reg-stack.c (subst_stack_regs_pat): Handle correctly USEs of dead registers.

	* reg-stack.c (subst_stack_regs_pat): Handle correctly USEs of
	dead registers.

	* i386.c (movsf splitter): Fix typo in my last checkin.

From-SVN: r31256

gcc/ChangeLog

+Thu Jan  6 13:44:59 CET 2000  Jan Hubicka  <jh@suse.cz>
+
+	* reg-stack.c (subst_stack_regs_pat): Handle correctly USEs of
+	dead registers.
+
+	* i386.c (movsf splitter): Fix typo in my last checkin.
+
 2000-01-05  Nick Clifton  <nickc@cygnus.com>
 
 	* varasm.c (IN_NAMED_SECTION): Allow targets to provide their

gcc/config/i386/i386.md

@@ -1788,7 +1788,7 @@
   [(set_attr "type" "fmov,fmov,fmov,imov,imov")])
 
 (define_split
-  [(set (match_operand:SF 0 "general_operand" "")
+  [(set (match_operand:SF 0 "nonimmediate_operand" "")
 	(match_operand:SF 1 "memory_operand" ""))]
   "reload_completed
    && GET_CODE (operands[1]) == MEM

gcc/reg-stack.c

@@ -1383,12 +1383,24 @@ subst_stack_regs_pat (insn, regstack, pat)
       if (STACK_REG_P (*src) 
           && find_regno_note (insn, REG_DEAD, REGNO (*src)))
         {
-	   emit_pop_insn (insn, regstack, *src, EMIT_AFTER);
+	   /* In stupid allocation the USE might be used to extend lifetime
+	      of variable to given scope.  This may end up as USE of dead
+	      register.  */
+	   if (optimize || get_hard_regnum (regstack, *src) != -1)
+	     emit_pop_insn (insn, regstack, *src, EMIT_AFTER);
 	   return;
         }
-      /* ??? Uninitialized USE should not happen.  */
       else if (get_hard_regnum (regstack, *src) == -1)
-	abort();
+	{
+	   if (optimize)
+	     abort();
+	   if (GET_CODE (PATTERN (insn)) != USE)
+	     abort();
+	   PATTERN (insn) = gen_rtx_SET (GET_MODE (*src), *src,
+					 CONST0_RTX (GET_MODE (*src)));
+	   subst_stack_regs_pat (insn, regstack, PATTERN (insn));
+	   return;
+	}
       break;
 
     case CLOBBER: