path: root/sim/common/sim-alu.h

/* The common simulator framework for GDB, the GNU Debugger.

   Copyright 2002-2021 Free Software Foundation, Inc.

   Contributed by Andrew Cagney and Red Hat.

   This file is part of GDB.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */


#ifndef SIM_ALU_H
#define SIM_ALU_H

#include "symcat.h"


/* INTEGER ALU MODULE:

   This module provides an implementation of 2's complement arithmetic
   including the recording of carry and overflow status bits.


   EXAMPLE:

   Code using this module includes it into sim-main.h and then, as a
   convention, defines macro's ALU*_END that records the result of any
   arithmetic performed.  Ex:

   	#include "sim-alu.h"
	#define ALU32_END(RES) \
	(RES) = ALU32_OVERFLOW_RESULT; \
	carry = ALU32_HAD_CARRY_BORROW; \
	overflow = ALU32_HAD_OVERFLOW

   The macro's are then used vis:

        {
	  ALU32_BEGIN (GPR[i]);
	  ALU32_ADDC (GPR[j]);
	  ALU32_END (GPR[k]);
	}


   NOTES:

   Macros exist for efficiently computing 8, 16, 32 and 64 bit
   arithmetic - ALU8_*, ALU16_*, ....  In addition, according to
   TARGET_WORD_BITSIZE a set of short-hand macros are defined - ALU_*

   Initialization:

	ALU*_BEGIN(ACC): Declare initialize the ALU accumulator with ACC.

   Results:

        The calculation of the final result may be computed a number
        of different ways.  Three different overflow macro's are
        defined, the most efficient one to use depends on which other
        outputs from the alu are being used.

	ALU*_RESULT: Generic ALU result output.

   	ALU*_HAD_OVERFLOW: Returns a nonzero value if signed overflow
   	occurred.

	ALU*_OVERFLOW_RESULT: If the macro ALU*_HAD_OVERFLOW is being
	used this is the most efficient result available.  Ex:

		#define ALU16_END(RES) \
		if (ALU16_HAD_OVERFLOW) \
		  sim_engine_halt (...); \
		(RES) = ALU16_OVERFLOW_RESULT

   	ALU*_HAD_CARRY_BORROW: Returns a nonzero value if unsigned
   	overflow or underflow (also referred to as carry and borrow)
   	occurred.

	ALU*_CARRY_BORROW_RESULT: If the macro ALU*_HAD_CARRY_BORROW is being
	used this is the most efficient result available.  Ex:

		#define ALU64_END(RES) \
		State.carry = ALU64_HAD_CARRY_BORROW; \
		(RES) = ALU64_CARRY_BORROW_RESULT


   Addition:

	ALU*_ADD(VAL): Add VAL to the ALU accumulator.  Record any
	overflow as well as the final result.

	ALU*_ADDC(VAL): Add VAL to the ALU accumulator.  Record any
	carry-out or overflow as well as the final result.

	ALU*_ADDC_C(VAL,CI): Add VAL and CI (carry-in).  Record any
	carry-out or overflow as well as the final result.

   Subtraction:

	ALU*_SUB(VAL): Subtract VAL from the ALU accumulator.  Record
	any underflow as well as the final result.

	ALU*_SUBC(VAL): Subtract VAL from the ALU accumulator using
	negated addition.  Record any underflow or carry-out as well
	as the final result.

	ALU*_SUBB(VAL): Subtract VAL from the ALU accumulator using
	direct subtraction (ACC+~VAL+1).  Record any underflow or
	borrow-out as well as the final result.

	ALU*_SUBC_X(VAL,CI): Subtract VAL and CI (carry-in) from the
	ALU accumulator using extended negated addition (ACC+~VAL+CI).
	Record any underflow or carry-out as well as the final result.

	ALU*_SUBB_B(VAL,BI): Subtract VAL and BI (borrow-in) from the
	ALU accumulator using direct subtraction.  Record any
	underflow or borrow-out as well as the final result.


 */



/* Twos complement arithmetic - addition/subtraction - carry/borrow
   (or you thought you knew the answer to 0-0)



   Notation and Properties:


   Xn denotes the value X stored in N bits.

