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Diffstat (limited to 'gdb/i387-nat.c')
| -rw-r--r-- | gdb/i387-nat.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/gdb/i387-nat.c b/gdb/i387-nat.c new file mode 100644 index 00000000000..17e67b47a32 --- /dev/null +++ b/gdb/i387-nat.c @@ -0,0 +1,125 @@ +/* Native-dependent code for the i387. + Copyright (C) 2000 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 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, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "defs.h" +#include "inferior.h" +#include "value.h" + +/* FIXME: kettenis/2000-05-21: Right now more than a few i386 targets + define their own routines to manage the floating-point registers in + GDB's register array. Most (if not all) of these targets use the + format used by the "fsave" instruction in their communication with + the OS. They should all be converted to use the routines below. */ + +/* At fsave_offset[REGNO] you'll find the offset to the location in + the data structure used by the "fsave" instruction where GDB + register REGNO is stored. */ + +static int fsave_offset[] = +{ + 28 + 0 * FPU_REG_RAW_SIZE, /* FP0_REGNUM through ... */ + 28 + 1 * FPU_REG_RAW_SIZE, + 28 + 2 * FPU_REG_RAW_SIZE, + 28 + 3 * FPU_REG_RAW_SIZE, + 28 + 4 * FPU_REG_RAW_SIZE, + 28 + 5 * FPU_REG_RAW_SIZE, + 28 + 6 * FPU_REG_RAW_SIZE, + 28 + 7 * FPU_REG_RAW_SIZE, /* ... FP7_REGNUM. */ + 0, /* FCTRL_REGNUM (16 bits). */ + 4, /* FSTAT_REGNUM (16 bits). */ + 8, /* FTAG_REGNUM (16 bits). */ + 16, /* FCS_REGNUM (16 bits). */ + 12, /* FCOFF_REGNUM. */ + 24, /* FDS_REGNUM. */ + 20, /* FDOFF_REGNUM. */ + 18 /* FOP_REGNUM (bottom 11 bits). */ +}; + +#define FSAVE_ADDR(fsave, regnum) (fsave + fsave_offset[regnum - FP0_REGNUM]) + + +/* Fill GDB's register array with the floating-point register values + in *FSAVE. This function masks off any of the reserved + bits in *FSAVE. */ + +void +i387_supply_fsave (char *fsave) +{ + int i; + + for (i = FP0_REGNUM; i <= LAST_FPU_CTRL_REGNUM; i++) + { + /* Most of the FPU control registers occupy only 16 bits in + the fsave area. Give those a special treatment. */ + if (i >= FIRST_FPU_CTRL_REGNUM + && i != FCOFF_REGNUM && i != FDOFF_REGNUM) + { + unsigned val = *(unsigned short *) (FSAVE_ADDR (fsave, i)); + + if (i == FOP_REGNUM) + { + val &= ((1 << 11) - 1); + supply_register (i, (char *) &val); + } + else + supply_register (i, (char *) &val); + } + else + supply_register (i, FSAVE_ADDR (fsave, i)); + } +} + +/* Fill register REGNO (if it is a floating-point register) in *FSAVE + with the value in GDB's register array. If REGNO is -1, do this + for all registers. This function doesn't touch any of the reserved + bits in *FSAVE. */ + +void +i387_fill_fsave (char *fsave, int regno) +{ + int i; + + for (i = FP0_REGNUM; i <= LAST_FPU_CTRL_REGNUM; i++) + if (regno == -1 || regno == i) + { + /* Most of the FPU control registers occupy only 16 bits in + the fsave area. Give those a special treatment. */ + if (i >= FIRST_FPU_CTRL_REGNUM + && i != FCOFF_REGNUM && i != FDOFF_REGNUM) + { + if (i == FOP_REGNUM) + { + unsigned short oldval, newval; + + /* The opcode occupies only 11 bits. */ + oldval = (*(unsigned short *) (FSAVE_ADDR (fsave, i))); + newval = *(unsigned short *) ®isters[REGISTER_BYTE (i)]; + newval &= ((1 << 11) - 1); + newval |= oldval & ~((1 << 11) - 1); + memcpy (FSAVE_ADDR (fsave, i), &newval, 2); + } + else + memcpy (FSAVE_ADDR (fsave, i), ®isters[REGISTER_BYTE (i)], 2); + } + else + memcpy (FSAVE_ADDR (fsave, i), ®isters[REGISTER_BYTE (i)], + REGISTER_RAW_SIZE (i)); + } +} |