Re: [Qemu-devel] [PATCH 1/5] disas/i386: Disassemble ANDN/SHLX/SHRX/SHAX

[Aurelien Jarno]

On Fri, Jan 31, 2014 at 08:43:34AM -0600, Richard Henderson wrote:
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  disas/i386.c | 146 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 132 insertions(+), 14 deletions(-)
> 
> diff --git a/disas/i386.c b/disas/i386.c
> index 044e02c..104524f 100644
> --- a/disas/i386.c
> +++ b/disas/i386.c
> @@ -171,6 +171,7 @@ static void print_operand_value (char *buf, size_t 
> bufsize, int hex, bfd_vma dis
>  static void print_displacement (char *, bfd_vma);
>  static void OP_E (int, int);
>  static void OP_G (int, int);
> +static void OP_vvvv (int, int);
>  static bfd_vma get64 (void);
>  static bfd_signed_vma get32 (void);
>  static bfd_signed_vma get32s (void);
> @@ -264,6 +265,9 @@ static int rex_used;
>     current instruction.  */
>  static int used_prefixes;
>  
> +/* The VEX.vvvv register, unencoded.  */
> +static int vex_reg;
> +
>  /* Flags stored in PREFIXES.  */
>  #define PREFIX_REPZ 1
>  #define PREFIX_REPNZ 2
> @@ -278,6 +282,10 @@ static int used_prefixes;
>  #define PREFIX_ADDR 0x400
>  #define PREFIX_FWAIT 0x800
>  
> +#define PREFIX_VEX_0F    0x1000
> +#define PREFIX_VEX_0F38  0x2000
> +#define PREFIX_VEX_0F3A  0x4000
> +
>  /* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive)
>     to ADDR (exclusive) are valid.  Returns 1 for success, longjmps
>     on error.  */
> @@ -323,6 +331,7 @@ fetch_data(struct disassemble_info *info, bfd_byte *addr)
>  
>  #define XX { NULL, 0 }
>  
> +#define Bv { OP_vvvv, v_mode }
>  #define Eb { OP_E, b_mode }
>  #define Ev { OP_E, v_mode }
>  #define Ed { OP_E, d_mode }
> @@ -671,7 +680,8 @@ fetch_data(struct disassemble_info *info, bfd_byte *addr)
>  #define PREGRP102 NULL, { { NULL, USE_PREFIX_USER_TABLE }, { NULL, 102 } }
>  #define PREGRP103 NULL, { { NULL, USE_PREFIX_USER_TABLE }, { NULL, 103 } }
>  #define PREGRP104 NULL, { { NULL, USE_PREFIX_USER_TABLE }, { NULL, 104 } }
> -
> +#define PREGRP105 NULL, { { NULL, USE_PREFIX_USER_TABLE }, { NULL, 105 } }
> +#define PREGRP106 NULL, { { NULL, USE_PREFIX_USER_TABLE }, { NULL, 106 } }
>  
>  #define X86_64_0  NULL, { { NULL, X86_64_SPECIAL }, { NULL, 0 } }
>  #define X86_64_1  NULL, { { NULL, X86_64_SPECIAL }, { NULL, 1 } }
> @@ -1449,7 +1459,7 @@ static const unsigned char 
> threebyte_0x38_uses_DATA_prefix[256] = {
>    /* c0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* cf */
>    /* d0 */ 0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1, /* df */
>    /* e0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* ef */
> -  /* f0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* ff */
> +  /* f0 */ 0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0, /* ff */
>    /*       -------------------------------        */
>    /*       0 1 2 3 4 5 6 7 8 9 a b c d e f        */
>  };
> @@ -1473,7 +1483,7 @@ static const unsigned char 
> threebyte_0x38_uses_REPNZ_prefix[256] = {
>    /* c0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* cf */
>    /* d0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* df */
