Re: [PATCH 5/7] x86: re-work insn/suffix recognition

["H.J. Lu" <hjl.tools@gmail.com>]

On Tue, Aug 16, 2022 at 12:32 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> x86: re-work insn/suffix recognition
>
> Having templates with a suffix explicitly present has always been
> quirky. Introduce a 2nd matching pass in case the 1st one couldn't find

I don't like the second pass.   What problem does it solve?

> a suitable template _and_ didn't itself already need to trim off a
> suffix to find a match at all. This requires error reporting adjustments
> (albeit luckily fewer than I was afraid might be necessary), as errors
> previously reported during matching now need deferring until after the
> 2nd pass (because, obviously, we must not emit any error if the 2nd pass
> succeeds).
>
> Note that with the dropped CMPSD and MOVSD Intel Syntax string insn
> templates, mixed IsString/non-IsString template groups cannot occur
> anymore. With that maybe_adjust_templates() becomes unnecessary (and is
> hence being removed).
>
> Note further that while the additions to the intel16 testcase aren't
> really proper Intel syntax, we've been permitting all of those except
> for the MOVD variant. The test therefore is to avoid re-introducing such
> an inconsistency.
> ---
> To limit code churn I'm using "goto" for the retry loop, but I'd be
> happy to make this a proper loop either right here or in a follow-on
> change doing just the necessary re-indentation.
>
> The "too many memory references" errors which are being deleted weren't
> fully consistent anyway - even the majority of IsString insns accepts
> only a single memory operand. If we want to retain that, it would need
> re-introducing in md_assemble(), latching the error into i.error just
> like match_template() does.
>
> Why is "MOVQ $imm64, %reg64" being optimized but "MOVABS $imm64, %reg64"
> is not?
>
> --- a/gas/config/tc-i386.c
> +++ b/gas/config/tc-i386.c
> @@ -297,9 +297,6 @@ struct _i386_insn
>         explicit segment overrides are given.  */
>      const reg_entry *seg[2];
>
> -    /* Copied first memory operand string, for re-checking.  */
> -    char *memop1_string;
> -
>      /* PREFIX holds all the given prefix opcodes (usually null).
>         PREFIXES is the number of prefix opcodes.  */
>      unsigned int prefixes;
> @@ -4273,7 +4270,20 @@ optimize_encoding (void)
>            movq $imm31, %r64   -> movl $imm31, %r32
>            movq $imm32, %r64   -> movl $imm32, %r32
>          */
> -      i.tm.opcode_modifier.norex64 = 1;
> +      i.tm.opcode_modifier.size = SIZE32;
> +      if (i.imm_operands)
> +       {
> +         i.types[0].bitfield.imm32 = 1;
> +         i.types[0].bitfield.imm32s = 0;
> +         i.types[0].bitfield.imm64 = 0;
> +       }
> +      else
> +       {
> +         i.types[0].bitfield.dword = 1;
> +         i.types[0].bitfield.qword = 0;
> +       }
> +      i.types[1].bitfield.dword = 1;
> +      i.types[1].bitfield.qword = 0;
>        if (i.tm.base_opcode == 0xb8 || (i.tm.base_opcode | 1) == 0xc7)
>         {
>           /* Handle
> @@ -4283,11 +4293,6 @@ optimize_encoding (void)
>           i.tm.operand_types[0].bitfield.imm32 = 1;
>           i.tm.operand_types[0].bitfield.imm32s = 0;
>           i.tm.operand_types[0].bitfield.imm64 = 0;
> -         i.types[0].bitfield.imm32 = 1;
> -         i.types[0].bitfield.imm32s = 0;
> -         i.types[0].bitfield.imm64 = 0;
> -         i.types[1].bitfield.dword = 1;
> -         i.types[1].bitfield.qword = 0;
>           if ((i.tm.base_opcode | 1) == 0xc7)
>             {
>               /* Handle
> @@ -4819,10 +4824,17 @@ void
>  md_assemble (char *line)
>  {
>    unsigned int j;
> -  char mnemonic[MAX_MNEM_SIZE], mnem_suffix;
> +  char mnemonic[MAX_MNEM_SIZE], mnem_suffix, *copy;
> +  const char *pass1_mnem = NULL;
> +  enum i386_error pass1_err = 0;
>    const insn_template *t;
>
> +  /* Make a copy of the full line in case we need to retry.  */
> +  copy = xstrdup (line);
> +
>    /* Initialize globals.  */
> +  current_templates = NULL;
> + retry:
>    memset (&i, '\0', sizeof (i));
>    i.rounding.type = rc_none;
>    for (j = 0; j < MAX_OPERANDS; j++)
> @@ -4837,15 +4849,21 @@ md_assemble (char *line)
>
>    line = parse_insn (line, mnemonic);
