* 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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@191493 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 41 insertions, 9 deletions

diff --git a/gcc/sched-int.h b/gcc/sched-int.h
index 2e462380bb8..32bdeb42ab9 100644
--- a/gcc/sched-int.h
+++ b/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.  */