regrename.c (scan_rtx_rtx): Skip to the next chain on encountering a terminated chain.

        * regrename.c (scan_rtx_rtx): Skip to the next chain on
        encountering a terminated chain.

From-SVN: r37473

gcc/ChangeLog

+2000-11-15  Graham Stott  <grahams@redhat.com>
+
+	* regrename.c (scan_rtx_rtx): Skip to the next chain on
+	encountering a terminated chain.
+
 2000-11-14  Mark Mitchell  <mark@codesourcery.com>
 
 	* configure.in: Move check for V3 above check for C++ header-file

gcc/regrename.c

@@ -307,6 +307,18 @@ scan_rtx_reg (insn, loc, class, action, type)
   for (p = &open_chains; *p;)
     {
       struct du_chain *this = *p;
+
+      /* Check if the chain has been terminated if it has then skip to
+	 the next chain.
+
+	 This can happen when we've already appended the location to
+	 the chain in Step 3, but are trying to hide in-out operands
+	 from terminate_write in Step 5.  */
+
+      if (*this->loc == cc0_rtx)
+	p = &this->next_chain;
+      else
+        {
 	  int regno = REGNO (*this->loc);
 	  int nregs = HARD_REGNO_NREGS (regno, GET_MODE (*this->loc));
 	  int exact_match = (regno == this_regno && nregs == this_nregs);
@@ -364,6 +376,7 @@ scan_rtx_reg (insn, loc, class, action, type)
 	  else
 	    p = &this->next_chain;
 	}
+    }
 }
 
 /* Adapted from find_reloads_address_1.  CLASS is INDEX_REG_CLASS or