re PR rtl-optimization/11320 (Scheduler bug)

PR optimization/11320 * sched-int.h (struct deps) [reg_conditional_sets]: New field. (struct sched_info) [compute_jump_reg_dependencies]: New prototype. * sched-deps.c (sched_analyze_insn) [JUMP_INSN]: Update call to current_sched_info->compute_jump_reg_dependencies. Record which registers are used and which registers are set by the jump. Clear deps->reg_conditional_sets after a barrier. Set deps->reg_conditional_sets if the insn is a COND_EXEC. Clear deps->reg_conditional_sets if the insn is not a COND_EXEC. (init_deps): Initialize reg_conditional_sets. (free_deps): Clear reg_conditional_sets. * sched-ebb.c (compute_jump_reg_dependencies): New prototype. Mark registers live on entry of the fallthrough block and conditionally set as set by the jump. Mark registers live on entry of non-fallthrough blocks as used by the jump. * sched-rgn.c (compute_jump_reg_dependencies): New prototype. Mark new parameters as unused. From-SVN: r69401
2003-07-15 15:02:21 +02:00 · 2003-07-15 15:02:21 +02:00 · 5a257872da
parent 9fa0903819
commit 5a257872da
7 changed files with 103 additions and 18 deletions
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@ -1,3 +1,23 @@
+2003-07-15  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	PR optimization/11320
+	* sched-int.h (struct deps) [reg_conditional_sets]: New field.
+	(struct sched_info) [compute_jump_reg_dependencies]: New prototype.
+	* sched-deps.c (sched_analyze_insn) [JUMP_INSN]: Update call to
+	current_sched_info->compute_jump_reg_dependencies. Record which
+	registers are used and which registers are set by the jump.
+	Clear deps->reg_conditional_sets after a barrier.
+	Set deps->reg_conditional_sets if the insn is a COND_EXEC.
+	Clear deps->reg_conditional_sets if the insn is not a COND_EXEC.
+	(init_deps): Initialize reg_conditional_sets.
+	(free_deps): Clear reg_conditional_sets.
+	* sched-ebb.c (compute_jump_reg_dependencies): New prototype.
+	Mark registers live on entry of the fallthrough block and conditionally
+	set as set by the jump. Mark registers live on entry of non-fallthrough
+	blocks as used by the jump.
+	* sched-rgn.c (compute_jump_reg_dependencies): New prototype.
+	Mark new parameters as unused.
+
 2003-07-15  Richard Sandiford  <rsandifo@redhat.com>

 	* doc/invoke.texi: Resync MIPS -march documentation.
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@ -864,12 +864,14 @@ sched_analyze_insn (struct deps *deps, rtx x, rtx insn, rtx loop_notes)
      else
 	{
 	  rtx pending, pending_mem;
-	  regset_head tmp;
-	  INIT_REG_SET (&tmp);
+	  regset_head tmp_uses, tmp_sets;
+	  INIT_REG_SET (&tmp_uses);
+	  INIT_REG_SET (&tmp_sets);

-	  (*current_sched_info->compute_jump_reg_dependencies) (insn, &tmp);
+	  (*current_sched_info->compute_jump_reg_dependencies)
+	    (insn, &deps->reg_conditional_sets, &tmp_uses, &tmp_sets);
 	  /* Make latency of jump equal to 0 by using anti-dependence.  */
-	  EXECUTE_IF_SET_IN_REG_SET (&tmp, 0, i,
+	  EXECUTE_IF_SET_IN_REG_SET (&tmp_uses, 0, i,
 	    {
 	      struct deps_reg *reg_last = &deps->reg_last[i];
 	      add_dependence_list (insn, reg_last->sets, REG_DEP_ANTI);
@ -877,7 +879,10 @@ sched_analyze_insn (struct deps *deps, rtx x, rtx insn, rtx loop_notes)
 	      reg_last->uses_length++;
 	      reg_last->uses = alloc_INSN_LIST (insn, reg_last->uses);
 	    });
-	  CLEAR_REG_SET (&tmp);
+	  IOR_REG_SET (reg_pending_sets, &tmp_sets);
+
+	  CLEAR_REG_SET (&tmp_uses);
+	  CLEAR_REG_SET (&tmp_sets);

