patch-2.4.20 linux-2.4.20/arch/parisc/math-emu/dfcmp.c

• Lines: 182
• Date: Thu Nov 28 15:53:10 2002
• Orig file: linux-2.4.19/arch/parisc/math-emu/dfcmp.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/parisc/math-emu/dfcmp.c linux-2.4.20/arch/parisc/math-emu/dfcmp.c
@@ -0,0 +1,181 @@
+/*
+ * Linux/PA-RISC Project (http://www.parisc-linux.org/)
+ *
+ * Floating-point emulation code
+ *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
+ *
+ *    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 2, 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, write to the Free Software
+ *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/*
+ * BEGIN_DESC
+ *
+ *  File:
+ *	@(#)	pa/spmath/dfcmp.c		$Revision: 1.1 $
+ *
+ *  Purpose:
+ *	dbl_cmp: compare two values
+ *
+ *  External Interfaces:
+ *	dbl_fcmp(leftptr, rightptr, cond, status)
+ *
+ *  Internal Interfaces:
+ *
+ *  Theory:
+ *	<<please update with a overview of the operation of this file>>
+ *
+ * END_DESC
+*/
+
+
+
+#include "float.h"
+#include "dbl_float.h"
+    
+/*
+ * dbl_cmp: compare two values
+ */
+int
+dbl_fcmp (dbl_floating_point * leftptr, dbl_floating_point * rightptr,
+	  unsigned int cond, unsigned int *status)
+                                           
+                       /* The predicate to be tested */
+                         
+    {
+    register unsigned int leftp1, leftp2, rightp1, rightp2;
+    register int xorresult;
+        
+    /* Create local copies of the numbers */
+    Dbl_copyfromptr(leftptr,leftp1,leftp2);
+    Dbl_copyfromptr(rightptr,rightp1,rightp2);
+    /*
+     * Test for NaN
+     */
+    if(    (Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
+        || (Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT) )
+	{
+	/* Check if a NaN is involved.  Signal an invalid exception when 
+	 * comparing a signaling NaN or when comparing quiet NaNs and the
+	 * low bit of the condition is set */
+        if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
+	    && Dbl_isnotzero_mantissa(leftp1,leftp2) 
+	    && (Exception(cond) || Dbl_isone_signaling(leftp1)))
+	   ||
+	    ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
+	    && Dbl_isnotzero_mantissa(rightp1,rightp2) 
+	    && (Exception(cond) || Dbl_isone_signaling(rightp1))) )
+	    {
+	    if( Is_invalidtrap_enabled() ) {
+	    	Set_status_cbit(Unordered(cond));
+		return(INVALIDEXCEPTION);
+	    }
+	    else Set_invalidflag();
+	    Set_status_cbit(Unordered(cond));
+	    return(NOEXCEPTION);
+	    }
+	/* All the exceptional conditions are handled, now special case
+	   NaN compares */
+        else if( ((Dbl_exponent(leftp1) == DBL_INFINITY_EXPONENT)
+	    && Dbl_isnotzero_mantissa(leftp1,leftp2))
+	   ||
+	    ((Dbl_exponent(rightp1) == DBL_INFINITY_EXPONENT)
+	    && Dbl_isnotzero_mantissa(rightp1,rightp2)) )
+	    {
+	    /* NaNs always compare unordered. */
+	    Set_status_cbit(Unordered(cond));
+	    return(NOEXCEPTION);
+	    }
+	/* infinities will drop down to the normal compare mechanisms */
+	}
+    /* First compare for unequal signs => less or greater or
+     * special equal case */
+    Dbl_xortointp1(leftp1,rightp1,xorresult);
+    if( xorresult < 0 )
+        {
+        /* left negative => less, left positive => greater.
+         * equal is possible if both operands are zeros. */
+        if( Dbl_iszero_exponentmantissa(leftp1,leftp2) 
+	  && Dbl_iszero_exponentmantissa(rightp1,rightp2) )
+            {
+	    Set_status_cbit(Equal(cond));
+	    }
+	else if( Dbl_isone_sign(leftp1) )
+	    {
+	    Set_status_cbit(Lessthan(cond));
+	    }
+	else
+	    {
+	    Set_status_cbit(Greaterthan(cond));
+	    }
+        }
+    /* Signs are the same.  Treat negative numbers separately
+     * from the positives because of the reversed sense.  */
+    else if(Dbl_isequal(leftp1,leftp2,rightp1,rightp2))
+        {
+        Set_status_cbit(Equal(cond));
+        }
+    else if( Dbl_iszero_sign(leftp1) )
+        {
+        /* Positive compare */
+	if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
+	    {
+	    Set_status_cbit(Lessthan(cond));
+	    }
+	else if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
+	    {
+	    Set_status_cbit(Greaterthan(cond));
+	    }
+	else
+	    {
+	    /* Equal first parts.  Now we must use unsigned compares to
+	     * resolve the two possibilities. */
+	    if( Dbl_allp2(leftp2) < Dbl_allp2(rightp2) )
+		{
+		Set_status_cbit(Lessthan(cond));
+		}
+	    else 
+		{
+		Set_status_cbit(Greaterthan(cond));
+		}
+	    }
+	}
+    else
+        {
+        /* Negative compare.  Signed or unsigned compares
+         * both work the same.  That distinction is only
+         * important when the sign bits differ. */
+	if( Dbl_allp1(leftp1) > Dbl_allp1(rightp1) )
+	    {
+	    Set_status_cbit(Lessthan(cond));
+	    }
+	else if( Dbl_allp1(leftp1) < Dbl_allp1(rightp1) )
+	    {
+	    Set_status_cbit(Greaterthan(cond));
+	    }
+	else
+	    {
+	    /* Equal first parts.  Now we must use unsigned compares to
+	     * resolve the two possibilities. */
+	    if( Dbl_allp2(leftp2) > Dbl_allp2(rightp2) )
+		{
+		Set_status_cbit(Lessthan(cond));
+		}
+	    else 
+		{
+		Set_status_cbit(Greaterthan(cond));
+		}
+	    }
+        }
+	return(NOEXCEPTION);
+    }