dbgcnt.def (sched_breakdep): New counter.

	* dbgcnt.def (sched_breakdep): New counter.
	* haifa-sched.c (update_insn_after_change): New static function,
	broken out of haifa_change_pattern.
	(haifa_change_pattern): Call it.
	(dep_t heap vecs): Declare.
	(INSN_COST): Define earlier.
	(next_cycle_replace_deps, next_cycle_apply): New static
	variables.
	(apply_replacement): New static function.
	(recompute_todo_spec): New argument FOR_BACKTRACK.  All callers
	changed.  Handle DEP_REPLACE deps.
	(contributes_to_priority_p): False for replaceable deps.
	(must_restore_pattern_p, restore_pattern): New static functions.
	(schedule_insn): Use them.  Apply replacements for broken deps.
	(struct haifa_saved_data): Add new fields to keep track of
	replacements.
	(save_backtrack_point): Initialize them.
	(undo_replacements_for_backtrack): New static function.
	(restore_last_backtrack_point, free_topmost_backtrack_point):
	Use it and keep track of replacements.
	(perform_replacements_new_cycle, undo_all_replacements): New static
	functions.
	(schedule_block): Call these two as necessary.  Call
	find_modifiable_mems.
	(try_ready): Tweak the assert.  Check for DEP_POSTPONED.
	* sched-deps.c: Include "emit-rtl.h".
	(init_dep_1): Initialize DEP_NONREG, DEP_MULTIPLE and DEP_REPLACE.
	(dep_spec_p): True for DEP_REPLACE deps.
	(mark_as_hard): New static variable.
	(update_dep): Update DEP_NONREG and DEP_MULTIPLE.
	(add_dependence_list): New argument hard.  All callers changed.  Set
	and clear mark_as_hard around function body.
	(add_dependence_list_and_free): Likewise.
	(haifa_note_mem_dep): Set DEP_NONREG.
	(haifa_note_dep): Likewise if mark_as_hard is true.
	(sched_analyze_insn): Switch loop with if statement testing for
	sel_sched_p.
	(struct mem_inc_info): New.
	(attempt_change, parse_add_or_inc, find_inc, find_mem): New static
	functions.
	(find_modifiable_mems): New function.
	* sched-int.h (struct dep_replacement): New.
	(struct _dep): Add replace, nonreg and multiple fields.  Make type and
	cost bitfields.
	(UNKNOWN_DEP_COST): Change to match the bitfield.
	(DEP_NONREG, DEP_MULTIPLE, DEP_REPLACE): New macros.
	(DEP_POSTPONED): New macro.
	(DEP_CANCELLED): Renumber.
	(find_modifiable_mems): Declare.
	(enum SCHED_FLAGS): Add DONT_BREAK_DEPENDENCIES.
	* sched-rgn.c (init_ready_list): Set TODO_SPEC here.
	(new_ready): Don't set HARD_DEP, use DEP_POSTPONED.
	(debug_dependencies): Dump DEP_NONREG and DEP_MULTIPLE.
	* Makefile.in (sched-deps.o): Update dependencies.
	* config/c6x/c6x.c (in_hwloop): New static variable.
	(c6x_set_sched_flags): If it is true, add DONT_BREAK_DEPENDENCIES.
	(hwloop_optimize): Set and clear it around preliminary scheduling
	pass.

