/* i387-specific utility functions, for the remote server for GDB.
  Copyright (C) 2000-2024 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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "i387-fp.h"
#include "gdbsupport/x86-xstate.h"
#include "nat/x86-xstate.h"

/* Default to SSE.  */
static uint64_t x86_xcr0 = X86_XSTATE_SSE_MASK;

static const int num_avx512_k_registers = 8;
static const int num_pkeys_registers = 1;

static x86_xsave_layout xsave_layout;

/* Note: These functions preserve the reserved bits in control registers.
  However, gdbserver promptly throws away that information.  */

/* These structs should have the proper sizes and alignment on both
  i386 and x86-64 machines.  */

struct i387_fsave
{
 /* All these are only sixteen bits, plus padding, except for fop (which
    is only eleven bits), and fooff / fioff (which are 32 bits each).  */
 unsigned short fctrl;
 unsigned short pad1;
 unsigned short fstat;
 unsigned short pad2;
 unsigned short ftag;
 unsigned short pad3;
 unsigned int fioff;
 unsigned short fiseg;
 unsigned short fop;
 unsigned int fooff;
 unsigned short foseg;
 unsigned short pad4;

 /* Space for eight 80-bit FP values.  */
 unsigned char st_space[80];
};

struct i387_fxsave
{
 /* All these are only sixteen bits, plus padding, except for fop (which
    is only eleven bits), and fooff / fioff (which are 32 bits each).  */
 unsigned short fctrl;
 unsigned short fstat;
 unsigned short ftag;
 unsigned short fop;
 unsigned int fioff;
 unsigned short fiseg;
 unsigned short pad1;
 unsigned int fooff;
 unsigned short foseg;
 unsigned short pad12;

 unsigned int mxcsr;
 unsigned int pad3;

 /* Space for eight 80-bit FP values in 128-bit spaces.  */
 unsigned char st_space[128];

 /* Space for eight 128-bit XMM values, or 16 on x86-64.  */
 unsigned char xmm_space[256];
};

static_assert (sizeof(i387_fxsave) == 416);

struct i387_xsave : public i387_fxsave
{
 unsigned char reserved1[48];

 /* The extended control register 0 (the XFEATURE_ENABLED_MASK
    register).  */
 unsigned long long xcr0;

 unsigned char reserved2[40];

 /* The XSTATE_BV bit vector.  */
 unsigned long long xstate_bv;

 /* The XCOMP_BV bit vector.  */
 unsigned long long xcomp_bv;

 unsigned char reserved3[48];

 /* Byte 576.  End of registers with fixed position in XSAVE.
    The position of other XSAVE registers will be calculated
    from the appropriate CPUID calls.  */

private:
 /* Base address of XSAVE data as an unsigned char *.  Used to derive
    pointers to XSAVE state components in the extended state
    area.  */
 unsigned char *xsave ()
 { return reinterpret_cast<unsigned char *> (this); }

public:
 /* Memory address of eight upper 128-bit YMM values, or 16 on x86-64.  */
 unsigned char *ymmh_space ()
 { return xsave () + xsave_layout.avx_offset; }

 /* Memory address of 8 OpMask register values of 64 bits.  */
 unsigned char *k_space ()
 { return xsave () + xsave_layout.k_offset; }

 /* Memory address of 16 256-bit zmm0-15.  */
 unsigned char *zmmh_space ()
 { return xsave () + xsave_layout.zmm_h_offset; }

 /* Memory address of 16 512-bit zmm16-31 values.  */
 unsigned char *zmm16_space ()
 { return xsave () + xsave_layout.zmm_offset; }

 /* Memory address of 1 32-bit PKRU register.  The HW XSTATE size for this
    feature is actually 64 bits, but WRPKRU/RDPKRU instructions ignore upper
    32 bits.  */
 unsigned char *pkru_space ()
 { return xsave () + xsave_layout.pkru_offset; }
};

static_assert (sizeof(i387_xsave) == 576);

void
i387_cache_to_fsave (struct regcache *regcache, void *buf)
{
 struct i387_fsave *fp = (struct i387_fsave *) buf;
 int i;
 int st0_regnum = find_regno (regcache->tdesc, "st0");
 unsigned long val2;

 for (i = 0; i < 8; i++)
   collect_register (regcache, i + st0_regnum,
                     ((char *) &fp->st_space[0]) + i * 10);

 fp->fioff = regcache_raw_get_unsigned_by_name (regcache, "fioff");
 fp->fooff = regcache_raw_get_unsigned_by_name (regcache, "fooff");