   MSBn (X): The most significant (sign) bit of X treated as an N bit
   value.

   SEXTn (X): The infinite sign extension of X treated as an N bit
   value.

   MAXn, MINn: The upper and lower bound of a signed, two's
   complement N bit value.

   UMAXn: The upper bound of an unsigned N bit value (the lower
   bound is always zero).

   Un: UMAXn + 1.  Unsigned arithmetic is computed `modulo (Un)'.

   X[p]: Is bit P of X.  X[0] denotes the least significant bit.

   ~X[p]: Is the inversion of bit X[p]. Also equal to 1-X[p],
   (1+X[p])mod(2).



   Addition - Overflow - Introduction:


   Overflow/Overflow indicates an error in computation of signed
   arithmetic.  i.e. given X,Y in [MINn..MAXn]; overflow
   indicates that the result X+Y > MAXn or X+Y < MIN_INTx.

   Hardware traditionally implements overflow by computing the XOR of
   carry-in/carry-out of the most significant bit of the ALU. Here
   other methods need to be found.



   Addition - Overflow - method 1:


   Overflow occurs when the sign (most significant bit) of the two N
   bit operands is identical but different to the sign of the result:

                Rn = (Xn + Yn)
		V = MSBn (~(Xn ^ Yn) & (Rn ^ Xn))



   Addition - Overflow - method 2:


   The two N bit operands are sign extended to M>N bits and then
   added.  Overflow occurs when SIGN_BIT<n> and SIGN_BIT<m> do not
   match.

   		Rm = (SEXTn (Xn) + SEXTn (Yn))
		V = MSBn ((Rm >> (M - N)) ^ Rm)



   Addition - Overflow - method 3:


   The two N bit operands are sign extended to M>N bits and then
   added.  Overflow occurs when the result is outside of the sign
   extended range [MINn .. MAXn].



   Addition - Overflow - method 4:


   Given the Result and Carry-out bits, the oVerflow from the addition
   of X, Y and carry-In can be computed using the equation:

                Rn = (Xn + Yn)
		V = (MSBn ((Xn ^ Yn) ^ Rn)) ^ C)

   As shown in the table below:

         I  X  Y  R  C | V | X^Y  ^R  ^C
        ---------------+---+-------------
         0  0  0  0  0 | 0 |  0    0   0
         0  0  1  1  0 | 0 |  1    0   0
         0  1  0  1  0 | 0 |  1    0   0
         0  1  1  0  1 | 1 |  0    0   1
         1  0  0  1  0 | 1 |  0    1   1
         1  0  1  0  1 | 0 |  1    1   0
         1  1  0  0  1 | 0 |  1    1   0
         1  1  1  1  1 | 0 |  0    1   0



   Addition - Carry - Introduction:


   Carry (poorly named) indicates that an overflow occurred for
   unsigned N bit addition.  i.e. given X, Y in [0..UMAXn] then
   carry indicates X+Y > UMAXn or X+Y >= Un.

   The following table lists the output for all given inputs into a
   full-adder.

         I  X  Y  R | C
        ------------+---
         0  0  0  0 | 0
         0  0  1  1 | 0
         0  1  0  1 | 0
         0  1  1  0 | 1
         1  0  0  1 | 0
         1  0  1  0 | 1
         1  1  0  0 | 1
         1  1  1  1 | 1

   (carry-In, X, Y, Result, Carry-out):



   Addition - Carry - method 1:


   Looking at the terms X, Y and R we want an equation for C.

       XY\R  0  1
          +-------
       00 |  0  0
       01 |  1  0
       11 |  1  1
       10 |  1  0

   This giving us the sum-of-prod equation:

		MSBn ((Xn & Yn) | (Xn & ~Rn) | (Yn & ~Rn))

   Verifying:

         I  X  Y  R | C | X&Y  X&~R Y&~R
        ------------+---+---------------
         0  0  0  0 | 0 |  0    0    0
         0  0  1  1 | 0 |  0    0    0
         0  1  0  1 | 0 |  0    0    0
         0  1  1  0 | 1 |  1    1    1
         1  0  0  1 | 0 |  0    0    0
         1  0  1  0 | 1 |  0    0    1
         1  1  0  0 | 1 |  0    1    0
         1  1  1  1 | 1 |  1    0    0



   Addition - Carry - method 2:


   Given two signed N bit numbers, a carry can be detected by treating
   the numbers as N bit unsigned and adding them using M>N unsigned
   arithmetic.  Carry is indicated by bit (1 << N) being set (result
   >= 2**N).