From-SVN: r191493

gcc/ChangeLog

+2012-09-19  Bernd Schmidt  <bernds@codesourcery.com>
+
+	* dbgcnt.def (sched_breakdep): New counter.
+	* haifa-sched.c (update_insn_after_change): New static function,
+	broken out of haifa_change_pattern.
+	(haifa_change_pattern): Call it.
+	(dep_t heap vecs): Declare.
+	(INSN_COST): Define earlier.
+	(next_cycle_replace_deps, next_cycle_apply): New static
+	variables.
+	(apply_replacement): New static function.
+	(recompute_todo_spec): New argument FOR_BACKTRACK.  All callers
+	changed.  Handle DEP_REPLACE deps.
+	(contributes_to_priority_p): False for replaceable deps.
+	(must_restore_pattern_p, restore_pattern): New static functions.
+	(schedule_insn): Use them.  Apply replacements for broken deps.
+	(struct haifa_saved_data): Add new fields to keep track of
+	replacements.
+	(save_backtrack_point): Initialize them.
+	(undo_replacements_for_backtrack): New static function.
+	(restore_last_backtrack_point, free_topmost_backtrack_point):
+	Use it and keep track of replacements.
+	(perform_replacements_new_cycle, undo_all_replacements): New static
+	functions.
+	(schedule_block): Call these two as necessary.  Call
+	find_modifiable_mems.
+	(try_ready): Tweak the assert.  Check for DEP_POSTPONED.
+	* sched-deps.c: Include "emit-rtl.h".
+	(init_dep_1): Initialize DEP_NONREG, DEP_MULTIPLE and DEP_REPLACE.
+	(dep_spec_p): True for DEP_REPLACE deps.
+	(mark_as_hard): New static variable.
+	(update_dep): Update DEP_NONREG and DEP_MULTIPLE.
+	(add_dependence_list): New argument hard.  All callers changed.  Set
+	and clear mark_as_hard around function body.
+	(add_dependence_list_and_free): Likewise.
+	(haifa_note_mem_dep): Set DEP_NONREG.
+	(haifa_note_dep): Likewise if mark_as_hard is true.
+	(sched_analyze_insn): Switch loop with if statement testing for
+	sel_sched_p.
+	(struct mem_inc_info): New.
+	(attempt_change, parse_add_or_inc, find_inc, find_mem): New static
+	functions.
+	(find_modifiable_mems): New function.
+	* sched-int.h (struct dep_replacement): New.
+	(struct _dep): Add replace, nonreg and multiple fields.  Make type and
+	cost bitfields.
+	(UNKNOWN_DEP_COST): Change to match the bitfield.
+	(DEP_NONREG, DEP_MULTIPLE, DEP_REPLACE): New macros.
+	(DEP_POSTPONED): New macro.
+	(DEP_CANCELLED): Renumber.
+	(find_modifiable_mems): Declare.
+	(enum SCHED_FLAGS): Add DONT_BREAK_DEPENDENCIES.
+	* sched-rgn.c (init_ready_list): Set TODO_SPEC here.
+	(new_ready): Don't set HARD_DEP, use DEP_POSTPONED.
+	(debug_dependencies): Dump DEP_NONREG and DEP_MULTIPLE.
+	* Makefile.in (sched-deps.o): Update dependencies.
+	* config/c6x/c6x.c (in_hwloop): New static variable.
+	(c6x_set_sched_flags): If it is true, add DONT_BREAK_DEPENDENCIES.
+	(hwloop_optimize): Set and clear it around preliminary scheduling
+	pass.
+
 2012-09-19  Tulio Magno Quites Machado Filho  <tuliom@linux.vnet.ibm.com>
 
 	* config/rs6000/rs6000-builtin.def: Add __builtin_ppc_get_timebase

gcc/Makefile.in

@@ -3239,7 +3239,7 @@ haifa-sched.o : haifa-sched.c $(CONFIG_H) $(SYSTEM_H) coretypes.h dumpfile.h \
 sched-deps.o : sched-deps.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
    $(RTL_H) $(SCHED_INT_H) $(REGS_H) hard-reg-set.h $(FLAGS_H) insn-config.h \
    $(FUNCTION_H) $(INSN_ATTR_H) $(DIAGNOSTIC_CORE_H) $(RECOG_H) $(EXCEPT_H) cselib.h \
-   ira.h $(PARAMS_H) $(TM_P_H) ira.h $(TARGET_H) $(TREE_H)
+   ira.h $(PARAMS_H) $(TM_P_H) ira.h $(TARGET_H) $(TREE_H) $(EMIT_RTL_H)
 sched-rgn.o : sched-rgn.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) \
    $(RTL_H) $(SCHED_INT_H) $(REGS_H) hard-reg-set.h $(FLAGS_H) insn-config.h \
    $(FUNCTION_H) $(INSN_ATTR_H) $(DIAGNOSTIC_CORE_H) $(RECOG_H) $(EXCEPT_H) $(PARAMS_H) \