>    /* e0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* ef */
> -  /* f0 */ 1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* ff */
> +  /* f0 */ 1,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0, /* ff */
>    /*       -------------------------------        */
>    /*       0 1 2 3 4 5 6 7 8 9 a b c d e f        */
>  };
> @@ -1497,7 +1507,7 @@ static const unsigned char 
> threebyte_0x38_uses_REPZ_prefix[256] = {
>    /* c0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* cf */
>    /* d0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* df */
>    /* e0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* ef */
> -  /* f0 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* ff */
> +  /* f0 */ 0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0, /* ff */
>    /*       -------------------------------        */
>    /*       0 1 2 3 4 5 6 7 8 9 a b c d e f        */
>  };
> @@ -2774,6 +2784,22 @@ static const struct dis386 prefix_user_table[][4] = {
>      { "(bad)",       { XX } },
>    },
>  
> +  /* PREGRP105 */
> +  {
> +    { "andnS",       { Gv, Bv, Ev } },
> +    { "(bad)",       { XX } },
> +    { "(bad)",       { XX } },
> +    { "(bad)",       { XX } },
> +  },
> +
> +  /* PREGRP106 */
> +  {
> +    { "bextrS",      { Gv, Ev, Bv } },
> +    { "sarxS",       { Gv, Ev, Bv } },
> +    { "shlxS",       { Gv, Ev, Bv } },
> +    { "shrxS",       { Gv, Ev, Bv } },
> +  },
> +
>  };
>  
>  static const struct dis386 x86_64_table[][2] = {
> @@ -3071,12 +3097,12 @@ static const struct dis386 three_byte_table[][256] = {
>      /* f0 */
>      { PREGRP87 },
>      { PREGRP88 },
> +    { PREGRP105 },
>      { "(bad)", { XX } },
>      { "(bad)", { XX } },
>      { "(bad)", { XX } },
>      { "(bad)", { XX } },
> -    { "(bad)", { XX } },
> -    { "(bad)", { XX } },
> +    { PREGRP106 },
>      /* f8 */
>      { "(bad)", { XX } },
>      { "(bad)", { XX } },
> @@ -3477,6 +3503,74 @@ ckprefix (void)
>      }
>  }
>  
> +static void
> +ckvexprefix (void)
> +{
> +    int op, vex2, vex3, newrex = REX_OPCODE, newpfx = prefixes;
> +
> +    if (address_mode == mode_16bit) {
> +        return;
> +    }
> +
> +    fetch_data(the_info, codep + 1);
> +    op = *codep;
> +
> +    if (op != 0xc4 && op != 0xc5) {
> +        return;
> +    }
> +
> +    fetch_data(the_info, codep + 2);
> +    vex2 = codep[1];
> +
> +    if (address_mode == mode_32bit && (vex2 & 0xc0) != 0xc0) {
> +        return;
> +    }
> +
> +    if (op == 0xc4) {
> +        /* Three byte VEX prefix.  */
> +        fetch_data(the_info, codep + 3);
> +        vex3 = codep[2];
> +
> +        newrex |= (vex2 & 0x80 ? 0 : REX_R);
> +        newrex |= (vex2 & 0x40 ? 0 : REX_X);
> +        newrex |= (vex2 & 0x20 ? 0 : REX_B);
> +        newrex |= (vex3 & 0x80 ? REX_W : 0);
> +        switch (vex2 & 0x1f) {      /* VEX.m-mmmm */
> +        case 1:
> +            newpfx |= PREFIX_VEX_0F;
> +            break;
> +        case 2:
> +            newpfx |= PREFIX_VEX_0F | PREFIX_VEX_0F38;
> +            break;
> +        case 3:
> +            newpfx |= PREFIX_VEX_0F | PREFIX_VEX_0F3A;
> +            break;
