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-rw-r--r--gcc/df-problems.c450
1 files changed, 447 insertions, 3 deletions
diff --git a/gcc/df-problems.c b/gcc/df-problems.c
index 84dc42a1361..5e56025ed8b 100644
--- a/gcc/df-problems.c
+++ b/gcc/df-problems.c
@@ -726,9 +726,8 @@ static struct df_problem problem_RD =
-/* Create a new DATAFLOW instance and add it to an existing instance
- of DF. The returned structure is what is used to get at the
- solution. */
+/* Create a new RD instance and add it to the existing instance
+ of DF. */
void
df_rd_add_problem (void)
@@ -3952,3 +3951,448 @@ df_simulate_finalize_forwards (basic_block bb, bitmap live)
bitmap_clear_bit (live, DF_REF_REGNO (def));
}
}
+
+
+
+/*----------------------------------------------------------------------------
+ MULTIPLE DEFINITIONS
+
+ Find the locations in the function reached by multiple definition sites
+ for a pseudo. In and out bitvectors are built for each basic
+ block.
+
+ The gen and kill sets for the problem are obvious. Together they
+ include all defined registers in a basic block; the gen set includes
+ registers where a partial or conditional or may-clobber definition is
+ last in the BB, while the kill set includes registers with a complete
+ definition coming last. However, the computation of the dataflow
+ itself is interesting.
+
+ The idea behind it comes from SSA form's iterated dominance frontier
+ criterion for inserting PHI functions. Just like in that case, we can use
+ the dominance frontier to find places where multiple definitions meet;
+ a register X defined in a basic block BB1 has multiple definitions in
+ basic blocks in BB1's dominance frontier.
+
+ So, the in-set of a basic block BB2 is not just the union of the
+ out-sets of BB2's predecessors, but includes some more bits that come
+ from the basic blocks of whose dominance frontier BB2 is part (BB1 in
+ the previous paragraph). I called this set the init-set of BB2.
+
+ (Note: I actually use the kill-set only to build the init-set.
+ gen bits are anyway propagated from BB1 to BB2 by dataflow).
+
+ For example, if you have
+
+ BB1 : r10 = 0
+ r11 = 0
+ if <...> goto BB2 else goto BB3;
+
+ BB2 : r10 = 1
+ r12 = 1
+ goto BB3;
+
+ BB3 :
+
+ you have BB3 in BB2's dominance frontier but not in BB1's, so that the
+ init-set of BB3 includes r10 and r12, but not r11. Note that we do
+ not need to iterate the dominance frontier, because we do not insert
+ anything like PHI functions there! Instead, dataflow will take care of
+ propagating the information to BB3's successors.
+ ---------------------------------------------------------------------------*/
+
+/* Set basic block info. */
+
+static void
+df_md_set_bb_info (unsigned int index,
+ struct df_md_bb_info *bb_info)
+{
+ gcc_assert (df_md);
+ gcc_assert (index < df_md->block_info_size);
+ df_md->block_info[index] = bb_info;
+}
+
+
+static void
+df_md_free_bb_info (basic_block bb ATTRIBUTE_UNUSED,
+ void *vbb_info)
+{
+ struct df_md_bb_info *bb_info = (struct df_md_bb_info *) vbb_info;
+ if (bb_info)
+ {
+ BITMAP_FREE (bb_info->kill);
+ BITMAP_FREE (bb_info->gen);
+ BITMAP_FREE (bb_info->init);
+ BITMAP_FREE (bb_info->in);
+ BITMAP_FREE (bb_info->out);
+ pool_free (df_md->block_pool, bb_info);
+ }
+}
+
+
+/* Allocate or reset bitmaps for DF_MD. The solution bits are
+ not touched unless the block is new. */
+
+static void
+df_md_alloc (bitmap all_blocks)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+
+ if (!df_md->block_pool)
+ df_md->block_pool = create_alloc_pool ("df_md_block pool",
+ sizeof (struct df_md_bb_info), 50);
+
+ df_grow_bb_info (df_md);
+
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
+ {
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb_index);
+ if (bb_info)
+ {
+ bitmap_clear (bb_info->init);
+ bitmap_clear (bb_info->gen);
+ bitmap_clear (bb_info->kill);
+ bitmap_clear (bb_info->in);
+ bitmap_clear (bb_info->out);
+ }
+ else
+ {
+ bb_info = (struct df_md_bb_info *) pool_alloc (df_md->block_pool);
+ df_md_set_bb_info (bb_index, bb_info);
