linux/arch/parisc/math-emu/sfrem.c
Thomas Gleixner 660662f857 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 150
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>
2019-05-30 11:25:19 -07:00

278 lines
7.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Linux/PA-RISC Project (http://www.parisc-linux.org/)
*
* Floating-point emulation code
* Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
*/
/*
* BEGIN_DESC
*
* File:
* @(#) pa/spmath/sfrem.c $Revision: 1.1 $
*
* Purpose:
* Single Precision Floating-point Remainder
*
* External Interfaces:
* sgl_frem(srcptr1,srcptr2,dstptr,status)
*
* Internal Interfaces:
*
* Theory:
* <<please update with a overview of the operation of this file>>
*
* END_DESC
*/
#include "float.h"
#include "sgl_float.h"
/*
* Single Precision Floating-point Remainder
*/
int
sgl_frem (sgl_floating_point * srcptr1, sgl_floating_point * srcptr2,
sgl_floating_point * dstptr, unsigned int *status)
{
register unsigned int opnd1, opnd2, result;
register int opnd1_exponent, opnd2_exponent, dest_exponent, stepcount;
register boolean roundup = FALSE;
opnd1 = *srcptr1;
opnd2 = *srcptr2;
/*
* check first operand for NaN's or infinity
*/
if ((opnd1_exponent = Sgl_exponent(opnd1)) == SGL_INFINITY_EXPONENT) {
if (Sgl_iszero_mantissa(opnd1)) {
if (Sgl_isnotnan(opnd2)) {
/* invalid since first operand is infinity */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
Set_invalidflag();
Sgl_makequietnan(result);
*dstptr = result;
return(NOEXCEPTION);
}
}
else {
/*
* is NaN; signaling or quiet?
*/
if (Sgl_isone_signaling(opnd1)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Sgl_set_quiet(opnd1);
}
/*
* is second operand a signaling NaN?
*/
else if (Sgl_is_signalingnan(opnd2)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled())
return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Sgl_set_quiet(opnd2);
*dstptr = opnd2;
return(NOEXCEPTION);
}
/*
* return quiet NaN
*/
*dstptr = opnd1;
return(NOEXCEPTION);
}
}
/*
* check second operand for NaN's or infinity
*/
if ((opnd2_exponent = Sgl_exponent(opnd2)) == SGL_INFINITY_EXPONENT) {
if (Sgl_iszero_mantissa(opnd2)) {
/*
* return first operand
*/
*dstptr = opnd1;
return(NOEXCEPTION);
}
/*
* is NaN; signaling or quiet?
*/
if (Sgl_isone_signaling(opnd2)) {
/* trap if INVALIDTRAP enabled */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
/* make NaN quiet */
Set_invalidflag();
Sgl_set_quiet(opnd2);
}
/*
* return quiet NaN
*/
*dstptr = opnd2;
return(NOEXCEPTION);
}
/*
* check second operand for zero
*/
if (Sgl_iszero_exponentmantissa(opnd2)) {
/* invalid since second operand is zero */
if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
Set_invalidflag();
Sgl_makequietnan(result);
*dstptr = result;
return(NOEXCEPTION);
}
/*
* get sign of result
*/
result = opnd1;
/*
* check for denormalized operands
*/
if (opnd1_exponent == 0) {
/* check for zero */
if (Sgl_iszero_mantissa(opnd1)) {
*dstptr = opnd1;
return(NOEXCEPTION);
}
/* normalize, then continue */
opnd1_exponent = 1;
Sgl_normalize(opnd1,opnd1_exponent);
}
else {
Sgl_clear_signexponent_set_hidden(opnd1);
}
if (opnd2_exponent == 0) {
/* normalize, then continue */
opnd2_exponent = 1;
Sgl_normalize(opnd2,opnd2_exponent);
}
else {
Sgl_clear_signexponent_set_hidden(opnd2);
}
/* find result exponent and divide step loop count */
dest_exponent = opnd2_exponent - 1;
stepcount = opnd1_exponent - opnd2_exponent;
/*
* check for opnd1/opnd2 < 1
*/
if (stepcount < 0) {
/*
* check for opnd1/opnd2 > 1/2
*
* In this case n will round to 1, so
* r = opnd1 - opnd2
*/
if (stepcount == -1 && Sgl_isgreaterthan(opnd1,opnd2)) {
Sgl_all(result) = ~Sgl_all(result); /* set sign */
/* align opnd2 with opnd1 */
Sgl_leftshiftby1(opnd2);
Sgl_subtract(opnd2,opnd1,opnd2);
/* now normalize */
while (Sgl_iszero_hidden(opnd2)) {
Sgl_leftshiftby1(opnd2);
dest_exponent--;
}
Sgl_set_exponentmantissa(result,opnd2);
goto testforunderflow;
}
/*
* opnd1/opnd2 <= 1/2
*
* In this case n will round to zero, so
* r = opnd1
*/
Sgl_set_exponentmantissa(result,opnd1);
dest_exponent = opnd1_exponent;
goto testforunderflow;
}
/*
* Generate result
*
* Do iterative subtract until remainder is less than operand 2.
*/
while (stepcount-- > 0 && Sgl_all(opnd1)) {
if (Sgl_isnotlessthan(opnd1,opnd2))
Sgl_subtract(opnd1,opnd2,opnd1);
Sgl_leftshiftby1(opnd1);
}
/*
* Do last subtract, then determine which way to round if remainder
* is exactly 1/2 of opnd2
*/
if (Sgl_isnotlessthan(opnd1,opnd2)) {
Sgl_subtract(opnd1,opnd2,opnd1);
roundup = TRUE;
}
if (stepcount > 0 || Sgl_iszero(opnd1)) {
/* division is exact, remainder is zero */
Sgl_setzero_exponentmantissa(result);
*dstptr = result;
return(NOEXCEPTION);
}
/*
* Check for cases where opnd1/opnd2 < n
*
* In this case the result's sign will be opposite that of
* opnd1. The mantissa also needs some correction.
*/
Sgl_leftshiftby1(opnd1);
if (Sgl_isgreaterthan(opnd1,opnd2)) {
Sgl_invert_sign(result);
Sgl_subtract((opnd2<<1),opnd1,opnd1);
}
/* check for remainder being exactly 1/2 of opnd2 */
else if (Sgl_isequal(opnd1,opnd2) && roundup) {
Sgl_invert_sign(result);
}
/* normalize result's mantissa */
while (Sgl_iszero_hidden(opnd1)) {
dest_exponent--;
Sgl_leftshiftby1(opnd1);
}
Sgl_set_exponentmantissa(result,opnd1);
/*
* Test for underflow
*/
testforunderflow:
if (dest_exponent <= 0) {
/* trap if UNDERFLOWTRAP enabled */
if (Is_underflowtrap_enabled()) {
/*
* Adjust bias of result
*/
Sgl_setwrapped_exponent(result,dest_exponent,unfl);
*dstptr = result;
/* frem is always exact */
return(UNDERFLOWEXCEPTION);
}
/*
* denormalize result or set to signed zero
*/
if (dest_exponent >= (1 - SGL_P)) {
Sgl_rightshift_exponentmantissa(result,1-dest_exponent);
}
else {
Sgl_setzero_exponentmantissa(result);
}
}
else Sgl_set_exponent(result,dest_exponent);
*dstptr = result;
return(NOEXCEPTION);
}