 /* This one's 11 bits... */
 val2 = regcache_raw_get_unsigned_by_name (regcache, "fop");
 fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);

 /* Some registers are 16-bit.  */
 fp->fctrl = regcache_raw_get_unsigned_by_name (regcache, "fctrl");
 fp->fstat = regcache_raw_get_unsigned_by_name (regcache, "fstat");
 fp->ftag = regcache_raw_get_unsigned_by_name (regcache, "ftag");
 fp->fiseg = regcache_raw_get_unsigned_by_name (regcache, "fiseg");
 fp->foseg = regcache_raw_get_unsigned_by_name (regcache, "foseg");
}

void
i387_fsave_to_cache (struct regcache *regcache, const void *buf)
{
 struct i387_fsave *fp = (struct i387_fsave *) buf;
 int i;
 int st0_regnum = find_regno (regcache->tdesc, "st0");
 unsigned long val;

 for (i = 0; i < 8; i++)
   supply_register (regcache, i + st0_regnum,
                    ((char *) &fp->st_space[0]) + i * 10);

 supply_register_by_name (regcache, "fioff", &fp->fioff);
 supply_register_by_name (regcache, "fooff", &fp->fooff);

 /* Some registers are 16-bit.  */
 val = fp->fctrl & 0xFFFF;
 supply_register_by_name (regcache, "fctrl", &val);

 val = fp->fstat & 0xFFFF;
 supply_register_by_name (regcache, "fstat", &val);

 val = fp->ftag & 0xFFFF;
 supply_register_by_name (regcache, "ftag", &val);

 val = fp->fiseg & 0xFFFF;
 supply_register_by_name (regcache, "fiseg", &val);

 val = fp->foseg & 0xFFFF;
 supply_register_by_name (regcache, "foseg", &val);

 /* fop has only 11 valid bits.  */
 val = (fp->fop) & 0x7FF;
 supply_register_by_name (regcache, "fop", &val);
}

void
i387_cache_to_fxsave (struct regcache *regcache, void *buf)
{
 struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 int i;
 int st0_regnum = find_regno (regcache->tdesc, "st0");
 int xmm0_regnum = find_regno (regcache->tdesc, "xmm0");
 unsigned long val, val2;
 /* Amd64 has 16 xmm regs; I386 has 8 xmm regs.  */
 int num_xmm_registers = register_size (regcache->tdesc, 0) == 8 ? 16 : 8;

 for (i = 0; i < 8; i++)
   collect_register (regcache, i + st0_regnum,
                     ((char *) &fp->st_space[0]) + i * 16);
 for (i = 0; i < num_xmm_registers; i++)
   collect_register (regcache, i + xmm0_regnum,
                     ((char *) &fp->xmm_space[0]) + i * 16);

 fp->fioff = regcache_raw_get_unsigned_by_name (regcache, "fioff");
 fp->fooff = regcache_raw_get_unsigned_by_name (regcache, "fooff");
 fp->mxcsr = regcache_raw_get_unsigned_by_name (regcache, "mxcsr");

 /* This one's 11 bits... */
 val2 = regcache_raw_get_unsigned_by_name (regcache, "fop");
 fp->fop = (val2 & 0x7FF) | (fp->fop & 0xF800);

 /* Some registers are 16-bit.  */
 fp->fctrl = regcache_raw_get_unsigned_by_name (regcache, "fctrl");
 fp->fstat = regcache_raw_get_unsigned_by_name (regcache, "fstat");