+ bb_info->init = BITMAP_ALLOC (NULL);
+ bb_info->gen = BITMAP_ALLOC (NULL);
+ bb_info->kill = BITMAP_ALLOC (NULL);
+ bb_info->in = BITMAP_ALLOC (NULL);
+ bb_info->out = BITMAP_ALLOC (NULL);
+ }
+ }
+
+ df_md->optional_p = true;
+}
+
+/* Add the effect of the top artificial defs of BB to the multiple definitions
+ bitmap LOCAL_MD. */
+
+void
+df_md_simulate_artificial_defs_at_top (basic_block bb, bitmap local_md)
+{
+ int bb_index = bb->index;
+ df_ref *def_rec;
+ for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
+ {
+ unsigned int dregno = DF_REF_REGNO (def);
+ if (DF_REF_FLAGS (def)
+ & (DF_REF_PARTIAL | DF_REF_CONDITIONAL | DF_REF_MAY_CLOBBER))
+ bitmap_set_bit (local_md, dregno);
+ else
+ bitmap_clear_bit (local_md, dregno);
+ }
+ }
+}
+
+
+/* Add the effect of the defs of INSN to the reaching definitions bitmap
+ LOCAL_MD. */
+
+void
+df_md_simulate_one_insn (basic_block bb ATTRIBUTE_UNUSED, rtx insn,
+ bitmap local_md)
+{
+ unsigned uid = INSN_UID (insn);
+ df_ref *def_rec;
+
+ for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ unsigned int dregno = DF_REF_REGNO (def);
+ if ((!(df->changeable_flags & DF_NO_HARD_REGS))
+ || (dregno >= FIRST_PSEUDO_REGISTER))
+ {
+ if (DF_REF_FLAGS (def)
+ & (DF_REF_PARTIAL | DF_REF_CONDITIONAL | DF_REF_MAY_CLOBBER))
+ bitmap_set_bit (local_md, DF_REF_ID (def));
+ else
+ bitmap_clear_bit (local_md, DF_REF_ID (def));
+ }
+ }
+}
+
+static void
+df_md_bb_local_compute_process_def (struct df_md_bb_info *bb_info,
+ df_ref *def_rec,
+ int top_flag)
+{
+ df_ref def;
+ bitmap_clear (seen_in_insn);
+
+ while ((def = *def_rec++) != NULL)
+ {
+ unsigned int dregno = DF_REF_REGNO (def);
+ if (((!(df->changeable_flags & DF_NO_HARD_REGS))
+ || (dregno >= FIRST_PSEUDO_REGISTER))
+ && top_flag == (DF_REF_FLAGS (def) & DF_REF_AT_TOP))
+ {
+ if (!bitmap_bit_p (seen_in_insn, dregno))
+ {
+ if (DF_REF_FLAGS (def)
+ & (DF_REF_PARTIAL | DF_REF_CONDITIONAL | DF_REF_MAY_CLOBBER))
+ {
+ bitmap_set_bit (bb_info->gen, dregno);
+ bitmap_clear_bit (bb_info->kill, dregno);
+ }
+ else
+ {
+ /* When we find a clobber and a regular def,
+ make sure the regular def wins. */
+ bitmap_set_bit (seen_in_insn, dregno);
+ bitmap_set_bit (bb_info->kill, dregno);
+ bitmap_clear_bit (bb_info->gen, dregno);
+ }
+ }
+ }
+ }
+}
+
+
+/* Compute local multiple def info for basic block BB. */
+
+static void
+df_md_bb_local_compute (unsigned int bb_index)
+{
+ basic_block bb = BASIC_BLOCK (bb_index);
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb_index);
+ rtx insn;
+
+ /* Artificials are only hard regs. */
+ if (!(df->changeable_flags & DF_NO_HARD_REGS))
+ df_md_bb_local_compute_process_def (bb_info,
+ df_get_artificial_defs (bb_index),
+ DF_REF_AT_TOP);
+
+ FOR_BB_INSNS (bb, insn)
+ {
+ unsigned int uid = INSN_UID (insn);
+ if (!INSN_P (insn))
+ continue;
+
+ df_md_bb_local_compute_process_def (bb_info, DF_INSN_UID_DEFS (uid), 0);
+ }
+
+ if (!(df->changeable_flags & DF_NO_HARD_REGS))
+ df_md_bb_local_compute_process_def (bb_info,
+ df_get_artificial_defs (bb_index),
+ 0);
+}
+
+/* Compute local reaching def info for each basic block within BLOCKS. */
+
+static void
+df_md_local_compute (bitmap all_blocks)
+{
+ unsigned int bb_index, df_bb_index;
+ bitmap_iterator bi1, bi2;
+ basic_block bb;
+ bitmap *frontiers;
+
+ df_set_seen ();
+
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi1)
+ {
+ df_md_bb_local_compute (bb_index);
+ }
+
+ df_unset_seen ();
+
+ frontiers = XNEWVEC (bitmap, last_basic_block);
+ FOR_ALL_BB (bb)
+ frontiers[bb->index] = BITMAP_ALLOC (NULL);
+
+ compute_dominance_frontiers (frontiers);
+
+ /* Add each basic block's kills to the nodes in the frontier of the BB. */
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi1)
+ {
+ bitmap kill = df_md_get_bb_info (bb_index)->kill;
+ EXECUTE_IF_SET_IN_BITMAP (frontiers[bb_index], 0, df_bb_index, bi2)
+ {
+ if (bitmap_bit_p (all_blocks, df_bb_index))
+ bitmap_ior_into (df_md_get_bb_info (df_bb_index)->init, kill);
+ }
+ }
+
+ FOR_ALL_BB (bb)
+ BITMAP_FREE (frontiers[bb->index]);
+ free (frontiers);
