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Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 42 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190524100845.259718220@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
284 lines
8.1 KiB
C
284 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Linux/PA-RISC Project (http://www.parisc-linux.org/)
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*
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* Floating-point emulation code
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* Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
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*/
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/*
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* BEGIN_DESC
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*
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* File:
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* @(#) pa/spmath/dfrem.c $Revision: 1.1 $
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*
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* Purpose:
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* Double Precision Floating-point Remainder
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*
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* External Interfaces:
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* dbl_frem(srcptr1,srcptr2,dstptr,status)
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*
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* Internal Interfaces:
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*
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* Theory:
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* <<please update with a overview of the operation of this file>>
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*
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* END_DESC
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*/
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#include "float.h"
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#include "dbl_float.h"
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/*
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* Double Precision Floating-point Remainder
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*/
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int
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dbl_frem (dbl_floating_point * srcptr1, dbl_floating_point * srcptr2,
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dbl_floating_point * dstptr, unsigned int *status)
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{
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register unsigned int opnd1p1, opnd1p2, opnd2p1, opnd2p2;
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register unsigned int resultp1, resultp2;
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register int opnd1_exponent, opnd2_exponent, dest_exponent, stepcount;
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register boolean roundup = FALSE;
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Dbl_copyfromptr(srcptr1,opnd1p1,opnd1p2);
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Dbl_copyfromptr(srcptr2,opnd2p1,opnd2p2);
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/*
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* check first operand for NaN's or infinity
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*/
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if ((opnd1_exponent = Dbl_exponent(opnd1p1)) == DBL_INFINITY_EXPONENT) {
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if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
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if (Dbl_isnotnan(opnd2p1,opnd2p2)) {
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/* invalid since first operand is infinity */
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if (Is_invalidtrap_enabled())
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return(INVALIDEXCEPTION);
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Set_invalidflag();
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Dbl_makequietnan(resultp1,resultp2);
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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}
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else {
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/*
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* is NaN; signaling or quiet?
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*/
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if (Dbl_isone_signaling(opnd1p1)) {
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/* trap if INVALIDTRAP enabled */
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if (Is_invalidtrap_enabled())
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return(INVALIDEXCEPTION);
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/* make NaN quiet */
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Set_invalidflag();
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Dbl_set_quiet(opnd1p1);
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}
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/*
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* is second operand a signaling NaN?
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*/
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else if (Dbl_is_signalingnan(opnd2p1)) {
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/* trap if INVALIDTRAP enabled */
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if (Is_invalidtrap_enabled())
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return(INVALIDEXCEPTION);
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/* make NaN quiet */
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Set_invalidflag();
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Dbl_set_quiet(opnd2p1);
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Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* return quiet NaN
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*/
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Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
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return(NOEXCEPTION);
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}
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}
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/*
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* check second operand for NaN's or infinity
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*/
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if ((opnd2_exponent = Dbl_exponent(opnd2p1)) == DBL_INFINITY_EXPONENT) {
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if (Dbl_iszero_mantissa(opnd2p1,opnd2p2)) {
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/*
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* return first operand
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*/
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Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* is NaN; signaling or quiet?
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*/
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if (Dbl_isone_signaling(opnd2p1)) {
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/* trap if INVALIDTRAP enabled */
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if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
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/* make NaN quiet */
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Set_invalidflag();
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Dbl_set_quiet(opnd2p1);
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}
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/*
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* return quiet NaN
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*/
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Dbl_copytoptr(opnd2p1,opnd2p2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* check second operand for zero
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*/
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if (Dbl_iszero_exponentmantissa(opnd2p1,opnd2p2)) {
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/* invalid since second operand is zero */
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if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
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Set_invalidflag();
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Dbl_makequietnan(resultp1,resultp2);
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* get sign of result
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*/
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resultp1 = opnd1p1;
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/*
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* check for denormalized operands
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*/
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if (opnd1_exponent == 0) {
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/* check for zero */
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if (Dbl_iszero_mantissa(opnd1p1,opnd1p2)) {
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Dbl_copytoptr(opnd1p1,opnd1p2,dstptr);
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return(NOEXCEPTION);
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}
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/* normalize, then continue */
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opnd1_exponent = 1;
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Dbl_normalize(opnd1p1,opnd1p2,opnd1_exponent);
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}
