| /* Intel 387 floating point stuff. |
| |
| Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1998, 1999, 2000, |
| 2001, 2002, 2003, 2004, 2005 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 "doublest.h" |
| #include "floatformat.h" |
| #include "frame.h" |
| #include "gdbcore.h" |
| #include "inferior.h" |
| #include "language.h" |
| #include "regcache.h" |
| #include "value.h" |
| |
| #include "gdb_assert.h" |
| #include "gdb_string.h" |
| |
| #include "i386-tdep.h" |
| #include "i387-tdep.h" |
| |
| /* Print the floating point number specified by RAW. */ |
| |
| static void |
| print_i387_value (const gdb_byte *raw, struct ui_file *file) |
| { |
| DOUBLEST value; |
| |
| /* Using extract_typed_floating here might affect the representation |
| of certain numbers such as NaNs, even if GDB is running natively. |
| This is fine since our caller already detects such special |
| numbers and we print the hexadecimal representation anyway. */ |
| value = extract_typed_floating (raw, builtin_type_i387_ext); |
| |
| /* We try to print 19 digits. The last digit may or may not contain |
| garbage, but we'd better print one too many. We need enough room |
| to print the value, 1 position for the sign, 1 for the decimal |
| point, 19 for the digits and 6 for the exponent adds up to 27. */ |
| #ifdef PRINTF_HAS_LONG_DOUBLE |
| fprintf_filtered (file, " %-+27.19Lg", (long double) value); |
| #else |
| fprintf_filtered (file, " %-+27.19g", (double) value); |
| #endif |
| } |
| |
| /* Print the classification for the register contents RAW. */ |
| |
| static void |
| print_i387_ext (const gdb_byte *raw, struct ui_file *file) |
| { |
| int sign; |
| int integer; |
| unsigned int exponent; |
| unsigned long fraction[2]; |
| |
| sign = raw[9] & 0x80; |
| 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 && integer) |
| { |
| if (fraction[0] == 0x00000000 && fraction[1] == 0x00000000) |
| /* Infinity. */ |
| fprintf_filtered (file, " %cInf", (sign ? '-' : '+')); |
| else if (sign && fraction[0] == 0x00000000 && fraction[1] == 0x40000000) |
| /* Real Indefinite (QNaN). */ |
| fputs_unfiltered (" Real Indefinite (QNaN)", file); |
| else if (fraction[1] & 0x40000000) |
| /* QNaN. */ |
| fputs_filtered (" QNaN", file); |
| else |
| /* SNaN. */ |
| fputs_filtered (" SNaN", file); |
| } |
| else if (exponent < 0x7fff && exponent > 0x0000 && integer) |
| /* Normal. */ |
| print_i387_value (raw, file); |
| else if (exponent == 0x0000) |
| { |
| /* Denormal or zero. */ |
| print_i387_value (raw, file); |
| |
| if (integer) |
| /* Pseudo-denormal. */ |
| fputs_filtered (" Pseudo-denormal", file); |
| else if (fraction[0] || fraction[1]) |
| /* Denormal. */ |
| fputs_filtered (" Denormal", file); |
| } |
| else |
| /* Unsupported. */ |
| fputs_filtered (" Unsupported", file); |
| } |
| |
| /* Print the status word STATUS. */ |
| |
| static void |
| print_i387_status_word (unsigned int status, struct ui_file *file) |
| { |
| fprintf_filtered (file, "Status Word: %s", |
| hex_string_custom (status, 4)); |
| fputs_filtered (" ", file); |
| fprintf_filtered (file, " %s", (status & 0x0001) ? "IE" : " "); |
| fprintf_filtered (file, " %s", (status & 0x0002) ? "DE" : " "); |
| fprintf_filtered (file, " %s", (status & 0x0004) ? "ZE" : " "); |
| fprintf_filtered (file, " %s", (status & 0x0008) ? "OE" : " "); |
| fprintf_filtered (file, " %s", (status & 0x0010) ? "UE" : " "); |
| fprintf_filtered (file, " %s", (status & 0x0020) ? "PE" : " "); |
| fputs_filtered (" ", file); |