>    if (line == NULL)
> -    return;
> +    {
> +      if (!copy)
> +       goto match_error;
> +      free (copy);
> +      return;
> +    }
>    mnem_suffix = i.suffix;
>
>    line = parse_operands (line, mnemonic);
>    this_operand = -1;
> -  xfree (i.memop1_string);
> -  i.memop1_string = NULL;
>    if (line == NULL)
> -    return;
> +    {
> +      free (copy);
> +      return;
> +    }
>
>    /* Now we've parsed the mnemonic into a set of templates, and have the
>       operands at hand.  */
> @@ -4921,7 +4939,97 @@ md_assemble (char *line)
>       with the template operand types.  */
>
>    if (!(t = match_template (mnem_suffix)))
> -    return;
> +    {
> +      const char *err_msg;
> +
> +      if (!mnem_suffix)
> +       {
> +         pass1_err = i.error;
> +         pass1_mnem = current_templates->start->name;
> +         line = copy;
> +         copy = NULL;
> +         goto retry;
> +       }
> +      free (copy);
> +  match_error:
> +      switch (pass1_mnem ? pass1_err : i.error)
> +       {
> +       default:
> +         abort ();
> +       case operand_size_mismatch:
> +         err_msg = _("operand size mismatch");
> +         break;
> +       case operand_type_mismatch:
> +         err_msg = _("operand type mismatch");
> +         break;
> +       case register_type_mismatch:
> +         err_msg = _("register type mismatch");
> +         break;
> +       case number_of_operands_mismatch:
> +         err_msg = _("number of operands mismatch");
> +         break;
> +       case invalid_instruction_suffix:
> +         err_msg = _("invalid instruction suffix");
> +         break;
> +       case bad_imm4:
> +         err_msg = _("constant doesn't fit in 4 bits");
> +         break;
> +       case unsupported_with_intel_mnemonic:
> +         err_msg = _("unsupported with Intel mnemonic");
> +         break;
> +       case unsupported_syntax:
> +         err_msg = _("unsupported syntax");
> +         break;
> +       case unsupported:
> +         as_bad (_("unsupported instruction `%s'"),
> +                 pass1_mnem ? pass1_mnem : current_templates->start->name);
> +         return;
> +       case invalid_sib_address:
> +         err_msg = _("invalid SIB address");
> +         break;
> +       case invalid_vsib_address:
> +         err_msg = _("invalid VSIB address");
> +         break;
> +       case invalid_vector_register_set:
> +         err_msg = _("mask, index, and destination registers must be distinct");
> +         break;
> +       case invalid_tmm_register_set:
> +         err_msg = _("all tmm registers must be distinct");
> +         break;
> +       case invalid_dest_and_src_register_set:
> +         err_msg = _("destination and source registers must be distinct");
> +         break;
> +       case unsupported_vector_index_register:
> +         err_msg = _("unsupported vector index register");
> +         break;
> +       case unsupported_broadcast:
> +         err_msg = _("unsupported broadcast");
> +         break;
> +       case broadcast_needed:
> +         err_msg = _("broadcast is needed for operand of such type");
> +         break;
> +       case unsupported_masking:
> +         err_msg = _("unsupported masking");
> +         break;
> +       case mask_not_on_destination:
> +         err_msg = _("mask not on destination operand");
> +         break;
> +       case no_default_mask:
> +         err_msg = _("default mask isn't allowed");
> +         break;
> +       case unsupported_rc_sae:
> +         err_msg = _("unsupported static rounding/sae");
> +         break;
> +       case invalid_register_operand:
> +         err_msg = _("invalid register operand");
> +         break;
> +       }
> +      as_bad (_("%s for `%s'"), err_msg,
> +             pass1_mnem ? pass1_mnem : current_templates->start->name);
> +      return;
> +    }
> +
> +  free (copy);
>
>    if (sse_check != check_none
>        /* The opcode space check isn't strictly needed; it's there only to
> @@ -5223,6 +5331,7 @@ parse_insn (char *line, char *mnemonic)
>    char *l = line;
>    char *token_start = l;
>    char *mnem_p;
> +  bool pass1 = !current_templates;
>    int supported;
>    const insn_template *t;
>    char *dot_p = NULL;
> @@ -5392,8 +5501,10 @@ parse_insn (char *line, char *mnemonic)