 /* Convert to the simplifed tag form stored in fxsave data.  */
 val = regcache_raw_get_unsigned_by_name (regcache, "ftag");
 val2 = 0;
 for (i = 7; i >= 0; i--)
   {
     int tag = (val >> (i * 2)) & 3;

     if (tag != 3)
       val2 |= (1 << i);
   }
 fp->ftag = val2;

 fp->fiseg = regcache_raw_get_unsigned_by_name (regcache, "fiseg");
 fp->foseg = regcache_raw_get_unsigned_by_name (regcache, "foseg");
}

void
i387_cache_to_xsave (struct regcache *regcache, void *buf)
{
 struct i387_xsave *fp = (struct i387_xsave *) buf;
 bool amd64 = register_size (regcache->tdesc, 0) == 8;
 int i;
 unsigned long val, val2;
 unsigned long long xstate_bv = 0;
 unsigned long long clear_bv = 0;
 char raw[64];
 unsigned char *p;

 /* Amd64 has 16 xmm regs; I386 has 8 xmm regs.  */
 int num_xmm_registers = amd64 ? 16 : 8;
 /* AVX512 adds 16 extra ZMM regs in Amd64 mode, but none in I386 mode.*/
 int num_zmm_high_registers = amd64 ? 16 : 0;

 /* The supported bits in `xstat_bv' are 8 bytes.  Clear part in
    vector registers if its bit in xstat_bv is zero.  */
 clear_bv = (~fp->xstate_bv) & x86_xcr0;

 /* Clear part in x87 and vector registers if its bit in xstat_bv is
    zero.  */
 if (clear_bv)
   {
     if ((clear_bv & X86_XSTATE_X87))
       {
         for (i = 0; i < 8; i++)
           memset (((char *) &fp->st_space[0]) + i * 16, 0, 10);

         fp->fioff = 0;
         fp->fooff = 0;
         fp->fctrl = I387_FCTRL_INIT_VAL;
         fp->fstat = 0;
         fp->ftag = 0;
         fp->fiseg = 0;
         fp->foseg = 0;
         fp->fop = 0;
       }

     if ((clear_bv & X86_XSTATE_SSE))
       for (i = 0; i < num_xmm_registers; i++)
         memset (((char *) &fp->xmm_space[0]) + i * 16, 0, 16);

     if ((clear_bv & X86_XSTATE_AVX))
       for (i = 0; i < num_xmm_registers; i++)
         memset (fp->ymmh_space () + i * 16, 0, 16);

     if ((clear_bv & X86_XSTATE_SSE) && (clear_bv & X86_XSTATE_AVX))
       memset (((char *) &fp->mxcsr), 0, 4);

     if ((clear_bv & X86_XSTATE_K))
       for (i = 0; i < num_avx512_k_registers; i++)
         memset (fp->k_space () + i * 8, 0, 8);

     if ((clear_bv & X86_XSTATE_ZMM_H))
       for (i = 0; i < num_xmm_registers; i++)
         memset (fp->zmmh_space () + i * 32, 0, 32);

     if ((clear_bv & X86_XSTATE_ZMM))
       for (i = 0; i < num_zmm_high_registers; i++)
         memset (fp->zmm16_space () + i * 64, 0, 64);

     if ((clear_bv & X86_XSTATE_PKRU))
       for (i = 0; i < num_pkeys_registers; i++)
         memset (fp->pkru_space () + i * 4, 0, 4);
   }

 /* Check if any x87 registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_X87))
   {
     int st0_regnum = find_regno (regcache->tdesc, "st0");

     for (i = 0; i < 8; i++)
       {
         collect_register (regcache, i + st0_regnum, raw);
         p = fp->st_space + i * 16;
         if (memcmp (raw, p, 10))
           {
             xstate_bv |= X86_XSTATE_X87;
             memcpy (p, raw, 10);
           }
       }
   }

 /* Check if any SSE registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_SSE))
   {
     int xmm0_regnum = find_regno (regcache->tdesc, "xmm0");

     for (i = 0; i < num_xmm_registers; i++)
       {
         collect_register (regcache, i + xmm0_regnum, raw);
         p = fp->xmm_space + i * 16;
         if (memcmp (raw, p, 16))
           {
             xstate_bv |= X86_XSTATE_SSE;
             memcpy (p, raw, 16);
           }
       }
   }