| fprintf_filtered (file, " %s", (status & 0x0080) ? "ES" : " "); |
| fputs_filtered (" ", file); |
| fprintf_filtered (file, " %s", (status & 0x0040) ? "SF" : " "); |
| fputs_filtered (" ", file); |
| fprintf_filtered (file, " %s", (status & 0x0100) ? "C0" : " "); |
| fprintf_filtered (file, " %s", (status & 0x0200) ? "C1" : " "); |
| fprintf_filtered (file, " %s", (status & 0x0400) ? "C2" : " "); |
| fprintf_filtered (file, " %s", (status & 0x4000) ? "C3" : " "); |
| |
| fputs_filtered ("\n", file); |
| |
| fprintf_filtered (file, |
| " TOP: %d\n", ((status >> 11) & 7)); |
| } |
| |
| /* Print the control word CONTROL. */ |
| |
| static void |
| print_i387_control_word (unsigned int control, struct ui_file *file) |
| { |
| fprintf_filtered (file, "Control Word: %s", |
| hex_string_custom (control, 4)); |
| fputs_filtered (" ", file); |
| fprintf_filtered (file, " %s", (control & 0x0001) ? "IM" : " "); |
| fprintf_filtered (file, " %s", (control & 0x0002) ? "DM" : " "); |
| fprintf_filtered (file, " %s", (control & 0x0004) ? "ZM" : " "); |
| fprintf_filtered (file, " %s", (control & 0x0008) ? "OM" : " "); |
| fprintf_filtered (file, " %s", (control & 0x0010) ? "UM" : " "); |
| fprintf_filtered (file, " %s", (control & 0x0020) ? "PM" : " "); |
| |
| fputs_filtered ("\n", file); |
| |
| fputs_filtered (" PC: ", file); |
| switch ((control >> 8) & 3) |
| { |
| case 0: |
| fputs_filtered ("Single Precision (24-bits)\n", file); |
| break; |
| case 1: |
| fputs_filtered ("Reserved\n", file); |
| break; |
| case 2: |
| fputs_filtered ("Double Precision (53-bits)\n", file); |
| break; |
| case 3: |
| fputs_filtered ("Extended Precision (64-bits)\n", file); |
| break; |
| } |
| |
| fputs_filtered (" RC: ", file); |
| switch ((control >> 10) & 3) |
| { |
| case 0: |
| fputs_filtered ("Round to nearest\n", file); |
| break; |
| case 1: |
| fputs_filtered ("Round down\n", file); |
| break; |
| case 2: |
| fputs_filtered ("Round up\n", file); |
| break; |
| case 3: |
| fputs_filtered ("Round toward zero\n", file); |
| break; |
| } |
| } |
| |
| /* Print out the i387 floating point state. Note that we ignore FRAME |
| in the code below. That's OK since floating-point registers are |
| never saved on the stack. */ |
| |
| void |
| i387_print_float_info (struct gdbarch *gdbarch, struct ui_file *file, |
| struct frame_info *frame, const char *args) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (frame)); |
| gdb_byte buf[4]; |
| ULONGEST fctrl; |
| ULONGEST fstat; |
| ULONGEST ftag; |
| ULONGEST fiseg; |
| ULONGEST fioff; |
| ULONGEST foseg; |
| ULONGEST fooff; |
| ULONGEST fop; |
| int fpreg; |
| int top; |
| |
| gdb_assert (gdbarch == get_frame_arch (frame)); |
| |
| /* Define I387_ST0_REGNUM such that we use the proper definitions |
| for FRAME's architecture. */ |
| #define I387_ST0_REGNUM tdep->st0_regnum |
| |
| fctrl = get_frame_register_unsigned (frame, I387_FCTRL_REGNUM); |
| fstat = get_frame_register_unsigned (frame, I387_FSTAT_REGNUM); |
| ftag = get_frame_register_unsigned (frame, I387_FTAG_REGNUM); |
| fiseg = get_frame_register_unsigned (frame, I387_FISEG_REGNUM); |
| fioff = get_frame_register_unsigned (frame, I387_FIOFF_REGNUM); |
| foseg = get_frame_register_unsigned (frame, I387_FOSEG_REGNUM); |
| fooff = get_frame_register_unsigned (frame, I387_FOOFF_REGNUM); |
| fop = get_frame_register_unsigned (frame, I387_FOP_REGNUM); |
| |
| top = ((fstat >> 11) & 7); |
| |
| for (fpreg = 7; fpreg >= 0; fpreg--) |
| { |
| gdb_byte raw[I386_MAX_REGISTER_SIZE]; |