gcc/config/c6x/c6x.c

@@ -3912,6 +3912,13 @@ c6x_free_sched_context (void *_sc)
   free (_sc);
 }
 
+/* True if we are currently performing a preliminary scheduling
+   pass before modulo scheduling; we can't allow the scheduler to
+   modify instruction patterns using packetization assumptions,
+   since there will be another scheduling pass later if modulo
+   scheduling fails.  */
+static bool in_hwloop;
+
 /* Provide information about speculation capabilities, and set the
    DO_BACKTRACKING flag.  */
 static void
@@ -3923,6 +3930,8 @@ c6x_set_sched_flags (spec_info_t spec_info)
     {
       *flags |= DO_BACKTRACKING | DO_PREDICATION;
     }
+  if (in_hwloop)
+    *flags |= DONT_BREAK_DEPENDENCIES;
 
   spec_info->mask = 0;
 }
@@ -5536,9 +5545,11 @@ hwloop_optimize (hwloop_info loop)
 
   reshuffle_units (loop->head);
 
+  in_hwloop = true;
   schedule_ebbs_init ();
   schedule_ebb (BB_HEAD (loop->tail), loop->loop_end, true);
   schedule_ebbs_finish ();
+  in_hwloop = false;
 
   bb = loop->head;
   loop_earliest = bb_earliest_end_cycle (bb, loop->loop_end) + 1;

gcc/dbgcnt.def

@@ -176,6 +176,7 @@ DEBUG_COUNTER (sched2_func)
 DEBUG_COUNTER (sched_block)
 DEBUG_COUNTER (sched_func)
 DEBUG_COUNTER (sched_insn)
+DEBUG_COUNTER (sched_breakdep)
 DEBUG_COUNTER (sched_region)
 DEBUG_COUNTER (sel_sched_cnt)
 DEBUG_COUNTER (sel_sched_region_cnt)

gcc/sched-int.h

@@ -206,6 +206,18 @@ typedef int dw_t;
 extern enum reg_note ds_to_dk (ds_t);
 extern ds_t dk_to_ds (enum reg_note);
 
+/* Describe a dependency that can be broken by making a replacement
+   in one of the patterns.  LOC is the location, ORIG and NEWVAL the
+   two alternative contents, and INSN the instruction that must be
+   changed.  */
+struct dep_replacement
+{
+  rtx *loc;
+  rtx orig;
+  rtx newval;
+  rtx insn;
+};
+
 /* Information about the dependency.  */
 struct _dep
 {
@@ -215,18 +227,30 @@ struct _dep
   /* Consumer.  */
   rtx con;
 
-  /* Dependency major type.  This field is superseded by STATUS below.
-     Though, it is still in place because some targets use it.  */
-  enum reg_note type;
+  /* If nonnull, holds a pointer to information about how to break the
+     dependency by making a replacement in one of the insns.  There is
+     only one such dependency for each insn that must be modified in
+     order to break such a dependency.  */
+  struct dep_replacement *replace;
 
   /* Dependency status.  This field holds all dependency types and additional
      information for speculative dependencies.  */
   ds_t status;
 
-  /* Cached cost of the dependency.  */
-  int cost;
+  /* Dependency major type.  This field is superseded by STATUS above.
+     Though, it is still in place because some targets use it.  */
+  ENUM_BITFIELD(reg_note) type:6;
+
+  unsigned nonreg:1;
+  unsigned multiple:1;
+
+  /* Cached cost of the dependency.  Make sure to update UNKNOWN_DEP_COST
+     when changing the size of this field.  */
+  int cost:20;
 };
 
+#define UNKNOWN_DEP_COST (-1<<19)
+
 typedef struct _dep dep_def;
 typedef dep_def *dep_t;
 
@@ -235,8 +259,9 @@ typedef dep_def *dep_t;
 #define DEP_TYPE(D) ((D)->type)
 #define DEP_STATUS(D) ((D)->status)
 #define DEP_COST(D) ((D)->cost)
-
-#define UNKNOWN_DEP_COST INT_MIN
+#define DEP_NONREG(D) ((D)->nonreg)
+#define DEP_MULTIPLE(D) ((D)->multiple)
+#define DEP_REPLACE(D) ((D)->replace)
 
