/* Copyright (c) 2002, Marek Michalkiewicz
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions are met:

   * Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.

   * Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.

   * Neither the name of the copyright holders nor the names of
     contributors may be used to endorse or promote products derived
     from this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  POSSIBILITY OF SUCH DAMAGE. */

/*
   macros.inc - macros for use in assembler sources

   Contributors:
     Created by Marek Michalkiewicz <marekm@linux.org.pl>
 */

#include <avr/io.h>

/* if not defined, assume old version with underscores */
#ifndef __USER_LABEL_PREFIX__
#define __USER_LABEL_PREFIX__ _
#endif

#ifndef __REGISTER_PREFIX__
#define __REGISTER_PREFIX__
#endif

/* the assembler line separator (just in case it ever changes) */
#define _L $

#define CONCAT1(a, b) CONCAT2(a, b)
#define CONCAT2(a, b) a ## b

#define _U(x) CONCAT1(__USER_LABEL_PREFIX__, x)

#define _R(x) CONCAT1(__REGISTER_PREFIX__, x)

/* these should help to fix the "can't have function named r1()" bug
   which may require adding '%' in front of register names.  */

#define r0 _R(r0)
#define r1 _R(r1)
#define r2 _R(r2)
#define r3 _R(r3)
#define r4 _R(r4)
#define r5 _R(r5)
#define r6 _R(r6)
#define r7 _R(r7)
#define r8 _R(r8)
#define r9 _R(r9)
#define r10 _R(r10)
#define r11 _R(r11)
#define r12 _R(r12)
#define r13 _R(r13)
#define r14 _R(r14)
#define r15 _R(r15)
#define r16 _R(r16)
#define r17 _R(r17)
#define r18 _R(r18)
#define r19 _R(r19)
#define r20 _R(r20)
#define r21 _R(r21)
#define r22 _R(r22)
#define r23 _R(r23)
#define r24 _R(r24)
#define r25 _R(r25)
#define r26 _R(r26)
#define r27 _R(r27)
#define r28 _R(r28)
#define r29 _R(r29)
#define r30 _R(r30)
#define r31 _R(r31)

#ifndef __tmp_reg__
#define __tmp_reg__ r0
#endif

#ifndef __zero_reg__
#define __zero_reg__ r1
#endif

#if __AVR_MEGA__
  #define XJMP jmp
  #define XCALL call
#else
  #define XJMP rjmp
  #define XCALL rcall
#endif

/* used only by fplib/strtod.S - libgcc internal function calls */
#define PROLOGUE_SAVES(offset) XJMP (__prologue_saves__ + 2 * (offset))
#define EPILOGUE_RESTORES(offset) XJMP (__epilogue_restores__ + 2 * (offset))

#if FLASHEND > 0x10000  /* ATmega103 */
  #define BIG_CODE 1
#else
  #define BIG_CODE 0
#endif

/*
   Smart version of movw (use register numbers as arguments):
    - uses "movw" if possible (supported by MCU, and both registers even)
    - handles overlapping register pairs correctly
    - no instruction generated if source and destination are the same
   (may expand to 0, 1 or 2 instructions).
 */

	.macro	X_movw dest src
		.if ((\src) - (\dest))  /* different registers */
			.if (((\src) | (\dest)) & 0x01)
				.if (((\src)-(\dest)) & 0x80) /* src < dest */
					mov	(\dest)+1, (\src)+1
					mov	(\dest), (\src)
				.else  /* src > dest */
					mov	(\dest), (\src)
					mov	(\dest)+1, (\src)+1
				.endif
			.else  /* both even -> overlap not possible */
#if __AVR_ENHANCED__
				movw	(\dest), (\src)
#else
				mov	(\dest), (\src)
				mov	(\dest)+1, (\src)+1
#endif
			.endif
		.endif
	.endm

#if __AVR_ENHANCED__
  #define LOAD_X(lo, hi) movw r26, lo
  #define LOAD_Z(lo, hi) movw r30, lo
#else
  #define LOAD_X(lo, hi)		\
	mov	r26, lo			_L\
	mov	r27, hi

  #define LOAD_Z(lo, hi)		\
	mov	r30, lo			_L\
	mov	r31, hi
#endif

/* LOAD_X_CONST(p) loads constant P into pointer register X.  */
#define LOAD_X_CONST(p)		\
	ldi	r26, lo8(p)		_L\
	ldi	r27, hi8(p)

/*
   LPM_R0_ZPLUS_INIT is used before the loop to initialize RAMPZ
   for future devices with RAMPZ:Z auto-increment - [e]lpm r0, Z+.

   LPM_R0_ZPLUS_NEXT is used inside the loop to load a byte from
   the program memory at [RAMPZ:]Z to R0, and increment [RAMPZ:]Z.

   The argument in both macros is a register that contains the
   high byte (bits 23-16) of the address, bits 15-0 should be in
   the Z (r31:r30) register.  It can be any register except for:
   r0, r1 (__zero_reg__ - assumed to always contain 0), r30, r31.
 */

	.macro	LPM_R0_ZPLUS_INIT hhi
#if __AVR_ENHANCED__
  #if BIG_CODE
	out	_SFR_IO_ADDR(RAMPZ), \hhi
  #endif
#endif
	.endm

	.macro	LPM_R0_ZPLUS_NEXT hhi
#if __AVR_ENHANCED__
  #if BIG_CODE
    /* ELPM with RAMPZ:Z post-increment, load RAMPZ only once */
	elpm	r0, Z+
  #else
    /* LPM with Z post-increment, max 64K, no RAMPZ (ATmega83/161/163/32) */
	lpm	r0, Z+
  #endif
#else
  #if BIG_CODE
    /* ELPM without post-increment, load RAMPZ each time (ATmega103) */
	out	_SFR_IO_ADDR(RAMPZ), \hhi
	elpm
	adiw	r30,1
	adc	\hhi, __zero_reg__
  #else
    /* LPM without post-increment, max 64K, no RAMPZ (AT90S*) */
	lpm
	adiw	r30,1
  #endif
#endif
	.endm

	.macro  LPM_R0_ZP
#if __AVR_ENHANCED__
	lpm	r0, Z+
#else
	lpm
	adiw	r30,1
#endif
	.endm