/* Register conflict graph computation routines.
- Copyright (C) 2000 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2003, 2004, 2005 Free Software Foundation, Inc.
Contributed by CodeSourcery, LLC
- This file is part of GNU CC.
+This file is part of GCC.
- GNU CC 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 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.
- GNU CC 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.
+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 GNU CC; see the file COPYING. If not, write to
- the Free Software Foundation, 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+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. */
/* References:
#include "config.h"
#include "system.h"
-
+#include "coretypes.h"
+#include "tm.h"
#include "obstack.h"
#include "hashtab.h"
#include "rtl.h"
+#include "hard-reg-set.h"
#include "basic-block.h"
-/* Use malloc to allocate obstack chunks. */
-#define obstack_chunk_alloc xmalloc
-#define obstack_chunk_free free
-
/* A register conflict graph is an undirected graph containing nodes
for some or all of the regs used in a function. Arcs represent
conflicts, i.e. two nodes are connected by an arc if there is a
};
typedef struct conflict_graph_arc_def *conflict_graph_arc;
+typedef const struct conflict_graph_arc_def *const_conflict_graph_arc;
/* A conflict graph. */
conflicts exist involving that reg. */
conflict_graph_arc *neighbor_heads;
- /* Arcs are allocated from here. */
+ /* Arcs are allocated from here. */
struct obstack arc_obstack;
};
/* The initial capacity (number of conflict arcs) for newly-created
conflict graphs. */
-#define INITIAL_ARC_CAPACITY (64)
+#define INITIAL_ARC_CAPACITY 64
/* Computes the hash value of the conflict graph arc connecting regs
- R1__ and R2__. R1__ is assumed to be smaller or equal to R2__. */
-#define CONFLICT_HASH_FN(r1__, r2__) ((r2__) * ((r2__) - 1) / 2 + (r1__))
-
-static unsigned arc_hash
- PARAMS ((const void *arcp));
-static int arc_eq
- PARAMS ((const void *arcp1, const void *arcp2));
-static int print_conflict
- PARAMS ((int reg1, int reg2, void *contextp));
-static void mark_reg
- PARAMS ((rtx reg, rtx setter, void *data));
-
+ R1 and R2. R1 is assumed to be smaller or equal to R2. */
+#define CONFLICT_HASH_FN(R1, R2) ((R2) * ((R2) - 1) / 2 + (R1))
+static hashval_t arc_hash (const void *);
+static int arc_eq (const void *, const void *);
+static int print_conflict (int, int, void *);
+\f
/* Callback function to compute the hash value of an arc. Uses
- current_graph to locate the graph to which the arc belongs. */
+ current_graph to locate the graph to which the arc belongs. */
-static unsigned
-arc_hash (arcp)
- const void *arcp;
+static hashval_t
+arc_hash (const void *arcp)
{
- conflict_graph_arc arc = (conflict_graph_arc) arcp;
+ const_conflict_graph_arc arc = (const_conflict_graph_arc) arcp;
+
return CONFLICT_HASH_FN (arc->smaller, arc->larger);
}
table. */
static int
-arc_eq (arcp1, arcp2)
- const void *arcp1;
- const void *arcp2;
+arc_eq (const void *arcp1, const void *arcp2)
{
- conflict_graph_arc arc1 = (conflict_graph_arc) arcp1;
- conflict_graph_arc arc2 = (conflict_graph_arc) arcp2;
+ const_conflict_graph_arc arc1 = (const_conflict_graph_arc) arcp1;
+ const_conflict_graph_arc arc2 = (const_conflict_graph_arc) arcp2;
+
return arc1->smaller == arc2->smaller && arc1->larger == arc2->larger;
}
registers. */
conflict_graph
-conflict_graph_new (num_regs)
- int num_regs;
+conflict_graph_new (int num_regs)
{
- conflict_graph graph =
- (conflict_graph) xmalloc (sizeof (struct conflict_graph_def));
+ conflict_graph graph = XNEW (struct conflict_graph_def);
graph->num_regs = num_regs;
/* Set up the hash table. No delete action is specified; memory
management of arcs is through the obstack. */
- graph->arc_hash_table =
- htab_create (INITIAL_ARC_CAPACITY, &arc_hash, &arc_eq, NULL);
+ graph->arc_hash_table
+ = htab_create (INITIAL_ARC_CAPACITY, &arc_hash, &arc_eq, NULL);
/* Create an obstack for allocating arcs. */
- obstack_init (&(graph->arc_obstack));
+ obstack_init (&graph->arc_obstack);
/* Create and zero the lookup table by register number. */
- graph->neighbor_heads = (conflict_graph_arc *)
- xmalloc (num_regs * sizeof (conflict_graph_arc));
- memset (graph->neighbor_heads, 0,
- num_regs * sizeof (conflict_graph_arc));
+ graph->neighbor_heads = XCNEWVEC (conflict_graph_arc, num_regs);
return graph;
}
/* Deletes a conflict graph. */
void
-conflict_graph_delete (graph)
- conflict_graph graph;
+conflict_graph_delete (conflict_graph graph)
{
- obstack_free (&(graph->arc_obstack), NULL);
+ obstack_free (&graph->arc_obstack, NULL);
htab_delete (graph->arc_hash_table);
free (graph->neighbor_heads);
free (graph);
}
/* Adds a conflict to GRAPH between regs REG1 and REG2, which must be
- distinct. Returns non-zero, unless the conflict is already present
+ distinct. Returns nonzero, unless the conflict is already present
in GRAPH, in which case it does nothing and returns zero. */
int
-conflict_graph_add (graph, reg1, reg2)
- conflict_graph graph;
- int reg1;
- int reg2;
+conflict_graph_add (conflict_graph graph, int reg1, int reg2)
{
int smaller = MIN (reg1, reg2);
int larger = MAX (reg1, reg2);
+ struct conflict_graph_arc_def dummy;
conflict_graph_arc arc;
- void **hash_table_slot;
+ void **slot;
/* A reg cannot conflict with itself. */
- if (reg1 == reg2)
- abort ();
-
- /* If the conflict is already there, do nothing.