 /* Check if any AVX registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_AVX))
   {
     int ymm0h_regnum = find_regno (regcache->tdesc, "ymm0h");

     for (i = 0; i < num_xmm_registers; i++)
       {
         collect_register (regcache, i + ymm0h_regnum, raw);
         p = fp->ymmh_space () + i * 16;
         if (memcmp (raw, p, 16))
           {
             xstate_bv |= X86_XSTATE_AVX;
             memcpy (p, raw, 16);
           }
       }
   }

 /* Check if any K registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_K))
   {
     int k0_regnum = find_regno (regcache->tdesc, "k0");

     for (i = 0; i < num_avx512_k_registers; i++)
       {
         collect_register (regcache, i + k0_regnum, raw);
         p = fp->k_space () + i * 8;
         if (memcmp (raw, p, 8) != 0)
           {
             xstate_bv |= X86_XSTATE_K;
             memcpy (p, raw, 8);
           }
       }
   }

 /* Check if any of ZMM0H-ZMM15H registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_ZMM_H))
   {
     int zmm0h_regnum = find_regno (regcache->tdesc, "zmm0h");

     for (i = 0; i < num_xmm_registers; i++)
       {
         collect_register (regcache, i + zmm0h_regnum, raw);
         p = fp->zmmh_space () + i * 32;
         if (memcmp (raw, p, 32) != 0)
           {
             xstate_bv |= X86_XSTATE_ZMM_H;
             memcpy (p, raw, 32);
           }
       }
   }

 /* Check if any of ZMM16-ZMM31 registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_ZMM) && num_zmm_high_registers != 0)
   {
     int zmm16h_regnum = find_regno (regcache->tdesc, "zmm16h");
     int ymm16h_regnum = find_regno (regcache->tdesc, "ymm16h");
     int xmm16_regnum = find_regno (regcache->tdesc, "xmm16");

     for (i = 0; i < num_zmm_high_registers; i++)
       {
         p = fp->zmm16_space () + i * 64;

         /* ZMMH sub-register.  */
         collect_register (regcache, i + zmm16h_regnum, raw);
         if (memcmp (raw, p + 32, 32) != 0)
           {
             xstate_bv |= X86_XSTATE_ZMM;
             memcpy (p + 32, raw, 32);
           }

         /* YMMH sub-register.  */
         collect_register (regcache, i + ymm16h_regnum, raw);
         if (memcmp (raw, p + 16, 16) != 0)
           {
             xstate_bv |= X86_XSTATE_ZMM;
             memcpy (p + 16, raw, 16);
           }

         /* XMM sub-register.  */
         collect_register (regcache, i + xmm16_regnum, raw);
         if (memcmp (raw, p, 16) != 0)
           {
             xstate_bv |= X86_XSTATE_ZMM;
             memcpy (p, raw, 16);
           }
       }
   }

 /* Check if any PKEYS registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_PKRU))
   {
     int pkru_regnum = find_regno (regcache->tdesc, "pkru");

     for (i = 0; i < num_pkeys_registers; i++)
       {
         collect_register (regcache, i + pkru_regnum, raw);
         p = fp->pkru_space () + i * 4;
         if (memcmp (raw, p, 4) != 0)
           {
             xstate_bv |= X86_XSTATE_PKRU;
             memcpy (p, raw, 4);
           }
       }
   }

 if ((x86_xcr0 & X86_XSTATE_SSE) || (x86_xcr0 & X86_XSTATE_AVX))
   {
     collect_register_by_name (regcache, "mxcsr", raw);
     if (memcmp (raw, &fp->mxcsr, 4) != 0)
       {
         if (((fp->xstate_bv | xstate_bv)
              & (X86_XSTATE_SSE | X86_XSTATE_AVX)) == 0)
           xstate_bv |= X86_XSTATE_SSE;
         memcpy (&fp->mxcsr, raw, 4);
       }
   }

 if (x86_xcr0 & X86_XSTATE_X87)
   {
     collect_register_by_name (regcache, "fioff", raw);
     if (memcmp (raw, &fp->fioff, 4) != 0)
       {
         xstate_bv |= X86_XSTATE_X87;
         memcpy (&fp->fioff, raw, 4);
       }

     collect_register_by_name (regcache, "fooff", raw);
     if (memcmp (raw, &fp->fooff, 4) != 0)
       {
         xstate_bv |= X86_XSTATE_X87;
         memcpy (&fp->fooff, raw, 4);
       }

