arch/arm26/nwfpe/fpa11.h

   1 /*
   2     NetWinder Floating Point Emulator
   3     (c) Rebel.com, 1998-1999
   4
   5     Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
   6
   7     This program is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #ifndef __FPA11_H__
  23 #define __FPA11_H__
  24
  25 #define GET_FPA11() ((FPA11 *)(&current_thread_info()->fpstate))
  26
  27 /*
  28  * The processes registers are always at the very top of the 8K
  29  * stack+task struct.  Use the same method as 'current' uses to
  30  * reach them.
  31  */
  32 register unsigned int *user_registers asm("sl");
  33
  34 #define GET_USERREG() (user_registers)
  35
  36 #include <linux/thread_info.h>
  37
  38 /* includes */
  39 #include "fpsr.h"               /* FP control and status register definitions */
  40 #include "softfloat.h"
  41
  42 #define         typeNone                0x00
  43 #define         typeSingle              0x01
  44 #define         typeDouble              0x02
  45 #define         typeExtended            0x03
  46
  47 /*
  48  * This must be no more and no less than 12 bytes.
  49  */
  50 typedef union tagFPREG {
  51    floatx80 fExtended;
  52    float64  fDouble;
  53    float32  fSingle;
  54 } FPREG;
  55
  56 /*
  57  * FPA11 device model.
  58  *
  59  * This structure is exported to user space.  Do not re-order.
  60  * Only add new stuff to the end, and do not change the size of
  61  * any element.  Elements of this structure are used by user
  62  * space, and must match struct user_fp in include/asm-arm/user.h.
  63  * We include the byte offsets below for documentation purposes.
  64  *
  65  * The size of this structure and FPREG are checked by fpmodule.c
  66  * on initialisation.  If the rules have been broken, NWFPE will
  67  * not initialise.
  68  */
  69 typedef struct tagFPA11 {
  70 /*   0 */  FPREG fpreg[8];              /* 8 floating point registers */
  71 /*  96 */  FPSR fpsr;                   /* floating point status register */
  72 /* 100 */  FPCR fpcr;                   /* floating point control register */
  73 /* 104 */  unsigned char fType[8];      /* type of floating point value held in
  74                                            floating point registers.  One of none
  75                                            single, double or extended. */
  76 /* 112 */  int initflag;                /* this is special.  The kernel guarantees
  77                                            to set it to 0 when a thread is launched,
  78                                            so we can use it to detect whether this
  79                                            instance of the emulator needs to be
  80                                            initialised. */
  81 } FPA11;
  82
  83 extern void resetFPA11(void);
  84 extern void SetRoundingMode(const unsigned int);
  85 extern void SetRoundingPrecision(const unsigned int);
  86
  87 #endif