include/math-emu/op-4.h

Source file repositories/reference/linux-study-clean/include/math-emu/op-4.h

File Facts

System
Linux kernel
Corpus path
include/math-emu/op-4.h
Extension
.h
Size
23795 bytes
Lines
693
Domain
Repository Root And Misc
Bucket
include
Inferred role
Repository Root And Misc: implementation source
Status
source implementation candidate

Why This File Exists

Top-level or miscellaneous repository surface. Use this as map coverage unless a later manual pass promotes the file into a deeper subsystem dossier.

Dependency Surface

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Annotated Snippet

Basic four-word fraction declaration and manipulation.
   Copyright (C) 1997,1998,1999 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Richard Henderson (rth@cygnus.com),
		  Jakub Jelinek (jj@ultra.linux.cz),
		  David S. Miller (davem@redhat.com) and
		  Peter Maydell (pmaydell@chiark.greenend.org.uk).

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If
   not, write to the Free Software Foundation, Inc.,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#ifndef __MATH_EMU_OP_4_H__
#define __MATH_EMU_OP_4_H__

#define _FP_FRAC_DECL_4(X)	_FP_W_TYPE X##_f[4]
#define _FP_FRAC_COPY_4(D,S)			\
  (D##_f[0] = S##_f[0], D##_f[1] = S##_f[1],	\
   D##_f[2] = S##_f[2], D##_f[3] = S##_f[3])
#define _FP_FRAC_SET_4(X,I)	__FP_FRAC_SET_4(X, I)
#define _FP_FRAC_HIGH_4(X)	(X##_f[3])
#define _FP_FRAC_LOW_4(X)	(X##_f[0])
#define _FP_FRAC_WORD_4(X,w)	(X##_f[w])

#define _FP_FRAC_SLL_4(X,N)						\
  do {									\
    _FP_I_TYPE _up, _down, _skip, _i;					\
    _skip = (N) / _FP_W_TYPE_SIZE;					\
    _up = (N) % _FP_W_TYPE_SIZE;					\
    _down = _FP_W_TYPE_SIZE - _up;					\
    if (!_up)								\
      for (_i = 3; _i >= _skip; --_i)					\
	X##_f[_i] = X##_f[_i-_skip];					\
    else								\
      {									\
	for (_i = 3; _i > _skip; --_i)					\
	  X##_f[_i] = X##_f[_i-_skip] << _up				\
		      | X##_f[_i-_skip-1] >> _down;			\
	X##_f[_i--] = X##_f[0] << _up; 					\
      }									\
    for (; _i >= 0; --_i)						\
      X##_f[_i] = 0;							\
  } while (0)

/* This one was broken too */
#define _FP_FRAC_SRL_4(X,N)						\
  do {									\
    _FP_I_TYPE _up, _down, _skip, _i;					\
    _skip = (N) / _FP_W_TYPE_SIZE;					\
    _down = (N) % _FP_W_TYPE_SIZE;					\
    _up = _FP_W_TYPE_SIZE - _down;					\
    if (!_down)								\
      for (_i = 0; _i <= 3-_skip; ++_i)					\
	X##_f[_i] = X##_f[_i+_skip];					\
    else								\
      {									\
	for (_i = 0; _i < 3-_skip; ++_i)				\
	  X##_f[_i] = X##_f[_i+_skip] >> _down				\
		      | X##_f[_i+_skip+1] << _up;			\
	X##_f[_i++] = X##_f[3] >> _down;				\
      }									\
    for (; _i < 4; ++_i)						\
      X##_f[_i] = 0;							\
  } while (0)


/* Right shift with sticky-lsb. 
 * What this actually means is that we do a standard right-shift,
 * but that if any of the bits that fall off the right hand side
 * were one then we always set the LSbit.
 */
#define _FP_FRAC_SRS_4(X,N,size)					\
  do {									\
    _FP_I_TYPE _up, _down, _skip, _i;					\
    _FP_W_TYPE _s;							\
    _skip = (N) / _FP_W_TYPE_SIZE;					\
    _down = (N) % _FP_W_TYPE_SIZE;					\
    _up = _FP_W_TYPE_SIZE - _down;					\
    for (_s = _i = 0; _i < _skip; ++_i)					\

Annotation

Implementation Notes