     /* This one's 11 bits... */
     val2 = regcache_raw_get_unsigned_by_name (regcache, "fop");
     val2 = (val2 & 0x7FF) | (fp->fop & 0xF800);
     if (fp->fop != val2)
       {
         xstate_bv |= X86_XSTATE_X87;
         fp->fop = val2;
       }

     /* Some registers are 16-bit.  */
     val = regcache_raw_get_unsigned_by_name (regcache, "fctrl");
     if (fp->fctrl != val)
       {
         xstate_bv |= X86_XSTATE_X87;
         fp->fctrl = val;
       }

     val = regcache_raw_get_unsigned_by_name (regcache, "fstat");
     if (fp->fstat != val)
       {
         xstate_bv |= X86_XSTATE_X87;
         fp->fstat = val;
       }

     /* Convert to the simplifed tag form stored in fxsave data.  */
     val = regcache_raw_get_unsigned_by_name (regcache, "ftag");
     val2 = 0;
     for (i = 7; i >= 0; i--)
       {
         int tag = (val >> (i * 2)) & 3;

         if (tag != 3)
           val2 |= (1 << i);
       }
     if (fp->ftag != val2)
       {
         xstate_bv |= X86_XSTATE_X87;
         fp->ftag = val2;
       }

     val = regcache_raw_get_unsigned_by_name (regcache, "fiseg");
     if (fp->fiseg != val)
       {
         xstate_bv |= X86_XSTATE_X87;
         fp->fiseg = val;
       }

     val = regcache_raw_get_unsigned_by_name (regcache, "foseg");
     if (fp->foseg != val)
       {
         xstate_bv |= X86_XSTATE_X87;
         fp->foseg = val;
       }
   }

 /* Update the corresponding bits in xstate_bv if any SSE/AVX
    registers are changed.  */
 fp->xstate_bv |= xstate_bv;
}

static int
i387_ftag (struct i387_fxsave *fp, int regno)
{
 unsigned char *raw = &fp->st_space[regno * 16];
 unsigned int exponent;
 unsigned long fraction[2];
 int integer;

 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);
       }
   }
}

void
i387_fxsave_to_cache (struct regcache *regcache, const void *buf)
{
 struct i387_fxsave *fp = (struct i387_fxsave *) buf;
 int i, top;
 int st0_regnum = find_regno (regcache->tdesc, "st0");
 int xmm0_regnum = find_regno (regcache->tdesc, "xmm0");
 unsigned long val;
 /* Amd64 has 16 xmm regs; I386 has 8 xmm regs.  */
 int num_xmm_registers = register_size (regcache->tdesc, 0) == 8 ? 16 : 8;

 for (i = 0; i < 8; i++)
   supply_register (regcache, i + st0_regnum,
                    ((char *) &fp->st_space[0]) + i * 16);
 for (i = 0; i < num_xmm_registers; i++)
   supply_register (regcache, i + xmm0_regnum,
                    ((char *) &fp->xmm_space[0]) + i * 16);

 supply_register_by_name (regcache, "fioff", &fp->fioff);
 supply_register_by_name (regcache, "fooff", &fp->fooff);
 supply_register_by_name (regcache, "mxcsr", &fp->mxcsr);

 /* Some registers are 16-bit.  */
 val = fp->fctrl & 0xFFFF;
 supply_register_by_name (regcache, "fctrl", &val);

 val = fp->fstat & 0xFFFF;
 supply_register_by_name (regcache, "fstat", &val);

