/* DDG - Data Dependence Graph implementation.
- Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
+ Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
Contributed by Ayal Zaks and Mustafa Hagog <zaks,mustafa@il.ibm.com>
#include "coretypes.h"
#include "tm.h"
#include "diagnostic-core.h"
-#include "toplev.h"
#include "rtl.h"
#include "tm_p.h"
#include "hard-reg-set.h"
return rtx_mem_access_p (PATTERN (insn));
}
+/* Return true if DEF_INSN contains address being auto-inc or auto-dec
+ which is used in USE_INSN. Otherwise return false. The result is
+ being used to decide whether to remove the edge between def_insn and
+ use_insn when -fmodulo-sched-allow-regmoves is set. This function
+ doesn't need to consider the specific address register; no reg_moves
+ will be allowed for any life range defined by def_insn and used
+ by use_insn, if use_insn uses an address register auto-inc'ed by
+ def_insn. */
+bool
+autoinc_var_is_used_p (rtx def_insn, rtx use_insn)
+{
+ rtx note;
+
+ for (note = REG_NOTES (def_insn); note; note = XEXP (note, 1))
+ if (REG_NOTE_KIND (note) == REG_INC
+ && reg_referenced_p (XEXP (note, 0), PATTERN (use_insn)))
+ return true;
+
+ return false;
+}
+
+/* Return true if one of the definitions in INSN has MODE_CC. Otherwise
+ return false. */
+static bool
+def_has_ccmode_p (rtx insn)
+{
+ df_ref *def;
+
+ for (def = DF_INSN_DEFS (insn); *def; def++)
+ {
+ enum machine_mode mode = GET_MODE (DF_REF_REG (*def));
+
+ if (GET_MODE_CLASS (mode) == MODE_CC)
+ return true;
+ }
+
+ return false;
+}
+
/* Computes the dependence parameters (latency, distance etc.), creates
a ddg_edge and adds it to the given DDG. */
static void
compensate for that by generating reg-moves based on the life-range
analysis. The anti-deps that will be deleted are the ones which
have true-deps edges in the opposite direction (in other words
- the kernel has only one def of the relevant register). TODO:
- support the removal of all anti-deps edges, i.e. including those
+ the kernel has only one def of the relevant register).
+ If the address that is being auto-inc or auto-dec in DEST_NODE
+ is used in SRC_NODE then do not remove the edge to make sure
+ reg-moves will not be created for this address.
+ TODO: support the removal of all anti-deps edges, i.e. including those
whose register has multiple defs in the loop. */
- if (flag_modulo_sched_allow_regmoves && (t == ANTI_DEP && dt == REG_DEP))
+ if (flag_modulo_sched_allow_regmoves
+ && (t == ANTI_DEP && dt == REG_DEP)
+ && !def_has_ccmode_p (dest_node->insn)
+ && !autoinc_var_is_used_p (dest_node->insn, src_node->insn))
{
rtx set;
#ifdef ENABLE_CHECKING
if (DF_REF_ID (last_def) != DF_REF_ID (first_def))
- gcc_assert (!bitmap_bit_p (&bb_info->gen, DF_REF_ID (first_def)));
+ gcc_assert (!bitmap_bit_p (&bb_info->gen,
+ DF_REF_ID (first_def)));
#endif
/* Create inter-loop true dependences and anti dependences. */
gcc_assert (first_def_node);
+ /* Always create the edge if the use node is a branch in
+ order to prevent the creation of reg-moves.