   Addition - Carry - method 3:


   Given the oVerflow bit.  The carry can be computed from:

		(~R&V) | (R&V)



   Addition - Carry - method 4:

   Given two signed numbers.  Treating them as unsigned we have:

		0 <= X < Un, 0 <= Y < Un
	==>	X + Y < 2 Un

   Consider Y when carry occurs:

		X + Y >= Un, Y < Un
	==>	(Un - X) <= Y < Un               # rearrange
	==>	Un <= X + Y < Un + X < 2 Un      # add Xn
	==>	0 <= (X + Y) mod Un < X mod Un

   or when carry as occurred:

               (X + Y) mod Un < X mod Un

   Consider Y when carry does not occur:

		X + Y < Un
	have	X < Un, Y >= 0
	==>	X <= X + Y < Un
	==>     X mod Un <= (X + Y) mod Un

   or when carry has not occurred:

	        ! ( (X + Y) mod Un < X mod Un)

   hence we get carry by computing in N bit unsigned arithmetic.

                carry <- (Xn + Yn) < Xn



   Subtraction - Introduction


   There are two different ways of computing the signed two's
   complement difference of two numbers.  The first is based on
   negative addition, the second on direct subtraction.



   Subtraction - Carry - Introduction - Negated Addition


   The equation X - Y can be computed using:

   		X + (-Y)
	==>	X + ~Y + 1		# -Y = ~Y + 1

   In addition to the result, the equation produces Carry-out.  For
   succeeding extended precision calculations, the more general
   equation can be used:

		C[p]:R[p]  =  X[p] + ~Y[p] + C[p-1]
 	where	C[0]:R[0]  =  X[0] + ~Y[0] + 1



   Subtraction - Borrow - Introduction - Direct Subtraction


   The alternative to negative addition is direct subtraction where
   `X-Y is computed directly.  In addition to the result of the
   calculation, a Borrow bit is produced.  In general terms:

		B[p]:R[p]  =  X[p] - Y[p] - B[p-1]
	where	B[0]:R[0]  =  X[0] - Y[0]

   The Borrow bit is the complement of the Carry bit produced by
   Negated Addition above.  A dodgy proof follows:

   	Case 0:
		C[0]:R[0] = X[0] + ~Y[0] + 1
	==>	C[0]:R[0] = X[0] + 1 - Y[0] + 1	# ~Y[0] = (1 - Y[0])?
	==>	C[0]:R[0] = 2 + X[0] - Y[0]
	==>	C[0]:R[0] = 2 + B[0]:R[0]
	==>	C[0]:R[0] = (1 + B[0]):R[0]
	==>	C[0] = ~B[0]			# (1 + B[0]) mod 2 = ~B[0]?

	Case P:
		C[p]:R[p] = X[p] + ~Y[p] + C[p-1]
	==>	C[p]:R[p] = X[p] + 1 - Y[0] + 1 - B[p-1]
	==>	C[p]:R[p] = 2 + X[p] - Y[0] - B[p-1]
	==>	C[p]:R[p] = 2 + B[p]:R[p]
	==>	C[p]:R[p] = (1 + B[p]):R[p]
	==>     C[p] = ~B[p]

   The table below lists all possible inputs/outputs for a
   full-subtractor:

   	X  Y  I  |  R  B
	0  0  0  |  0  0
	0  0  1  |  1  1
	0  1  0  |  1  1
	0  1  1  |  0  1
	1  0  0  |  1  0
	1  0  1  |  0  0
	1  1  0  |  0  0
	1  1  1  |  1  1



   Subtraction - Method 1


   Treating Xn and Yn as unsigned values then a borrow (unsigned
   underflow) occurs when:

		B = Xn < Yn
	==>	C = Xn >= Yn

 */



/* 8 bit target expressions:

   Since the host's natural bitsize > 8 bits, carry method 2 and
   overflow method 2 are used. */

#define ALU8_BEGIN(VAL) \
unsigned alu8_cr = (unsigned8) (VAL); \
signed alu8_vr = (signed8) (alu8_cr)

#define ALU8_SET(VAL) \
alu8_cr = (unsigned8) (VAL); \
alu8_vr = (signed8) (alu8_cr)

#define ALU8_SET_CARRY_BORROW(CARRY)					\
do {									\
  if (CARRY)								\
    alu8_cr |= ((signed)-1) << 8;					\
  else									\
    alu8_cr &= 0xff;							\
} while (0)

#define ALU8_HAD_CARRY_BORROW (alu8_cr & LSBIT32(8))
#define ALU8_HAD_OVERFLOW (((alu8_vr >> 8) ^ alu8_vr) & LSBIT32 (8-1))

#define ALU8_RESULT ((unsigned8) alu8_cr)
#define ALU8_CARRY_BORROW_RESULT ((unsigned8) alu8_cr)
#define ALU8_OVERFLOW_RESULT ((unsigned8) alu8_vr)

/* #define ALU8_END ????? - target dependant */



/* 16 bit target expressions:

   Since the host's natural bitsize > 16 bits, carry method 2 and
   overflow method 2 are used. */

#define ALU16_BEGIN(VAL) \
signed alu16_cr = (unsigned16) (VAL); \
unsigned alu16_vr = (signed16) (alu16_cr)

#define ALU16_SET(VAL) \
alu16_cr = (unsigned16) (VAL); \
alu16_vr = (signed16) (alu16_cr)

#define ALU16_SET_CARRY_BORROW(CARRY)					\
do {									\
  if (CARRY)								\
    alu16_cr |= ((signed)-1) << 16;					\
  else									\
    alu16_cr &= 0xffff;							\
} while (0)

#define ALU16_HAD_CARRY_BORROW (alu16_cr & LSBIT32(16))
#define ALU16_HAD_OVERFLOW (((alu16_vr >> 16) ^ alu16_vr) & LSBIT32 (16-1))

#define ALU16_RESULT ((unsigned16) alu16_cr)
#define ALU16_CARRY_BORROW_RESULT ((unsigned16) alu16_cr)
#define ALU16_OVERFLOW_RESULT ((unsigned16) alu16_vr)

/* #define ALU16_END ????? - target dependant */



/* 32 bit target expressions:

   Since most hosts do not support 64 (> 32) bit arithmetic, carry
   method 4 and overflow method 4 are used. */

#define ALU32_BEGIN(VAL) \
unsigned32 alu32_r = (VAL); \
int alu32_c = 0; \
int alu32_v = 0

#define ALU32_SET(VAL) \
alu32_r = (VAL); \
alu32_c = 0; \
alu32_v = 0

#define ALU32_SET_CARRY_BORROW(CARRY) alu32_c = (CARRY)

#define ALU32_HAD_CARRY_BORROW (alu32_c)
#define ALU32_HAD_OVERFLOW (alu32_v)

#define ALU32_RESULT (alu32_r)
#define ALU32_CARRY_BORROW_RESULT (alu32_r)
#define ALU32_OVERFLOW_RESULT (alu32_r)



/* 64 bit target expressions:

   Even though the host typically doesn't support native 64 bit
   arithmetic, it is still used. */

#define ALU64_BEGIN(VAL) \
unsigned64 alu64_r = (VAL); \
int alu64_c = 0; \
int alu64_v = 0

#define ALU64_SET(VAL) \
alu64_r = (VAL); \
alu64_c = 0; \
alu64_v = 0

#define ALU64_SET_CARRY_BORROW(CARRY) alu64_c = (CARRY)

#define ALU64_HAD_CARRY_BORROW (alu64_c)
#define ALU64_HAD_OVERFLOW (alu64_v)

#define ALU64_RESULT (alu64_r)
#define ALU64_CARRY_BORROW_RESULT (alu64_r)
#define ALU64_OVERFLOW_RESULT (alu64_r)



/* Generic versions of above macros */

#define ALU_BEGIN	    XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_BEGIN)
#define ALU_SET		    XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SET)
#define ALU_SET_CARRY	    XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SET_CARRY)