+}
+
+
+/* Reset the global solution for recalculation. */
+
+static void
+df_md_reset (bitmap all_blocks)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
+ {
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb_index);
+ gcc_assert (bb_info);
+ bitmap_clear (bb_info->in);
+ bitmap_clear (bb_info->out);
+ }
+}
+
+static bool
+df_md_transfer_function (int bb_index)
+{
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb_index);
+ bitmap in = bb_info->in;
+ bitmap out = bb_info->out;
+ bitmap gen = bb_info->gen;
+ bitmap kill = bb_info->kill;
+
+ return bitmap_ior_and_compl (out, gen, in, kill);
+}
+
+/* Initialize the solution bit vectors for problem. */
+
+static void
+df_md_init (bitmap all_blocks)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
+ {
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb_index);
+
+ bitmap_copy (bb_info->in, bb_info->init);
+ df_md_transfer_function (bb_index);
+ }
+}
+
+static void
+df_md_confluence_0 (basic_block bb)
+{
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb->index);
+ bitmap_copy (bb_info->in, bb_info->init);
+}
+
+/* In of target gets or of out of source. */
+
+static void
+df_md_confluence_n (edge e)
+{
+ bitmap op1 = df_md_get_bb_info (e->dest->index)->in;
+ bitmap op2 = df_md_get_bb_info (e->src->index)->out;
+
+ if (e->flags & EDGE_FAKE)
+ return;
+
+ if (e->flags & EDGE_EH)
+ bitmap_ior_and_compl_into (op1, op2, regs_invalidated_by_call_regset);
+ else
+ bitmap_ior_into (op1, op2);
+}
+
+/* Free all storage associated with the problem. */
+
+static void
+df_md_free (void)
+{
+ unsigned int i;
+ for (i = 0; i < df_md->block_info_size; i++)
+ {
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (i);
+ if (bb_info)
+ {
+ BITMAP_FREE (bb_info->kill);
+ BITMAP_FREE (bb_info->gen);
+ BITMAP_FREE (bb_info->init);
+ BITMAP_FREE (bb_info->in);
+ BITMAP_FREE (bb_info->out);
+ }
+ }
+
+ free_alloc_pool (df_md->block_pool);
+
+ df_md->block_info_size = 0;
+ free (df_md->block_info);
+ free (df_md);
+}
+
+
+/* Debugging info at top of bb. */
+
+static void
+df_md_top_dump (basic_block bb, FILE *file)
+{
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb->index);
+ if (!bb_info || !bb_info->in)
+ return;
+
+ fprintf (file, ";; md in \t");
+ df_print_regset (file, bb_info->in);
+ fprintf (file, ";; md init \t");
+ df_print_regset (file, bb_info->init);
+ fprintf (file, ";; md gen \t");
+ df_print_regset (file, bb_info->gen);
+ fprintf (file, ";; md kill \t");
+ df_print_regset (file, bb_info->kill);
+}
+
+/* Debugging info at bottom of bb. */
+
+static void
+df_md_bottom_dump (basic_block bb, FILE *file)
+{
+ struct df_md_bb_info *bb_info = df_md_get_bb_info (bb->index);
+ if (!bb_info || !bb_info->out)
+ return;
+
+ fprintf (file, ";; md out \t");
+ df_print_regset (file, bb_info->out);
+}
+
+static struct df_problem problem_MD =
+{
+ DF_MD, /* Problem id. */
+ DF_FORWARD, /* Direction. */
+ df_md_alloc, /* Allocate the problem specific data. */
+ df_md_reset, /* Reset global information. */
+ df_md_free_bb_info, /* Free basic block info. */
+ df_md_local_compute, /* Local compute function. */
+ df_md_init, /* Init the solution specific data. */
+ df_worklist_dataflow, /* Worklist solver. */
+ df_md_confluence_0, /* Confluence operator 0. */
+ df_md_confluence_n, /* Confluence operator n. */
+ df_md_transfer_function, /* Transfer function. */
+ NULL, /* Finalize function. */
+ df_md_free, /* Free all of the problem information. */
+ df_md_free, /* Remove this problem from the stack of dataflow problems. */
+ NULL, /* Debugging. */
+ df_md_top_dump, /* Debugging start block. */
+ df_md_bottom_dump, /* Debugging end block. */
+ NULL, /* Incremental solution verify start. */
+ NULL, /* Incremental solution verify end. */
+ NULL, /* Dependent problem. */
+ TV_DF_MD, /* Timing variable. */
+ false /* Reset blocks on dropping out of blocks_to_analyze. */
+};
+
+/* Create a new MD instance and add it to the existing instance
+ of DF. */
+
+void
+df_md_add_problem (void)
+{
+ df_add_problem (&problem_MD);
+}
+
+
+