 /* Generate the form of ftag data that GDB expects.  */
 top = (fp->fstat >> 11) & 0x7;
 val = 0;
 for (i = 7; i >= 0; i--)
   {
     int tag;
     if (fp->ftag & (1 << i))
       tag = i387_ftag (fp, (i + 8 - top) % 8);
     else
       tag = 3;
     val |= tag << (2 * i);
   }
 supply_register_by_name (regcache, "ftag", &val);

 val = fp->fiseg & 0xFFFF;
 supply_register_by_name (regcache, "fiseg", &val);

 val = fp->foseg & 0xFFFF;
 supply_register_by_name (regcache, "foseg", &val);

 val = (fp->fop) & 0x7FF;
 supply_register_by_name (regcache, "fop", &val);
}

void
i387_xsave_to_cache (struct regcache *regcache, const void *buf)
{
 struct i387_xsave *fp = (struct i387_xsave *) buf;
 bool amd64 = register_size (regcache->tdesc, 0) == 8;
 int i, top;
 unsigned long val;
 unsigned long long clear_bv;
 unsigned char *p;

  /* Amd64 has 16 xmm regs; I386 has 8 xmm regs.  */
 int num_xmm_registers = amd64 ? 16 : 8;
 /* AVX512 adds 16 extra ZMM regs in Amd64 mode, but none in I386 mode.*/
 int num_zmm_high_registers = amd64 ? 16 : 0;

 /* The supported bits in `xstat_bv' are 8 bytes.  Clear part in
    vector registers if its bit in xstat_bv is zero.  */
 clear_bv = (~fp->xstate_bv) & x86_xcr0;

 /* Check if any x87 registers are changed.  */
 if ((x86_xcr0 & X86_XSTATE_X87) != 0)
   {
     int st0_regnum = find_regno (regcache->tdesc, "st0");

     if ((clear_bv & X86_XSTATE_X87) != 0)
       {
         for (i = 0; i < 8; i++)
           supply_register_zeroed (regcache, i + st0_regnum);
       }
     else
       {
         p = (gdb_byte *) &fp->st_space[0];
         for (i = 0; i < 8; i++)
           supply_register (regcache, i + st0_regnum, p + i * 16);
       }
   }

 if ((x86_xcr0 & X86_XSTATE_SSE) != 0)
   {
     int xmm0_regnum = find_regno (regcache->tdesc, "xmm0");

     if ((clear_bv & X86_XSTATE_SSE))
       {
         for (i = 0; i < num_xmm_registers; i++)
           supply_register_zeroed (regcache, i + xmm0_regnum);
       }
     else
       {
         p = (gdb_byte *) &fp->xmm_space[0];
         for (i = 0; i < num_xmm_registers; i++)
           supply_register (regcache, i + xmm0_regnum, p + i * 16);
       }
   }

 if ((x86_xcr0 & X86_XSTATE_AVX) != 0)
   {
     int ymm0h_regnum = find_regno (regcache->tdesc, "ymm0h");

     if ((clear_bv & X86_XSTATE_AVX) != 0)
       {
         for (i = 0; i < num_xmm_registers; i++)
           supply_register_zeroed (regcache, i + ymm0h_regnum);
       }
     else
       {
         p = fp->ymmh_space ();
         for (i = 0; i < num_xmm_registers; i++)
           supply_register (regcache, i + ymm0h_regnum, p + i * 16);
       }
   }

 if ((x86_xcr0 & X86_XSTATE_K) != 0)
   {
     int k0_regnum = find_regno (regcache->tdesc, "k0");

     if ((clear_bv & X86_XSTATE_K) != 0)
       {
         for (i = 0; i < num_avx512_k_registers; i++)
           supply_register_zeroed (regcache, i + k0_regnum);
       }
     else
       {
         p = fp->k_space ();
         for (i = 0; i < num_avx512_k_registers; i++)
           supply_register (regcache, i + k0_regnum, p + i * 8);
       }
   }

 if ((x86_xcr0 & X86_XSTATE_ZMM_H) != 0)
   {
     int zmm0h_regnum = find_regno (regcache->tdesc, "zmm0h");

     if ((clear_bv & X86_XSTATE_ZMM_H) != 0)
       {
         for (i = 0; i < num_xmm_registers; i++)
           supply_register_zeroed (regcache, i + zmm0h_regnum);
       }
     else
       {
         p = fp->zmmh_space ();
         for (i = 0; i < num_xmm_registers; i++)
           supply_register (regcache, i + zmm0h_regnum, p + i * 32);
       }
   }