| int tag = (ftag >> (fpreg * 2)) & 3; |
| int i; |
| |
| fprintf_filtered (file, "%sR%d: ", fpreg == top ? "=>" : " ", fpreg); |
| |
| switch (tag) |
| { |
| case 0: |
| fputs_filtered ("Valid ", file); |
| break; |
| case 1: |
| fputs_filtered ("Zero ", file); |
| break; |
| case 2: |
| fputs_filtered ("Special ", file); |
| break; |
| case 3: |
| fputs_filtered ("Empty ", file); |
| break; |
| } |
| |
| get_frame_register (frame, (fpreg + 8 - top) % 8 + I387_ST0_REGNUM, raw); |
| |
| fputs_filtered ("0x", file); |
| for (i = 9; i >= 0; i--) |
| fprintf_filtered (file, "%02x", raw[i]); |
| |
| if (tag != 3) |
| print_i387_ext (raw, file); |
| |
| fputs_filtered ("\n", file); |
| } |
| |
| fputs_filtered ("\n", file); |
| |
| print_i387_status_word (fstat, file); |
| print_i387_control_word (fctrl, file); |
| fprintf_filtered (file, "Tag Word: %s\n", |
| hex_string_custom (ftag, 4)); |
| fprintf_filtered (file, "Instruction Pointer: %s:", |
| hex_string_custom (fiseg, 2)); |
| fprintf_filtered (file, "%s\n", hex_string_custom (fioff, 8)); |
| fprintf_filtered (file, "Operand Pointer: %s:", |
| hex_string_custom (foseg, 2)); |
| fprintf_filtered (file, "%s\n", hex_string_custom (fooff, 8)); |
| fprintf_filtered (file, "Opcode: %s\n", |
| hex_string_custom (fop ? (fop | 0xd800) : 0, 4)); |
| |
| #undef I387_ST0_REGNUM |
| } |
| |
| |
| /* Read a value of type TYPE from register REGNUM in frame FRAME, and |
| return its contents in TO. */ |
| |
| void |
| i387_register_to_value (struct frame_info *frame, int regnum, |
| struct type *type, gdb_byte *to) |
| { |
| gdb_byte from[I386_MAX_REGISTER_SIZE]; |
| |
| gdb_assert (i386_fp_regnum_p (regnum)); |
| |
| /* We only support floating-point values. */ |
| if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| { |
| warning (_("Cannot convert floating-point register value " |
| "to non-floating-point type.")); |
| return; |
| } |
| |
| /* Convert to TYPE. This should be a no-op if TYPE is equivalent to |
| the extended floating-point format used by the FPU. */ |
| get_frame_register (frame, regnum, from); |
| convert_typed_floating (from, builtin_type_i387_ext, to, type); |
| } |
| |
| /* Write the contents FROM of a value of type TYPE into register |
| REGNUM in frame FRAME. */ |
| |
| void |
| i387_value_to_register (struct frame_info *frame, int regnum, |
| struct type *type, const gdb_byte *from) |
| { |
| gdb_byte to[I386_MAX_REGISTER_SIZE]; |
| |
| gdb_assert (i386_fp_regnum_p (regnum)); |
| |
| /* We only support floating-point values. */ |
| if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| { |
| warning (_("Cannot convert non-floating-point type " |
| "to floating-point register value.")); |
| return; |
| } |
| |
| /* Convert from TYPE. This should be a no-op if TYPE is equivalent |
| to the extended floating-point format used by the FPU. */ |
| convert_typed_floating (from, type, to, builtin_type_i387_ext); |
| put_frame_register (frame, regnum, to); |
| } |
| |
| |
| /* Handle FSAVE and FXSAVE formats. */ |
| |
| /* 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 * 10, /* %st(0) ... */ |
| 28 + 1 * 10, |
| 28 + 2 * 10, |
| 28 + 3 * 10, |
| 28 + 4 * 10, |
| 28 + 5 * 10, |
| 28 + 6 * 10, |
| 28 + 7 * 10, /* ... %st(7). */ |
| 0, /* `fctrl' (16 bits). */ |
| 4, /* `fstat' (16 bits). */ |
| 8, /* `ftag' (16 bits). */ |
| 16, /* `fiseg' (16 bits). */ |
| 12, /* `fioff'. */ |
| 24, /* `foseg' (16 bits). */ |
| 20, /* `fooff'. */ |
| 18 /* `fop' (bottom 11 bits). */ |
| }; |
| |
| #define FSAVE_ADDR(fsave, regnum) \ |
| (fsave + fsave_offset[regnum - I387_ST0_REGNUM]) |
| |
| |
| /* Fill register REGNUM in REGCACHE with the appropriate value from |
| *FSAVE. This function masks off any of the reserved bits in |
| *FSAVE. */ |
| |
| void |
| i387_supply_fsave (struct regcache *regcache, int regnum, const void *fsave) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache)); |
| const gdb_byte *regs = fsave; |
| int i; |
| |
| gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM); |
| |
| /* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the |
| proper definitions for REGCACHE's architecture. */ |
| |
| #define I387_ST0_REGNUM tdep->st0_regnum |
| #define I387_NUM_XMM_REGS tdep->num_xmm_regs |
| |
| for (i = I387_ST0_REGNUM; i < I387_XMM0_REGNUM; i++) |
| if (regnum == -1 || regnum == i) |
| { |
| if (fsave == NULL) |
| { |
| regcache_raw_supply (regcache, i, NULL); |
| continue; |
| } |
| |
| /* Most of the FPU control registers occupy only 16 bits in the |
| fsave area. Give those a special treatment. */ |
| if (i >= I387_FCTRL_REGNUM |
| && i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM) |
| { |
| gdb_byte val[4]; |
| |
| memcpy (val, FSAVE_ADDR (regs, i), 2); |
| val[2] = val[3] = 0; |
| if (i == I387_FOP_REGNUM) |
| val[1] &= ((1 << 3) - 1); |
| regcache_raw_supply (regcache, i, val); |
| } |
| else |
| regcache_raw_supply (regcache, i, FSAVE_ADDR (regs, i)); |
| } |
| |
| /* Provide dummy values for the SSE registers. */ |
| for (i = I387_XMM0_REGNUM; i < I387_MXCSR_REGNUM; i++) |
| if (regnum == -1 || regnum == i) |
| regcache_raw_supply (regcache, i, NULL); |
| if (regnum == -1 || regnum == I387_MXCSR_REGNUM) |
| { |
| gdb_byte buf[4]; |
| |
| store_unsigned_integer (buf, 4, 0x1f80); |
| regcache_raw_supply (regcache, I387_MXCSR_REGNUM, buf); |
| } |
| |
| #undef I387_ST0_REGNUM |
| #undef I387_NUM_XMM_REGS |
| } |
| |
| /* Fill register REGNUM (if it is a floating-point register) in *FSAVE |
| with the value from REGCACHE. If REGNUM is -1, do this for all |
| registers. This function doesn't touch any of the reserved bits in |
| *FSAVE. */ |
| |
| void |
| i387_collect_fsave (const struct regcache *regcache, int regnum, void *fsave) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| gdb_byte *regs = fsave; |
| int i; |
| |
| gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM); |
| |
| /* Define I387_ST0_REGNUM such that we use the proper definitions |
| for REGCACHE's architecture. */ |
| #define I387_ST0_REGNUM tdep->st0_regnum |
| |
| for (i = I387_ST0_REGNUM; i < I387_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 >= I387_FCTRL_REGNUM |
| && i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM) |
| { |
| gdb_byte buf[4]; |
| |
| regcache_raw_collect (regcache, i, buf); |
| |
| if (i == I387_FOP_REGNUM) |
| { |
| /* The opcode occupies only 11 bits. Make sure we |
| don't touch the other bits. */ |
| buf[1] &= ((1 << 3) - 1); |
| buf[1] |= ((FSAVE_ADDR (regs, i))[1] & ~((1 << 3) - 1)); |
| } |
| memcpy (FSAVE_ADDR (regs, i), buf, 2); |
| } |
| else |
| regcache_raw_collect (regcache, i, FSAVE_ADDR (regs, i)); |
| } |
| #undef I387_ST0_REGNUM |
| } |
| |
| /* Fill register REGNUM (if it is a floating-point register) in *FSAVE |
| with the value in GDB's register cache. 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 (void *fsave, int regnum) |
| { |
| i387_collect_fsave (current_regcache, regnum, fsave); |
| } |
| |
| |
| /* 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, /* %st(0) through ... */ |