#define ALU_HAD_OVERFLOW    XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_HAD_OVERFLOW)
#define ALU_HAD_CARRY       XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_HAD_CARRY)

#define ALU_RESULT          XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_RESULT)
#define ALU_OVERFLOW_RESULT XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_OVERFLOW_RESULT)
#define ALU_CARRY_RESULT    XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_CARRY_RESULT)



/* Basic operation - add (overflowing) */

#define ALU8_ADD(VAL)							\
do {									\
  unsigned8 alu8add_val = (VAL);					\
  ALU8_ADDC (alu8add_val);						\
} while (0)

#define ALU16_ADD(VAL)							\
do {									\
  unsigned16 alu16add_val = (VAL);					\
  ALU16_ADDC (alu8add_val);						\
} while (0)

#define ALU32_ADD(VAL)							\
do {									\
  unsigned32 alu32add_val = (VAL);					\
  ALU32_ADDC (alu32add_val);						\
} while (0)

#define ALU64_ADD(VAL)							\
do {									\
  unsigned64 alu64add_val = (unsigned64) (VAL);				\
  ALU64_ADDC (alu64add_val);						\
} while (0)

#define ALU_ADD XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_ADD)



/* Basic operation - add carrying (and overflowing) */

#define ALU8_ADDC(VAL)							\
do {									\
  unsigned8 alu8addc_val = (VAL);					\
  alu8_cr += (unsigned8)(alu8addc_val);					\
  alu8_vr += (signed8)(alu8addc_val);					\
} while (0)

#define ALU16_ADDC(VAL)							\
do {									\
  unsigned16 alu16addc_val = (VAL);					\
  alu16_cr += (unsigned16)(alu16addc_val);				\
  alu16_vr += (signed16)(alu16addc_val);				\
} while (0)

#define ALU32_ADDC(VAL)							\
do {									\
  unsigned32 alu32addc_val = (VAL);					\
  unsigned32 alu32addc_sign = alu32addc_val ^ alu32_r;			\
  alu32_r += (alu32addc_val);						\
  alu32_c = (alu32_r < alu32addc_val);					\
  alu32_v = ((alu32addc_sign ^ - (unsigned32)alu32_c) ^ alu32_r) >> 31;	\
} while (0)

#define ALU64_ADDC(VAL)							\
do {									\
  unsigned64 alu64addc_val = (unsigned64) (VAL);			\
  unsigned64 alu64addc_sign = alu64addc_val ^ alu64_r;			\
  alu64_r += (alu64addc_val);						\
  alu64_c = (alu64_r < alu64addc_val);					\
  alu64_v = ((alu64addc_sign ^ - (unsigned64)alu64_c) ^ alu64_r) >> 63;	\
} while (0)

#define ALU_ADDC XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_ADDC)



/* Compound operation - add carrying (and overflowing) with carry-in */

#define ALU8_ADDC_C(VAL,C)						\
do {									\
  unsigned8 alu8addcc_val = (VAL);					\
  unsigned8 alu8addcc_c = (C);						\
  alu8_cr += (unsigned)(unsigned8)alu8addcc_val + alu8addcc_c;		\
  alu8_vr += (signed)(signed8)(alu8addcc_val) + alu8addcc_c;		\
} while (0)

#define ALU16_ADDC_C(VAL,C)						\
do {									\
  unsigned16 alu16addcc_val = (VAL);					\
  unsigned16 alu16addcc_c = (C);					\
  alu16_cr += (unsigned)(unsigned16)alu16addcc_val + alu16addcc_c;	\
  alu16_vr += (signed)(signed16)(alu16addcc_val) + alu16addcc_c;	\
} while (0)

#define ALU32_ADDC_C(VAL,C)						\
do {									\
  unsigned32 alu32addcc_val = (VAL);					\
  unsigned32 alu32addcc_c = (C);					\
  unsigned32 alu32addcc_sign = (alu32addcc_val ^ alu32_r);		\
  alu32_r += (alu32addcc_val + alu32addcc_c);				\
  alu32_c = ((alu32_r < alu32addcc_val)					\
             || (alu32addcc_c && alu32_r == alu32addcc_val));		\
  alu32_v = ((alu32addcc_sign ^ - (unsigned32)alu32_c) ^ alu32_r) >> 31;\
} while (0)