 if ((x86_xcr0 & X86_XSTATE_ZMM) != 0 && num_zmm_high_registers != 0)
   {
     int zmm16h_regnum = find_regno (regcache->tdesc, "zmm16h");
     int ymm16h_regnum = find_regno (regcache->tdesc, "ymm16h");
     int xmm16_regnum = find_regno (regcache->tdesc, "xmm16");

     if ((clear_bv & X86_XSTATE_ZMM) != 0)
       {
         for (i = 0; i < num_zmm_high_registers; i++)
           {
             supply_register_zeroed (regcache, i + zmm16h_regnum);
             supply_register_zeroed (regcache, i + ymm16h_regnum);
             supply_register_zeroed (regcache, i + xmm16_regnum);
           }
       }
     else
       {
         p = fp->zmm16_space ();
         for (i = 0; i < num_zmm_high_registers; i++)
           {
             supply_register (regcache, i + zmm16h_regnum, p + 32 + i * 64);
             supply_register (regcache, i + ymm16h_regnum, p + 16 + i * 64);
             supply_register (regcache, i + xmm16_regnum, p + i * 64);
           }
       }
   }

 if ((x86_xcr0 & X86_XSTATE_PKRU) != 0)
   {
     int pkru_regnum = find_regno (regcache->tdesc, "pkru");

     if ((clear_bv & X86_XSTATE_PKRU) != 0)
       {
         for (i = 0; i < num_pkeys_registers; i++)
           supply_register_zeroed (regcache, i + pkru_regnum);
       }
     else
       {
         p = fp->pkru_space ();
         for (i = 0; i < num_pkeys_registers; i++)
           supply_register (regcache, i + pkru_regnum, p + i * 4);
       }
   }

 if ((clear_bv & (X86_XSTATE_SSE | X86_XSTATE_AVX))
     == (X86_XSTATE_SSE | X86_XSTATE_AVX))
   {
     unsigned int default_mxcsr = I387_MXCSR_INIT_VAL;
     supply_register_by_name (regcache, "mxcsr", &default_mxcsr);
   }
 else
   supply_register_by_name (regcache, "mxcsr", &fp->mxcsr);

 if ((clear_bv & X86_XSTATE_X87) != 0)
   {
     supply_register_by_name_zeroed (regcache, "fioff");
     supply_register_by_name_zeroed (regcache, "fooff");

     val = I387_FCTRL_INIT_VAL;
     supply_register_by_name (regcache, "fctrl", &val);

     supply_register_by_name_zeroed (regcache, "fstat");

     val = 0xFFFF;
     supply_register_by_name (regcache, "ftag", &val);

     supply_register_by_name_zeroed (regcache, "fiseg");
     supply_register_by_name_zeroed (regcache, "foseg");
     supply_register_by_name_zeroed (regcache, "fop");
   }
 else
   {
     supply_register_by_name (regcache, "fioff", &fp->fioff);
     supply_register_by_name (regcache, "fooff", &fp->fooff);

     /* Some registers are 16-bit.  */
     val = fp->fctrl & 0xFFFF;
     supply_register_by_name (regcache, "fctrl", &val);

     val = fp->fstat & 0xFFFF;
     supply_register_by_name (regcache, "fstat", &val);

     /* Generate the form of ftag data that GDB expects.  */
     top = (fp->fstat >> 11) & 0x7;
     val = 0;
     for (i = 7; i >= 0; i--)
       {
         int tag;
         if (fp->ftag & (1 << i))
           tag = i387_ftag (fp, (i + 8 - top) % 8);
         else
           tag = 3;
         val |= tag << (2 * i);
       }
     supply_register_by_name (regcache, "ftag", &val);

     val = fp->fiseg & 0xFFFF;
     supply_register_by_name (regcache, "fiseg", &val);

     val = fp->foseg & 0xFFFF;
     supply_register_by_name (regcache, "foseg", &val);

     val = (fp->fop) & 0x7FF;
     supply_register_by_name (regcache, "fop", &val);
   }
}

/* See i387-fp.h.  */

std::pair<uint64_t *, x86_xsave_layout *>
i387_get_xsave_storage ()
{
 return { &x86_xcr0, &xsave_layout };
}