>        current_templates = (const templates *) str_hash_find (op_hash, mnemonic);
>      }
>
> -  if (!current_templates)
> +  if (!current_templates || !pass1)
>      {
> +      current_templates = NULL;
> +
>      check_suffix:
>        if (mnem_p > mnemonic)
>         {
> @@ -5441,7 +5552,8 @@ parse_insn (char *line, char *mnemonic)
>
>        if (!current_templates)
>         {
> -         as_bad (_("no such instruction: `%s'"), token_start);
> +         if (pass1)
> +           as_bad (_("no such instruction: `%s'"), token_start);
>           return NULL;
>         }
>      }
> @@ -6851,81 +6963,7 @@ match_template (char mnem_suffix)
>    if (t == current_templates->end)
>      {
>        /* We found no match.  */
> -      const char *err_msg;
> -      switch (specific_error)
> -       {
> -       default:
> -         abort ();
> -       case operand_size_mismatch:
> -         err_msg = _("operand size mismatch");
> -         break;
> -       case operand_type_mismatch:
> -         err_msg = _("operand type mismatch");
> -         break;
> -       case register_type_mismatch:
> -         err_msg = _("register type mismatch");
> -         break;
> -       case number_of_operands_mismatch:
> -         err_msg = _("number of operands mismatch");
> -         break;
> -       case invalid_instruction_suffix:
> -         err_msg = _("invalid instruction suffix");
> -         break;
> -       case bad_imm4:
> -         err_msg = _("constant doesn't fit in 4 bits");
> -         break;
> -       case unsupported_with_intel_mnemonic:
> -         err_msg = _("unsupported with Intel mnemonic");
> -         break;
> -       case unsupported_syntax:
> -         err_msg = _("unsupported syntax");
> -         break;
> -       case unsupported:
> -         as_bad (_("unsupported instruction `%s'"),
> -                 current_templates->start->name);
> -         return NULL;
> -       case invalid_sib_address:
> -         err_msg = _("invalid SIB address");
> -         break;
> -       case invalid_vsib_address:
> -         err_msg = _("invalid VSIB address");
> -         break;
> -       case invalid_vector_register_set:
> -         err_msg = _("mask, index, and destination registers must be distinct");
> -         break;
> -       case invalid_tmm_register_set:
> -         err_msg = _("all tmm registers must be distinct");
> -         break;
> -       case invalid_dest_and_src_register_set:
> -         err_msg = _("destination and source registers must be distinct");
> -         break;
> -       case unsupported_vector_index_register:
> -         err_msg = _("unsupported vector index register");
> -         break;
> -       case unsupported_broadcast:
> -         err_msg = _("unsupported broadcast");
> -         break;
> -       case broadcast_needed:
> -         err_msg = _("broadcast is needed for operand of such type");
> -         break;
> -       case unsupported_masking:
> -         err_msg = _("unsupported masking");
> -         break;
> -       case mask_not_on_destination:
> -         err_msg = _("mask not on destination operand");
> -         break;
> -       case no_default_mask:
> -         err_msg = _("default mask isn't allowed");
> -         break;
> -       case unsupported_rc_sae:
> -         err_msg = _("unsupported static rounding/sae");
> -         break;
> -       case invalid_register_operand:
> -         err_msg = _("invalid register operand");
> -         break;
> -       }
> -      as_bad (_("%s for `%s'"), err_msg,
> -             current_templates->start->name);
> +      i.error = specific_error;
>        return NULL;
>      }
>
> @@ -11334,49 +11372,6 @@ RC_SAE_immediate (const char *imm_start)
>    return 1;
>  }
>
> -/* Only string instructions can have a second memory operand, so
> -   reduce current_templates to just those if it contains any.  */
> -static int
> -maybe_adjust_templates (void)
> -{
> -  const insn_template *t;
> -
> -  gas_assert (i.mem_operands == 1);
> -
> -  for (t = current_templates->start; t < current_templates->end; ++t)
> -    if (t->opcode_modifier.isstring)
> -      break;
> -
> -  if (t < current_templates->end)
> -    {
> -      static templates aux_templates;
> -      bool recheck;
> -
> -      aux_templates.start = t;
