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Diffstat (limited to 'contrib/gdb/gdb/i387-nat.c')
| -rw-r--r-- | contrib/gdb/gdb/i387-nat.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/contrib/gdb/gdb/i387-nat.c b/contrib/gdb/gdb/i387-nat.c new file mode 100644 index 0000000..62c26f8 --- /dev/null +++ b/contrib/gdb/gdb/i387-nat.c @@ -0,0 +1,346 @@ +/* Native-dependent code for the i387. + Copyright 2000, 2001 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" +#include "regcache.h" + +#include "i387-nat.h" +#include "i386-tdep.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[REGNUM] you'll find the offset to the location in + the data structure used by the "fsave" instruction where GDB + register REGNUM 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, /* FISEG_REGNUM (16 bits). */ + 12, /* FIOFF_REGNUM. */ + 24, /* FOSEG_REGNUM. */ + 20, /* FOOFF_REGNUM. */ + 18 /* FOP_REGNUM (bottom 11 bits). */ +}; + +#define FSAVE_ADDR(fsave, regnum) (fsave + fsave_offset[regnum - FP0_REGNUM]) + + +/* Fill register REGNUM in GDB's register array with the appropriate + value from *FSAVE. This function masks off any of the reserved + bits in *FSAVE. */ + +void +i387_supply_register (int regnum, char *fsave) +{ + /* Most of the FPU control registers occupy only 16 bits in + the fsave area. Give those a special treatment. */ + if (regnum >= FPC_REGNUM + && regnum != FIOFF_REGNUM && regnum != FOOFF_REGNUM) + { + unsigned int val = *(unsigned short *) (FSAVE_ADDR (fsave, regnum)); + + if (regnum == FOP_REGNUM) + { + val &= ((1 << 11) - 1); + supply_register (regnum, (char *) &val); + } + else + supply_register (regnum, (char *) &val); + } + else + supply_register (regnum, FSAVE_ADDR (fsave, 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 < XMM0_REGNUM; i++) + i387_supply_register (i, fsave); +} + +/* Fill register REGNUM (if it is a floating-point register) in *FSAVE + with the value in GDB's register array. If REGNUM 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 regnum) +{ + int i; + + for (i = FP0_REGNUM; i < XMM0_REGNUM; i++) + if (regnum == -1 || regnum == i) + { + /* Most of the FPU control registers occupy only 16 bits in + the fsave area. Give those a special treatment. */ + if (i >= FPC_REGNUM + && i != FIOFF_REGNUM && i != FOOFF_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)); + } +} + + +/* At fxsave_offset[REGNUM] you'll find the offset to the location in + the data structure used by the "fxsave" instruction where GDB + register REGNUM is stored. */ + +static int fxsave_offset[] = +{ + 32, /* FP0_REGNUM through ... */ + 48, + 64, + 80, + 96, + 112, + 128, + 144, /* ... FP7_REGNUM (80 bits each). */ + 0, /* FCTRL_REGNUM (16 bits). */ + 2, /* FSTAT_REGNUM (16 bits). */ + 4, /* FTAG_REGNUM (16 bits). */ + 12, /* FISEG_REGNUM (16 bits). */ + 8, /* FIOFF_REGNUM. */ + 20, /* FOSEG_REGNUM (16 bits). */ + 16, /* FOOFF_REGNUM. */ + 6, /* FOP_REGNUM (bottom 11 bits). */ + 160, /* XMM0_REGNUM through ... */ + 176, + 192, + 208, + 224, + 240, + 256, + 272, /* ... XMM7_REGNUM (128 bits each). */ + 24, /* MXCSR_REGNUM. */ +}; + +#define FXSAVE_ADDR(fxsave, regnum) \ + (fxsave + fxsave_offset[regnum - FP0_REGNUM]) + +static int i387_tag (unsigned char *raw); + + +/* Fill GDB's register array with the floating-point and SSE register + values in *FXSAVE. This function masks off any of the reserved + bits in *FXSAVE. */ + +void +i387_supply_fxsave (char *fxsave) +{ + int i; + + for (i = FP0_REGNUM; i <= MXCSR_REGNUM; i++) + { + /* Most of the FPU control registers occupy only 16 bits in + the fxsave area. Give those a special treatment. */ + if (i >= FPC_REGNUM && i < XMM0_REGNUM + && i != FIOFF_REGNUM && i != FOOFF_REGNUM) + { + unsigned long val = *(unsigned short *) (FXSAVE_ADDR (fxsave, i)); + + if (i == FOP_REGNUM) + { + val &= ((1 << 11) - 1); + supply_register (i, (char *) &val); + } + else if (i== FTAG_REGNUM) + { + /* The fxsave area contains a simplified version of the + tag word. We have to look at the actual 80-bit FP + data to recreate the traditional i387 tag word. */ + + unsigned long ftag = 0; + unsigned long fstat; + int fpreg; + int top; + + fstat = *(unsigned short *) (FXSAVE_ADDR (fxsave, FSTAT_REGNUM)); + top = ((fstat >> 11) & 0x7); + + for (fpreg = 7; fpreg >= 0; fpreg--) + { + int tag; + + if (val & (1 << fpreg)) + { + int regnum = (fpreg + 8 - top) % 8 + FP0_REGNUM; + tag = i387_tag (FXSAVE_ADDR (fxsave, regnum)); + } + else + tag = 3; /* Empty */ + + ftag |= tag << (2 * fpreg); + } + supply_register (i, (char *) &ftag); + } + else + supply_register (i, (char *) &val); + } + else + supply_register (i, FXSAVE_ADDR (fxsave, i)); + } +} + +/* Fill register REGNUM (if it is a floating-point or SSE register) in + *FXSAVE with the value in GDB's register array. If REGNUM is -1, do + this for all registers. This function doesn't touch any of the + reserved bits in *FXSAVE. */ + +void +i387_fill_fxsave (char *fxsave, int regnum) +{ + int i; + + for (i = FP0_REGNUM; i <= MXCSR_REGNUM; i++) + if (regnum == -1 || regnum == i) + { + /* Most of the FPU control registers occupy only 16 bits in + the fxsave area. Give those a special treatment. */ + if (i >= FPC_REGNUM && i < XMM0_REGNUM + && i != FIOFF_REGNUM && i != FDOFF_REGNUM) + { + if (i == FOP_REGNUM) + { + unsigned short oldval, newval; + + /* The opcode occupies only 11 bits. */ + oldval = (*(unsigned short *) (FXSAVE_ADDR (fxsave, i))); + newval = *(unsigned short *) ®isters[REGISTER_BYTE (i)]; + newval &= ((1 << 11) - 1); + newval |= oldval & ~((1 << 11) - 1); + memcpy (FXSAVE_ADDR (fxsave, i), &newval, 2); + } + else if (i == FTAG_REGNUM) + { + /* Converting back is much easier. */ + + unsigned short val = 0; + unsigned short ftag; + int fpreg; + + ftag = *(unsigned short *) ®isters[REGISTER_BYTE (i)]; + + for (fpreg = 7; fpreg >= 0; fpreg--) + { + int tag = (ftag >> (fpreg * 2)) & 3; + + if (tag != 3) + val |= (1 << fpreg); + } + + memcpy (FXSAVE_ADDR (fxsave, i), &val, 2); + } + else + memcpy (FXSAVE_ADDR (fxsave, i), + ®isters[REGISTER_BYTE (i)], 2); + } + else + memcpy (FXSAVE_ADDR (fxsave, i), ®isters[REGISTER_BYTE (i)], + REGISTER_RAW_SIZE (i)); + } +} + +/* Recreate the FTW (tag word) valid bits from the 80-bit FP data in + *RAW. */ + +static int +i387_tag (unsigned char *raw) +{ + int integer; + unsigned int exponent; + unsigned long fraction[2]; + + integer = raw[7] & 0x80; + exponent = (((raw[9] & 0x7f) << 8) | raw[8]); + fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]); + fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16) + | (raw[5] << 8) | raw[4]); + + if (exponent == 0x7fff) + { + /* Special. */ + return (2); + } + else if (exponent == 0x0000) + { + if (fraction[0] == 0x0000 && fraction[1] == 0x0000 && !integer) + { + /* Zero. */ + return (1); + } + else + { + /* Special. */ + return (2); + } + } + else + { + if (integer) + { + /* Valid. */ + return (0); + } + else + { + /* Special. */ + return (2); + } + } +} |
