Gcc 3.3.1-release.

1 files changed, 19 insertions, 10 deletions

diff --git a/contrib/gcc/sched-ebb.c b/contrib/gcc/sched-ebb.c
index e9d7482..47dd83f 100644
--- a/contrib/gcc/sched-ebb.c
+++ b/contrib/gcc/sched-ebb.c
@@ -52,7 +52,8 @@ static int schedule_more_p PARAMS ((void));
 static const char *ebb_print_insn PARAMS ((rtx, int));
 static int rank PARAMS ((rtx, rtx));
 static int contributes_to_priority PARAMS ((rtx, rtx));
-static void compute_jump_reg_dependencies PARAMS ((rtx, regset));
+static void compute_jump_reg_dependencies PARAMS ((rtx, regset, regset,
+						   regset));
 static void schedule_ebb PARAMS ((rtx, rtx));
 
 /* Return nonzero if there are more insns that should be scheduled.  */
@@ -160,22 +161,30 @@ contributes_to_priority (next, insn)
   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 (insn, set)
+compute_jump_reg_dependencies (insn, cond_set, used, set)
      rtx insn;
-     regset set;
+     regset cond_set, used, 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