From: Revital Eres Date: Wed, 11 May 2011 12:38:12 +0000 (+0000) Subject: Support closing_branch_deps X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fc6970e432491e8bd0451c69bdca14985ccbe8df;p=gcc.git Support closing_branch_deps From-SVN: r173654 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a439ef80558..74a6e7cb202 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,24 @@ +2011-05-11 Revital Eres + + * ddg.c (create_ddg_dep_from_intra_loop_link): If a true dep edge + enters the branch create an anti edge in the opposite direction + to prevent the creation of reg-moves. + * modulo-sched.c: Adjust comment to reflect the fact we are + scheduling closing branch. + (PS_STAGE_COUNT): Rename to CALC_STAGE_COUNT and redefine. + (stage_count): New field in struct partial_schedule. + (calculate_stage_count): New function. + (normalize_sched_times): Rename to reset_sched_times and handle + incrementing the sched time of the nodes by a constant value + passed as parameter. + (duplicate_insns_of_cycles): Skip closing branch. + (sms_schedule_by_order): Schedule closing branch. + (ps_insn_find_column): Handle closing branch. + (sms_schedule): Call reset_sched_times and adjust the code to + support scheduling of the closing branch. + (ps_insert_empty_row): Update calls to normalize_sched_times + and rotate_partial_schedule functions. + 2011-05-11 Richard Guenther PR middle-end/48953 diff --git a/gcc/ddg.c b/gcc/ddg.c index 4543ba7d170..b8ae375f153 100644 --- a/gcc/ddg.c +++ b/gcc/ddg.c @@ -197,6 +197,11 @@ create_ddg_dep_from_intra_loop_link (ddg_ptr g, ddg_node_ptr src_node, } } + /* If a true dep edge enters the branch create an anti edge in the + opposite direction to prevent the creation of reg-moves. */ + if ((DEP_TYPE (link) == REG_DEP_TRUE) && JUMP_P (dest_node->insn)) + create_ddg_dep_no_link (g, dest_node, src_node, ANTI_DEP, REG_DEP, 1); + latency = dep_cost (link); e = create_ddg_edge (src_node, dest_node, t, dt, latency, distance); add_edge_to_ddg (g, e); diff --git a/gcc/modulo-sched.c b/gcc/modulo-sched.c index 0f525afb676..4937a56a7c4 100644 --- a/gcc/modulo-sched.c +++ b/gcc/modulo-sched.c @@ -84,14 +84,13 @@ along with GCC; see the file COPYING3. If not see II cycles (i.e. use register copies to prevent a def from overwriting itself before reaching the use). - SMS works with countable loops (1) whose control part can be easily - decoupled from the rest of the loop and (2) whose loop count can - be easily adjusted. This is because we peel a constant number of - iterations into a prologue and epilogue for which we want to avoid - emitting the control part, and a kernel which is to iterate that - constant number of iterations less than the original loop. So the - control part should be a set of insns clearly identified and having - its own iv, not otherwise used in the loop (at-least for now), which + SMS works with countable loops whose loop count can be easily + adjusted. This is because we peel a constant number of iterations + into a prologue and epilogue for which we want to avoid emitting + the control part, and a kernel which is to iterate that constant + number of iterations less than the original loop. So the control + part should be a set of insns clearly identified and having its + own iv, not otherwise used in the loop (at-least for now), which initializes a register before the loop to the number of iterations. Currently SMS relies on the do-loop pattern to recognize such loops, where (1) the control part comprises of all insns defining and/or @@ -116,8 +115,10 @@ typedef struct ps_insn *ps_insn_ptr; /* The number of different iterations the nodes in ps span, assuming the stage boundaries are placed efficiently. */ -#define PS_STAGE_COUNT(ps) ((PS_MAX_CYCLE (ps) - PS_MIN_CYCLE (ps) \ - + 1 + (ps)->ii - 1) / (ps)->ii) +#define CALC_STAGE_COUNT(max_cycle,min_cycle,ii) ((max_cycle - min_cycle \ + + 1 + ii - 1) / ii) +/* The stage count of ps. */ +#define PS_STAGE_COUNT(ps) (((partial_schedule_ptr)(ps))->stage_count) /* A single instruction in the partial schedule. */ struct ps_insn @@ -155,6 +156,8 @@ struct partial_schedule int max_cycle; ddg_ptr g; /* The DDG of the insns in the