| 48, |
| 64, |
| 80, |
| 96, |
| 112, |
| 128, |
| 144, /* ... %st(7) (80 bits each). */ |
| 0, /* `fctrl' (16 bits). */ |
| 2, /* `fstat' (16 bits). */ |
| 4, /* `ftag' (16 bits). */ |
| 12, /* `fiseg' (16 bits). */ |
| 8, /* `fioff'. */ |
| 20, /* `foseg' (16 bits). */ |
| 16, /* `fooff'. */ |
| 6, /* `fop' (bottom 11 bits). */ |
| 160 + 0 * 16, /* %xmm0 through ... */ |
| 160 + 1 * 16, |
| 160 + 2 * 16, |
| 160 + 3 * 16, |
| 160 + 4 * 16, |
| 160 + 5 * 16, |
| 160 + 6 * 16, |
| 160 + 7 * 16, |
| 160 + 8 * 16, |
| 160 + 9 * 16, |
| 160 + 10 * 16, |
| 160 + 11 * 16, |
| 160 + 12 * 16, |
| 160 + 13 * 16, |
| 160 + 14 * 16, |
| 160 + 15 * 16, /* ... %xmm15 (128 bits each). */ |
| }; |
| |
| #define FXSAVE_ADDR(fxsave, regnum) \ |
| (fxsave + fxsave_offset[regnum - I387_ST0_REGNUM]) |
| |
| /* We made an unfortunate choice in putting %mxcsr after the SSE |
| registers %xmm0-%xmm7 instead of before, since it makes supporting |
| the registers %xmm8-%xmm15 on AMD64 a bit involved. Therefore we |
| don't include the offset for %mxcsr here above. */ |
| |
| #define FXSAVE_MXCSR_ADDR(fxsave) (fxsave + 24) |
| |
| static int i387_tag (const gdb_byte *raw); |
| |
| |
| /* Fill register REGNUM in REGCACHE with the appropriate |
| floating-point or SSE register value from *FXSAVE. This function |
| masks off any of the reserved bits in *FXSAVE. */ |
| |
| void |
| i387_supply_fxsave (struct regcache *regcache, int regnum, const void *fxsave) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache)); |
| const gdb_byte *regs = fxsave; |
| int i; |
| |
| gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM); |
| gdb_assert (tdep->num_xmm_regs > 0); |
| |
| /* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the |
| proper definitions for REGCACHE's architecture. */ |
| |
| #define I387_ST0_REGNUM tdep->st0_regnum |
| #define I387_NUM_XMM_REGS tdep->num_xmm_regs |
| |
| for (i = I387_ST0_REGNUM; i < I387_MXCSR_REGNUM; i++) |
| if (regnum == -1 || regnum == i) |
| { |
| if (regs == NULL) |
| { |
| regcache_raw_supply (regcache, i, NULL); |
| continue; |
| } |
| |
| /* Most of the FPU control registers occupy only 16 bits in |
| the fxsave area. Give those a special treatment. */ |
| if (i >= I387_FCTRL_REGNUM && i < I387_XMM0_REGNUM |
| && i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM) |
| { |
| gdb_byte val[4]; |
| |
| memcpy (val, FXSAVE_ADDR (regs, i), 2); |
| val[2] = val[3] = 0; |
| if (i == I387_FOP_REGNUM) |
| val[1] &= ((1 << 3) - 1); |
| else if (i== I387_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; |
| int fpreg; |
| int top; |
| |
| top = ((FXSAVE_ADDR (regs, I387_FSTAT_REGNUM))[1] >> 3); |
| top &= 0x7; |
| |
| for (fpreg = 7; fpreg >= 0; fpreg--) |
| { |
| int tag; |
| |
| if (val[0] & (1 << fpreg)) |
| { |
| int regnum = (fpreg + 8 - top) % 8 + I387_ST0_REGNUM; |
| tag = i387_tag (FXSAVE_ADDR (regs, regnum)); |
| } |
| else |
| tag = 3; /* Empty */ |
| |
| ftag |= tag << (2 * fpreg); |
| } |
| val[0] = ftag & 0xff; |
| val[1] = (ftag >> 8) & 0xff; |
| } |
| regcache_raw_supply (regcache, i, val); |
| } |
| else |
| regcache_raw_supply (regcache, i, FXSAVE_ADDR (regs, i)); |
| } |
| |
| if (regnum == I387_MXCSR_REGNUM || regnum == -1) |
| { |
| if (regs == NULL) |
| regcache_raw_supply (regcache, I387_MXCSR_REGNUM, NULL); |
| else |
| regcache_raw_supply (regcache, I387_MXCSR_REGNUM, |
| FXSAVE_MXCSR_ADDR (regs)); |
| } |
| |
| #undef I387_ST0_REGNUM |
| #undef I387_NUM_XMM_REGS |
| } |
| |
