Mercurial > hg > CbC > CbC_gcc
diff gcc/loop-unroll.c @ 111:04ced10e8804
gcc 7
| author | kono |
|---|---|
| date | Fri, 27 Oct 2017 22:46:09 +0900 |
| parents | f6334be47118 |
| children | 84e7813d76e9 |
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line diff
--- a/gcc/loop-unroll.c Sun Aug 21 07:07:55 2011 +0900 +++ b/gcc/loop-unroll.c Fri Oct 27 22:46:09 2017 +0900 @@ -1,6 +1,5 @@ -/* Loop unrolling and peeling. - Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2010 - Free Software Foundation, Inc. +/* Loop unrolling. + Copyright (C) 2002-2017 Free Software Foundation, Inc. This file is part of GCC. @@ -21,22 +20,25 @@ #include "config.h" #include "system.h" #include "coretypes.h" -#include "tm.h" +#include "backend.h" +#include "target.h" #include "rtl.h" -#include "hard-reg-set.h" -#include "obstack.h" -#include "basic-block.h" +#include "tree.h" +#include "cfghooks.h" +#include "memmodel.h" +#include "optabs.h" +#include "emit-rtl.h" +#include "recog.h" +#include "profile.h" +#include "cfgrtl.h" #include "cfgloop.h" -#include "cfglayout.h" #include "params.h" -#include "output.h" +#include "dojump.h" #include "expr.h" -#include "hashtab.h" -#include "recog.h" -#include "target.h" +#include "dumpfile.h" -/* This pass performs loop unrolling and peeling. We only perform these - optimizations on innermost loops (with single exception) because +/* This pass performs loop unrolling. We only perform this + optimization on innermost loops (with single exception) because the impact on performance is greatest here, and we want to avoid unnecessary code size growth. The gain is caused by greater sequentiality of code, better code to optimize for further passes and in some cases @@ -45,12 +47,6 @@ What we do: - -- complete peeling of once-rolling loops; this is the above mentioned - exception, as this causes loop to be cancelled completely and - does not cause code growth - -- complete peeling of loops that roll (small) constant times. - -- simple peeling of first iterations of loops that do not roll much - (according to profile feedback) -- unrolling of loops that roll constant times; this is almost always win, as we get rid of exit condition tests. -- unrolling of loops that roll number of times that we can compute @@ -63,7 +59,7 @@ appropriate function below. There is a lot of parameters (defined and described in params.def) that - control how much we unroll/peel. + control how much we unroll. ??? A great problem is that we don't have a good way how to determine how many times we should unroll the loop; the experiments I have made @@ -74,25 +70,21 @@ struct iv_to_split { - rtx insn; /* The insn in that the induction variable occurs. */ + rtx_insn *insn; /* The insn in that the induction variable occurs. */ + rtx orig_var; /* The variable (register) for the IV before split. */ rtx base_var; /* The variable on that the values in the further iterations are based. */ rtx step; /* Step of the induction variable. */ struct iv_to_split *next; /* Next entry in walking order. */ - unsigned n_loc; - unsigned loc[3]; /* Location where the definition of the induction - variable occurs in the insn. For example if - N_LOC is 2, the expression is located at - XEXP (XEXP (single_set, loc[0]), loc[1]). */ }; /* Information about accumulators to expand. */ struct var_to_expand { - rtx insn; /* The insn in that the variable expansion occurs. */ + rtx_insn *insn; /* The insn in that the variable expansion occurs. */ rtx reg; /* The accumulator which is expanded. */ - VEC(rtx,heap) *var_expansions; /* The copies of the accumulator which is expanded. */ + vec<rtx> var_expansions; /* The copies of the accumulator which is expanded. */ struct var_to_expand *next; /* Next entry in walking order. */ enum rtx_code op; /* The type of the accumulation - addition, subtraction or multiplication. */ @@ -101,22 +93,68 @@ the accumulator. If REUSE_EXPANSION is 0 reuse the original accumulator. Else use var_expansions[REUSE_EXPANSION - 1]. */ - unsigned accum_pos; /* The position in which the accumulator is placed in - the insn src. For example in x = x + something - accum_pos is 0 while in x = something + x accum_pos - is 1. */ +}; + +/* Hashtable helper for iv_to_split. */ + +struct iv_split_hasher : free_ptr_hash <iv_to_split> +{ + static inline hashval_t hash (const iv_to_split *); + static inline bool equal (const iv_to_split *, const iv_to_split *); }; + +/* A hash function for information about insns to split. */ + +inline hashval_t +iv_split_hasher::hash (const iv_to_split *ivts) +{ + return (hashval_t) INSN_UID (ivts->insn); +} + +/* An equality functions for information about insns to split. */ + +inline bool +iv_split_hasher::equal (const iv_to_split *i1, const iv_to_split *i2) +{ + return i1->insn == i2->insn; +} + +/* Hashtable helper for iv_to_split. */ + +struct var_expand_hasher : free_ptr_hash <var_to_expand> +{ + static inline hashval_t hash (const var_to_expand *); + static inline bool equal (const var_to_expand *, const var_to_expand *); +}; + +/* Return a hash for VES. */ + +inline hashval_t +var_expand_hasher::hash (const var_to_expand *ves) +{ + return (hashval_t) INSN_UID (ves->insn); +} + +/* Return true if I1 and I2 refer to the same instruction. */ + +inline bool +var_expand_hasher::equal (const var_to_expand *i1, const var_to_expand *i2) +{ + return i1->insn == i2->insn; +} + /* Information about optimization applied in the unrolled loop. */ struct opt_info { - htab_t insns_to_split; /* A hashtable of insns to split. */ + hash_table<iv_split_hasher> *insns_to_split; /* A hashtable of insns to + split. */ struct iv_to_split *iv_to_split_head; /* The first iv to split. */ struct iv_to_split **iv_to_split_tail; /* Pointer to the tail of the list. */ - htab_t insns_with_var_to_expand; /* A hashtable of insns with accumulators - to expand. */ + hash_table<var_expand_hasher> *insns_with_var_to_expand; /* A hashtable of + insns with accumulators to expand. */ struct var_to_expand *var_to_expand_head; /* The first var to expand. */ struct var_to_expand **var_to_expand_tail; /* Pointer to the tail of the list. */ unsigned first_new_block; /* The first basic block that was @@ -125,157 +163,70 @@ basic_block loop_preheader; /* The loop preheader basic block. */ }; -static void decide_unrolling_and_peeling (int); -static void peel_loops_completely (int); -static void decide_peel_simple (struct loop *, int); -static void decide_peel_once_rolling (struct loop *, int); -static void decide_peel_completely (struct loop *, int); static void decide_unroll_stupid (struct loop *, int); static void decide_unroll_constant_iterations (struct loop *, int); static void decide_unroll_runtime_iterations (struct loop *, int); -static void peel_loop_simple (struct loop *); -static void peel_loop_completely (struct loop *); static void unroll_loop_stupid (struct loop *); +static void decide_unrolling (int); static void unroll_loop_constant_iterations (struct loop *); static void unroll_loop_runtime_iterations (struct loop *); static struct opt_info *analyze_insns_in_loop (struct loop *); static void opt_info_start_duplication (struct opt_info *); static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool); static