partial schedule. */ + + int stage_count; /* The stage count of the partial schedule. */ }; /* We use this to record all the register replacements we do in @@ -195,7 +198,7 @@ static void generate_prolog_epilog (partial_schedule_ptr, struct loop *, rtx, rtx); static void duplicate_insns_of_cycles (partial_schedule_ptr, int, int, int, rtx); - +static int calculate_stage_count (partial_schedule_ptr ps); #define SCHED_ASAP(x) (((node_sched_params_ptr)(x)->aux.info)->asap) #define SCHED_TIME(x) (((node_sched_params_ptr)(x)->aux.info)->time) #define SCHED_FIRST_REG_MOVE(x) \ @@ -569,13 +572,13 @@ free_undo_replace_buff (struct undo_replace_buff_elem *reg_move_replaces) } } -/* Bump the SCHED_TIMEs of all nodes to start from zero. Set the values - of SCHED_ROW and SCHED_STAGE. */ +/* Bump the SCHED_TIMEs of all nodes by AMOUNT. Set the values of + SCHED_ROW and SCHED_STAGE. Instruction scheduled on cycle AMOUNT + will move to cycle zero. */ static void -normalize_sched_times (partial_schedule_ptr ps) +reset_sched_times (partial_schedule_ptr ps, int amount) { int row; - int amount = PS_MIN_CYCLE (ps); int ii = ps->ii; ps_insn_ptr crr_insn; @@ -584,19 +587,43 @@ normalize_sched_times (partial_schedule_ptr ps) { ddg_node_ptr u = crr_insn->node; int normalized_time = SCHED_TIME (u) - amount; + int new_min_cycle = PS_MIN_CYCLE (ps) - amount; + int sc_until_cycle_zero, stage; - if (dump_file) - fprintf (dump_file, "crr_insn->node=%d, crr_insn->cycle=%d,\ - min_cycle=%d\n", crr_insn->node->cuid, SCHED_TIME - (u), ps->min_cycle); + if (dump_file) + { + /* Print the scheduling times after the rotation. */ + fprintf (dump_file, "crr_insn->node=%d (insn id %d), " + "crr_insn->cycle=%d, min_cycle=%d", crr_insn->node->cuid, + INSN_UID (crr_insn->node->insn), SCHED_TIME (u), + normalized_time); + if (JUMP_P (crr_insn->node->insn)) + fprintf (dump_file, " (branch)"); + fprintf (dump_file, "\n"); + } + gcc_assert (SCHED_TIME (u) >= ps->min_cycle); gcc_assert (SCHED_TIME (u) <= ps->max_cycle); SCHED_TIME (u) = normalized_time; - SCHED_ROW (u) = normalized_time % ii; - SCHED_STAGE (u) = normalized_time / ii; + SCHED_ROW (u) = SMODULO (normalized_time, ii); + + /* The calculation of stage count is done adding the number + of stages before cycle zero and after cycle zero. */ + sc_until_cycle_zero = CALC_STAGE_COUNT (-1, new_min_cycle, ii); + + if (SCHED_TIME (u) < 0) + { + stage = CALC_STAGE_COUNT (-1, SCHED_TIME (u), ii); + SCHED_STAGE (u) = sc_until_cycle_zero - stage; + } + else + { + stage = CALC_STAGE_COUNT (SCHED_TIME (u), 0, ii); + SCHED_STAGE (u) = sc_until_cycle_zero + stage - 1; + } } } - + /* Set SCHED_COLUMN of each node according to its position in PS. */ static void set_columns_for_ps (partial_schedule_ptr ps) @@ -646,9 +673,12 @@ duplicate_insns_of_cycles (partial_schedule_ptr ps, int from_stage, /* Do not duplicate any insn which refers to count_reg as it belongs to the control part. + The closing branch is scheduled as well and thus should + be ignored. TODO: This should be done by analyzing the control part of the loop. */ - if (reg_mentioned_p (count_reg, u_node->insn)) + if (reg_mentioned_p (count_reg, u_node->insn) + || JUMP_P (ps_ij->node->insn)) continue; if (for_prolog) @@ -1052,7 +1082,11 @@ sms_schedule (void) continue; } - if (! (g = create_ddg (bb, 0))) + /* Always schedule the closing branch with the rest of the + instructions. The branch is rotated to be in row ii-1 at the + end of the scheduling procedure to make sure it's the last + instruction in the iteration. */ + if (! (g = create_ddg (bb, 1))) { if (dump_file) fprintf (dump_file, "SMS create_ddg failed\n"); @@ -1160,10 +1194,12 @@ sms_schedule (void) ps = sms_schedule_by_order (g, mii, maxii, node_order); - if (ps){ - stage_count = PS_STAGE_COUNT (ps); - gcc_assert(stage_count >= 1); - } + if (ps) + { + stage_count = calculate_stage_count (ps); + gcc_assert(stage_count >= 1); + PS_STAGE_COUNT(ps) = stage_count; + } /* The default value of PARAM_SMS_MIN_SC is 2 as stage count of 1 means that there is no interleaving between iterations thus @@ -1185,32 +1221,24 @@ sms_schedule (void) else { struct undo_replace_buff_elem *reg_move_replaces; + int amount = SCHED_TIME (g->closing_branch) + 1; + + /* Set the stage boundaries. The closing_branch was scheduled + and should appear in the last (ii-1) row. */ + reset_sched_times (ps, amount); + rotate_partial_schedule (ps, amount); + set_columns_for_ps (ps); - if (dump_file) - { + canon_loop (loop); + + if (dump_file) + { fprintf (dump_file, "SMS succeeded %d %d (with ii, sc)\n", ps->ii, stage_count); print_partial_schedule (ps, dump_file); - fprintf (dump_file, - "SMS Branch (%d) will later be scheduled at cycle %d.