NODE: + *def = PHI_RESULT (*def_stmt); + gcc_assert (*dt == vect_induction_def || *dt == vect_reduction_def + || *dt == vect_invariant_def); + break; + + case MODIFY_EXPR: + *def = TREE_OPERAND (*def_stmt, 0); + gcc_assert (*dt == vect_loop_def || *dt == vect_invariant_def); + break; + + default: + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "unsupported defining stmt: "); + return false; + } + + if (*dt == vect_induction_def) + { + if (vect_print_dump_info (REPORT_DETAILS)) + fprintf (vect_dump, "induction not supported."); + return false; + } + + return true; +} + + +/* 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. */ + +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; + } +} + + +/* Function vect_is_simple_reduction + + Detect a cross-iteration def-use cucle 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. */ + +tree +vect_is_simple_reduction (struct loop *loop, tree phi) +{ + edge latch_e = loop_latch_edge (loop); + tree loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e); + tree def_stmt, def1, def2; + enum tree_code code; + int op_type; + tree operation, op1, op2; + tree type; + + 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_TREE; + } + + 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_TREE; + } + + if (TREE_CODE (def_stmt) != MODIFY_EXPR) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + print_generic_expr (vect_dump, def_stmt, TDF_SLIM); + } + return NULL_TREE; + } + + operation = TREE_OPERAND (def_stmt, 1); + code = TREE_CODE (operation); + if (!commutative_tree_code (code) || !associative_tree_code (code)) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: not commutative/associative: "); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return NULL_TREE; + } + + op_type = TREE_CODE_LENGTH (code); + if (op_type != binary_op) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: not binary operation: "); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return NULL_TREE; + } + + op1 = TREE_OPERAND (operation, 0); + op2 = TREE_OPERAND (operation, 1); + if (TREE_CODE (op1) != SSA_NAME || TREE_CODE (op2) != SSA_NAME) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: uses not ssa_names: "); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return NULL_TREE; + } + + /* Check that it's ok to change the order of the computation. */ + type = TREE_TYPE (operation); + 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_TREE; + } + + /* CHECKME: check for !flag_finite_math_only too? */ + if (SCALAR_FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations) + { + /* Changing the order of operations changes the semantics. */ + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: unsafe fp math optimization: "); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return NULL_TREE; + } + else if (INTEGRAL_TYPE_P (type) && TYPE_OVERFLOW_TRAPS (type)) + { + /* Changing the order of operations changes the semantics. */ + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: unsafe int math optimization: "); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return NULL_TREE; + } + + /* 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) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: no defs for operands: "); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return NULL_TREE; + } + + if (TREE_CODE (def1) == MODIFY_EXPR + && flow_bb_inside_loop_p (loop, bb_for_stmt (def1)) + && def2 == phi) + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "detected reduction:"); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return def_stmt; + } + else if (TREE_CODE (def2) == MODIFY_EXPR + && flow_bb_inside_loop_p (loop, bb_for_stmt (def2)) + && def1 == phi) + { + /* 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)) + { + fprintf (vect_dump, "detected reduction: need to swap operands:"); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + swap_tree_operands (def_stmt, &TREE_OPERAND (operation, 0), + &TREE_OPERAND (operation, 1)); + return def_stmt; + } + else + { + if (vect_print_dump_info (REPORT_DETAILS)) + { + fprintf (vect_dump, "reduction: unknown pattern."); + print_generic_expr (vect_dump, operation, TDF_SLIM); + } + return NULL_TREE; + } +} + + +/* 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. */ + +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 vectorize_loops. + + Entry Point to loop vectorization phase. */ + +void +vectorize_loops (struct loops *loops) +{ + unsigned int i; + unsigned int num_vectorized_loops = 0; + + /* Fix the verbosity level if not defined explicitly by the user. */ + vect_set_dump_settings (); + + /* Allocate the bitmap that records which virtual variables that + need to be renamed. */ + vect_vnames_to_rename = BITMAP_ALLOC (NULL); + + /* ----------- Analyze loops. ----------- */ + + /* If some loop was duplicated, it gets bigger number + than all previously defined loops. This fact allows us to run + only over initial loops skipping newly generated ones. */ + vect_loops_num = loops->num; + for (i = 1; i < vect_loops_num; i++) + { + loop_vec_info loop_vinfo; + struct loop *loop = loops->parray[i]; + + if (!loop) + continue; + + vect_loop_location = find_loop_location (loop); + loop_vinfo = vect_analyze_loop (loop); + loop->aux = loop_vinfo; + + if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo)) + continue; + + vect_transform_loop (loop_vinfo, loops); + /* APPLE LOCAL begin 4095567 */ + /* Now this function uses vectors. */ + DECL_STRUCT_FUNCTION (current_function_decl)->uses_vector = 1; + /* APPLE LOCAL end 4095567 */ + /* APPLE LOCAL begin opt diary */ + if (flag_opt_diary && debug_hooks->opt_diary_entry) + (*debug_hooks->opt_diary_entry) (OD_msg_loop_vectorized, + *vect_loop_location); + /* APPLE LOCAL end opt diary */ + num_vectorized_loops++; + } + vect_loop_location = UNKNOWN_LOC; + + if (vect_print_dump_info (REPORT_VECTORIZED_LOOPS)) + fprintf (vect_dump, "vectorized %u loops in function.\n", + num_vectorized_loops); + + /* ----------- Finalize. ----------- */ + + BITMAP_FREE (vect_vnames_to_rename); + + for (i = 1; i < vect_loops_num; i++) + { + struct loop *loop = loops->parray[i]; + loop_vec_info loop_vinfo; + + if (!loop) + continue; + loop_vinfo = loop->aux; + destroy_loop_vec_info (loop_vinfo); + loop->aux = NULL; + } +} |