-
- FIXME: This is a little wastful; it would be faster to look up the
- conflict in the hash table, returning it if it exists and
- inserting a new entry if it doesn't, all in one operation. This
- would save an extra hash lookup. However, the hashtab interface
- doesn't really allow this right now. */
- if (conflict_graph_conflict_p (graph, reg1, reg2))
+ gcc_assert (reg1 != reg2);
+
+ dummy.smaller = smaller;
+ dummy.larger = larger;
+ slot = htab_find_slot (graph->arc_hash_table, (void *) &dummy, INSERT);
+
+ /* If the conflict is already there, do nothing. */
+ if (*slot != NULL)
return 0;
/* Allocate an arc. */
- arc = (conflict_graph_arc)
- obstack_alloc (&(graph->arc_obstack),
- sizeof (struct conflict_graph_arc_def));
-
+ arc
+ = obstack_alloc (&graph->arc_obstack,
+ sizeof (struct conflict_graph_arc_def));
+
/* Record the reg numbers. */
arc->smaller = smaller;
arc->larger = larger;
- /* Link the conflict into into two lists, one for each reg. */
+ /* Link the conflict into two lists, one for each reg. */
arc->smaller_next = graph->neighbor_heads[smaller];
graph->neighbor_heads[smaller] = arc;
arc->larger_next = graph->neighbor_heads[larger];
graph->neighbor_heads[larger] = arc;
/* Put it in the hash table. */
- hash_table_slot = htab_find_slot (graph->arc_hash_table,
- (void *) arc, 1);
- *hash_table_slot = (void *) arc;
+ *slot = (void *) arc;
return 1;
}
-/* Returns non-zero if a conflict exists in GRAPH between regs REG1
+/* Returns nonzero if a conflict exists in GRAPH between regs REG1
and REG2. */
int
-conflict_graph_conflict_p (graph, reg1, reg2)
- conflict_graph graph;
- int reg1;
- int reg2;
+conflict_graph_conflict_p (conflict_graph graph, int reg1, int reg2)
{
/* Build an arc to search for. */
struct conflict_graph_arc_def arc;
passed back to ENUM_FN. */
void
-conflict_graph_enum (graph, reg, enum_fn, extra)
- conflict_graph graph;
- int reg;
- conflict_graph_enum_fn enum_fn;
- void *extra;
+conflict_graph_enum (conflict_graph graph, int reg,
+ conflict_graph_enum_fn enum_fn, void *extra)
{
conflict_graph_arc arc = graph->neighbor_heads[reg];
while (arc != NULL)
conflict to GRAPH between x and TARGET. */
void
-conflict_graph_merge_regs (graph, target, src)
- conflict_graph graph;
- int target;
- int src;
+conflict_graph_merge_regs (conflict_graph graph, int target, int src)
{
conflict_graph_arc arc = graph->neighbor_heads[src];
while (arc != NULL)
{
int other = arc->smaller;
+
if (other == src)
other = arc->larger;
/* Callback function when enumerating conflicts during printing. */
static int
-print_conflict (reg1, reg2, contextp)
- int reg1;
- int reg2;
- void *contextp;
+print_conflict (int reg1, int reg2, void *contextp)
{
struct print_context *context = (struct print_context *) contextp;
int reg;
is the interesting one. */
if (reg1 == context->reg)
reg = reg2;
- else if (reg2 == context->reg)
- reg = reg1;
else
- abort ();
+ {
+ gcc_assert (reg2 == context->reg);
+ reg = reg1;
+ }
/* Print the conflict. */
fprintf (context->fp, " %d", reg);
/* Prints the conflicts in GRAPH to FP. */
void
-conflict_graph_print (graph, fp)
- conflict_graph graph;
- FILE *fp;
+conflict_graph_print (conflict_graph graph, FILE *fp)
{
int reg;
struct print_context context;
- context.fp = fp;
+ context.fp = fp;
fprintf (fp, "Conflicts:\n");
+
/* Loop over registers supported in this graph. */
for (reg = 0; reg < graph->num_regs; ++reg)
{
context.reg = reg;
context.started = 0;
+
/* Scan the conflicts for reg, printing as we go. A label for
this line will be printed the first time a conflict is
printed for the reg; we won't start a new line if this reg
has no conflicts. */
conflict_graph_enum (graph, reg, &print_conflict, &context);
+
/* If this reg does have conflicts, end the line. */
if (context.started)
fputc ('\n', fp);
}
}
-
-/* Callback function for note_stores. */
-
-static void
-mark_reg (reg, setter, data)
- rtx reg;
- rtx setter ATTRIBUTE_UNUSED;
- void *data;
-{
- regset set = (regset) data;
-
- if (GET_CODE (reg) == SUBREG)
- reg = SUBREG_REG (reg);
-
- /* We're only interested in regs. */
- if (GET_CODE (reg) != REG)
- return;
-
- SET_REGNO_REG_SET (set, REGNO (reg));
-}
-
-/* Allocates a conflict graph and computes conflicts over the current
- function for the registers set in REGS. The caller is responsible
- for deallocating the return value.