#define ALU64_ADDC_C(VAL,C)						\
do {									\
  unsigned64 alu64addcc_val = (VAL);					\
  unsigned64 alu64addcc_c = (C);					\
  unsigned64 alu64addcc_sign = (alu64addcc_val ^ alu64_r);		\
  alu64_r += (alu64addcc_val + alu64addcc_c);				\
  alu64_c = ((alu64_r < alu64addcc_val)					\
             || (alu64addcc_c && alu64_r == alu64addcc_val));		\
  alu64_v = ((alu64addcc_sign ^ - (unsigned64)alu64_c) ^ alu64_r) >> 63;\
} while (0)

#define ALU_ADDC_C XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_ADDC_C)



/* Basic operation - subtract (overflowing) */

#define ALU8_SUB(VAL)							\
do {									\
  unsigned8 alu8sub_val = (VAL);					\
  ALU8_ADDC_C (~alu8sub_val, 1);					\
} while (0)

#define ALU16_SUB(VAL)							\
do {									\
  unsigned16 alu16sub_val = (VAL);					\
  ALU16_ADDC_C (~alu16sub_val, 1);					\
} while (0)

#define ALU32_SUB(VAL)							\
do {									\
  unsigned32 alu32sub_val = (VAL);					\
  ALU32_ADDC_C (~alu32sub_val, 1);					\
} while (0)

#define ALU64_SUB(VAL)							\
do {									\
  unsigned64 alu64sub_val = (VAL);					\
  ALU64_ADDC_C (~alu64sub_val, 1);					\
} while (0)

#define ALU_SUB XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SUB)



/* Basic operation - subtract carrying (and overflowing) */

#define ALU8_SUBC(VAL)							\
do {									\
  unsigned8 alu8subc_val = (VAL);					\
  ALU8_ADDC_C (~alu8subc_val, 1);					\
} while (0)

#define ALU16_SUBC(VAL)							\
do {									\
  unsigned16 alu16subc_val = (VAL);					\
  ALU16_ADDC_C (~alu16subc_val, 1);					\
} while (0)

#define ALU32_SUBC(VAL)							\
do {									\
  unsigned32 alu32subc_val = (VAL);					\
  ALU32_ADDC_C (~alu32subc_val, 1);					\
} while (0)

#define ALU64_SUBC(VAL)							\
do {									\
  unsigned64 alu64subc_val = (VAL);					\
  ALU64_ADDC_C (~alu64subc_val, 1);					\
} while (0)

#define ALU_SUBC XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SUBC)



/* Compound operation - subtract carrying (and overflowing), extended */

#define ALU8_SUBC_X(VAL,C)						\
do {									\
  unsigned8 alu8subcx_val = (VAL);					\
  unsigned8 alu8subcx_c = (C);						\
  ALU8_ADDC_C (~alu8subcx_val, alu8subcx_c);				\
} while (0)

#define ALU16_SUBC_X(VAL,C)						\
do {									\
  unsigned16 alu16subcx_val = (VAL);					\
  unsigned16 alu16subcx_c = (C);					\
  ALU16_ADDC_C (~alu16subcx_val, alu16subcx_c);				\
} while (0)

#define ALU32_SUBC_X(VAL,C)						\
do {									\
  unsigned32 alu32subcx_val = (VAL);					\
  unsigned32 alu32subcx_c = (C);					\
  ALU32_ADDC_C (~alu32subcx_val, alu32subcx_c);				\
} while (0)

#define ALU64_SUBC_X(VAL,C)						\
do {									\
  unsigned64 alu64subcx_val = (VAL);					\
  unsigned64 alu64subcx_c = (C);					\
  ALU64_ADDC_C (~alu64subcx_val, alu64subcx_c);				\
} while (0)

#define ALU_SUBC_X XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SUBC_X)



/* Basic operation - subtract borrowing (and overflowing) */

#define ALU8_SUBB(VAL)							\
do {									\
  unsigned8 alu8subb_val = (VAL);					\
  alu8_cr -= (unsigned)(unsigned8)alu8subb_val;				\
  alu8_vr -= (signed)(signed8)alu8subb_val;				\
} while (0)