> +        }
> +        vex2 = vex3;
> +        codep += 3;
> +    } else {
> +        /* Two byte VEX prefix.  */
> +        newrex |= (vex2 & 0x80 ? 0 : REX_R);
> +        codep += 2;
> +    }
> +
> +    vex_reg = (~vex2 >> 3) & 15;     /* VEX.vvvv */
> +    switch (vex2 & 3) {              /* VEX.pp */
> +    case 1:
> +        newpfx |= PREFIX_DATA;     /* 0x66 */
> +        break;
> +    case 2:
> +        newpfx |= PREFIX_REPZ;     /* 0xf3 */
> +        break;
> +    case 3:
> +        newpfx |= PREFIX_REPNZ;    /* 0xf2 */
> +        break;
> +    }
> +
> +    rex = newrex;
> +    prefixes = newpfx;
> +}
> +
>  /* Return the name of the prefix byte PREF, or NULL if PREF is not a
>     prefix byte.  */
>  
> @@ -3598,6 +3692,7 @@ print_insn (bfd_vma pc, disassemble_info *info)
>    const char *p;
>    struct dis_private priv;
>    unsigned char op;
> +  unsigned char threebyte;
>  
>    if (info->mach == bfd_mach_x86_64_intel_syntax
>        || info->mach == bfd_mach_x86_64)
> @@ -3752,6 +3847,7 @@ print_insn (bfd_vma pc, disassemble_info *info)
>  
>    obufp = obuf;
>    ckprefix ();
> +  ckvexprefix ();
>  
>    insn_codep = codep;
>    sizeflag = priv.orig_sizeflag;
> @@ -3775,18 +3871,29 @@ print_insn (bfd_vma pc, disassemble_info *info)
>      }
>  
>    op = 0;
> +  if (prefixes & PREFIX_VEX_0F)
> +    {
> +      used_prefixes |= PREFIX_VEX_0F | PREFIX_VEX_0F38 | PREFIX_VEX_0F3A;
> +      if (prefixes & PREFIX_VEX_0F38)
> +        threebyte = 0x38;
> +      else if (prefixes & PREFIX_VEX_0F3A)
> +        threebyte = 0x3a;
> +      else
> +        threebyte = *codep++;
> +      goto vex_opcode;
> +    }
>    if (*codep == 0x0f)
>      {
> -      unsigned char threebyte;
>        fetch_data(info, codep + 2);
> -      threebyte = *++codep;
> +      threebyte = codep[1];
> +      codep += 2;
> +    vex_opcode:
>        dp = &dis386_twobyte[threebyte];
> -      need_modrm = twobyte_has_modrm[*codep];
> -      uses_DATA_prefix = twobyte_uses_DATA_prefix[*codep];
> -      uses_REPNZ_prefix = twobyte_uses_REPNZ_prefix[*codep];
> -      uses_REPZ_prefix = twobyte_uses_REPZ_prefix[*codep];
> -      uses_LOCK_prefix = (*codep & ~0x02) == 0x20;
> -      codep++;
> +      need_modrm = twobyte_has_modrm[threebyte];
> +      uses_DATA_prefix = twobyte_uses_DATA_prefix[threebyte];
> +      uses_REPNZ_prefix = twobyte_uses_REPNZ_prefix[threebyte];
> +      uses_REPZ_prefix = twobyte_uses_REPZ_prefix[threebyte];
> +      uses_LOCK_prefix = (threebyte & ~0x02) == 0x20;
>        if (dp->name == NULL && dp->op[0].bytemode == IS_3BYTE_OPCODE)
>       {
>            fetch_data(info, codep + 2);
> @@ -5291,6 +5398,17 @@ OP_G (int bytemode, int sizeflag)
>      }
>  }
>  
> +static void
> +OP_vvvv (int bytemode, int sizeflags)
> +{
> +    USED_REX (REX_W);
> +    if (rex & REX_W) {
> +        oappend(names64[vex_reg]);
> +    } else {
> +        oappend(names32[vex_reg]);
> +    }
> +}
> +
>  static bfd_vma
>  get64 (void)
>  {

Reviewed-by: Aurelien Jarno <address@hidden>


-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
address@hidden                 http://www.aurel32.net