/* 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) { char buf[4]; regcache_collect (i, buf); if (i == FOP_REGNUM) { unsigned short oldval, newval; /* The opcode occupies only 11 bits. */ oldval = (*(unsigned short *) (FSAVE_ADDR (fsave, i))); newval = *(unsigned short *) buf; newval &= ((1 << 11) - 1); newval |= oldval & ~((1 << 11) - 1); memcpy (FSAVE_ADDR (fsave, i), &newval, 2); } else memcpy (FSAVE_ADDR (fsave, i), buf, 2); } else regcache_collect (i, FSAVE_ADDR (fsave, 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) { char buf[4]; regcache_collect (i, buf); if (i == FOP_REGNUM) { unsigned short oldval, newval; /* The opcode occupies only 11 bits. */ oldval = (*(unsigned short *) (FXSAVE_ADDR (fxsave, i))); newval = *(unsigned short *) buf; 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 *) buf; 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), buf, 2); } else regcache_collect (i, FXSAVE_ADDR (fxsave, 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); } } }