diff --git a/gcc/config/stormy16/constraints.md b/gcc/config/stormy16/constraints.md
new file mode 100644
index 0000000..aab5ec1
--- /dev/null
+++ b/gcc/config/stormy16/constraints.md
@@ -0,0 +1,119 @@
+;; Constraint definitions for XSTORMY16.
+;; Copyright (C) 2011 Free Software Foundation, Inc.
+;;
+;; This file is part of GCC.
+;;
+;; GCC is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+;;
+;; GCC is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with GCC; see the file COPYING3.  If not see
+;; <http://www.gnu.org/licenses/>.
+
+;; Register constraints.
+(define_register_constraint "a" "R0_REGS"
+  "@internal")
+
+(define_register_constraint "b" "R1_REGS"
+  "@internal")
+
+(define_register_constraint "c" "R2_REGS"
+  "@internal")
+
+(define_register_constraint "d" "R8_REGS"
+  "@internal")
+
+(define_register_constraint "e" "EIGHT_REGS"
+  "@internal")
+
+(define_register_constraint "t" "TWO_REGS"
+  "@internal")
+
+(define_register_constraint "z" "ICALL_REGS"
+  "@internal")
+
+;; Integer constraints.
+(define_constraint "I"
+  "An integer between 0 and 3."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, 0, 3)")))
+
+(define_constraint "J"
+  "A power of two."
+  (and (match_code "const_int")
+       (match_test "exact_log2 (ival) != -1")))
+
+(define_constraint "K"
+  "A power of two when inverted."
+  (and (match_code "const_int")
+       (match_test "exact_log2 (~ival) != -1")))
+
+(define_constraint "L"
+  "An 8-bit unsigned integer."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, 0, 255)")))
+
+(define_constraint "M"
+  "An integer between -255 and 0."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, -255, 0)")))
+
+(define_constraint "N"
+  "An integer between -3 and 0."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, -3, 0)")))
+
+(define_constraint "O"
+  "An integer between 1 and 4."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, 1, 4)")))
+
+(define_constraint "P"
+  "An integer between -4 and -1."
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (ival, -4, -1)")))
+
+;; Extra constraints.
+(define_constraint "Q"
+  "A register push operation."
+  (and (match_code "mem")
+       (match_code "post_inc" "0")
+       (match_test "XEXP (XEXP (op, 0), 0) == stack_pointer_rtx")))
+
+(define_constraint "R"
+  "A register pop operation."
+  (and (match_code "mem")
+       (match_code "pre_dec" "0")
+       (match_test "XEXP (XEXP (op, 0), 0) == stack_pointer_rtx")))
+
+(define_constraint "S"
+  "An immediate memory address."
+  (and (match_code "mem")
+       (match_code "const_int" "0")
+       (match_test "xstormy16_legitimate_address_p (VOIDmode, XEXP (op, 0), false)")))
+
+(define_constraint "T"
+  "@internal"
+  ;; For Rx; not implemented yet.
+  (match_test "0"))
+
+(define_constraint "U"
+  "An integer not between 2 and 15."
+  (and (match_code "const_int")
+       (match_test "!IN_RANGE (ival, 2, 15)")))
+
+(define_constraint "W"
+  "@internal"
+  (match_test "xstormy16_below100_operand (op, mode)"))
+
+(define_constraint "Z"
+  "Zero."
+  (and (match_code "const_int")
+       (match_test "ival == 0")))
\ No newline at end of file
diff --git a/gcc/config/stormy16/predicates.md b/gcc/config/stormy16/predicates.md
index 0e1d394..7270c7f 100644
--- a/gcc/config/stormy16/predicates.md
+++ b/gcc/config/stormy16/predicates.md
@@ -140,8 +140,8 @@
 {
   /* 'Q' is for pushes, 'R' for pops.  */
   return (nonimmediate_operand (op, mode) 
-	  && ! xstormy16_extra_constraint_p (op, 'Q')
-	  && ! xstormy16_extra_constraint_p (op, 'R'));
+	  && ! satisfies_constraint_Q (op)
+	  && ! satisfies_constraint_R (op));
 })
 