 /* Functions to work with dep.  */
 
@@ -1047,7 +1072,11 @@ enum SPEC_TYPES_OFFSETS {
    Therefore, it can appear only in TODO_SPEC field of an instruction.  */
 #define HARD_DEP (DEP_CONTROL << 1)
 
-#define DEP_CANCELLED (HARD_DEP << 1)
+/* Set in the TODO_SPEC field of an instruction for which new_ready
+   has decided not to schedule it speculatively.  */
+#define DEP_POSTPONED (HARD_DEP << 1)
+
+#define DEP_CANCELLED (DEP_POSTPONED << 1)
 
 /* This represents the results of calling sched-deps.c functions,
    which modify dependencies.  */
@@ -1074,7 +1103,8 @@ enum SCHED_FLAGS {
   DO_SPECULATION = USE_DEPS_LIST << 1,
   DO_BACKTRACKING = DO_SPECULATION << 1,
   DO_PREDICATION = DO_BACKTRACKING << 1,
-  SCHED_RGN = DO_PREDICATION << 1,
+  DONT_BREAK_DEPENDENCIES = DO_PREDICATION << 1,
+  SCHED_RGN = DONT_BREAK_DEPENDENCIES << 1,
   SCHED_EBB = SCHED_RGN << 1,
   /* Scheduler can possibly create new basic blocks.  Used for assertions.  */
   NEW_BBS = SCHED_EBB << 1,
@@ -1406,6 +1436,8 @@ extern void dump_region_dot_file (const char *, int);
 extern void haifa_sched_init (void);
 extern void haifa_sched_finish (void);
 
+extern void find_modifiable_mems (rtx, rtx);
+
 /* sched-deps.c interface to walk, add, search, update, resolve, delete
    and debug instruction dependencies.  */
 

gcc/sched-rgn.c

@@ -2103,6 +2103,8 @@ init_ready_list (void)
      Count number of insns in the target block being scheduled.  */
   for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn))
     {
+      gcc_assert (TODO_SPEC (insn) == HARD_DEP || TODO_SPEC (insn) == DEP_POSTPONED);
+      TODO_SPEC (insn) = HARD_DEP;
       try_ready (insn);
       target_n_insns++;
 
@@ -2126,7 +2128,11 @@ init_ready_list (void)
 
 	for (insn = src_head; insn != src_next_tail; insn = NEXT_INSN (insn))
 	  if (INSN_P (insn))
-	    try_ready (insn);
+	    {
+	      gcc_assert (TODO_SPEC (insn) == HARD_DEP || TODO_SPEC (insn) == DEP_POSTPONED);
+	      TODO_SPEC (insn) = HARD_DEP;
+	      try_ready (insn);
+	    }
       }
 }
 
@@ -2218,11 +2224,11 @@ new_ready (rtx next, ds_t ts)
 		ts = new_ds;
 	      else
 		/* NEXT isn't ready yet.  */
-		ts = (ts & ~SPECULATIVE) | HARD_DEP;
+		ts = DEP_POSTPONED;
 	    }
 	  else
 	    /* NEXT isn't ready yet.  */
-            ts = (ts & ~SPECULATIVE) | HARD_DEP;
+            ts = DEP_POSTPONED;
 	}
     }
 
@@ -2826,7 +2832,9 @@ void debug_dependencies (rtx head, rtx tail)
 	dep_t dep;
 
 	FOR_EACH_DEP (insn, SD_LIST_FORW, sd_it, dep)
-	  fprintf (sched_dump, "%d ", INSN_UID (DEP_CON (dep)));
+	  fprintf (sched_dump, "%d%s%s ", INSN_UID (DEP_CON (dep)),
+		   DEP_NONREG (dep) ? "n" : "",
+		   DEP_MULTIPLE (dep) ? "m" : "");
       }
       fprintf (sched_dump, "\n");
     }