fp64_isinf.S

/* Copyright (c) 2017-2020  Uwe Bissinger
   Based on 32bit floating point arithmetic routines which are:
   Copyright (c) 2002, Joerg Wunsch
   Copyright (c) 2006  Dmitry Xmelkov
   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
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/* $Id$ */

#if !defined(__AVR_TINY__)

#include "fp64def.h"
#include "asmdef.h"

/* int fp64_isinf (float64_t x)
     The fp64_isinf() function returns -1 if value represents negative
     infinity, 1 if value represents positive infinity, and 0 otherwise.
 */

FUNCTION fp64_isinf
ENTRY fp64_isinf
	XCALL	_U(__fp64_splitA)
	ldi	r24, 0
	ldi	r25, 0
	brcc	2f			; normal value
	brne	2f			; NaN
	brtc	1f			; +Inf -->  0 + 1 = +1
	sbiw	r24, 2		; -Inf --> -2 + 1 = -1
1:	inc	r24				
2:	ret
ENDFUNC

#endif /* !defined(__AVR_TINY__) */