> -      for (; t < current_templates->end; ++t)
> -       if (!t->opcode_modifier.isstring)
> -         break;
> -      aux_templates.end = t;
> -
> -      /* Determine whether to re-check the first memory operand.  */
> -      recheck = (aux_templates.start != current_templates->start
> -                || t != current_templates->end);
> -
> -      current_templates = &aux_templates;
> -
> -      if (recheck)
> -       {
> -         i.mem_operands = 0;
> -         if (i.memop1_string != NULL
> -             && i386_index_check (i.memop1_string) == 0)
> -           return 0;
> -         i.mem_operands = 1;
> -       }
> -    }
> -
> -  return 1;
> -}
> -
>  static INLINE bool starts_memory_operand (char c)
>  {
>    return ISDIGIT (c)
> @@ -11527,17 +11522,6 @@ i386_att_operand (char *operand_string)
>        char *displacement_string_end;
>
>      do_memory_reference:
> -      if (i.mem_operands == 1 && !maybe_adjust_templates ())
> -       return 0;
> -      if ((i.mem_operands == 1
> -          && !current_templates->start->opcode_modifier.isstring)
> -         || i.mem_operands == 2)
> -       {
> -         as_bad (_("too many memory references for `%s'"),
> -                 current_templates->start->name);
> -         return 0;
> -       }
> -
>        /* Check for base index form.  We detect the base index form by
>          looking for an ')' at the end of the operand, searching
>          for the '(' matching it, and finding a REGISTER_PREFIX or ','
> @@ -11737,8 +11721,6 @@ i386_att_operand (char *operand_string)
>        if (i386_index_check (operand_string) == 0)
>         return 0;
>        i.flags[this_operand] |= Operand_Mem;
> -      if (i.mem_operands == 0)
> -       i.memop1_string = xstrdup (operand_string);
>        i.mem_operands++;
>      }
>    else
> --- a/gas/config/tc-i386-intel.c
> +++ b/gas/config/tc-i386-intel.c
> @@ -993,10 +993,7 @@ i386_intel_operand (char *operand_string
>            || intel_state.is_mem)
>      {
>        /* Memory operand.  */
> -      if (i.mem_operands == 1 && !maybe_adjust_templates ())
> -       return 0;
> -      if ((int) i.mem_operands
> -         >= 2 - !current_templates->start->opcode_modifier.isstring)
> +      if (i.mem_operands)
>         {
>           /* Handle
>
> @@ -1041,10 +1038,6 @@ i386_intel_operand (char *operand_string
>                     }
>                 }
>             }
> -
> -         as_bad (_("too many memory references for `%s'"),
> -                 current_templates->start->name);
> -         return 0;
>         }
>
>        /* Swap base and index in 16-bit memory operands like
> @@ -1158,8 +1151,6 @@ i386_intel_operand (char *operand_string
>         return 0;
>
>        i.flags[this_operand] |= Operand_Mem;
> -      if (i.mem_operands == 0)
> -       i.memop1_string = xstrdup (operand_string);
>        ++i.mem_operands;
>      }
>    else
> --- a/gas/testsuite/gas/i386/code16.s
> +++ b/gas/testsuite/gas/i386/code16.s
> @@ -1,9 +1,9 @@
>         .text
>         .code16
> -       rep; movsd
> -       rep; cmpsd
> -       rep movsd %ds:(%si),%es:(%di)
> -       rep cmpsd %es:(%di),%ds:(%si)
> +       rep; movsl
> +       rep; cmpsl
> +       rep movsl %ds:(%si),%es:(%di)
> +       rep cmpsl %es:(%di),%ds:(%si)
>
>         mov     %cr2, %ecx
>         mov     %ecx, %cr2
> --- a/gas/testsuite/gas/i386/i386.exp
> +++ b/gas/testsuite/gas/i386/i386.exp
> @@ -73,6 +73,7 @@ if [gas_32_check] then {
>      run_dump_test "amd"
>      run_dump_test "katmai"
>      run_dump_test "jump"
> +    run_dump_test "movs32"
>      run_dump_test "movz32"
>      run_dump_test "relax-1"
>      run_dump_test "relax-2"
> @@ -806,6 +807,7 @@ if [gas_64_check] then {
>      run_dump_test "x86-64-segovr"
>      run_list_test "x86-64-inval-seg" "-al"
>      run_dump_test "x86-64-branch"
> +    run_dump_test "movs64"
>      run_dump_test "movz64"
>      run_dump_test "x86-64-relax-1"
>      run_dump_test "svme64"
> --- a/gas/testsuite/gas/i386/intel16.d
> +++ b/gas/testsuite/gas/i386/intel16.d
> @@ -20,4 +20,12 @@ Disassembly of section .text:
>    2c:  8d 02 [         ]*lea    \(%bp,%si\),%ax
>    2e:  8d 01 [         ]*lea    \(%bx,%di\),%ax
>    30:  8d 03 [         ]*lea    \(%bp,%di\),%ax
> -       ...