+ If the address that is being auto-inc or auto-dec in LAST_DEF
+ is used in USE_INSN then do not remove the edge to make sure
+ reg-moves will not be created for that address. */
if (DF_REF_ID (last_def) != DF_REF_ID (first_def)
- || !flag_modulo_sched_allow_regmoves)
+ || !flag_modulo_sched_allow_regmoves
+ || JUMP_P (use_node->insn)
+ || autoinc_var_is_used_p (DF_REF_INSN (last_def), use_insn)
+ || def_has_ccmode_p (DF_REF_INSN (last_def)))
create_ddg_dep_no_link (g, use_node, first_def_node, ANTI_DEP,
REG_DEP, 1);
}
+static int
+walk_mems_2 (rtx *x, rtx mem)
+{
+ if (MEM_P (*x))
+ {
+ if (may_alias_p (*x, mem))
+ return 1;
+
+ return -1;
+ }
+ return 0;
+}
+
+static int
+walk_mems_1 (rtx *x, rtx *pat)
+{
+ if (MEM_P (*x))
+ {
+ /* Visit all MEMs in *PAT and check indepedence. */
+ if (for_each_rtx (pat, (rtx_function) walk_mems_2, *x))
+ /* Indicate that dependence was determined and stop traversal. */
+ return 1;
+
+ return -1;
+ }
+ return 0;
+}
+
+/* Return 1 if two specified instructions have mem expr with conflict alias sets*/
+static int
+insns_may_alias_p (rtx insn1, rtx insn2)
+{
+ /* For each pair of MEMs in INSN1 and INSN2 check their independence. */
+ return for_each_rtx (&PATTERN (insn1), (rtx_function) walk_mems_1,
+ &PATTERN (insn2));
+}
+
+/* Given two nodes, analyze their RTL insns and add intra-loop mem deps
+ to ddg G. */
+static void
+add_intra_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to)
+{
+
+ if ((from->cuid == to->cuid)
+ || !insns_may_alias_p (from->insn, to->insn))
+ /* Do not create edge if memory references have disjoint alias sets
+ or 'to' and 'from' are the same instruction. */
+ return;
+
+ if (mem_write_insn_p (from->insn))
+ {
+ if (mem_read_insn_p (to->insn))
+ create_ddg_dep_no_link (g, from, to,
+ DEBUG_INSN_P (to->insn)
+ ? ANTI_DEP : TRUE_DEP, MEM_DEP, 0);
+ else
+ create_ddg_dep_no_link (g, from, to,
+ DEBUG_INSN_P (to->insn)
+ ? ANTI_DEP : OUTPUT_DEP, MEM_DEP, 0);
+ }
+ else if (!mem_read_insn_p (to->insn))
+ create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 0);
+}
+
/* Given two nodes, analyze their RTL insns and add inter-loop mem deps
to ddg G. */
static void
add_inter_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to)
{
- if (!insn_alias_sets_conflict_p (from->insn, to->insn))
+ if (!insns_may_alias_p (from->insn, to->insn))
/* Do not create edge if memory references have disjoint alias sets. */
return;
if (DEBUG_INSN_P (j_node->insn))
continue;
if (mem_access_insn_p (j_node->insn))
- /* Don't bother calculating inter-loop dep if an intra-loop dep
- already exists. */
+ {
+ /* Don't bother calculating inter-loop dep if an intra-loop dep
+ already exists. */
if (! TEST_BIT (dest_node->successors, j))
add_inter_loop_mem_dep (g, dest_node, j_node);
+ /* If -fmodulo-sched-allow-regmoves
+ is set certain anti-dep edges are not created.
+ It might be that these anti-dep edges are on the
+ path from one memory instruction to another such that
+ removing these edges could cause a violation of the
+ memory dependencies. Thus we add intra edges between
+ every two memory instructions in this case. */
+ if (flag_modulo_sched_allow_regmoves
+ && !TEST_BIT (dest_node->predecessors, j))
+ add_intra_loop_mem_dep (g, j_node, dest_node);
+ }
}
}
}
}
/* There is nothing to do for this BB. */
- if (num_nodes <= 1)
+ if ((num_nodes - g->num_debug) <= 1)
{
free (g);
return NULL;
for (i = 0; i < all_sccs->num_sccs; i++)
free_scc (all_sccs->sccs[i]);
+ free (all_sccs->sccs);
free (all_sccs);
}
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