From b69208e6b2b66f0bbb71ad6a8168566c688bb2db Mon Sep 17 00:00:00 2001
From: rth <rth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Sat, 12 May 2001 05:21:09 +0000
Subject: [PATCH]         * config/ia64/ia64.c (group_barrier_needed_p): Don't
 allow         calls and jumps to be bundled together.         (ia64_reorg):
 Emit a break after a noreturn call that ends         a function.         *
 config/ia64/ia64.md (break_f): New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@41979 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ChangeLog           |  8 ++++++++
 gcc/config/ia64/ia64.c  | 44 ++++++++++++++++++++++++++++++++++++++++++++
 gcc/config/ia64/ia64.md |  6 ++++++
 3 files changed, 58 insertions(+)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c04386c..63309d3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2001-05-11  Richard Henderson  <rth@redhat.com>
+
+	* config/ia64/ia64.c (group_barrier_needed_p): Don't allow
+	calls and jumps to be bundled together.
+	(ia64_reorg): Emit a break after a noreturn call that ends
+	a function.
+	* config/ia64/ia64.md (break_f): New.
+
 2001-05-12  Neil Booth  <neil@daikokuya.demon.co.uk>
 
 	* c-lex.c (lex_charconst): Convert into a simple wrapper
diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index 31907fa..0a1284a 100644
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -4509,11 +4509,28 @@ group_barrier_needed_p (insn)
       flags.is_branch = 1;
       flags.is_sibcall = SIBLING_CALL_P (insn);
       memset (rws_insn, 0, sizeof (rws_insn));
+
+      /* Don't bundle a call following another call.  */
+      if ((pat = prev_active_insn (insn))
+	  && GET_CODE (pat) == CALL_INSN)
+	{
+	  need_barrier = 1;
+	  break;
+	}
+
       need_barrier = rtx_needs_barrier (PATTERN (insn), flags, 0);
       break;
 
     case JUMP_INSN:
       flags.is_branch = 1;
+
+      /* Don't bundle a jump following a call.  */
+      if ((pat = prev_active_insn (insn))
+	  && GET_CODE (pat) == CALL_INSN)
+	{
+	  need_barrier = 1;
+	  break;
+	}
       /* FALLTHRU */
 
     case INSN:
@@ -6411,6 +6428,33 @@ ia64_reorg (insns)
   else
     emit_all_insn_group_barriers (rtl_dump_file, insns);
 
+  /* A call must not be the last instruction in a function, so that the
+     return address is still within the function, so that unwinding works
+     properly.  Note that IA-64 differs from dwarf2 on this point.  */
+  if (flag_unwind_tables || (flag_exceptions && !USING_SJLJ_EXCEPTIONS))
+    {
+      rtx insn;
+      int saw_stop = 0;
+
+      insn = get_last_insn ();
+      if (! INSN_P (insn))
+        insn = prev_active_insn (insn);
+      if (GET_CODE (insn) == INSN
+	  && GET_CODE (PATTERN (insn)) == UNSPEC_VOLATILE
+	  && XINT (PATTERN (insn), 1) == 2)
+	{
+	  saw_stop = 1;
+	  insn = prev_active_insn (insn);
+	}
+      if (GET_CODE (insn) == CALL_INSN)
+	{
+	  if (! saw_stop)
+	    emit_insn (gen_insn_group_barrier (GEN_INT (3)));
+	  emit_insn (gen_break_f ());
+	  emit_insn (gen_insn_group_barrier (GEN_INT (3)));
+	}
+    }
+
   fixup_errata ();
   emit_predicate_relation_info ();
 }
diff --git a/gcc/config/ia64/ia64.md b/gcc/config/ia64/ia64.md
index 6a6f91f..36823d6 100644
--- a/gcc/config/ia64/ia64.md
+++ b/gcc/config/ia64/ia64.md
@@ -71,6 +71,7 @@
 ;;	0	alloc
 ;;	1	blockage
 ;;	2	insn_group_barrier
+;;	3	break
 ;;	5	set_bsp
 ;;	8	pred.safe_across_calls all
 ;;	9	pred.safe_across_calls normal
@@ -4940,6 +4941,11 @@
   [(set_attr "itanium_class" "stop_bit")
    (set_attr "predicable" "no")])
 
+(define_insn "break_f"
+  [(unspec_volatile [(const_int 0)] 3)]
+  ""
+  "break.f 0"
+  [(set_attr "itanium_class" "nop_f")])
 
 ;; Non-local goto support.
 
-- 
2.7.4