> +[      ]*[0-9a-f]+:    67 f7 13[       ]+notw[         ]+\(%ebx\)
> +[      ]*[0-9a-f]+:    66 f7 17[       ]+notl[         ]+\(%bx\)
> +[      ]*[0-9a-f]+:    67 0f 1f 03[    ]+nopw[         ]+\(%ebx\)
> +[      ]*[0-9a-f]+:    66 0f 1f 07[    ]+nopl[         ]+\(%bx\)
> +[      ]*[0-9a-f]+:    67 83 03 05[    ]+addw[         ]+\$0x5,\(%ebx\)
> +[      ]*[0-9a-f]+:    66 83 07 05[    ]+addl[         ]+\$0x5,\(%bx\)
> +[      ]*[0-9a-f]+:    67 c7 03 05 00[         ]+movw[         ]+\$0x5,\(%ebx\)
> +[      ]*[0-9a-f]+:    66 c7 07 05 00 00 00[   ]+movl[         ]+\$0x5,\(%bx\)
> +#pass
> --- a/gas/testsuite/gas/i386/intel16.s
> +++ b/gas/testsuite/gas/i386/intel16.s
> @@ -18,4 +18,14 @@
>   lea   ax, [di][bx]
>   lea   ax, [di][bp]
>
> - .p2align 4,0
> + notw  [ebx]
> + notd  [bx]
> +
> + nopw  [ebx]
> + nopd  [bx]
> +
> + addw  [ebx], 5
> + addd  [bx], 5
> +
> + movw  [ebx], 5
> + movd  [bx], 5
> --- /dev/null
> +++ b/gas/testsuite/gas/i386/movs.s
> @@ -0,0 +1,33 @@
> +       .text
> +movs:
> +       movsb   %al,%ax
> +       movsb   (%eax),%ax
> +       movsb   %al,%eax
> +       movsb   (%eax),%eax
> +.ifdef x86_64
> +       movsb   %al,%rax
> +       movsb   (%rax),%rax
> +.endif
> +
> +       movsbw  %al,%ax
> +       movsbw  (%eax),%ax
> +       movsbl  %al,%eax
> +       movsbl  (%eax),%eax
> +.ifdef x86_64
> +       movsbq  %al,%rax
> +       movsbq  (%rax),%rax
> +.endif
> +
> +       movsw   %ax,%eax
> +       movsw   (%eax),%eax
> +.ifdef x86_64
> +       movsw   %ax,%rax
> +       movsw   (%rax),%rax
> +.endif
> +
> +       movswl  %ax,%eax
> +       movswl  (%eax),%eax
> +.ifdef x86_64
> +       movswq  %ax,%rax
> +       movswq  (%rax),%rax
> +.endif
> --- /dev/null
> +++ b/gas/testsuite/gas/i386/movs32.d
> @@ -0,0 +1,22 @@
> +#objdump: -dw
> +#source: movs.s
> +#name: x86 mov with sign-extend (32-bit object)
> +
> +.*: +file format .*
> +
> +Disassembly of section .text:
> +
> +0+ <movs>:
> +[      ]*[a-f0-9]+:    66 0f be c0 *   movsbw %al,%ax
> +[      ]*[a-f0-9]+:    66 0f be 00 *   movsbw \(%eax\),%ax
> +[      ]*[a-f0-9]+:    0f be c0 *      movsbl %al,%eax
> +[      ]*[a-f0-9]+:    0f be 00 *      movsbl \(%eax\),%eax
> +[      ]*[a-f0-9]+:    66 0f be c0 *   movsbw %al,%ax
> +[      ]*[a-f0-9]+:    66 0f be 00 *   movsbw \(%eax\),%ax
> +[      ]*[a-f0-9]+:    0f be c0 *      movsbl %al,%eax
> +[      ]*[a-f0-9]+:    0f be 00 *      movsbl \(%eax\),%eax