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else {
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Dbl_clear_signexponent_set_hidden(opnd1p1);
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}
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if (opnd2_exponent == 0) {
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/* normalize, then continue */
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opnd2_exponent = 1;
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Dbl_normalize(opnd2p1,opnd2p2,opnd2_exponent);
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}
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else {
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Dbl_clear_signexponent_set_hidden(opnd2p1);
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}
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/* find result exponent and divide step loop count */
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dest_exponent = opnd2_exponent - 1;
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stepcount = opnd1_exponent - opnd2_exponent;
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/*
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* check for opnd1/opnd2 < 1
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*/
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if (stepcount < 0) {
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/*
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* check for opnd1/opnd2 > 1/2
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*
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* In this case n will round to 1, so
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* r = opnd1 - opnd2
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*/
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if (stepcount == -1 &&
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Dbl_isgreaterthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
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/* set sign */
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Dbl_allp1(resultp1) = ~Dbl_allp1(resultp1);
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/* align opnd2 with opnd1 */
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Dbl_leftshiftby1(opnd2p1,opnd2p2);
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Dbl_subtract(opnd2p1,opnd2p2,opnd1p1,opnd1p2,
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opnd2p1,opnd2p2);
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/* now normalize */
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while (Dbl_iszero_hidden(opnd2p1)) {
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Dbl_leftshiftby1(opnd2p1,opnd2p2);
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dest_exponent--;
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}
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Dbl_set_exponentmantissa(resultp1,resultp2,opnd2p1,opnd2p2);
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goto testforunderflow;
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}
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/*
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* opnd1/opnd2 <= 1/2
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*
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* In this case n will round to zero, so
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* r = opnd1
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*/
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Dbl_set_exponentmantissa(resultp1,resultp2,opnd1p1,opnd1p2);
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dest_exponent = opnd1_exponent;
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goto testforunderflow;
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}
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/*
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* Generate result
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*
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* Do iterative subtract until remainder is less than operand 2.
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*/
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while (stepcount-- > 0 && (Dbl_allp1(opnd1p1) || Dbl_allp2(opnd1p2))) {
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if (Dbl_isnotlessthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
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Dbl_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2,opnd1p1,opnd1p2);
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}
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Dbl_leftshiftby1(opnd1p1,opnd1p2);
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}
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/*
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* Do last subtract, then determine which way to round if remainder
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* is exactly 1/2 of opnd2
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*/
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if (Dbl_isnotlessthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
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Dbl_subtract(opnd1p1,opnd1p2,opnd2p1,opnd2p2,opnd1p1,opnd1p2);
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roundup = TRUE;
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}
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if (stepcount > 0 || Dbl_iszero(opnd1p1,opnd1p2)) {
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/* division is exact, remainder is zero */
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Dbl_setzero_exponentmantissa(resultp1,resultp2);
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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/*
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* Check for cases where opnd1/opnd2 < n
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*
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* In this case the result's sign will be opposite that of
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* opnd1. The mantissa also needs some correction.
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*/
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Dbl_leftshiftby1(opnd1p1,opnd1p2);
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if (Dbl_isgreaterthan(opnd1p1,opnd1p2,opnd2p1,opnd2p2)) {
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Dbl_invert_sign(resultp1);
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Dbl_leftshiftby1(opnd2p1,opnd2p2);
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Dbl_subtract(opnd2p1,opnd2p2,opnd1p1,opnd1p2,opnd1p1,opnd1p2);
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}
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/* check for remainder being exactly 1/2 of opnd2 */
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else if (Dbl_isequal(opnd1p1,opnd1p2,opnd2p1,opnd2p2) && roundup) {
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Dbl_invert_sign(resultp1);
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}
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/* normalize result's mantissa */
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while (Dbl_iszero_hidden(opnd1p1)) {
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dest_exponent--;
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Dbl_leftshiftby1(opnd1p1,opnd1p2);
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}
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Dbl_set_exponentmantissa(resultp1,resultp2,opnd1p1,opnd1p2);
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/*
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* Test for underflow
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*/
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testforunderflow:
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if (dest_exponent <= 0) {
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/* trap if UNDERFLOWTRAP enabled */
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if (Is_underflowtrap_enabled()) {
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/*
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* Adjust bias of result
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*/
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Dbl_setwrapped_exponent(resultp1,dest_exponent,unfl);
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/* frem is always exact */
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(UNDERFLOWEXCEPTION);
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}
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/*
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* denormalize result or set to signed zero
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*/
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if (dest_exponent >= (1 - DBL_P)) {
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Dbl_rightshift_exponentmantissa(resultp1,resultp2,
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1-dest_exponent);
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}
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else {
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Dbl_setzero_exponentmantissa(resultp1,resultp2);
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}
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}
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else Dbl_set_exponent(resultp1,dest_exponent);
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Dbl_copytoptr(resultp1,resultp2,dstptr);
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return(NOEXCEPTION);
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}
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