125 lines
3.9 KiB
C
125 lines
3.9 KiB
C
/* Native-dependent code for the i387.
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Copyright (C) 2000 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "inferior.h"
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#include "value.h"
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/* FIXME: kettenis/2000-05-21: Right now more than a few i386 targets
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define their own routines to manage the floating-point registers in
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GDB's register array. Most (if not all) of these targets use the
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format used by the "fsave" instruction in their communication with
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the OS. They should all be converted to use the routines below. */
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/* At fsave_offset[REGNO] you'll find the offset to the location in
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the data structure used by the "fsave" instruction where GDB
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register REGNO is stored. */
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static int fsave_offset[] =
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{
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28 + 0 * FPU_REG_RAW_SIZE, /* FP0_REGNUM through ... */
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28 + 1 * FPU_REG_RAW_SIZE,
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28 + 2 * FPU_REG_RAW_SIZE,
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28 + 3 * FPU_REG_RAW_SIZE,
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28 + 4 * FPU_REG_RAW_SIZE,
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28 + 5 * FPU_REG_RAW_SIZE,
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28 + 6 * FPU_REG_RAW_SIZE,
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28 + 7 * FPU_REG_RAW_SIZE, /* ... FP7_REGNUM. */
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0, /* FCTRL_REGNUM (16 bits). */
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4, /* FSTAT_REGNUM (16 bits). */
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8, /* FTAG_REGNUM (16 bits). */
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16, /* FCS_REGNUM (16 bits). */
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12, /* FCOFF_REGNUM. */
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24, /* FDS_REGNUM. */
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20, /* FDOFF_REGNUM. */
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18 /* FOP_REGNUM (bottom 11 bits). */
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};
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#define FSAVE_ADDR(fsave, regnum) (fsave + fsave_offset[regnum - FP0_REGNUM])
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/* Fill GDB's register array with the floating-point register values
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in *FSAVE. This function masks off any of the reserved
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bits in *FSAVE. */
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void
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i387_supply_fsave (char *fsave)
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{
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int i;
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for (i = FP0_REGNUM; i <= LAST_FPU_CTRL_REGNUM; i++)
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{
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/* Most of the FPU control registers occupy only 16 bits in
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the fsave area. Give those a special treatment. */
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if (i >= FIRST_FPU_CTRL_REGNUM
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&& i != FCOFF_REGNUM && i != FDOFF_REGNUM)
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{
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unsigned val = *(unsigned short *) (FSAVE_ADDR (fsave, i));
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if (i == FOP_REGNUM)
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{
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val &= ((1 << 11) - 1);
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supply_register (i, (char *) &val);
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}
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else
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supply_register (i, (char *) &val);
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}
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else
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supply_register (i, FSAVE_ADDR (fsave, i));
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}
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}
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/* Fill register REGNO (if it is a floating-point register) in *FSAVE
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with the value in GDB's register array. If REGNO is -1, do this
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for all registers. This function doesn't touch any of the reserved
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bits in *FSAVE. */
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void
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i387_fill_fsave (char *fsave, int regno)
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{
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int i;
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for (i = FP0_REGNUM; i <= LAST_FPU_CTRL_REGNUM; i++)
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if (regno == -1 || regno == i)
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{
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/* Most of the FPU control registers occupy only 16 bits in
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the fsave area. Give those a special treatment. */
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if (i >= FIRST_FPU_CTRL_REGNUM
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&& i != FCOFF_REGNUM && i != FDOFF_REGNUM)
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{
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if (i == FOP_REGNUM)
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{
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unsigned short oldval, newval;
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/* The opcode occupies only 11 bits. */
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oldval = (*(unsigned short *) (FSAVE_ADDR (fsave, i)));
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newval = *(unsigned short *) ®isters[REGISTER_BYTE (i)];
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newval &= ((1 << 11) - 1);
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newval |= oldval & ~((1 << 11) - 1);
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memcpy (FSAVE_ADDR (fsave, i), &newval, 2);
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}
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else
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memcpy (FSAVE_ADDR (fsave, i), ®isters[REGISTER_BYTE (i)], 2);
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}
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else
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memcpy (FSAVE_ADDR (fsave, i), ®isters[REGISTER_BYTE (i)],
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REGISTER_RAW_SIZE (i));
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}
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}
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