re PR rtl-optimization/34808 (ICE in prescan_insns_for_dce)

	PR rtl-optimization/34808
	* emit-rtl.c (try_split): Handle REG_RETVAL notes.
	* gcc.c-torture/compile/pr34808.c: New test.

From-SVN: r131680

gcc/ChangeLog

+2008-01-20  Kaz Kojima  <kkojima@gcc.gnu.org>
+
+	PR rtl-optimization/34808
+	* emit-rtl.c (try_split): Handle REG_RETVAL notes.
+
 2008-01-20  Richard Sandiford  <rsandifo@nildram.co.uk>
 
 	* global.c (find_reg): Only compute EH_RETURN_DATA_REGNO once per

gcc/emit-rtl.c

@@ -3136,7 +3136,7 @@ try_split (rtx pat, rtx trial, int last)
   rtx before = PREV_INSN (trial);
   rtx after = NEXT_INSN (trial);
   int has_barrier = 0;
-  rtx tem, note_retval;
+  rtx tem, note_retval, note_libcall;
   rtx note, seq;
   int probability;
   rtx insn_last, insn;
@@ -3284,6 +3284,18 @@ try_split (rtx pat, rtx trial, int last)
 	  XEXP (note_retval, 0) = insn_last;
 	  break;
 
+	case REG_RETVAL:
+	  /* Relink the insns with REG_LIBCALL note and with REG_RETVAL note
+	     after split.  */
+	  REG_NOTES (insn_last) 
+	    = gen_rtx_INSN_LIST (REG_RETVAL,
+				 XEXP (note, 0),
+				 REG_NOTES (insn_last)); 
+
+	  note_libcall = find_reg_note (XEXP (note, 0), REG_LIBCALL, NULL);
+	  XEXP (note_libcall, 0) = insn_last;
+	  break;
+
 	default:
 	  break;
 	}

gcc/testsuite/ChangeLog

+2008-01-20  Kaz Kojima  <kkojima@gcc.gnu.org>
+
+	PR rtl-optimization/34808
+	* gcc.c-torture/compile/pr34808.c: New test.
+
 2008-01-20  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/34784

gcc/testsuite/gcc.c-torture/compile/pr34808.c

+/* PR 34808 */
+/* { dg-do compile }
+/* { dg-options "-fno-tree-dominator-opts" } */
+
+extern int flags;
+
+struct r { int code; int val;};
+
+int
+foo (struct r *home)
+{
+  int n = 0;
+  int regno = -1;
+
+  if (home->code == 0)
+    regno = home->val;
+
+  if (home->code == 1)
+      bar ();
+  else if (regno >= 0)
+    n = (regno == 16
+	 ? 16
+	 : (regno - (unsigned long long) (flags != 0 ? 63 : 15)
+	    ? regno - 128
+	    : -1));
+
+  baz ();
+  return n;
+}