void free_opt_info (struct opt_info *); -static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx); +static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx_insn *); static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx, int *); -static struct iv_to_split *analyze_iv_to_split_insn (rtx); -static void expand_var_during_unrolling (struct var_to_expand *, rtx); +static struct iv_to_split *analyze_iv_to_split_insn (rtx_insn *); +static void expand_var_during_unrolling (struct var_to_expand *, rtx_insn *); static void insert_var_expansion_initialization (struct var_to_expand *, basic_block); static void combine_var_copies_in_loop_exit (struct var_to_expand *, basic_block); static rtx get_expansion (struct var_to_expand *); -/* Unroll and/or peel (depending on FLAGS) LOOPS. */ -void -unroll_and_peel_loops (int flags) +/* Emit a message summarizing the unroll that will be + performed for LOOP, along with the loop's location LOCUS, if + appropriate given the dump or -fopt-info settings. */ + +static void +report_unroll (struct loop *loop, location_t locus) { - struct loop *loop; - bool check; - loop_iterator li; + dump_flags_t report_flags = MSG_OPTIMIZED_LOCATIONS | TDF_DETAILS; - /* First perform complete loop peeling (it is almost surely a win, - and affects parameters for further decision a lot). */ - peel_loops_completely (flags); - - /* Now decide rest of unrolling and peeling. */ - decide_unrolling_and_peeling (flags); + if (loop->lpt_decision.decision == LPT_NONE) + return; - /* Scan the loops, inner ones first. */ - FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) - { - check = true; - /* And perform the appropriate transformations. */ - switch (loop->lpt_decision.decision) - { - case LPT_PEEL_COMPLETELY: - /* Already done. */ - gcc_unreachable (); - case LPT_PEEL_SIMPLE: - peel_loop_simple (loop); - break; - case LPT_UNROLL_CONSTANT: - unroll_loop_constant_iterations (loop); - break; - case LPT_UNROLL_RUNTIME: - unroll_loop_runtime_iterations (loop); - break; - case LPT_UNROLL_STUPID: - unroll_loop_stupid (loop); - break; - case LPT_NONE: - check = false; - break; - default: - gcc_unreachable (); - } - if (check) - { -#ifdef ENABLE_CHECKING - verify_dominators (CDI_DOMINATORS); - verify_loop_structure (); -#endif - } - } + if (!dump_enabled_p ()) + return; - iv_analysis_done (); + dump_printf_loc (report_flags, locus, + "loop unrolled %d times", + loop->lpt_decision.times); + if (profile_info && loop->header->count.initialized_p ()) + dump_printf (report_flags, + " (header execution count %d)", + (int)loop->header->count.to_gcov_type ()); + + dump_printf (report_flags, "\n"); } -/* Check whether exit of the LOOP is at the end of loop body. */ - -static bool -loop_exit_at_end_p (struct loop *loop) -{ - struct niter_desc *desc = get_simple_loop_desc (loop); - rtx insn; - - if (desc->in_edge->dest != loop->latch) - return false; - - /* Check that the latch is empty. */ - FOR_BB_INSNS (loop->latch, insn) - { - if (INSN_P (insn)) - return false; - } - - return true; -} - -/* Depending on FLAGS, check whether to peel loops completely and do so. */ +/* Decide whether unroll loops and how much. */ static void -peel_loops_completely (int flags) +decide_unrolling (int flags) { struct loop *loop; - loop_iterator li; - /* Scan the loops, the inner ones first. */ - FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) + /* Scan the loops, inner ones first. */ + FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) { loop->lpt_decision.decision = LPT_NONE; - - if (dump_file) - fprintf (dump_file, - "\n;; *** Considering loop %d for complete peeling ***\n", - loop->num); - - loop->ninsns = num_loop_insns (loop); - - decide_peel_once_rolling (loop, flags); - if (loop->lpt_decision.decision == LPT_NONE) - decide_peel_completely (loop, flags); + location_t locus = get_loop_location (loop); - if (loop->lpt_decision.decision == LPT_PEEL_COMPLETELY) - { - peel_loop_completely (loop); -#ifdef ENABLE_CHECKING - verify_dominators (CDI_DOMINATORS); - verify_loop_structure (); -#endif - } - } -} - -/* Decide whether unroll or peel loops (depending on FLAGS) and how much. */ -static void -decide_unrolling_and_peeling (int flags) -{ - struct loop *loop; - loop_iterator li; - - /* Scan the loops, inner ones first. */ - FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) - { - loop->lpt_decision.decision = LPT_NONE; - - if (dump_file) - fprintf (dump_file, "\n;; *** Considering loop %d ***\n", loop->num); + if (dump_enabled_p ()) + dump_printf_loc (MSG_NOTE, locus, + ";; *** Considering loop %d at BB %d for " + "unrolling ***\n", + loop->num, loop->header->index); /* Do not peel cold areas. */ if (optimize_loop_for_size_p (loop)) @@ -313,208 +264,77 @@ decide_unroll_runtime_iterations (loop, flags); if (loop->lpt_decision.decision == LPT_NONE) decide_unroll_stupid (loop, flags); - if (loop->lpt_decision.decision == LPT_NONE) - decide_peel_simple (loop, flags); + + report_unroll (loop, locus); } } -/* Decide whether the LOOP is once rolling and suitable for complete - peeling. */ -static void -decide_peel_once_rolling (struct loop *loop, int flags ATTRIBUTE_UNUSED) +/* Unroll LOOPS. */ +void +unroll_loops (int flags) { - struct niter_desc *desc; - - if (dump_file) - fprintf (dump_file, "\n;; Considering peeling once rolling loop\n"); - - /* Is the loop small enough? */ - if ((unsigned) PARAM_VALUE (PARAM_MAX_ONCE_PEELED_INSNS) < loop->ninsns) - { - if (dump_file) - fprintf (dump_file, ";; Not considering loop, is too big\n"); - return; - } + struct loop *loop; + bool changed = false; - /* Check for simple loops. */ - desc = get_simple_loop_desc (loop); - - /* Check number of iterations. */ - if (!desc->simple_p - || desc->assumptions - || desc->infinite - || !desc->const_iter - || desc->niter != 0) - { - if (dump_file) - fprintf (dump_file, - ";; Unable to prove that the loop rolls exactly once\n"); - return; - } - - /* Success. */ - if (dump_file) - fprintf (dump_file, ";; Decided to peel exactly once rolling loop\n"); - loop->lpt_decision.decision = LPT_PEEL_COMPLETELY; -} + /* Now decide rest of unrolling. */ + decide_unrolling (flags); -/* Decide whether the LOOP is suitable for complete peeling. */ -static void -decide_peel_completely (struct loop *loop, int flags ATTRIBUTE_UNUSED) -{ - unsigned npeel; - struct niter_desc *desc; - - if (dump_file) - fprintf (dump_file, "\n;; Considering peeling completely\n"); - - /* Skip non-innermost loops. */ - if (loop->inner) - { - if (dump_file) - fprintf (dump_file, ";; Not considering loop, is not innermost\n"); - return; - } - - /* Do not peel cold areas. */ - if (optimize_loop_for_size_p (loop)) + /* Scan the loops, inner ones first. */ + FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) { - if (dump_file) - fprintf (dump_file, ";; Not considering loop, cold area\n"); - return; - } - - /* Can the loop be manipulated? */ - if (!can_duplicate_loop_p (loop)) - { - if (dump_file) - fprintf (dump_file, - ";; Not considering loop, cannot duplicate\n"); - return; - } - - /* npeel = number of iterations to peel. */ - npeel = PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS) / loop->ninsns; - if (npeel > (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEEL_TIMES)) - npeel = PARAM_VALUE (PARAM_MAX_COMPLETELY_PEEL_TIMES); - - /* Is the loop small enough? */ - if (!npeel) - { - if (dump_file) - fprintf (dump_file, ";; Not considering loop, is too big\n"); - return; + /* And perform the appropriate transformations. */ + switch (loop->lpt_decision.decision) + { + case LPT_UNROLL_CONSTANT: + unroll_loop_constant_iterations (loop); + changed = true; + break; + case LPT_UNROLL_RUNTIME: + unroll_loop_runtime_iterations (loop); + changed = true; + break; + case LPT_UNROLL_STUPID: + unroll_loop_stupid (loop); + changed = true; + break; + case LPT_NONE: + break; + default: + gcc_unreachable (); + } } - /* Check for simple loops. */ - desc = get_simple_loop_desc (loop); - - /* Check number of iterations. */ - if (!desc->simple_p - || desc->assumptions - || !desc->const_iter - || desc->infinite) - { - if (dump_file) - fprintf (dump_file, - ";; Unable to prove that the loop iterates constant times\n"); - return; - } + if (changed) + { + calculate_dominance_info (CDI_DOMINATORS); + fix_loop_structure (NULL); + } - if (desc->niter > npeel - 1) - { - if (dump_file) - { - fprintf (dump_file, - ";; Not peeling loop completely, rolls too much ("); - fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC, desc->niter); - fprintf (dump_file, " iterations > %d [maximum peelings])\n", npeel); - } - return; - } - - /* Success. */ - if (dump_file) - fprintf (dump_file, ";; Decided to peel loop completely\n"); - loop->lpt_decision.decision = LPT_PEEL_COMPLETELY; + iv_analysis_done (); } -/* Peel all iterations of LOOP, remove exit edges and cancel the loop - completely. The transformation done: - - for (i = 0; i < 4; i++) - body; - - ==> +/* Check whether exit of the LOOP is at the end of loop body. */ - i = 0; - body; i++; - body; i++; - body; i++; - body; i++; - */ -static void -peel_loop_completely (struct loop *loop) +static bool +loop_exit_at_end_p (struct loop *loop) { - sbitmap wont_exit; - unsigned HOST_WIDE_INT npeel; - unsigned i; - VEC (edge, heap) *remove_edges; - edge ein; struct niter_desc *desc = get_simple_loop_desc (loop); - struct opt_info *opt_info = NULL; - - npeel = desc->niter; - - if (npeel) - { - bool ok; + rtx_insn *insn; - wont_exit = sbitmap_alloc (npeel + 1); - sbitmap_ones (wont_exit); - RESET_BIT (wont_exit, 0); - if (desc->noloop_assumptions) - RESET_BIT (wont_exit, 1); + /* We should never have conditional in latch block. */ + gcc_assert (desc->in_edge->dest != loop->header); - remove_edges = NULL; - - if (flag_split_ivs_in_unroller) - opt_info = analyze_insns_in_loop (loop); + if (desc->in_edge->dest != loop->latch) + return false; - opt_info_start_duplication (opt_info); - ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), - npeel, - wont_exit, desc->out_edge, - &remove_edges, - DLTHE_FLAG_UPDATE_FREQ - | DLTHE_FLAG_COMPLETTE_PEEL - | (opt_info - ? DLTHE_RECORD_COPY_NUMBER : 0)); - gcc_assert (ok); - - free (wont_exit); - - if (opt_info) - { - apply_opt_in_copies (opt_info, npeel, false, true); - free_opt_info (opt_info); - } - - /* Remove the exit edges. */ - FOR_EACH_VEC_ELT (edge, remove_edges, i, ein) - remove_path (ein); - VEC_free (edge, heap, remove_edges); + /* Check that the latch is empty. */ + FOR_BB_INSNS (loop->latch, insn) + { + if (INSN_P (insn) && active_insn_p (insn)) + return false; } - ein = desc->in_edge; - free_simple_loop_desc (loop); - - /* Now remove the unreachable part of the last iteration and cancel - the loop. */ - remove_path (ein); - - if (dump_file) - fprintf (dump_file, ";; Peeled loop completely, %d times\n", (int) npeel); + return true; } /* Decide whether to unroll LOOP iterating constant number of times @@ -525,6 +345,7 @@ { unsigned nunroll, nunroll_by_av, best_copies, best_unroll = 0, n_copies, i; struct niter_desc *desc; + widest_int iterations; if (!(flags & UAP_UNROLL)) { @@ -547,6 +368,9 @@ if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES)) nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES); + if (targetm.loop_unroll_adjust) + nunroll = targetm.loop_unroll_adjust (nunroll, loop); + /* Skip big loops. */ if (nunroll <= 1) { @@ -567,8 +391,14 @@ return; } - /* Check whether the loop rolls enough to consider. */ - if (desc->niter < 2 * nunroll) + /* Check whether the loop rolls enough to consider. + Consult also loop bounds and profile; in the case the loop has more + than one exit it may well loop less than determined maximal number + of iterations. */ + if (desc->niter < 2 * nunroll + || ((get_estimated_loop_iterations (loop, &iterations) + || get_likely_max_loop_iterations (loop, &iterations)) + && wi::ltu_p (iterations, 2 * nunroll))) { if (dump_file) fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); @@ -604,26 +434,17 @@ } } - if (dump_file) - fprintf (dump_file, ";; max_unroll %d (%d copies, initial %d).\n", - best_unroll + 1, best_copies, nunroll); - loop->lpt_decision.decision = LPT_UNROLL_CONSTANT; loop->lpt_decision.times = best_unroll; - - if (dump_file) - fprintf (dump_file, - ";; Decided to unroll the constant times rolling loop, %d times.\n", - loop->lpt_decision.times); } -/* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES + 1 - times. The transformation does this: +/* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES times. + The transformation does this: for (i = 0; i < 102; i++) body; - ==> + ==> (LOOP->LPT_DECISION.TIMES == 3) i = 0; body; i++; @@ -641,9 +462,7 @@ { unsigned HOST_WIDE_INT niter; unsigned exit_mod; - sbitmap wont_exit; unsigned i; - VEC (edge, heap) *remove_edges; edge e; unsigned max_unroll = loop->lpt_decision.times; struct niter_desc *desc = get_simple_loop_desc (loop); @@ -658,10 +477,10 @@ exit_mod = niter % (max_unroll + 1); - wont_exit = sbitmap_alloc (max_unroll + 1); - sbitmap_ones (wont_exit); + auto_sbitmap wont_exit (max_unroll + 1); + bitmap_ones (wont_exit); - remove_edges = NULL; + auto_vec<edge> remove_edges; if (flag_split_ivs_in_unroller || flag_variable_expansion_in_unroller) opt_info = analyze_insns_in_loop (loop); @@ -673,12 +492,12 @@ of exit condition have continuous body after unrolling. */ if (dump_file) - fprintf (dump_file, ";; Condition on beginning of loop.\n"); + fprintf (dump_file, ";; Condition at beginning of loop.\n"); /* Peel exit_mod iterations. */ - RESET_BIT (wont_exit, 0); + bitmap_clear_bit (wont_exit, 0); if (desc->noloop_assumptions) - RESET_BIT (wont_exit, 1); + bitmap_clear_bit (wont_exit, 1); if (exit_mod) { @@ -698,10 +517,20 @@ desc->noloop_assumptions = NULL_RTX; desc->niter -= exit_mod; - desc->niter_max -= exit_mod; + loop->nb_iterations_upper_bound -= exit_mod; + if (loop->any_estimate + && wi::leu_p (exit_mod, loop->nb_iterations_estimate)) + loop->nb_iterations_estimate -= exit_mod; + else + loop->any_estimate = false; + if (loop->any_likely_upper_bound + && wi::leu_p (exit_mod, loop->nb_iterations_likely_upper_bound)) + loop->nb_iterations_likely_upper_bound -= exit_mod; + else + loop->any_likely_upper_bound = false; } - SET_BIT (wont_exit, 1); + bitmap_set_bit (wont_exit, 1); } else { @@ -709,7 +538,7 @@ the loop tests the condition at the end of loop body. */ if (dump_file) - fprintf (dump_file, ";; Condition on end of loop.