 	  /* All memory writes and volatile reads must happen before the
 	     jump.  Non-volatile reads must happen before the jump iff
@ -984,6 +989,7 @@ sched_analyze_insn (struct deps *deps, rtx x, rtx insn, rtx loop_notes)
 	}

      flush_pending_lists (deps, insn, true, true);
+      CLEAR_REG_SET (&deps->reg_conditional_sets);
      reg_pending_barrier = NOT_A_BARRIER;
    }
  else
@ -1015,6 +1021,7 @@ sched_analyze_insn (struct deps *deps, rtx x, rtx insn, rtx loop_notes)
 	      add_dependence_list (insn, reg_last->clobbers, REG_DEP_OUTPUT);
 	      add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI);
 	      reg_last->sets = alloc_INSN_LIST (insn, reg_last->sets);
+	      SET_REGNO_REG_SET (&deps->reg_conditional_sets, i);
 	    });
 	}
      else
@ -1063,6 +1070,7 @@ sched_analyze_insn (struct deps *deps, rtx x, rtx insn, rtx loop_notes)
 	      reg_last->sets = alloc_INSN_LIST (insn, reg_last->sets);
 	      reg_last->uses_length = 0;
 	      reg_last->clobbers_length = 0;
+	      CLEAR_REGNO_REG_SET (&deps->reg_conditional_sets, i);
 	    });
 	}

@ -1385,6 +1393,7 @@ init_deps (struct deps *deps)
  deps->reg_last = (struct deps_reg *)
    xcalloc (max_reg, sizeof (struct deps_reg));
  INIT_REG_SET (&deps->reg_last_in_use);
+  INIT_REG_SET (&deps->reg_conditional_sets);

  deps->pending_read_insns = 0;
  deps->pending_read_mems = 0;
@ -1426,6 +1435,7 @@ free_deps (struct deps *deps)
 	free_INSN_LIST_list (&reg_last->clobbers);
    });
  CLEAR_REG_SET (&deps->reg_last_in_use);
+  CLEAR_REG_SET (&deps->reg_conditional_sets);

  free (deps->reg_last);
 }
--- a/gcc/sched-ebb.c
+++ b/gcc/sched-ebb.c
@ -55,7 +55,7 @@ static int schedule_more_p (void);
 static const char *ebb_print_insn (rtx, int);
 static int rank (rtx, rtx);
 static int contributes_to_priority (rtx, rtx);
-static void compute_jump_reg_dependencies (rtx, regset);
+static void compute_jump_reg_dependencies (rtx, regset, regset, regset);
 static basic_block earliest_block_with_similiar_load (basic_block, rtx);
 static void add_deps_for_risky_insns (rtx, rtx);
 static basic_block schedule_ebb (rtx, rtx);
@ -163,20 +163,29 @@ contributes_to_priority (rtx next ATTRIBUTE_UNUSED,
  return 1;
 }

-/* INSN is a JUMP_INSN.  Store the set of registers that must be considered
-   to be set by this jump in SET.  */
+ /* INSN is a JUMP_INSN, COND_SET is the set of registers that are
+    conditionally set before INSN.  Store the set of registers that
+    must be considered as used by this jump in USED and that of
+    registers that must be considered as set in SET.  */

 static void
-compute_jump_reg_dependencies (rtx insn, regset set)
+compute_jump_reg_dependencies (rtx insn, regset cond_set, regset used,
+			       regset set)
 {
  basic_block b = BLOCK_FOR_INSN (insn);
  edge e;
  for (e = b->succ; e; e = e->succ_next)
-    if ((e->flags & EDGE_FALLTHRU) == 0)
-      {
-	bitmap_operation (set, set, e->dest->global_live_at_start,
-			  BITMAP_IOR);
-      }
+    if (e->flags & EDGE_FALLTHRU)
+      /* The jump may be a by-product of a branch that has been merged
+	 in the main codepath after being conditionalized.  Therefore
+	 it may guard the fallthrough block from using a value that has
+	 conditionally overwritten that of the main codepath.  So we
+	 consider that it restores the value of the main codepath.  */
+      bitmap_operation (set, e->dest->global_live_at_start, cond_set,
+			BITMAP_AND);
+    else
+      bitmap_operation (used, used, e->dest->global_live_at_start,
+			BITMAP_IOR);
 }