\n", - g->closing_branch->cuid, PS_MIN_CYCLE (ps) - 1); } - - /* Set the stage boundaries. If the DDG is built with closing_branch_deps, - the closing_branch was scheduled and should appear in the last (ii-1) - row. Otherwise, we are free to schedule the branch, and we let nodes - that were scheduled at the first PS_MIN_CYCLE cycle appear in the first - row; this should reduce stage_count to minimum. - TODO: Revisit the issue of scheduling the insns of the - control part relative to the branch when the control part - has more than one insn. */ - normalize_sched_times (ps); - rotate_partial_schedule (ps, PS_MIN_CYCLE (ps)); - set_columns_for_ps (ps); - - canon_loop (loop); - + /* case the BCT count is not known , Do loop-versioning */ if (count_reg && ! count_init) { @@ -1763,12 +1791,6 @@ sms_schedule_by_order (ddg_ptr g, int mii, int maxii, int *nodes_order) continue; } - if (JUMP_P (insn)) /* Closing branch handled later. */ - { - RESET_BIT (tobe_scheduled, u); - continue; - } - if (TEST_BIT (sched_nodes, u)) continue; @@ -1896,8 +1918,8 @@ ps_insert_empty_row (partial_schedule_ptr ps, int split_row, if (dump_file) fprintf (dump_file, "split_row=%d\n", split_row); - normalize_sched_times (ps); - rotate_partial_schedule (ps, ps->min_cycle); + reset_sched_times (ps, PS_MIN_CYCLE (ps)); + rotate_partial_schedule (ps, PS_MIN_CYCLE (ps)); rows_new = (ps_insn_ptr *) xcalloc (new_ii, sizeof (ps_insn_ptr)); for (row = 0; row < split_row; row++) @@ -2574,6 +2596,7 @@ ps_insn_find_column (partial_schedule_ptr ps, ps_insn_ptr ps_i, ps_insn_ptr next_ps_i; ps_insn_ptr first_must_follow = NULL; ps_insn_ptr last_must_precede = NULL; + ps_insn_ptr last_in_row = NULL; int row; if (! ps_i) @@ -2600,8 +2623,37 @@ ps_insn_find_column (partial_schedule_ptr ps, ps_insn_ptr ps_i, else last_must_precede = next_ps_i; } + /* The closing branch must be the last in the row. */ + if (must_precede + && TEST_BIT (must_precede, next_ps_i->node->cuid) + && JUMP_P (next_ps_i->node->insn)) + return false; + + last_in_row = next_ps_i; } + /* The closing branch is scheduled as well. Make sure there is no + dependent instruction after it as the branch should be the last + instruction in the row. */ + if (JUMP_P (ps_i->node->insn)) + { + if (first_must_follow) + return false; + if (last_in_row) + { + /* Make the branch the last in the row. New instructions + will be inserted at the beginning of the row or after the + last must_precede instruction thus the branch is guaranteed + to remain the last instruction in the row. */ + last_in_row->next_in_row = ps_i; + ps_i->prev_in_row = last_in_row; + ps_i->next_in_row = NULL; + } + else + ps->rows[row] = ps_i; + return true; + } + /* Now insert the node after INSERT_AFTER_PSI. */ if (! last_must_precede) @@ -2823,6 +2875,24 @@ ps_add_node_check_conflicts (partial_schedule_ptr ps, ddg_node_ptr n, return ps_i; } +/* Calculate the stage count of the partial schedule PS. The calculation + takes into account the rotation to bring the closing branch to row + ii-1. */ +int +calculate_stage_count (partial_schedule_ptr ps) +{ + int rotation_amount = (SCHED_TIME (ps->g->closing_branch)) + 1; + int new_min_cycle = PS_MIN_CYCLE (ps) - rotation_amount; + int new_max_cycle = PS_MAX_CYCLE (ps) - rotation_amount; + int stage_count = CALC_STAGE_COUNT (-1, new_min_cycle, ps->ii); + + /* The calculation of stage count is done adding the number of stages + before cycle zero and after cycle zero. */ + stage_count += CALC_STAGE_COUNT (new_max_cycle, 0, ps->ii); + + return stage_count; +} + /* Rotate the rows of PS such that insns scheduled at time START_CYCLE will appear in row 0. Updates max/min_cycles. */ void