From e4b535b66ca6126684ba8e2cd19ea043f64ca145 Mon Sep 17 00:00:00 2001 From: Michael Shalayeff Date: Tue, 23 Jun 1998 20:34:10 +0000 Subject: import the original hp sources for the spmath library w/ the a bsd-like hp licensing on 'em. w/ many thanks to: Mike Hibler James Loveluck Patrick Roudaud --- sys/arch/hppa/spmath/dfsqrt.c | 196 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 196 insertions(+) create mode 100644 sys/arch/hppa/spmath/dfsqrt.c (limited to 'sys/arch/hppa/spmath/dfsqrt.c') diff --git a/sys/arch/hppa/spmath/dfsqrt.c b/sys/arch/hppa/spmath/dfsqrt.c new file mode 100644 index 00000000000..918e1024ec0 --- /dev/null +++ b/sys/arch/hppa/spmath/dfsqrt.c @@ -0,0 +1,196 @@ +/* + * Copyright 1996 1995 by Open Software Foundation, Inc. + * All Rights Reserved + * + * Permission to use, copy, modify, and distribute this software and + * its documentation for any purpose and without fee is hereby granted, + * provided that the above copyright notice appears in all copies and + * that both the copyright notice and this permission notice appear in + * supporting documentation. + * + * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE. + * + * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, + * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION + * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ +/* + * pmk1.1 + */ +/* + * (c) Copyright 1986 HEWLETT-PACKARD COMPANY + * + * To anyone who acknowledges that this file is provided "AS IS" + * without any express or implied warranty: + * permission to use, copy, modify, and distribute this file + * for any purpose is hereby granted without fee, provided that + * the above copyright notice and this notice appears in all + * copies, and that the name of Hewlett-Packard Company not be + * used in advertising or publicity pertaining to distribution + * of the software without specific, written prior permission. + * Hewlett-Packard Company makes no representations about the + * suitability of this software for any purpose. + */ +/* $Source: /cvs/OpenBSD/src/sys/arch/hppa/spmath/dfsqrt.c,v $ + * $Revision: 1.1 $ $Author: mickey $ + * $State: Exp $ $Locker: $ + * $Date: 1998/06/23 20:33:54 $ + */ + +#include "../spmath/float.h" +#include "../spmath/dbl_float.h" + +/* + * Double Floating-point Square Root + */ + +/*ARGSUSED*/ +dbl_fsqrt(srcptr,nullptr,dstptr,status) + +dbl_floating_point *srcptr, *dstptr; +unsigned int *nullptr, *status; +{ + register unsigned int srcp1, srcp2, resultp1, resultp2; + register unsigned int newbitp1, newbitp2, sump1, sump2; + register int src_exponent; + register boolean guardbit = FALSE, even_exponent; + + Dbl_copyfromptr(srcptr,srcp1,srcp2); + /* + * check source operand for NaN or infinity + */ + if ((src_exponent = Dbl_exponent(srcp1)) == DBL_INFINITY_EXPONENT) { + /* + * is signaling NaN? + */ + if (Dbl_isone_signaling(srcp1)) { + /* trap if INVALIDTRAP enabled */ + if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION); + /* make NaN quiet */ + Set_invalidflag(); + Dbl_set_quiet(srcp1); + } + /* + * Return quiet NaN or positive infinity. + * Fall thru to negative test if negative infinity. + */ + if (Dbl_iszero_sign(srcp1) || + Dbl_isnotzero_mantissa(srcp1,srcp2)) { + Dbl_copytoptr(srcp1,srcp2,dstptr); + return(NOEXCEPTION); + } + } + + /* + * check for zero source operand + */ + if (Dbl_iszero_exponentmantissa(srcp1,srcp2)) { + Dbl_copytoptr(srcp1,srcp2,dstptr); + return(NOEXCEPTION); + } + + /* + * check for negative source operand + */ + if (Dbl_isone_sign(srcp1)) { + /* trap if INVALIDTRAP enabled */ + if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION); + /* make NaN quiet */ + Set_invalidflag(); + Dbl_makequietnan(srcp1,srcp2); + Dbl_copytoptr(srcp1,srcp2,dstptr); + return(NOEXCEPTION); + } + + /* + * Generate result + */ + if (src_exponent > 0) { + even_exponent = Dbl_hidden(srcp1); + Dbl_clear_signexponent_set_hidden(srcp1); + } + else { + /* normalize operand */ + Dbl_clear_signexponent(srcp1); + src_exponent++; + Dbl_normalize(srcp1,srcp2,src_exponent); + even_exponent = src_exponent & 1; + } + if (even_exponent) { + /* exponent is even */ + /* Add comment here. Explain why odd exponent needs correction */ + Dbl_leftshiftby1(srcp1,srcp2); + } + /* + * Add comment here. Explain following algorithm. + * + * Trust me, it works. + * + */ + Dbl_setzero(resultp1,resultp2); + Dbl_allp1(newbitp1) = 1 << (DBL_P - 32); + Dbl_setzero_mantissap2(newbitp2); + while (Dbl_isnotzero(newbitp1,newbitp2) && Dbl_isnotzero(srcp1,srcp2)) { + Dbl_addition(resultp1,resultp2,newbitp1,newbitp2,sump1,sump2); + if(Dbl_isnotgreaterthan(sump1,sump2,srcp1,srcp2)) { + Dbl_leftshiftby1(newbitp1,newbitp2); + /* update result */ + Dbl_addition(resultp1,resultp2,newbitp1,newbitp2, + resultp1,resultp2); + Dbl_subtract(srcp1,srcp2,sump1,sump2,srcp1,srcp2); + Dbl_rightshiftby2(newbitp1,newbitp2); + } + else { + Dbl_rightshiftby1(newbitp1,newbitp2); + } + Dbl_leftshiftby1(srcp1,srcp2); + } + /* correct exponent for pre-shift */ + if (even_exponent) { + Dbl_rightshiftby1(resultp1,resultp2); + } + + /* check for inexact */ + if (Dbl_isnotzero(srcp1,srcp2)) { + if (!even_exponent & Dbl_islessthan(resultp1,resultp2,srcp1,srcp2)) { + Dbl_increment(resultp1,resultp2); + } + guardbit = Dbl_lowmantissap2(resultp2); + Dbl_rightshiftby1(resultp1,resultp2); + + /* now round result */ + switch (Rounding_mode()) { + case ROUNDPLUS: + Dbl_increment(resultp1,resultp2); + break; + case ROUNDNEAREST: + /* stickybit is always true, so guardbit + * is enough to determine rounding */ + if (guardbit) { + Dbl_increment(resultp1,resultp2); + } + break; + } + /* increment result exponent by 1 if mantissa overflowed */ + if (Dbl_isone_hiddenoverflow(resultp1)) src_exponent+=2; + + if (Is_inexacttrap_enabled()) { + Dbl_set_exponent(resultp1, + ((src_exponent-DBL_BIAS)>>1)+DBL_BIAS); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(INEXACTEXCEPTION); + } + else Set_inexactflag(); + } + else { + Dbl_rightshiftby1(resultp1,resultp2); + } + Dbl_set_exponent(resultp1,((src_exponent-DBL_BIAS)>>1)+DBL_BIAS); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); +} -- cgit v1.2.3