haifa-sched.c (sched_analyze_insn): Only create scheduling barriers for LOOP...

[gcc.git] / gcc / haifa-sched.c

diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index 0eebda9e38a5f3b2da4982489eadb22222305ebc..12e82d6dfaf2f786f76d4918309a68be268af9a2 100644 (file)
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -3687,36 +3687,54 @@ sched_analyze_insn (x, insn, loop_notes)
          sched_analyze_2 (XEXP (link, 0), insn);
       }
 
-  /* If there is a {LOOP,EHREGION}_{BEG,END} note in the middle of a basic block, then
-     we must be sure that no instructions are scheduled across it.
+  /* If there is a {LOOP,EHREGION}_{BEG,END} note in the middle of a basic
+     block, then we must be sure that no instructions are scheduled across it.
      Otherwise, the reg_n_refs info (which depends on loop_depth) would
      become incorrect.  */
 
   if (loop_notes)
     {
       int max_reg = max_reg_num ();
+      int schedule_barrier_found = 0;
       rtx link;
 
-      for (i = 0; i < max_reg; i++)
+      /* Update loop_notes with any notes from this insn.  Also determine
+        if any of the notes on the list correspond to instruction scheduling
+        barriers (loop, eh & setjmp notes, but not range notes.  */
+      link = loop_notes;
+      while (XEXP (link, 1))
        {
-         rtx u;
-         for (u = reg_last_uses[i]; u; u = XEXP (u, 1))
-           add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
-         reg_last_uses[i] = 0;
+         if (XINT (link, 0) == NOTE_INSN_LOOP_BEG
+             || XINT (link, 0) == NOTE_INSN_LOOP_END
+             || XINT (link, 0) == NOTE_INSN_EH_REGION_BEG
+             || XINT (link, 0) == NOTE_INSN_EH_REGION_END
+             || XINT (link, 0) == NOTE_INSN_SETJMP)
+           schedule_barrier_found = 1;
 
-         /* reg_last_sets[r] is now a list of insns */
-         for (u = reg_last_sets[i]; u; u = XEXP (u, 1))
-           add_dependence (insn, XEXP (u, 0), 0);
+         link = XEXP (link, 1);
        }
-      reg_pending_sets_all = 1;
-
-      flush_pending_lists (insn, 0);
-
-      link = loop_notes;
-      while (XEXP (link, 1))
-       link = XEXP (link, 1);
       XEXP (link, 1) = REG_NOTES (insn);
       REG_NOTES (insn) = loop_notes;
+
+      /* Add dependencies if a scheduling barrier was found.  */
+      if (schedule_barrier_found)
+       {
+         for (i = 0; i < max_reg; i++)
+           {
+             rtx u;
+             for (u = reg_last_uses[i]; u; u = XEXP (u, 1))
+               add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
+             reg_last_uses[i] = 0;
+
+             /* reg_last_sets[r] is now a list of insns */
+             for (u = reg_last_sets[i]; u; u = XEXP (u, 1))
+               add_dependence (insn, XEXP (u, 0), 0);
+           }
+         reg_pending_sets_all = 1;
+
+         flush_pending_lists (insn, 0);
+       }
+
     }
 
   /* After reload, it is possible for an instruction to have a REG_DEAD note