Fix bad constraints in prologue_allocate_stack in i386.md

From-SVN: r29868

gcc/ChangeLog

+Fri Oct  8 18:46:11 1999  Bernd Schmidt  <bernds@cygnus.co.uk>
+
+	* i386.md (prologue_allocate_stack): Add '=' constraint letter on
+	output operand.
+
 Thu Oct  7 23:06:50 1999  Richard Henderson  <rth@cygnus.com>
 
 	* rs6000.md (fix_truncdfsi2_internal+1): Emit a clobber

gcc/config/i386/i386.md

@@ -7740,7 +7740,7 @@
 ;; in proper program order.
 
 (define_insn "prologue_allocate_stack"
-  [(set (match_operand:SI 0 "register_operand" "r")
+  [(set (match_operand:SI 0 "register_operand" "=r")
 	(plus:SI (match_operand:SI 1 "register_operand" "0")
 		 (match_operand:SI 2 "nonmemory_operand" "ri")))
    (set (match_operand:SI 3 "register_operand" "r")