\n"); + fprintf (dump_file, ";; Condition at end of loop.\n"); /* We know that niter >= max_unroll + 2; so we do not need to care of case when we would exit before reaching the loop. So just peel @@ -717,9 +546,9 @@ if (exit_mod != max_unroll || desc->noloop_assumptions) { - RESET_BIT (wont_exit, 0); + bitmap_clear_bit (wont_exit, 0); if (desc->noloop_assumptions) - RESET_BIT (wont_exit, 1); + bitmap_clear_bit (wont_exit, 1); opt_info_start_duplication (opt_info); ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), @@ -736,14 +565,24 @@ apply_opt_in_copies (opt_info, exit_mod + 1, false, false); desc->niter -= exit_mod + 1; - desc->niter_max -= exit_mod + 1; + loop->nb_iterations_upper_bound -= exit_mod + 1; + if (loop->any_estimate + && wi::leu_p (exit_mod + 1, loop->nb_iterations_estimate)) + loop->nb_iterations_estimate -= exit_mod + 1; + else + loop->any_estimate = false; + if (loop->any_likely_upper_bound + && wi::leu_p (exit_mod + 1, loop->nb_iterations_likely_upper_bound)) + loop->nb_iterations_likely_upper_bound -= exit_mod + 1; + else + loop->any_likely_upper_bound = false; desc->noloop_assumptions = NULL_RTX; - SET_BIT (wont_exit, 0); - SET_BIT (wont_exit, 1); + bitmap_set_bit (wont_exit, 0); + bitmap_set_bit (wont_exit, 1); } - RESET_BIT (wont_exit, max_unroll); + bitmap_clear_bit (wont_exit, max_unroll); } /* Now unroll the loop. */ @@ -765,8 +604,6 @@ free_opt_info (opt_info); } - free (wont_exit); - if (exit_at_end) { basic_block exit_block = get_bb_copy (desc->in_edge->src); @@ -785,13 +622,19 @@ } desc->niter /= max_unroll + 1; - desc->niter_max /= max_unroll + 1; + loop->nb_iterations_upper_bound + = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); + if (loop->any_estimate) + loop->nb_iterations_estimate + = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); + if (loop->any_likely_upper_bound) + loop->nb_iterations_likely_upper_bound + = wi::udiv_trunc (loop->nb_iterations_likely_upper_bound, max_unroll + 1); desc->niter_expr = GEN_INT (desc->niter); /* Remove the edges. */ - FOR_EACH_VEC_ELT (edge, remove_edges, i, e) + FOR_EACH_VEC_ELT (remove_edges, i, e) remove_path (e); - VEC_free (edge, heap, remove_edges); if (dump_file) fprintf (dump_file, @@ -806,6 +649,7 @@ { unsigned nunroll, nunroll_by_av, i; struct niter_desc *desc; + widest_int iterations; if (!(flags & UAP_UNROLL)) { @@ -858,8 +702,10 @@ return; } - /* If we have profile feedback, check whether the loop rolls. */ - if (loop->header->count && expected_loop_iterations (loop) < 2 * nunroll) + /* Check whether the loop rolls. */ + if ((get_estimated_loop_iterations (loop, &iterations) + || get_likely_max_loop_iterations (loop, &iterations)) + && wi::ltu_p (iterations, 2 * nunroll)) { if (dump_file) fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); @@ -873,12 +719,6 @@ loop->lpt_decision.decision = LPT_UNROLL_RUNTIME; loop->lpt_decision.times = i - 1; - - if (dump_file) - fprintf (dump_file, - ";; Decided to unroll the runtime computable " - "times rolling loop, %d times.\n", - loop->lpt_decision.times); } /* Splits edge E and inserts the sequence of instructions INSNS on it, and @@ -886,7 +726,7 @@ and NULL is returned instead. */ basic_block -split_edge_and_insert (edge e, rtx insns) +split_edge_and_insert (edge e, rtx_insn *insns) { basic_block bb; @@ -900,7 +740,7 @@ CFG. For this purpose we used to set the BB_SUPERBLOCK flag on BB and call break_superblocks when going out of cfglayout mode. But it turns out that this never happens; and that if it does ever happen, - the TODO_verify_flow at the end of the RTL loop passes would fail. + the verify_flow_info at the end of the RTL loop passes would fail. There are two reasons why we expected we could have control flow insns in INSNS. The first is when a comparison has to be done in parts, and @@ -928,14 +768,70 @@ return bb; } -/* Unroll LOOP for that we are able to count number of iterations in runtime - LOOP->LPT_DECISION.TIMES + 1 times. The transformation does this (with some +/* Prepare a sequence comparing OP0 with OP1 using COMP and jumping to LABEL if + true, with probability PROB. If CINSN is not NULL, it is the insn to copy + in order to create a jump. */ + +static rtx_insn * +compare_and_jump_seq (rtx op0, rtx op1, enum rtx_code comp, + rtx_code_label *label, profile_probability prob, + rtx_insn *cinsn) +{ + rtx_insn *seq; + rtx_jump_insn *jump; + rtx cond; + machine_mode mode; + + mode = GET_MODE (op0); + if (mode == VOIDmode) + mode = GET_MODE (op1); + + start_sequence (); + if (GET_MODE_CLASS (mode) == MODE_CC) + { + /* A hack -- there seems to be no easy generic way how to make a + conditional jump from a ccmode comparison. */ + gcc_assert (cinsn); + cond = XEXP (SET_SRC (pc_set (cinsn)), 0); + gcc_assert (GET_CODE (cond) == comp); + gcc_assert (rtx_equal_p (op0, XEXP (cond, 0))); + gcc_assert (rtx_equal_p (op1, XEXP (cond, 1))); + emit_jump_insn (copy_insn (PATTERN (cinsn))); + jump = as_a <rtx_jump_insn *> (get_last_insn ()); + JUMP_LABEL (jump) = JUMP_LABEL (cinsn); + LABEL_NUSES (JUMP_LABEL (jump))++; + redirect_jump (jump, label, 0); + } + else + { + gcc_assert (!cinsn); + + op0 = force_operand (op0, NULL_RTX); + op1 = force_operand (op1, NULL_RTX); + do_compare_rtx_and_jump (op0, op1, comp, 0, + mode, NULL_RTX, NULL, label, + profile_probability::uninitialized ()); + jump = as_a <rtx_jump_insn *> (get_last_insn ()); + jump->set_jump_target (label); + LABEL_NUSES (label)++; + } + if (prob.initialized_p ()) + add_reg_br_prob_note (jump, prob); + + seq = get_insns (); + end_sequence (); + + return seq; +} + +/* Unroll LOOP for which we are able to count number of iterations in runtime + LOOP->LPT_DECISION.TIMES times. The transformation does this (with some extra care for case n < 0): for (i = 0; i < n; i++) body; - ==> + ==> (LOOP->LPT_DECISION.TIMES == 3) i = 0; mod = n % 4; @@ -962,14 +858,14 @@ static void unroll_loop_runtime_iterations (struct loop *loop) { - rtx old_niter, niter, init_code, branch_code, tmp; - unsigned i, j, p; - basic_block preheader, *body, swtch, ezc_swtch; - VEC (basic_block, heap) *dom_bbs; - sbitmap wont_exit; - int may_exit_copy; + rtx old_niter, niter, tmp; + rtx_insn *init_code, *branch_code; + unsigned i, j; + profile_probability p; + basic_block preheader, *body, swtch, ezc_swtch = NULL; + int may_exit_copy, iter_freq, new_freq; + profile_count iter_count, new_count; unsigned n_peel; - VEC (edge, heap) *remove_edges; edge e; bool extra_zero_check, last_may_exit; unsigned max_unroll = loop->lpt_decision.times; @@ -983,20 +879,20 @@ opt_info = analyze_insns_in_loop (loop); /* Remember blocks whose dominators will have to be updated. */ - dom_bbs = NULL; + auto_vec<basic_block> dom_bbs; body = get_loop_body (loop); for (i = 0; i < loop->num_nodes; i++) { - VEC (basic_block, heap) *ldom; + vec<basic_block> ldom; basic_block bb; ldom = get_dominated_by (CDI_DOMINATORS, body[i]); - FOR_EACH_VEC_ELT (basic_block, ldom, j, bb) + FOR_EACH_VEC_ELT (ldom, j, bb) if (!flow_bb_inside_loop_p (loop, bb)) - VEC_safe_push (basic_block, heap, dom_bbs, bb); + dom_bbs.safe_push (bb); - VEC_free (basic_block, heap, ldom); + ldom.release (); } free (body); @@ -1026,12 +922,22 @@ if (tmp != niter) emit_move_insn (niter, tmp); + /* For loops that exit at end and whose number of iterations is reliable, + add one to niter to account for first pass through loop body before + reaching exit test. */ + if (exit_at_end && !desc->noloop_assumptions) + { + niter = expand_simple_binop (desc->mode, PLUS, + niter, const1_rtx, + NULL_RTX, 0, OPTAB_LIB_WIDEN); + old_niter = niter; + } + /* Count modulo by ANDing it with max_unroll; we use the fact that the number of unrollings is a power of two, and thus this is correct even if there is overflow in the computation. */ niter = expand_simple_binop (desc->mode, AND, - niter, - GEN_INT (max_unroll), + niter, gen_int_mode (max_unroll, desc->mode), NULL_RTX, 0, OPTAB_LIB_WIDEN); init_code = get_insns (); @@ -1041,34 +947,43 @@ /* Precondition the loop. */ split_edge_and_insert (loop_preheader_edge (loop), init_code); - remove_edges = NULL; + auto_vec<edge> remove_edges; - wont_exit = sbitmap_alloc (max_unroll + 2); + auto_sbitmap wont_exit (max_unroll + 2); - /* Peel the first copy of loop body (almost always we must leave exit test - here; the only exception is when we have extra zero check and the number - of iterations is reliable. Also record the place of (possible) extra - zero check. */ - sbitmap_zero (wont_exit); - if (extra_zero_check - && !desc->noloop_assumptions) - SET_BIT (wont_exit, 1); - ezc_swtch = loop_preheader_edge (loop)->src; - ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), - 1, wont_exit, desc->out_edge, - &remove_edges, - DLTHE_FLAG_UPDATE_FREQ); - gcc_assert (ok); + if (extra_zero_check || desc->noloop_assumptions) + { + /* Peel the first copy of loop body. Leave the exit test if the number + of iterations is not reliable. Also record the place of the extra zero + check. */ + bitmap_clear (wont_exit); + if (!desc->noloop_assumptions) + bitmap_set_bit (wont_exit, 1); + ezc_swtch = loop_preheader_edge (loop)->src; + ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), + 1, wont_exit, desc->out_edge, + &remove_edges, + DLTHE_FLAG_UPDATE_FREQ); + gcc_assert (ok); + } /* Record the place where switch will be built for preconditioning. */ swtch = split_edge (loop_preheader_edge (loop)); + /* Compute frequency/count increments for each switch block and initialize + innermost switch block. Switch blocks and peeled loop copies are built + from innermost outward. */ + iter_freq = new_freq = swtch->frequency / (max_unroll + 1); + iter_count = new_count = swtch->count.apply_scale (1, max_unroll + 1); + swtch->frequency = new_freq; + swtch->count = new_count; + for (i = 0; i < n_peel; i++) { /* Peel the copy. */ - sbitmap_zero (wont_exit); + bitmap_clear (wont_exit); if (i != n_peel - 1 || !last_may_exit) - SET_BIT (wont_exit, 1); + bitmap_set_bit (wont_exit, 1); ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), 1, wont_exit, desc->out_edge, &remove_edges, @@ -1077,12 +992,15 @@ /* Create item for switch. */ j = n_peel - i - (extra_zero_check ? 0 : 1); - p = REG_BR_PROB_BASE / (i + 2); + p = profile_probability::always ().apply_scale (1, i + 2); preheader = split_edge (loop_preheader_edge (loop)); + /* Add in frequency/count of edge from switch block. */ + preheader->frequency += iter_freq; + preheader->count += iter_count; branch_code = compare_and_jump_seq (copy_rtx (niter), GEN_INT (j), EQ, block_label (preheader), p, - NULL_RTX); + NULL); /* We rely on the fact that the compare and jump cannot be optimized out, and hence the cfg we create is correct. */ @@ -1090,7 +1008,11 @@ swtch = split_edge_and_insert (single_pred_edge (swtch), branch_code); set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); - single_pred_edge (swtch)->probability = REG_BR_PROB_BASE - p; + single_succ_edge (swtch)->probability = p.invert (); + new_freq += iter_freq; + new_count += iter_count; + swtch->frequency = new_freq; + swtch->count = new_count; e = make_edge (swtch, preheader, single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); e->probability = p; @@ -1099,17 +1021,24 @@ if (extra_zero_check) { /* Add branch for zero iterations. */ - p = REG_BR_PROB_BASE / (max_unroll + 1); + p = profile_probability::always ().apply_scale (1, max_unroll + 1); swtch = ezc_swtch; preheader = split_edge (loop_preheader_edge (loop)); + /* Recompute frequency/count adjustments since initial peel copy may + have exited and reduced those values that were computed above. */ + iter_freq = swtch->frequency / (max_unroll + 1); + iter_count = swtch->count.apply_scale (1, max_unroll + 1); + /* Add in frequency/count of edge from switch block. */ + preheader->frequency += iter_freq; + preheader->count += iter_count; branch_code = compare_and_jump_seq (copy_rtx (niter), const0_rtx, EQ, block_label (preheader), p, - NULL_RTX); + NULL); gcc_assert (branch_code != NULL_RTX); swtch = split_edge_and_insert (single_succ_edge (swtch), branch_code); set_immediate_dominator (CDI_DOMINATORS, preheader, swtch); - single_succ_edge (swtch)->probability = REG_BR_PROB_BASE - p; + single_succ_edge (swtch)->probability = p.invert (); e = make_edge (swtch, preheader, single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP); e->probability = p; @@ -1120,8 +1049,8 @@ /* And unroll loop. */ - sbitmap_ones (wont_exit); - RESET_BIT (wont_exit, may_exit_copy); + bitmap_ones (wont_exit); + bitmap_clear_bit (wont_exit, may_exit_copy); opt_info_start_duplication (opt_info); ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), @@ -1140,8 +1069,6 @@ free_opt_info (opt_info); } - free (wont_exit); - if (exit_at_end) { basic_block exit_block = get_bb_copy (desc->in_edge->src); @@ -1161,9 +1088,8 @@ } /* Remove the edges. */ - FOR_EACH_VEC_ELT (edge, remove_edges, i, e) + FOR_EACH_VEC_ELT (remove_edges, i, e) remove_path (e); - VEC_free (edge, heap, remove_edges); /* We must be careful when updating the number of iterations due to preconditioning and the fact that the value must be valid at entry @@ -1172,14 +1098,31 @@ gcc_assert (!desc->const_iter); desc->niter_expr = simplify_gen_binary (UDIV, desc->mode, old_niter, - GEN_INT (max_unroll + 1)); - desc->niter_max /= max_unroll + 1; + gen_int_mode (max_unroll + 1, desc->mode)); + loop->nb_iterations_upper_bound + = wi::udiv_trunc (loop->nb_iterations_upper_bound, max_unroll + 1); + if (loop->any_estimate) + loop->nb_iterations_estimate + = wi::udiv_trunc (loop->nb_iterations_estimate, max_unroll + 1); + if (loop->any_likely_upper_bound) + loop->nb_iterations_likely_upper_bound + = wi::udiv_trunc (loop->nb_iterations_likely_upper_bound, max_unroll + 1); if (exit_at_end) { desc->niter_expr = simplify_gen_binary (MINUS, desc->mode, desc->niter_expr, const1_rtx); desc->noloop_assumptions = NULL_RTX; - desc->niter_max--; + --loop->nb_iterations_upper_bound; + if (loop->any_estimate + && loop->nb_iterations_estimate != 0) + --loop->nb_iterations_estimate; + else + loop->any_estimate = false; + if (loop->any_likely_upper_bound + && loop->nb_iterations_likely_upper_bound != 0) + --loop->nb_iterations_likely_upper_bound; + else + loop->any_likely_upper_bound = false; } if (dump_file) @@ -1187,161 +1130,6 @@ ";; Unrolled loop %d times, counting # of iterations " "in runtime, %i insns\n", max_unroll, num_loop_insns (loop)); - - VEC_free (basic_block, heap, dom_bbs); -} - -/* Decide whether to simply peel LOOP and how much. */ -static void -decide_peel_simple (struct loop *loop, int flags) -{ - unsigned npeel; - struct niter_desc *desc; - - if (!(flags & UAP_PEEL)) - { - /* We were not asked to, just return back silently. */ - return; - } - - if (dump_file) - fprintf (dump_file, "\n;; Considering simply peeling loop\n"); - - /* npeel = number of iterations to peel. */ - npeel = PARAM_VALUE (PARAM_MAX_PEELED_INSNS) / loop->ninsns; - if (npeel > (unsigned) PARAM_VALUE (PARAM_MAX_PEEL_TIMES)) - npeel = PARAM_VALUE (PARAM_MAX_PEEL_TIMES); - - /* Skip big loops. */ - if (!npeel) - { - if (dump_file) - fprintf (dump_file, ";; Not considering loop, is too big\n"); - return; - } - - /* Check for simple loops. */ - desc = get_simple_loop_desc (loop); - - /* Check number of iterations. */ - if (desc->simple_p && !desc->assumptions && desc->const_iter) - { - if (dump_file) - fprintf (dump_file, ";; Loop iterates constant times\n"); - return; - } - - /* Do not simply peel loops with branches inside -- it increases number - of mispredicts. */ - if (num_loop_branches (loop) > 1) - { - if (dump_file) - fprintf (dump_file, ";; Not peeling, contains branches\n"); - return; - } - - if (loop->header->count) - { - unsigned niter = expected_loop_iterations (loop); - if (niter + 1 > npeel) - { - if (dump_file) - { - fprintf (dump_file, ";; Not peeling loop, rolls too much ("); - fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC, - (HOST_WIDEST_INT) (niter + 1)); - fprintf (dump_file, " iterations > %d [maximum peelings])\n", - npeel); - } - return; - } - npeel = niter + 1; - } - else - { - /* For now we have no good heuristics to decide whether loop peeling - will be effective, so disable it. */ - if (dump_file) - fprintf (dump_file, - ";; Not peeling loop, no evidence it will be profitable\n"); - return; - } - - /* Success. */ - loop->lpt_decision.decision = LPT_PEEL_SIMPLE; - loop->lpt_decision.times = npeel; - - if (dump_file) - fprintf (dump_file, ";; Decided to simply peel the loop, %d times.\n", - loop->lpt_decision.times); -} - -/* Peel a LOOP LOOP->LPT_DECISION.TIMES times. The transformation: - while (cond) - body; - - ==> - - if (!cond) goto end; - body; - if (!cond) goto end; - body; - while (cond) - body; - end: ; - */ -static void -peel_loop_simple (struct loop *loop) -{ - sbitmap wont_exit; - unsigned npeel = loop->lpt_decision.times; - struct niter_desc *desc = get_simple_loop_desc (loop); - struct opt_info *opt_info = NULL; - bool ok; - - if (flag_split_ivs_in_unroller && npeel > 1) - opt_info = analyze_insns_in_loop (loop); - - wont_exit = sbitmap_alloc (npeel + 1); - sbitmap_zero (wont_exit); - - opt_info_start_duplication (opt_info); - - ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), - npeel, wont_exit, NULL, - NULL, DLTHE_FLAG_UPDATE_FREQ - | (opt_info - ? DLTHE_RECORD_COPY_NUMBER - : 0)); - gcc_assert (ok); - - free (wont_exit); - - if (opt_info) - { - apply_opt_in_copies (opt_info, npeel, false, false); - free_opt_info (opt_info); - } - - if (desc->simple_p) - { - if (desc->const_iter) - { - desc->niter -= npeel; - desc->niter_expr = GEN_INT (desc->niter); - desc->noloop_assumptions = NULL_RTX; - } - else - { - /* We cannot just update niter_expr, as its value might be clobbered - inside loop. We could handle this by counting the number into - temporary just like we do in runtime unrolling, but it does not - seem worthwhile. */ - free_simple_loop_desc (loop); - } - } - if (dump_file) - fprintf (dump_file, ";; Peeling loop %d times\n", npeel); } /* Decide whether to unroll LOOP stupidly and how much. */ @@ -1350,6 +1138,7 @@ { unsigned nunroll, nunroll_by_av, i; struct niter_desc *desc; + widest_int iterations; if (!(flags & UAP_UNROLL_ALL)) { @@ -1393,7 +1182,9 @@ } /* Do not unroll loops with branches inside -- it increases number - of mispredicts. */ + of mispredicts. + TODO: this heuristic needs tunning; call inside the loop body + is also relatively good reason to not unroll. */ if (num_loop_branches (loop) > 1) { if (dump_file) @@ -1401,9 +1192,10 @@ return; } - /* If we have profile feedback, check whether the loop rolls. */ - if (loop->header->count - && expected_loop_iterations (loop) < 2 * nunroll) + /* Check whether the loop rolls. */ + if ((get_estimated_loop_iterations (loop, &iterations) + || get_likely_max_loop_iterations (loop, &iterations)) + && wi::ltu_p (iterations, 2 * nunroll)) { if (dump_file) fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n"); @@ -1418,18 +1210,14 @@ loop->lpt_decision.decision = LPT_UNROLL_STUPID; loop->lpt_decision.times = i - 1; - - if (dump_file) - fprintf (dump_file, - ";; Decided to unroll the loop stupidly, %d times.\n", - loop->lpt_decision.times); } -/* Unroll a LOOP LOOP->LPT_DECISION.TIMES times. The transformation: +/* Unroll a LOOP LOOP->LPT_DECISION.TIMES times. The transformation does this: + while (cond) body; - ==> + ==> (LOOP->LPT_DECISION.TIMES == 3) while (cond) { @@ -1445,7 +1233,6 @@ static void unroll_loop_stupid (struct loop *loop) { - sbitmap wont_exit; unsigned nunroll = loop->lpt_decision.times; struct niter_desc *desc = get_simple_loop_desc (loop); struct opt_info *opt_info = NULL; @@ -1455,9 +1242,8 @@ || flag_variable_expansion_in_unroller) opt_info = analyze_insns_in_loop (loop); - - wont_exit = sbitmap_alloc (nunroll + 1); - sbitmap_zero (wont_exit); + auto_sbitmap wont_exit (nunroll + 1); + bitmap_clear (wont_exit); opt_info_start_duplication (opt_info); ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop), @@ -1475,15 +1261,13 @@ free_opt_info (opt_info); } - free (wont_exit); - if (desc->simple_p) { /* We indeed may get here provided that there are nontrivial assumptions for a loop to be really simple. We could update the counts, but the problem is that we are unable to decide which exit will be taken (not really true in case the number of iterations is constant, - but noone will do anything with this information, so we do not + but no one will do anything with this information, so we do not worry about it). */ desc->simple_p = false; } @@ -1493,57 +1277,18 @@ nunroll, num_loop_insns (loop)); } -/* A hash function for information about insns to split. */ - -static hashval_t -si_info_hash (const void *ivts) -{ - return (hashval_t) INSN_UID (((const struct iv_to_split *) ivts)->insn); -} - -/* An equality functions for information about insns to split. */ - -static int -si_info_eq (const void *ivts1, const void *ivts2) -{ - const struct iv_to_split *const i1 = (const struct iv_to_split *) ivts1; - const struct iv_to_split *const i2 = (const struct iv_to_split *) ivts2; - - return i1->insn == i2->insn; -} - -/* Return a hash for VES, which is really a "var_to_expand *". */ - -static hashval_t -ve_info_hash (const void *ves) -{ - return (hashval_t) INSN_UID (((const struct var_to_expand *) ves)->insn); -} - -/* Return true if IVTS1 and IVTS2 (which are really both of type - "var_to_expand *") refer to the same instruction. */ - -static int -ve_info_eq (const void *ivts1, const void *ivts2) -{ - const struct var_to_expand *const i1 = (const struct var_to_expand *) ivts1; - const struct var_to_expand *const i2 = (const struct