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+/*
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+/*
+ * BEGIN_DESC
+ *
+ * File:
+ * @(#) pa/spmath/sfcmp.c $Revision: 1.1 $
+ *
+ * Purpose:
+ * sgl_cmp: compare two values
+ *
+ * External Interfaces:
+ * sgl_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 "sgl_float.h"
+
+/*
+ * sgl_cmp: compare two values
+ */
+int
+sgl_fcmp (sgl_floating_point * leftptr, sgl_floating_point * rightptr,
+ unsigned int cond, unsigned int *status)
+
+ /* The predicate to be tested */
+
+ {
+ register unsigned int left, right;
+ register int xorresult;
+
+ /* Create local copies of the numbers */
+ left = *leftptr;
+ right = *rightptr;
+
+ /*
+ * Test for NaN
+ */
+ if( (Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
+ || (Sgl_exponent(right) == SGL_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( ( (Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
+ && Sgl_isnotzero_mantissa(left)
+ && (Exception(cond) || Sgl_isone_signaling(left)))
+ ||
+ ( (Sgl_exponent(right) == SGL_INFINITY_EXPONENT)
+ && Sgl_isnotzero_mantissa(right)
+ && (Exception(cond) || Sgl_isone_signaling(right)) ) )
+ {
+ 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( ((Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
+ && Sgl_isnotzero_mantissa(left))
+ ||
+ ((Sgl_exponent(right) == SGL_INFINITY_EXPONENT)
+ && Sgl_isnotzero_mantissa(right)) )
+ {
+ /* 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 */
+ Sgl_xortointp1(left,right,xorresult);
+ if( xorresult < 0 )
+ {
+ /* left negative => less, left positive => greater.
+ * equal is possible if both operands are zeros. */
+ if( Sgl_iszero_exponentmantissa(left)
+ && Sgl_iszero_exponentmantissa(right) )
+ {
+ Set_status_cbit(Equal(cond));
+ }
+ else if( Sgl_isone_sign(left) )
+ {
+ 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( Sgl_all(left) == Sgl_all(right) )
+ {
+ Set_status_cbit(Equal(cond));
+ }
+ else if( Sgl_iszero_sign(left) )
+ {
+ /* Positive compare */
+ if( Sgl_all(left) < Sgl_all(right) )
+ {
+ 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( Sgl_all(left) > Sgl_all(right) )
+ {
+ Set_status_cbit(Lessthan(cond));
+ }
+ else
+ {
+ Set_status_cbit(Greaterthan(cond));
+ }
+ }
+ return(NOEXCEPTION);
+ }