re PR rtl-optimization/48826 (ICE in dwarf2out_var_location, at dwarf2out.c:22013)

gcc/
	PR rtl-optimization/48826
	* emit-rtl.c (try_split): When splitting a call that is followed
	by a NOTE_INSN_CALL_ARG_LOCATION, move the note after the new call.

From-SVN: r174080

gcc/ChangeLog

+2011-05-23  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	PR rtl-optimization/48826
+	* emit-rtl.c (try_split): When splitting a call that is followed
+	by a NOTE_INSN_CALL_ARG_LOCATION, move the note after the new call.
+
 2011-05-23  Jakub Jelinek  <jakub@redhat.com>
 
 	* cfgexpand.c (expand_debug_expr): For unused non-addressable

gcc/emit-rtl.c

@@ -3470,17 +3470,40 @@ try_split (rtx pat, rtx trial, int last)
     }
 
   /* If we are splitting a CALL_INSN, look for the CALL_INSN
-     in SEQ and copy our CALL_INSN_FUNCTION_USAGE to it.  */
+     in SEQ and copy any additional information across.  */
   if (CALL_P (trial))
     {
       for (insn = insn_last; insn ; insn = PREV_INSN (insn))
 	if (CALL_P (insn))
 	  {
-	    rtx *p = &CALL_INSN_FUNCTION_USAGE (insn);
+	    rtx next, *p;
+
+	    /* Add the old CALL_INSN_FUNCTION_USAGE to whatever the
+	       target may have explicitly specified.  */
+	    p = &CALL_INSN_FUNCTION_USAGE (insn);
 	    while (*p)
 	      p = &XEXP (*p, 1);
 	    *p = CALL_INSN_FUNCTION_USAGE (trial);
+
+	    /* If the old call was a sibling call, the new one must
+	       be too.  */
 	    SIBLING_CALL_P (insn) = SIBLING_CALL_P (trial);
+
+	    /* If the new call is the last instruction in the sequence,
+	       it will effectively replace the old call in-situ.  Otherwise
+	       we must move any following NOTE_INSN_CALL_ARG_LOCATION note
+	       so that it comes immediately after the new call.  */
+	    if (NEXT_INSN (insn))
+	      {
+		next = NEXT_INSN (trial);
+		if (next
+		    && NOTE_P (next)
+		    && NOTE_KIND (next) == NOTE_INSN_CALL_ARG_LOCATION)
+		  {
+		    remove_insn (next);
+		    add_insn_after (next, insn, NULL);
+		  }
+	      }
 	  }
     }