alias.c (find_base_value): Recall base values for fixed hard regs.

	* alias.c (find_base_value): Recall base values for fixed hard regs.
	* loop.c (loop_regs_update): Don't use single_set on non-insns.

From-SVN: r49570

gcc/ChangeLog

+2002-02-07  Richard Henderson  <rth@redhat.com>
+
+	* alias.c (find_base_value): Recall base values for fixed hard regs.
+	* loop.c (loop_regs_update): Don't use single_set on non-insns.
+
 2002-02-07  Alexandre Oliva  <aoliva@redhat.com>
 
 	* config/mips/mips.md (define_delay) [mips16]: Adjust required

gcc/alias.c

@@ -744,12 +744,12 @@ find_base_value (src)
 	return new_reg_base_value[regno];
 
       /* If a pseudo has a known base value, return it.  Do not do this
-	 for hard regs since it can result in a circular dependency
-	 chain for registers which have values at function entry.
+	 for non-fixed hard regs since it can result in a circular
+	 dependency chain for registers which have values at function entry.
 
 	 The test above is not sufficient because the scheduler may move
 	 a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN.  */
-      if (regno >= FIRST_PSEUDO_REGISTER
+      if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno])
 	  && regno < reg_base_value_size
 	  && reg_base_value[regno])
 	return reg_base_value[regno];

gcc/loop.c

@@ -7637,9 +7637,9 @@ loop_regs_update (loop, seq)
     }
   else
     {
-      rtx set = single_set (seq);
-      if (set && GET_CODE (SET_DEST (set)) == REG)
-	record_base_value (REGNO (SET_DEST (set)), SET_SRC (set), 0);
+      if (GET_CODE (seq) == SET
+	  && GET_CODE (SET_DEST (seq)) == REG)
+	record_base_value (REGNO (SET_DEST (seq)), SET_SRC (seq), 0);
     }
 }