 (define_predicate "xstormy16_carry_plus_operand"
diff --git a/gcc/config/stormy16/stormy16-protos.h b/gcc/config/stormy16/stormy16-protos.h
index 3edbc33..ad44e15 100644
--- a/gcc/config/stormy16/stormy16-protos.h
+++ b/gcc/config/stormy16/stormy16-protos.h
@@ -45,7 +45,6 @@ extern void xstormy16_emit_cbranch (enum rtx_code, rtx, rtx, rtx);
 extern char *xstormy16_output_cbranch_hi (rtx, const char *, int, rtx);
 extern char *xstormy16_output_cbranch_si (rtx, const char *, int, rtx);
 extern int xstormy16_mode_dependent_address_p (rtx);
-extern int xstormy16_extra_constraint_p (rtx, int);
 
 extern void xstormy16_print_operand (FILE *, rtx, int);
 extern void xstormy16_print_operand_address (FILE *, rtx);
@@ -72,5 +71,6 @@ extern const char * xstormy16_output_shift (enum machine_mode, enum rtx_code,
 					    rtx, rtx, rtx);
 extern int  xstormy16_below100_symbol (rtx, enum machine_mode);
 extern int  xstormy16_splittable_below100_operand (rtx, enum machine_mode);
+extern bool xstormy16_legitimate_address_p (enum machine_mode, rtx, bool);
 #endif
 
diff --git a/gcc/config/stormy16/stormy16.c b/gcc/config/stormy16/stormy16.c
index fa5c5b5..e4cd10e 100644
--- a/gcc/config/stormy16/stormy16.c
+++ b/gcc/config/stormy16/stormy16.c
@@ -615,7 +615,7 @@ xstormy16_expand_andqi3 (rtx *operands)
   && INTVAL (X) + (OFFSET) < 0x8000					 \
   && (INTVAL (X) + (OFFSET) < 0x100 || INTVAL (X) + (OFFSET) >= 0x7F00))
 
-static bool
+bool
 xstormy16_legitimate_address_p (enum machine_mode mode ATTRIBUTE_UNUSED,
 				rtx x, bool strict)
 {
@@ -683,60 +683,6 @@ xstormy16_mode_dependent_address_p (rtx x)
   return 0;
 }
 
-/* A C expression that defines the optional machine-dependent constraint
-   letters (`Q', `R', `S', `T', `U') that can be used to segregate specific
-   types of operands, usually memory references, for the target machine.
-   Normally this macro will not be defined.  If it is required for a particular
-   target machine, it should return 1 if VALUE corresponds to the operand type
-   represented by the constraint letter C.  If C is not defined as an extra
-   constraint, the value returned should be 0 regardless of VALUE.  */
-
-int
-xstormy16_extra_constraint_p (rtx x, int c)
-{
-  switch (c)
-    {
-      /* 'Q' is for pushes.  */
-    case 'Q':
-      return (MEM_P (x)
-	      && GET_CODE (XEXP (x, 0)) == POST_INC
-	      && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx);
-
-      /* 'R' is for pops.  */
-    case 'R':
-      return (MEM_P (x)
-	      && GET_CODE (XEXP (x, 0)) == PRE_DEC
-	      && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx);
-
-      /* 'S' is for immediate memory addresses.  */
-    case 'S':
-      return (MEM_P (x)
-	      && CONST_INT_P (XEXP (x, 0))
-	      && xstormy16_legitimate_address_p (VOIDmode, XEXP (x, 0), 0));
-
-      /* 'T' is for Rx.  */
-    case 'T':
-      /* Not implemented yet.  */
-      return 0;
-
-      /* 'U' is for CONST_INT values not between 2 and 15 inclusive,
-	 for allocating a scratch register for 32-bit shifts.  */
-    case 'U':
-      return (CONST_INT_P (x) && (! IN_RANGE (INTVAL (x), 2, 15)));
-
-      /* 'Z' is for CONST_INT value zero.  This is for adding zero to
-	 a register in addhi3, which would otherwise require a carry.  */
-    case 'Z':
-      return (CONST_INT_P (x) && (INTVAL (x) == 0));
-
-    case 'W':
-      return xstormy16_below100_operand (x, GET_MODE (x));
-
-    default:
-      return 0;
-    }
-}
-
 int
 short_memory_operand (rtx x, enum machine_mode mode)
 {
diff --git a/gcc/config/stormy16/stormy16.h b/gcc/config/stormy16/stormy16.h
index 8789d90..c92af1d 100644
--- a/gcc/config/stormy16/stormy16.h
+++ b/gcc/config/stormy16/stormy16.h
@@ -225,26 +225,6 @@ enum reg_class
 
