Ask for help: constraints error

[Ye, Joey]

I got following error after changing some GCC code, can anyone give me
some hints what's wrong here?

---
error: insn does not satisfy its constraints:
(insn:HI 690 689 1267 79 libgcc/config/libbid/bid_binarydecimal.c:146450
(parallel [
            (set (mem/c:DI (plus:SI (reg:SI 2 cx [59])
                        (const_int -264 [0xfffffffffffffef8])) [1440
lC.3833+0 S8 A64])
                (sign_extend:DI (reg:SI 0 ax [351])))
            (clobber (reg:CC 17 flags))
            (clobber (reg:SI 2 cx))
        ]) 123 {*extendsidi2_1} (nil))

*extendsidi2_1 is like:
(define_insn "*extendsidi2_1"
  [(set (match_operand:DI 0 "nonimmediate_operand" "=*A,r,?r,?*o")
        (sign_extend:DI (match_operand:SI 1 "register_operand"
"0,0,r,r")))
   (clobber (reg:CC FLAGS_REG))
   (clobber (match_scratch:SI 2 "=X,X,X,&r"))]
  "!TARGET_64BIT"
  "#") 

Thanks - Joey