re PR target/21716 (ICE in reg-stack.c's swap_rtx_condition)

	PR target/21716
	* reg-stack.c (swap_rtx_condition): Don't crash if %ax user was not
	found in the basic block and last insn in the basic block is not
	INSN_P.  Remove explicit unspec numbers that are no longer valid
	from comments.

From-SVN: r100196

gcc/ChangeLog

+2005-05-26  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/21716
+	* reg-stack.c (swap_rtx_condition): Don't crash if %ax user was not
+	found in the basic block and last insn in the basic block is not
+	INSN_P.  Remove explicit unspec numbers that are no longer valid
+	from comments.
+
 2005-05-26  Paolo Bonzini  <bonzini@gnu.org>
 
 	* tree-vect-transform.c (vectorizable_operation): Try word_mode

gcc/reg-stack.c

@@ -1231,9 +1231,9 @@ swap_rtx_condition (rtx insn)
       pat = PATTERN (insn);
     }
 
-  /* See if this is, or ends in, a fnstsw, aka unspec 9.  If so, we're
-     not doing anything with the cc value right now.  We may be able to
-     search for one though.  */
+  /* See if this is, or ends in, a fnstsw.  If so, we're not doing anything
+     with the cc value right now.  We may be able to search for one
+     though.  */
 
   if (GET_CODE (pat) == SET
       && GET_CODE (SET_SRC (pat)) == UNSPEC
@@ -1252,9 +1252,13 @@ swap_rtx_condition (rtx insn)
 	    return 0;
 	}
 
+      /* We haven't found it.  */
+      if (insn == BB_END (current_block))
+	return 0;
+
       /* So we've found the insn using this value.  If it is anything
-	 other than sahf, aka unspec 10, or the value does not die
-	 (meaning we'd have to search further), then we must give up.  */
+	 other than sahf or the value does not die (meaning we'd have
+	 to search further), then we must give up.  */
       pat = PATTERN (insn);
       if (GET_CODE (pat) != SET
 	  || GET_CODE (SET_SRC (pat)) != UNSPEC