#define ALU16_SUBB(VAL)							\
do {									\
  unsigned16 alu16subb_val = (VAL);					\
  alu16_cr -= (unsigned)(unsigned16)alu16subb_val;			\
  alu16_vr -= (signed)(signed16)alu16subb_val;				\
} while (0)

#define ALU32_SUBB(VAL)							\
do {									\
  unsigned32 alu32subb_val = (VAL);					\
  unsigned32 alu32subb_sign = alu32subb_val ^ alu32_r;			\
  alu32_c = (alu32_r < alu32subb_val);					\
  alu32_r -= (alu32subb_val);						\
  alu32_v = ((alu32subb_sign ^ - (unsigned32)alu32_c) ^ alu32_r) >> 31;	\
} while (0)

#define ALU64_SUBB(VAL)							\
do {									\
  unsigned64 alu64subb_val = (VAL);					\
  unsigned64 alu64subb_sign = alu64subb_val ^ alu64_r;			\
  alu64_c = (alu64_r < alu64subb_val);					\
  alu64_r -= (alu64subb_val);						\
  alu64_v = ((alu64subb_sign ^ - (unsigned64)alu64_c) ^ alu64_r) >> 31;	\
} while (0)

#define ALU_SUBB XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SUBB)



/* Compound operation - subtract borrowing (and overflowing) with borrow-in */

#define ALU8_SUBB_B(VAL,B)						\
do {									\
  unsigned8 alu8subbb_val = (VAL);					\
  unsigned8 alu8subbb_b = (B);						\
  alu8_cr -= (unsigned)(unsigned8)alu8subbb_val;			\
  alu8_cr -= (unsigned)(unsigned8)alu8subbb_b;				\
  alu8_vr -= (signed)(signed8)alu8subbb_val + alu8subbb_b;		\
} while (0)

#define ALU16_SUBB_B(VAL,B)						\
do {									\
  unsigned16 alu16subbb_val = (VAL);					\
  unsigned16 alu16subbb_b = (B);					\
  alu16_cr -= (unsigned)(unsigned16)alu16subbb_val;			\
  alu16_cr -= (unsigned)(unsigned16)alu16subbb_b;			\
  alu16_vr -= (signed)(signed16)alu16subbb_val + alu16subbb_b;		\
} while (0)

#define ALU32_SUBB_B(VAL,B)						\
do {									\
  unsigned32 alu32subbb_val = (VAL);					\
  unsigned32 alu32subbb_b = (B);					\
  ALU32_ADDC_C (~alu32subbb_val, !alu32subbb_b);			\
  alu32_c = !alu32_c;							\
} while (0)

#define ALU64_SUBB_B(VAL,B)						\
do {									\
  unsigned64 alu64subbb_val = (VAL);					\
  unsigned64 alu64subbb_b = (B);					\
  ALU64_ADDC_C (~alu64subbb_val, !alu64subbb_b);			\
  alu64_c = !alu64_c;							\
} while (0)

#define ALU_SUBB_B XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SUBB_B)



/* Basic operation - negate (overflowing) */

#define ALU8_NEG()							\
do {									\
  signed alu8neg_val = (ALU8_RESULT);					\
  ALU8_SET (1);								\
  ALU8_ADDC (~alu8neg_val);						\
} while (0)

#define ALU16_NEG()							\
do {									\
  signed alu16neg_val = (ALU16_RESULT);				\
  ALU16_SET (1);							\
  ALU16_ADDC (~alu16neg_val);						\
} while (0)

#define ALU32_NEG()							\
do {									\
  unsigned32 alu32neg_val = (ALU32_RESULT);				\
  ALU32_SET (1);							\
  ALU32_ADDC (~alu32neg_val);						\
} while(0)

#define ALU64_NEG()							\
do {									\
  unsigned64 alu64neg_val = (ALU64_RESULT);				\
  ALU64_SET (1);							\
  ALU64_ADDC (~alu64neg_val);						\
} while (0)

#define ALU_NEG XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_NEG)




