PageRenderTime 20ms CodeModel.GetById 6ms app.highlight 10ms RepoModel.GetById 1ms app.codeStats 0ms

/arch/parisc/math-emu/sfcmp.c

https://github.com/aicjofs/android_kernel_lge_v500_20d_f2fs
C | 155 lines | 84 code | 7 blank | 64 comment | 33 complexity | 11a5a7bb3047e01188c708163dc6d5d6 MD5 | raw file
  1/*
  2 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
  3 *
  4 * Floating-point emulation code
  5 *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
  6 *
  7 *    This program is free software; you can redistribute it and/or modify
  8 *    it under the terms of the GNU General Public License as published by
  9 *    the Free Software Foundation; either version 2, or (at your option)
 10 *    any later version.
 11 *
 12 *    This program is distributed in the hope that it will be useful,
 13 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 *    GNU General Public License for more details.
 16 *
 17 *    You should have received a copy of the GNU General Public License
 18 *    along with this program; if not, write to the Free Software
 19 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 20 */
 21/*
 22 * BEGIN_DESC
 23 *
 24 *  File:
 25 *	@(#)	pa/spmath/sfcmp.c		$Revision: 1.1 $
 26 *
 27 *  Purpose:
 28 *	sgl_cmp: compare two values
 29 *
 30 *  External Interfaces:
 31 *	sgl_fcmp(leftptr, rightptr, cond, status)
 32 *
 33 *  Internal Interfaces:
 34 *
 35 *  Theory:
 36 *	<<please update with a overview of the operation of this file>>
 37 *
 38 * END_DESC
 39*/
 40
 41
 42#include "float.h"
 43#include "sgl_float.h"
 44    
 45/*
 46 * sgl_cmp: compare two values
 47 */
 48int
 49sgl_fcmp (sgl_floating_point * leftptr, sgl_floating_point * rightptr,
 50	  unsigned int cond, unsigned int *status)
 51                                           
 52                       /* The predicate to be tested */
 53                         
 54    {
 55    register unsigned int left, right;
 56    register int xorresult;
 57        
 58    /* Create local copies of the numbers */
 59    left = *leftptr;
 60    right = *rightptr;
 61
 62    /*
 63     * Test for NaN
 64     */
 65    if(    (Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
 66        || (Sgl_exponent(right) == SGL_INFINITY_EXPONENT) )
 67	{
 68	/* Check if a NaN is involved.  Signal an invalid exception when 
 69	 * comparing a signaling NaN or when comparing quiet NaNs and the
 70	 * low bit of the condition is set */
 71        if( (  (Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
 72	    && Sgl_isnotzero_mantissa(left) 
 73	    && (Exception(cond) || Sgl_isone_signaling(left)))
 74	   ||
 75	    (  (Sgl_exponent(right) == SGL_INFINITY_EXPONENT)
 76	    && Sgl_isnotzero_mantissa(right) 
 77	    && (Exception(cond) || Sgl_isone_signaling(right)) ) )
 78	    {
 79	    if( Is_invalidtrap_enabled() ) {
 80	    	Set_status_cbit(Unordered(cond));
 81		return(INVALIDEXCEPTION);
 82	    }
 83	    else Set_invalidflag();
 84	    Set_status_cbit(Unordered(cond));
 85	    return(NOEXCEPTION);
 86	    }
 87	/* All the exceptional conditions are handled, now special case
 88	   NaN compares */
 89        else if( ((Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
 90	    && Sgl_isnotzero_mantissa(left))
 91	   ||
 92	    ((Sgl_exponent(right) == SGL_INFINITY_EXPONENT)
 93	    && Sgl_isnotzero_mantissa(right)) )
 94	    {
 95	    /* NaNs always compare unordered. */
 96	    Set_status_cbit(Unordered(cond));
 97	    return(NOEXCEPTION);
 98	    }
 99	/* infinities will drop down to the normal compare mechanisms */
100	}
101    /* First compare for unequal signs => less or greater or
102     * special equal case */
103    Sgl_xortointp1(left,right,xorresult);
104    if( xorresult < 0 )
105        {
106        /* left negative => less, left positive => greater.
107         * equal is possible if both operands are zeros. */
108        if( Sgl_iszero_exponentmantissa(left) 
109	  && Sgl_iszero_exponentmantissa(right) )
110            {
111	    Set_status_cbit(Equal(cond));
112	    }
113	else if( Sgl_isone_sign(left) )
114	    {
115	    Set_status_cbit(Lessthan(cond));
116	    }
117	else
118	    {
119	    Set_status_cbit(Greaterthan(cond));
120	    }
121        }
122    /* Signs are the same.  Treat negative numbers separately
123     * from the positives because of the reversed sense.  */
124    else if( Sgl_all(left) == Sgl_all(right) )
125        {
126        Set_status_cbit(Equal(cond));
127        }
128    else if( Sgl_iszero_sign(left) )
129        {
130        /* Positive compare */
131        if( Sgl_all(left) < Sgl_all(right) )
132	    {
133	    Set_status_cbit(Lessthan(cond));
134	    }
135	else
136	    {
137	    Set_status_cbit(Greaterthan(cond));
138	    }
139	}
140    else
141        {
142        /* Negative compare.  Signed or unsigned compares
143         * both work the same.  That distinction is only
144         * important when the sign bits differ. */
145        if( Sgl_all(left) > Sgl_all(right) )
146	    {
147	    Set_status_cbit(Lessthan(cond));
148	    }
149        else
150	    {
151	    Set_status_cbit(Greaterthan(cond));
152	    }
153        }
154	return(NOEXCEPTION);
155    }