* sched-deps.c (sched_analyze_insn): Consolidate scheduling

        barrier code.  Add a scheduling barrier if a non-call insn
        can throw internally.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@40915 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0b0379d..09307a9 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2001-03-27  Richard Henderson  <rth@redhat.com>
 
+       * sched-deps.c (sched_analyze_insn): Consolidate scheduling
+       barrier code.  Add a scheduling barrier if a non-call insn
+       can throw internally.
+
        * rtlanal.c (rtx_addr_can_trap_p): Virtual registers cannot trap.
        Auto-inc addresses trap only if their base register does.
 

diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index 904b37e..0d13a20 100644 (file)
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -972,6 +972,7 @@ sched_analyze_insn (deps, x, insn, loop_notes)
      rtx loop_notes;
 {
   register RTX_CODE code = GET_CODE (x);
+  int schedule_barrier_found = 0;
   rtx link;
   int i;
 
@@ -1021,22 +1022,10 @@ sched_analyze_insn (deps, x, insn, loop_notes)
 
   if (GET_CODE (insn) == JUMP_INSN)
     {
-      rtx next, u, pending, pending_mem;
+      rtx next, u;
       next = next_nonnote_insn (insn);
       if (next && GET_CODE (next) == BARRIER)
-       {
-         for (i = 0; i < deps->max_reg; i++)
-           {
-             struct deps_reg *reg_last = &deps->reg_last[i];
-
-             for (u = reg_last->uses; u; u = XEXP (u, 1))
-               add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
-             for (u = reg_last->sets; u; u = XEXP (u, 1))
-               add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
-             for (u = reg_last->clobbers; u; u = XEXP (u, 1))
-               add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
-           }
-       }
+       schedule_barrier_found = 1;
       else
        {
          regset_head tmp;
@@ -1054,33 +1043,19 @@ sched_analyze_insn (deps, x, insn, loop_notes)
 
          CLEAR_REG_SET (&tmp);
        }
-      pending = deps->pending_write_insns;
-      pending_mem = deps->pending_write_mems;
-      while (pending)
-       {
-         add_dependence (insn, XEXP (pending, 0), 0);
-
-         pending = XEXP (pending, 1);
-         pending_mem = XEXP (pending_mem, 1);
-       }
-
-      for (u = deps->last_pending_memory_flush; u; u = XEXP (u, 1))
-       add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
     }
 
   /* 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 schedule_barrier_found = 0;
       rtx link;
 
       /* 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.  */
+        barriers (loop, eh & setjmp notes, but not range notes).  */
       link = loop_notes;
       while (XEXP (link, 1))
        {
@@ -1095,30 +1070,48 @@ sched_analyze_insn (deps, x, insn, loop_notes)
        }
       XEXP (link, 1) = REG_NOTES (insn);
       REG_NOTES (insn) = loop_notes;
+    }
+
+  /* If this instruction can throw an exception, then moving it changes
+     where block boundaries fall.  This is mighty confusing elsewhere. 
+     Therefore, prevent such an instruction from being moved.  */
+  if (flag_non_call_exceptions && can_throw_internal (insn))
+    schedule_barrier_found = 1;
 
-      /* Add dependencies if a scheduling barrier was found.  */
-      if (schedule_barrier_found)
+  /* Add dependencies if a scheduling barrier was found.  */
+  if (schedule_barrier_found)
+    {
+      rtx u, pending, pending_mem;
+
+      for (i = 0; i < deps->max_reg; i++)
        {
-         for (i = 0; i < deps->max_reg; i++)
-           {
-             struct deps_reg *reg_last = &deps->reg_last[i];
-             rtx u;
+         struct deps_reg *reg_last = &deps->reg_last[i];
 
-             for (u = reg_last->uses; u; u = XEXP (u, 1))
-               add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
-             for (u = reg_last->sets; u; u = XEXP (u, 1))
-               add_dependence (insn, XEXP (u, 0), 0);
-             for (u = reg_last->clobbers; u; u = XEXP (u, 1))
-               add_dependence (insn, XEXP (u, 0), 0);
+         for (u = reg_last->uses; u; u = XEXP (u, 1))
+           add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
+         for (u = reg_last->sets; u; u = XEXP (u, 1))
+           add_dependence (insn, XEXP (u, 0), 0);
+         for (u = reg_last->clobbers; u; u = XEXP (u, 1))
+           add_dependence (insn, XEXP (u, 0), 0);
 
-             if (GET_CODE (PATTERN (insn)) != COND_EXEC)
-               free_INSN_LIST_list (&reg_last->uses);
-           }
-         reg_pending_sets_all = 1;
+         if (GET_CODE (PATTERN (insn)) != COND_EXEC)
+           free_INSN_LIST_list (&reg_last->uses);
+       }
+      flush_pending_lists (deps, insn, 0);
 
-         flush_pending_lists (deps, insn, 0);
+      pending = deps->pending_write_insns;
+      pending_mem = deps->pending_write_mems;
+      while (pending)
+       {
+         add_dependence (insn, XEXP (pending, 0), 0);
+         pending = XEXP (pending, 1);
+         pending_mem = XEXP (pending_mem, 1);
        }
 
+      for (u = deps->last_pending_memory_flush; u; u = XEXP (u, 1))
+       add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
+
+      reg_pending_sets_all = 1;
     }
 
   /* Accumulate clobbers until the next set so that it will be output