/* Basic operation - negate carrying (and overflowing) */

#define ALU8_NEGC()							\
do {									\
  signed alu8negc_val = (ALU8_RESULT);					\
  ALU8_SET (1);								\
  ALU8_ADDC (~alu8negc_val);						\
} while (0)

#define ALU16_NEGC()							\
do {									\
  signed alu16negc_val = (ALU16_RESULT);				\
  ALU16_SET (1);							\
  ALU16_ADDC (~alu16negc_val);						\
} while (0)

#define ALU32_NEGC()							\
do {									\
  unsigned32 alu32negc_val = (ALU32_RESULT);				\
  ALU32_SET (1);							\
  ALU32_ADDC (~alu32negc_val);						\
} while(0)

#define ALU64_NEGC()							\
do {									\
  unsigned64 alu64negc_val = (ALU64_RESULT);				\
  ALU64_SET (1);							\
  ALU64_ADDC (~alu64negc_val);						\
} while (0)

#define ALU_NEGC XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_NEGC)




/* Basic operation - negate borrowing (and overflowing) */

#define ALU8_NEGB()							\
do {									\
  signed alu8negb_val = (ALU8_RESULT);					\
  ALU8_SET (0);								\
  ALU8_SUBB (alu8negb_val);						\
} while (0)

#define ALU16_NEGB()							\
do {									\
  signed alu16negb_val = (ALU16_RESULT);				\
  ALU16_SET (0);							\
  ALU16_SUBB (alu16negb_val);						\
} while (0)

#define ALU32_NEGB()							\
do {									\
  unsigned32 alu32negb_val = (ALU32_RESULT);				\
  ALU32_SET (0);							\
  ALU32_SUBB (alu32negb_val);						\
} while(0)

#define ALU64_NEGB()							\
do {									\
  unsigned64 alu64negb_val = (ALU64_RESULT);				\
  ALU64_SET (0);							\
  ALU64_SUBB (alu64negb_val);						\
} while (0)

#define ALU_NEGB XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_NEGB)




/* Other */

#define ALU8_OR(VAL)							\
do {									\
  error("ALU16_OR");							\
} while (0)

#define ALU16_OR(VAL)							\
do {									\
  error("ALU16_OR");							\
} while (0)

#define ALU32_OR(VAL)							\
do {									\
  alu32_r |= (VAL);							\
  alu32_c = 0;								\
  alu32_v = 0;								\
} while (0)

#define ALU64_OR(VAL)							\
do {									\
  alu64_r |= (VAL);							\
  alu64_c = 0;								\
  alu64_v = 0;								\
} while (0)

#define ALU_OR(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_OR)(VAL)



#define ALU16_XOR(VAL)							\
do {									\
  error("ALU16_XOR");							\
} while (0)

#define ALU32_XOR(VAL)							\
do {									\
  alu32_r ^= (VAL);							\
  alu32_c = 0;								\
  alu32_v = 0;								\
} while (0)

#define ALU64_XOR(VAL)							\
do {									\
  alu64_r ^= (VAL);							\
  alu64_c = 0;								\
  alu64_v = 0;								\
} while (0)

#define ALU_XOR(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_XOR)(VAL)




#define ALU16_AND(VAL)							\
do {									\
  error("ALU_AND16");							\
} while (0)

#define ALU32_AND(VAL)							\
do {									\
  alu32_r &= (VAL);							\
  alu32_c = 0;								\
  alu32_v = 0;								\
} while (0)

#define ALU64_AND(VAL)							\
do {									\
  alu64_r &= (VAL);							\
  alu64_c = 0;								\
  alu64_v = 0;								\
} while (0)

#define ALU_AND(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_AND)(VAL)




#define ALU16_NOT(VAL)							\
do {									\
  error("ALU_NOT16");							\
} while (0)

#define ALU32_NOT							\
do {									\
  alu32_r = ~alu32_r;							\
  alu32_c = 0;								\
  alu32_v = 0;								\
} while (0)

#define ALU64_NOT							\
do {									\
  alu64_r = ~alu64_r;							\
  alu64_c = 0;								\
  alu64_v = 0;								\
} while (0)

#define ALU_NOT XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_NOT)

#endif