| /* Fill register REGNUM (if it is a floating-point or SSE register) in |
| *FXSAVE with the value from REGCACHE. If REGNUM is -1, do this for |
| all registers. This function doesn't touch any of the reserved |
| bits in *FXSAVE. */ |
| |
| void |
| i387_collect_fxsave (const struct regcache *regcache, int regnum, void *fxsave) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| gdb_byte *regs = fxsave; |
| int i; |
| |
| gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM); |
| gdb_assert (tdep->num_xmm_regs > 0); |
| |
| /* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the |
| proper definitions for REGCACHE's architecture. */ |
| |
| #define I387_ST0_REGNUM tdep->st0_regnum |
| #define I387_NUM_XMM_REGS tdep->num_xmm_regs |
| |
| for (i = I387_ST0_REGNUM; i < I387_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 >= I387_FCTRL_REGNUM && i < I387_XMM0_REGNUM |
| && i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM) |
| { |
| gdb_byte buf[4]; |
| |
| regcache_raw_collect (regcache, i, buf); |
| |
| if (i == I387_FOP_REGNUM) |
| { |
| /* The opcode occupies only 11 bits. Make sure we |
| don't touch the other bits. */ |
| buf[1] &= ((1 << 3) - 1); |
| buf[1] |= ((FXSAVE_ADDR (regs, i))[1] & ~((1 << 3) - 1)); |
| } |
| else if (i == I387_FTAG_REGNUM) |
| { |
| /* Converting back is much easier. */ |
| |
| unsigned short ftag; |
| int fpreg; |
| |
| ftag = (buf[1] << 8) | buf[0]; |
| buf[0] = 0; |
| buf[1] = 0; |
| |
| for (fpreg = 7; fpreg >= 0; fpreg--) |
| { |
| int tag = (ftag >> (fpreg * 2)) & 3; |
| |
| if (tag != 3) |
| buf[0] |= (1 << fpreg); |
| } |
| } |
| memcpy (FXSAVE_ADDR (regs, i), buf, 2); |
| } |
| else |
| regcache_raw_collect (regcache, i, FXSAVE_ADDR (regs, i)); |
| } |
| |
| if (regnum == I387_MXCSR_REGNUM || regnum == -1) |
| regcache_raw_collect (regcache, I387_MXCSR_REGNUM, |
| FXSAVE_MXCSR_ADDR (regs)); |
| |
| #undef I387_ST0_REGNUM |
| #undef I387_NUM_XMM_REGS |
| } |
| |
| /* Fill register REGNUM (if it is a floating-point or SSE register) in |
| *FXSAVE with the value in GDB's register cache. 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 (void *fxsave, int regnum) |
| { |
| i387_collect_fxsave (current_regcache, regnum, fxsave); |
| } |
| |
| /* Recreate the FTW (tag word) valid bits from the 80-bit FP data in |
| *RAW. */ |
| |
| static int |
| i387_tag (const gdb_byte *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); |
| } |
| } |
| } |
| |
| /* Prepare the FPU stack in REGCACHE for a function return. */ |
| |
| void |
| i387_return_value (struct gdbarch *gdbarch, struct regcache *regcache) |
| { |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| ULONGEST fstat; |
| |
| /* Define I387_ST0_REGNUM such that we use the proper |
| definitions for the architecture. */ |
| #define I387_ST0_REGNUM tdep->st0_regnum |
| |
| /* Set the top of the floating-point register stack to 7. The |
| actual value doesn't really matter, but 7 is what a normal |
| function return would end up with if the program started out with |
| a freshly initialized FPU. */ |
| regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM, &fstat); |
| fstat |= (7 << 11); |
| regcache_raw_write_unsigned (regcache, I387_FSTAT_REGNUM, fstat); |
| |
| /* Mark %st(1) through %st(7) as empty. Since we set the top of the |
| floating-point register stack to 7, the appropriate value for the |
| tag word is 0x3fff. */ |
| regcache_raw_write_unsigned (regcache, I387_FTAG_REGNUM, 0x3fff); |
| |
| #undef I387_ST0_REGNUM |
| } |