 /* Used in schedule_insns to initialize current_sched_info for scheduling
--- a/gcc/sched-int.h
+++ b/gcc/sched-int.h
@ -112,6 +112,9 @@ struct deps
  /* Element N is set for each register that has any nonzero element
     in reg_last[N].{uses,sets,clobbers}.  */
  regset_head reg_last_in_use;
+
+  /* Element N is set for each register that is conditionally set.  */
+  regset_head reg_conditional_sets;
 };

 /* This structure holds some state of the current scheduling pass, and
@ -148,7 +151,7 @@ struct sched_info
  /* Called when computing dependencies for a JUMP_INSN.  This function
     should store the set of registers that must be considered as set by
     the jump in the regset.  */
-  void (*compute_jump_reg_dependencies) (rtx, regset);
+  void (*compute_jump_reg_dependencies) (rtx, regset, regset, regset);

  /* The boundaries of the set of insns to be scheduled.  */
  rtx prev_head, next_tail;
--- a/gcc/sched-rgn.c
+++ b/gcc/sched-rgn.c
@ -1701,7 +1701,7 @@ static int schedule_more_p (void);
 static const char *rgn_print_insn (rtx, int);
 static int rgn_rank (rtx, rtx);
 static int contributes_to_priority (rtx, rtx);
-static void compute_jump_reg_dependencies (rtx, regset);
+static void compute_jump_reg_dependencies (rtx, regset, regset, regset);

 /* Return nonzero if there are more insns that should be scheduled.  */

@ -1951,11 +1951,15 @@ contributes_to_priority (rtx next, rtx insn)
  return BLOCK_NUM (next) == BLOCK_NUM (insn);
 }

-/* INSN is a JUMP_INSN.  Store the set of registers that must be considered
-   to be set by this jump in SET.  */
+/* INSN is a JUMP_INSN, COND_SET is the set of registers that are
+   conditionally set before INSN.  Store the set of registers that
+   must be considered as used by this jump in USED and that of
+   registers that must be considered as set in SET.  */

 static void
 compute_jump_reg_dependencies (rtx insn ATTRIBUTE_UNUSED,
+			       regset cond_exec ATTRIBUTE_UNUSED,
+			       regset used ATTRIBUTE_UNUSED,
 			       regset set ATTRIBUTE_UNUSED)
 {
  /* Nothing to do here, since we postprocess jumps in
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@ -1,3 +1,7 @@
+2003-07-15  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	* gcc.c-torture/execute/20030715-1.c: New test.
+
 2003-07-14  Geoffrey Keating  <geoffk@apple.com>

 	* gcc.dg/pch/inline-3.c: New file.
--- a/gcc/testsuite/gcc.c-torture/execute/20030715-1.c
+++ b/gcc/testsuite/gcc.c-torture/execute/20030715-1.c
@ -0,0 +1,35 @@
+/* PR optimization/11320 */
+/* Origin: Andreas Schwab <schwab@suse.de> */
+
+/* Verify that the scheduler correctly computes the dependencies
+   in the presence of conditional instructions.  */
+
+int strcmp (const char *, const char *);
+int ap_standalone;
+
+const char *ap_check_cmd_context (void *a, int b)
+{
+  return 0;
+}
+
+const char *server_type (void *a, void *b, char *arg)
+{
+  const char *err = ap_check_cmd_context (a, 0x01|0x02|0x04|0x08|0x10);
+  if (err)
+    return err;
+
+  if (!strcmp (arg, "inetd"))
+    ap_standalone = 0;
+  else if (!strcmp (arg, "standalone"))
+      ap_standalone = 1;
+  else
+    return "ServerType must be either 'inetd' or 'standalone'";
+
+  return 0;
+}
+
+int main ()
+{
+  server_type (0, 0, "standalone");
+  return 0;
+}