 #define INDEX_REG_CLASS GENERAL_REGS
 
-/*   The following letters are unavailable, due to being used as
-   constraints:
-	'0'..'9'
-	'<', '>'
-	'E', 'F', 'G', 'H'
-	'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P'
-	'Q', 'R', 'S', 'T', 'U'
-	'V', 'X'
-	'g', 'i', 'm', 'n', 'o', 'p', 'r', 's'.  */
-
-#define REG_CLASS_FROM_LETTER(CHAR)		\
- (  (CHAR) == 'a' ? R0_REGS			\
-  : (CHAR) == 'b' ? R1_REGS			\
-  : (CHAR) == 'c' ? R2_REGS			\
-  : (CHAR) == 'd' ? R8_REGS			\
-  : (CHAR) == 'e' ? EIGHT_REGS			\
-  : (CHAR) == 't' ? TWO_REGS			\
-  : (CHAR) == 'z' ? ICALL_REGS			\
-  : NO_REGS)
-
 #define REGNO_OK_FOR_BASE_P(NUM) 1
 
 #define REGNO_OK_FOR_INDEX_P(NUM) REGNO_OK_FOR_BASE_P (NUM)
@@ -263,22 +243,6 @@ enum reg_class
 #define CLASS_MAX_NREGS(CLASS, MODE) \
   ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
 
-#define CONST_OK_FOR_LETTER_P(VALUE, C)			\
-  (  (C) == 'I' ? (VALUE) >= 0 && (VALUE) <= 3		\
-   : (C) == 'J' ? exact_log2 (VALUE) != -1		\
-   : (C) == 'K' ? exact_log2 (~(VALUE)) != -1		\
-   : (C) == 'L' ? (VALUE) >= 0 && (VALUE) <= 255	\
-   : (C) == 'M' ? (VALUE) >= -255 && (VALUE) <= 0	\
-   : (C) == 'N' ? (VALUE) >= -3 && (VALUE) <= 0		\
-   : (C) == 'O' ? (VALUE) >= 1 && (VALUE) <= 4		\
-   : (C) == 'P' ? (VALUE) >= -4 && (VALUE) <= -1	\
-   : 0 )
-
-#define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C) 0
-
-#define EXTRA_CONSTRAINT(VALUE, C) \
-  xstormy16_extra_constraint_p (VALUE, C)
-
 
 /* Basic Stack Layout.  */
 
diff --git a/gcc/config/stormy16/stormy16.md b/gcc/config/stormy16/stormy16.md
index 8c6fd9d..3eb74b7 100644
--- a/gcc/config/stormy16/stormy16.md
+++ b/gcc/config/stormy16/stormy16.md
@@ -95,6 +95,7 @@
 			(set_attr "psw_operand" "clobber")])
 
 (include "predicates.md")
+(include "constraints.md")
 
 ;; ::::::::::::::::::::
 ;; ::