var_to_expand *) ivts2; - - return i1->insn == i2->insn; -} - /* Returns true if REG is referenced in one nondebug insn in LOOP. Set *DEBUG_USES to the number of debug insns that reference the variable. */ -bool +static bool referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg, int *debug_uses) { basic_block *body, bb; unsigned i; int count_ref = 0; - rtx insn; + rtx_insn *insn; body = get_loop_body (loop); for (i = 0; i < loop->num_nodes; i++) @@ -1569,7 +1314,7 @@ { basic_block *body, bb; unsigned i; - rtx insn; + rtx_insn *insn; body = get_loop_body (loop); for (i = 0; debug_uses && i < loop->num_nodes; i++) @@ -1614,7 +1359,7 @@ */ static struct var_to_expand * -analyze_insn_to_expand_var (struct loop *loop, rtx insn) +analyze_insn_to_expand_var (struct loop *loop, rtx_insn *insn) { rtx set, dest, src; struct var_to_expand *ves; @@ -1706,7 +1451,7 @@ if (debug_uses) /* Instead of resetting the debug insns, we could replace each debug use in the loop with the sum or product of all expanded - accummulators. Since we'll only know of all expansions at the + accumulators. Since we'll only know of all expansions at the end, we'd have to keep track of which vars_to_expand a debug insn in the loop references, take note of each copy of the debug insn during unrolling, and when it's all done, compute @@ -1718,12 +1463,11 @@ ves = XNEW (struct var_to_expand); ves->insn = insn; ves->reg = copy_rtx (dest); - ves->var_expansions = VEC_alloc (rtx, heap, 1); + ves->var_expansions.create (1); ves->next = NULL; ves->op = GET_CODE (src); ves->expansion_count = 0; ves->reuse_expansion = 0; - ves->accum_pos = accum_pos; return ves; } @@ -1753,11 +1497,12 @@ pointer to it. */ static struct iv_to_split * -analyze_iv_to_split_insn (rtx insn) +analyze_iv_to_split_insn (rtx_insn *insn) { rtx set, dest; struct rtx_iv iv; struct iv_to_split *ivts; + scalar_int_mode mode; bool ok; /* For now we just split the basic induction variables. Later this may be @@ -1767,10 +1512,10 @@ return NULL; dest = SET_DEST (set); - if (!REG_P (dest)) + if (!REG_P (dest) || !is_a <scalar_int_mode> (GET_MODE (dest), &mode)) return NULL; - if (!biv_p (insn, dest)) + if (!biv_p (insn, mode, dest)) return NULL; ok = iv_analyze_result (insn, dest, &iv); @@ -1793,11 +1538,10 @@ /* Record the insn to split. */ ivts = XNEW (struct iv_to_split); ivts->insn = insn; + ivts->orig_var = dest; ivts->base_var = NULL_RTX; ivts->step = iv.step; ivts->next = NULL; - ivts->n_loc = 1; - ivts->loc[0] = 1; return ivts; } @@ -1813,12 +1557,12 @@ basic_block *body, bb; unsigned i; struct opt_info *opt_info = XCNEW (struct opt_info); - rtx insn; + rtx_insn *insn; struct iv_to_split *ivts = NULL; struct var_to_expand *ves = NULL; - PTR *slot1; - PTR *slot2; - VEC (edge, heap) *edges = get_loop_exit_edges (loop); + iv_to_split **slot1; + var_to_expand **slot2; + vec<edge> edges = get_loop_exit_edges (loop); edge exit; bool can_apply = false; @@ -1828,8 +1572,8 @@ if (flag_split_ivs_in_unroller) { - opt_info->insns_to_split = htab_create (5 * loop->num_nodes, - si_info_hash, si_info_eq, free); + opt_info->insns_to_split + = new hash_table<iv_split_hasher> (5 * loop->num_nodes); opt_info->iv_to_split_head = NULL; opt_info->iv_to_split_tail = &opt_info->iv_to_split_head; } @@ -1837,9 +1581,9 @@ /* Record the loop exit bb and loop preheader before the unrolling. */ opt_info->loop_preheader = loop_preheader_edge (loop)->src; - if (VEC_length (edge, edges) == 1) + if (edges.length () == 1) { - exit = VEC_index (edge, edges, 0); + exit = edges[0]; if (!(exit->flags & EDGE_COMPLEX)) { opt_info->loop_exit = split_edge (exit); @@ -1850,9 +1594,8 @@ if (flag_variable_expansion_in_unroller && can_apply) { - opt_info->insns_with_var_to_expand = htab_create (5 * loop->num_nodes, - ve_info_hash, - ve_info_eq, free); + opt_info->insns_with_var_to_expand + = new hash_table<var_expand_hasher> (5 * loop->num_nodes); opt_info->var_to_expand_head = NULL; opt_info->var_to_expand_tail = &opt_info->var_to_expand_head; } @@ -1873,7 +1616,7 @@ if (ivts) { - slot1 = htab_find_slot (opt_info->insns_to_split, ivts, INSERT); + slot1 = opt_info->insns_to_split->find_slot (ivts, INSERT); gcc_assert (*slot1 == NULL); *slot1 = ivts; *opt_info->iv_to_split_tail = ivts; @@ -1886,7 +1629,7 @@ if (ves) { - slot2 = htab_find_slot (opt_info->insns_with_var_to_expand, ves, INSERT); + slot2 = opt_info->insns_with_var_to_expand->find_slot (ves, INSERT); gcc_assert (*slot2 == NULL); *slot2 = ves; *opt_info->var_to_expand_tail = ves; @@ -1895,7 +1638,7 @@ } } - VEC_free (edge, heap, edges); + edges.release (); free (body); return opt_info; } @@ -1907,7 +1650,7 @@ opt_info_start_duplication (struct opt_info *opt_info) { if (opt_info) - opt_info->first_new_block = last_basic_block; + opt_info->first_new_block = last_basic_block_for_fn (cfun); } /* Determine the number of iterations between initialization of the base @@ -1935,27 +1678,12 @@ } } -/* Locate in EXPR the expression corresponding to the location recorded - in IVTS, and return a pointer to the RTX for this location. */ - -static rtx * -get_ivts_expr (rtx expr, struct iv_to_split *ivts) -{ - unsigned i; - rtx *ret = &expr; - - for (i = 0; i < ivts->n_loc; i++) - ret = &XEXP (*ret, ivts->loc[i]); - - return ret; -} - /* Allocate basic variable for the induction variable chain. */ static void allocate_basic_variable (struct iv_to_split *ivts) { - rtx expr = *get_ivts_expr (single_set (ivts->insn), ivts); + rtx expr = SET_SRC (single_set (ivts->insn)); ivts->base_var = gen_reg_rtx (GET_MODE (expr)); } @@ -1964,10 +1692,10 @@ the initial value from INSN. */ static void -insert_base_initialization (struct iv_to_split *ivts, rtx insn) +insert_base_initialization (struct iv_to_split *ivts, rtx_insn *insn) { - rtx expr = copy_rtx (*get_ivts_expr (single_set (insn), ivts)); - rtx seq; + rtx expr = copy_rtx (SET_SRC (single_set (insn))); + rtx_insn *seq; start_sequence (); expr = force_operand (expr, ivts->base_var); @@ -1983,10 +1711,11 @@ by base variable + DELTA * step. */ static void -split_iv (struct iv_to_split *ivts, rtx insn, unsigned delta) +split_iv (struct iv_to_split *ivts, rtx_insn *insn, unsigned delta) { - rtx expr, *loc, seq, incr, var; - enum machine_mode mode = GET_MODE (ivts->base_var); + rtx expr, *loc, incr, var; + rtx_insn *seq; + machine_mode mode = GET_MODE (ivts->base_var); rtx src, dest, set; /* Construct base + DELTA * step. */ @@ -1995,13 +1724,14 @@ else { incr = simplify_gen_binary (MULT, mode, - ivts->step, gen_int_mode (delta, mode)); + copy_rtx (ivts->step), + gen_int_mode (delta, mode)); expr = simplify_gen_binary (PLUS, GET_MODE (ivts->base_var), ivts->base_var, incr); } /* Figure out where to do the replacement. */ - loc = get_ivts_expr (single_set (insn), ivts); + loc = &SET_SRC (single_set (insn)); /* If we can make the replacement right away, we're done. */ if (validate_change (insn, loc, expr, 0)) @@ -2050,9 +1780,9 @@ if (ve->reuse_expansion == 0) reg = ve->reg; else - reg = VEC_index (rtx, ve->var_expansions, ve->reuse_expansion - 1); + reg = ve->var_expansions[ve->reuse_expansion - 1]; - if (VEC_length (rtx, ve->var_expansions) == (unsigned) ve->reuse_expansion) + if (ve->var_expansions.length () == (unsigned) ve->reuse_expansion) ve->reuse_expansion = 0; else ve->reuse_expansion++; @@ -2065,7 +1795,7 @@ with a new register. */ static void -expand_var_during_unrolling (struct var_to_expand *ve, rtx insn) +expand_var_during_unrolling (struct var_to_expand *ve, rtx_insn *insn) { rtx new_reg, set; bool really_new_expansion = false; @@ -2083,13 +1813,11 @@ else new_reg = get_expansion (ve); - validate_change (insn, &SET_DEST (set), new_reg, 1); - validate_change (insn, &XEXP (SET_SRC (set), ve->accum_pos), new_reg, 1); - + validate_replace_rtx_group (SET_DEST (set), new_reg, insn); if (apply_change_group ()) if (really_new_expansion) { - VEC_safe_push (rtx, heap, ve->var_expansions, new_reg); + ve->var_expansions.safe_push (new_reg); ve->expansion_count++; } } @@ -2125,12 +1853,13 @@ insert_var_expansion_initialization (struct var_to_expand *ve, basic_block place) { - rtx seq, var, zero_init, insn; + rtx_insn *seq; + rtx var, zero_init; unsigned i; - enum machine_mode mode = GET_MODE (ve->reg); + machine_mode mode = GET_MODE (ve->reg); bool honor_signed_zero_p = HONOR_SIGNED_ZEROS (mode); - if (VEC_length (rtx, ve->var_expansions) == 0) + if (ve->var_expansions.length () == 0) return; start_sequence (); @@ -2140,7 +1869,7 @@ /* Note that we only accumulate FMA via the ADD operand. */ case PLUS: case MINUS: - FOR_EACH_VEC_ELT (rtx, ve->var_expansions, i, var) + FOR_EACH_VEC_ELT (ve->var_expansions, i, var) { if (honor_signed_zero_p) zero_init = simplify_gen_unary (NEG, mode, CONST0_RTX (mode), mode); @@ -2151,7 +1880,7 @@ break; case MULT: - FOR_EACH_VEC_ELT (rtx, ve->var_expansions, i, var) + FOR_EACH_VEC_ELT (ve->var_expansions, i, var) { zero_init = CONST1_RTX (GET_MODE (var)); emit_move_insn (var, zero_init); @@ -2165,11 +1894,7 @@ seq = get_insns (); end_sequence (); - insn = BB_HEAD (place); - while (!NOTE_INSN_BASIC_BLOCK_P (insn)) - insn = NEXT_INSN (insn); - - emit_insn_after (seq, insn); + emit_insn_after (seq, BB_END (place)); } /* Combine the variable expansions at the loop exit. PLACE is the @@ -2180,12 +1905,16 @@ combine_var_copies_in_loop_exit (struct var_to_expand *ve, basic_block place) { rtx sum = ve->reg; - rtx expr, seq, var, insn; + rtx expr, var; + rtx_insn *seq, *insn; unsigned i; - if (VEC_length (rtx, ve->var_expansions) == 0) + if (ve->var_expansions.length () == 0) return; + /* ve->reg might be SUBREG or some other non-shareable RTL, and we use + it both here and as the destination of the assignment. */ + sum = copy_rtx (sum); start_sequence (); switch (ve->op) { @@ -2193,12 +1922,12 @@ /* Note that we only accumulate FMA via the ADD operand. */ case PLUS: case MINUS: - FOR_EACH_VEC_ELT (rtx, ve->var_expansions, i, var) + FOR_EACH_VEC_ELT (ve->var_expansions, i, var) sum = simplify_gen_binary (PLUS, GET_MODE (ve->reg), var, sum); break; case MULT: - FOR_EACH_VEC_ELT (rtx, ve->var_expansions, i, var) + FOR_EACH_VEC_ELT (ve->var_expansions, i, var) sum = simplify_gen_binary (MULT, GET_MODE (ve->reg), var, sum); break; @@ -2219,6 +1948,32 @@ emit_insn_after (seq, insn); } +/* Strip away REG_EQUAL notes for IVs we're splitting. + + Updating REG_EQUAL notes for IVs we split is tricky: We + cannot tell until after unrolling, DF-rescanning, and liveness + updating, whether an EQ_USE is reached by the split IV while + the IV reg is still live. See PR55006. + + ??? We cannot use remove_reg_equal_equiv_notes_for_regno, + because RTL loop-iv requires us to defer rescanning insns and + any notes attached to them. So resort to old techniques... */ + +static void +maybe_strip_eq_note_for_split_iv (struct opt_info *opt_info, rtx_insn *insn) +{ + struct iv_to_split *ivts; + rtx note = find_reg_equal_equiv_note (insn); + if (! note) + return; + for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) + if (reg_mentioned_p (ivts->orig_var, note)) + { + remove_note (insn, note); + return; + } +} + /* Apply loop optimizations in loop copies using the data which gathered during the unrolling. Structure OPT_INFO record that data. @@ -2235,7 +1990,7 @@ { unsigned i, delta; basic_block bb, orig_bb; - rtx insn, orig_insn, next; + rtx_insn *insn, *orig_insn, *next; struct iv_to_split ivts_templ, *ivts; struct var_to_expand ve_templ, *ves; @@ -2248,9 +2003,11 @@ for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next) allocate_basic_variable (ivts); - for (i = opt_info->first_new_block; i < (unsigned) last_basic_block; i++) + for (i = opt_info->first_new_block; + i < (unsigned) last_basic_block_for_fn (cfun); + i++) { - bb = BASIC_BLOCK (i); + bb = BASIC_BLOCK_FOR_FN (cfun, i); orig_bb = get_bb_original (bb); /* bb->aux holds position in copy sequence initialized by @@ -2259,13 +2016,17 @@ unrolling); bb->aux = 0; orig_insn = BB_HEAD (orig_bb); - for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb)); insn = next) + FOR_BB_INSNS_SAFE (bb, insn, next) { - next = NEXT_INSN (insn); - if (!INSN_P (insn)) + if (!INSN_P (insn) + || (DEBUG_INSN_P (insn) + && TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL)) continue; - while (!INSN_P (orig_insn)) + while (!INSN_P (orig_insn) + || (DEBUG_INSN_P (orig_insn) + && (TREE_CODE (INSN_VAR_LOCATION_DECL (orig_insn)) + == LABEL_DECL))) orig_insn = NEXT_INSN (orig_insn); ivts_templ.insn = orig_insn; @@ -2274,8 +2035,9 @@ /* Apply splitting iv optimization. */ if (opt_info->insns_to_split) { - ivts = (struct iv_to_split *) - htab_find (opt_info->insns_to_split, &ivts_templ); + maybe_strip_eq_note_for_split_iv (opt_info, insn); + + ivts = opt_info->insns_to_split->find (&ivts_templ); if (ivts) { @@ -2291,7 +2053,7 @@ if (unrolling && opt_info->insns_with_var_to_expand) { ves = (struct var_to_expand *) - htab_find (opt_info->insns_with_var_to_expand, &ve_templ); + opt_info->insns_with_var_to_expand->find (&ve_templ); if (ves) { gcc_assert (GET_CODE (PATTERN (insn)) @@ -2319,9 +2081,11 @@ /* Rewrite also the original loop body. Find them as originals of the blocks in the last copied iteration, i.e. those that have get_bb_copy (get_bb_original (bb)) == bb. */ - for (i = opt_info->first_new_block; i < (unsigned) last_basic_block; i++) + for (i = opt_info->first_new_block; + i < (unsigned) last_basic_block_for_fn (cfun); + i++) { - bb = BASIC_BLOCK (i); + bb = BASIC_BLOCK_FOR_FN (cfun, i); orig_bb = get_bb_original (bb); if (get_bb_copy (orig_bb) != bb) continue; @@ -2339,8 +2103,10 @@ ivts_templ.insn = orig_insn; if (opt_info->insns_to_split) { + maybe_strip_eq_note_for_split_iv (opt_info, orig_insn); + ivts = (struct iv_to_split *) - htab_find (opt_info->insns_to_split, &ivts_templ); + opt_info->insns_to_split->find (&ivts_templ); if (ivts) { if (!delta) @@ -2359,15 +2125,16 @@ static void free_opt_info (struct opt_info *opt_info) { - if (opt_info->insns_to_split) - htab_delete (opt_info->insns_to_split); + delete opt_info->insns_to_split; + opt_info->insns_to_split = NULL; if (opt_info->insns_with_var_to_expand) { struct var_to_expand *ves; for (ves = opt_info->var_to_expand_head; ves; ves = ves->next) - VEC_free (rtx, heap, ves->var_expansions); - htab_delete (opt_info->insns_with_var_to_expand); + ves->var_expansions.release (); + delete opt_info->insns_with_var_to_expand; + opt_info->insns_with_var_to_expand = NULL; } free (opt_info); }