/* * 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/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); }