Subversion Repositories openrisc_2011-10-31

/*> cp1.h <*/

/* MIPS Simulator FPU (CoProcessor 1) definitions.

   Copyright (C) 1997, 1998, 2002, 2007, 2008, 2009, 2010

   Free Software Foundation, Inc.

   Derived from sim-main.h contributed by Cygnus Solutions,

   modified substantially by Ed Satterthwaite of Broadcom Corporation

   (SiByte).

This file is part of GDB, the GNU debugger.

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 3 of the License, 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, see <http://www.gnu.org/licenses/>.  */

#ifndef CP1_H

#define CP1_H

/* See sim-main.h for allocation of registers FCR0 and FCR31 (FCSR)

   in CPU state (struct sim_cpu), and for FPU functions.  */

#define fcsr_FCC_mask      (0xFE800000)

#define fcsr_FCC_shift     (23)

#define fcsr_FCC_bit(cc)   ((cc) == 0 ? 23 : (24 + (cc)))

#define fcsr_FS            (1 << 24) /* MIPS III onwards : Flush to Zero */

#define fcsr_ZERO_mask     (0x007C0000)

#define fcsr_CAUSE_mask    (0x0003F000)

#define fcsr_CAUSE_shift   (12)

#define fcsr_ENABLES_mask  (0x00000F80)

#define fcsr_ENABLES_shift (7)

#define fcsr_FLAGS_mask    (0x0000007C)

#define fcsr_FLAGS_shift   (2)

#define fcsr_RM_mask       (0x00000003)

#define fcsr_RM_shift      (0)

#define fenr_FS            (0x00000004)

/* Macros to update and retrieve the FCSR condition-code bits.  This

   is complicated by the fact that there is a hole in the index range

   of the bits within the FCSR register.  (Note that the number of bits

   visible depends on the ISA in use, but that is handled elsewhere.)  */

#define SETFCC(cc,v) \

  do { \

    (FCSR = ((FCSR & ~(1 << fcsr_FCC_bit(cc))) | ((v) << fcsr_FCC_bit(cc)))); \

  } while (0)

#define GETFCC(cc) ((FCSR & (1 << fcsr_FCC_bit(cc))) != 0 ? 1 : 0)

/* Read flush-to-zero bit (not right-justified).  */

#define GETFS()            ((int)(FCSR & fcsr_FS))

/* FCSR flag bits definitions and access macros.  */

#define IR            0   /* I: Inexact Result */

#define UF            1   /* U: UnderFlow */

#define OF            2   /* O: OverFlow */

#define DZ            3   /* Z: Division by Zero */

#define IO            4   /* V: Invalid Operation */

#define UO            5   /* E: Unimplemented Operation (CAUSE field only) */

#define FP_FLAGS(b)   (1 << ((b) + fcsr_FLAGS_shift))

#define FP_ENABLE(b)  (1 << ((b) + fcsr_ENABLES_shift))

#define FP_CAUSE(b)   (1 << ((b) + fcsr_CAUSE_shift))

/* Rounding mode bit definitions and access macros.  */

#define FP_RM_NEAREST 0   /* Round to nearest (Round).  */

#define FP_RM_TOZERO  1   /* Round to zero (Trunc).  */

#define FP_RM_TOPINF  2   /* Round to Plus infinity (Ceil).  */

#define FP_RM_TOMINF  3   /* Round to Minus infinity (Floor).  */

#define GETRM()       ((FCSR >> fcsr_RM_shift) & fcsr_RM_mask)

#endif /* CP1_H */