-
- Preconditions: the flow graph must be in SSA form, and life
- analysis (specifically, regs live at exit from each block) must be
- up-to-date.
-
- This algorithm determines conflicts by walking the insns in each
- block backwards. We maintain the set of live regs at each insn,
- starting with the regs live on exit from the block. For each insn:
-
- 1. If a reg is set in this insns, it must be born here, since
- we're in SSA. Therefore, it was not live before this insns,
- so remove it from the set of live regs.
-
- 2. For each reg born in this insn, record a conflict between it
- and every other reg live coming into this insn. For each
- existing conflict, one of the two regs must be born while the
- other is alive. See Morgan or elsewhere for a proof of this.
-
- 3. Regs clobbered by this insn must have been live coming into
- it, so record them as such.
-
- The resulting conflict graph is not built for regs in REGS
- themselves; rather, partition P is used to obtain the canonical reg
- for each of these. The nodes of the conflict graph are these
- canonical regs instead. */
-
-conflict_graph
-conflict_graph_compute (regs, p)
- regset regs;
- partition p;
-{
- int b;
- conflict_graph graph = conflict_graph_new (max_reg_num ());
-
- for (b = n_basic_blocks; --b >= 0; )
- {
- basic_block bb = BASIC_BLOCK (b);
- regset_head live_head;
- regset live = &live_head;
- regset_head born_head;
- regset born = &born_head;
- rtx insn;
- rtx head;
-
- INIT_REG_SET (live);
- INIT_REG_SET (born);
-
- /* Start with the regs that are live on exit, limited to those
- we're interested in. */
- COPY_REG_SET (live, bb->global_live_at_end);
- AND_REG_SET (live, regs);
-
- /* Walk the instruction stream backwards. */
- head = bb->head;
- insn = bb->end;
- for (insn = bb->end;
- insn != head;
- insn = PREV_INSN (insn))
- {
- int born_reg;
- int live_reg;
- rtx link;
-
- /* Are we interested in this insn? */
- if (INSN_P (insn))
- {
- /* Determine which regs are set in this insn. Since
- we're in SSA form, if a reg is set here it isn't set
- anywhere elso, so this insn is where the reg is born. */
- CLEAR_REG_SET (born);
- note_stores (PATTERN (insn), mark_reg, (void *) born);
-#ifdef AUTO_INC_DEC
- for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
- if (REG_NOTE_KIND (link) == REG_INC)
- mark_reg (XEXP (link, 0), NULL_RTX, NULL);
-#endif
- AND_REG_SET (born, regs);
-
- /* Regs born here were not live before this insn. */
- AND_COMPL_REG_SET (live, born);
-
- /* For every reg born here, add a conflict with every other
- reg live coming into this insn. */
- EXECUTE_IF_SET_IN_REG_SET (born,
- FIRST_PSEUDO_REGISTER,
- born_reg, {
- EXECUTE_IF_SET_IN_REG_SET (live,
- FIRST_PSEUDO_REGISTER,
- live_reg, {
- /* Build the conflict graph in terms of canonical
- regnos. */
- int b = partition_find (p, born_reg);
- int l = partition_find (p, live_reg);
- if (b != l)
- conflict_graph_add (graph, b, l);
- });
- });
-
- /* Morgan's algorithm checks the operands of the insn
- and adds them to the set of live regs. Instead, we
- use death information added by life analysis. Regs
- dead after this instruction were live before it. */
- for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
- if (REG_NOTE_KIND (link) == REG_DEAD)
- {
- int regno = REGNO (XEXP (link, 0));
- if (REGNO_REG_SET_P (regs, regno))
- SET_REGNO_REG_SET (live, regno);
- }
- }
- }
- }
-
- return graph;
-}
-
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