cse.c (delete_trivially_dead_insns): Do not delete stores to the internal_arg_pointer.

        * cse.c (delete_trivially_dead_insns): Do not delete stores to
        the internal_arg_pointer.

From-SVN: r29017

gcc/ChangeLog

+Tue Aug 31 16:44:52 1999  Jeffrey A Law  (law@cygnus.com)
+
+	* cse.c (delete_trivially_dead_insns): Do not delete stores to
+	the internal_arg_pointer.
+
 Tue Aug 31 13:35:42 1999  Richard Henderson  <rth@cygnus.com>
 
 	Merge peephole2 from new_ia32_branch:

gcc/cse.c

@@ -9191,7 +9191,13 @@ delete_trivially_dead_insns (insns, nreg)
 	  else if (GET_CODE (SET_DEST (PATTERN (insn))) != REG
 		   || REGNO (SET_DEST (PATTERN (insn))) < FIRST_PSEUDO_REGISTER
 		   || counts[REGNO (SET_DEST (PATTERN (insn)))] != 0
-		   || side_effects_p (SET_SRC (PATTERN (insn))))
+		   || side_effects_p (SET_SRC (PATTERN (insn)))
+		   /* An ADDRESSOF expression can turn into a use of the
+		      internal arg pointer, so always consider the
+		      internal arg pointer live.  If it is truly dead,
+		      flow will delete the initializing insn.  */
+		   || (SET_DEST (PATTERN (insn))
+		       == current_function_internal_arg_pointer))
 	    live_insn = 1;
 	}
       else if (GET_CODE (PATTERN (insn)) == PARALLEL)