> +[      ]*[a-f0-9]+:    0f bf c0 *      movswl %ax,%eax
> +[      ]*[a-f0-9]+:    0f bf 00 *      movswl \(%eax\),%eax
> +[      ]*[a-f0-9]+:    0f bf c0 *      movswl %ax,%eax
> +[      ]*[a-f0-9]+:    0f bf 00 *      movswl \(%eax\),%eax
> +#pass
> --- /dev/null
> +++ b/gas/testsuite/gas/i386/movs64.d
> @@ -0,0 +1,30 @@
> +#objdump: -dw
> +#source: movs.s
> +#name: x86 mov with sign-extend (64-bit object)
> +
> +.*: +file format .*
> +
> +Disassembly of section .text:
> +
> +0+ <movs>:
> +[      ]*[a-f0-9]+:    66 0f be c0 *   movsbw %al,%ax
> +[      ]*[a-f0-9]+:    67 66 0f be 00 *        movsbw \(%eax\),%ax
> +[      ]*[a-f0-9]+:    0f be c0 *      movsbl %al,%eax
> +[      ]*[a-f0-9]+:    67 0f be 00 *   movsbl \(%eax\),%eax
> +[      ]*[a-f0-9]+:    48 0f be c0 *   movsbq %al,%rax
> +[      ]*[a-f0-9]+:    48 0f be 00 *   movsbq \(%rax\),%rax
> +[      ]*[a-f0-9]+:    66 0f be c0 *   movsbw %al,%ax
> +[      ]*[a-f0-9]+:    67 66 0f be 00 *        movsbw \(%eax\),%ax
> +[      ]*[a-f0-9]+:    0f be c0 *      movsbl %al,%eax
> +[      ]*[a-f0-9]+:    67 0f be 00 *   movsbl \(%eax\),%eax
> +[      ]*[a-f0-9]+:    48 0f be c0 *   movsbq %al,%rax
> +[      ]*[a-f0-9]+:    48 0f be 00 *   movsbq \(%rax\),%rax
> +[      ]*[a-f0-9]+:    0f bf c0 *      movswl %ax,%eax
> +[      ]*[a-f0-9]+:    67 0f bf 00 *   movswl \(%eax\),%eax
> +[      ]*[a-f0-9]+:    48 0f bf c0 *   movswq %ax,%rax
> +[      ]*[a-f0-9]+:    48 0f bf 00 *   movswq \(%rax\),%rax
> +[      ]*[a-f0-9]+:    0f bf c0 *      movswl %ax,%eax
> +[      ]*[a-f0-9]+:    67 0f bf 00 *   movswl \(%eax\),%eax
> +[      ]*[a-f0-9]+:    48 0f bf c0 *   movswq %ax,%rax
> +[      ]*[a-f0-9]+:    48 0f bf 00 *   movswq \(%rax\),%rax
> +#pass
> --- a/gas/testsuite/gas/i386/movx16.l
> +++ b/gas/testsuite/gas/i386/movx16.l
> @@ -41,11 +41,11 @@
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %cl
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %cl
>  [      ]*[1-9][0-9]*[  ]*
> -[      ]*[1-9][0-9]*[  ]+movsb %al, %cx
> +[      ]*[1-9][0-9]* \?\?\?\? 0FBEC8[  ]+movsb %al, %cx
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %cx
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %cx
>  [      ]*[1-9][0-9]*[  ]*
> -[      ]*[1-9][0-9]*[  ]+movsb %al, %ecx
> +[      ]*[1-9][0-9]* \?\?\?\? 660FBEC8[        ]+movsb %al, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %ecx
>  [      ]*[1-9][0-9]*[  ]*
> @@ -82,7 +82,7 @@
>  [      ]*[1-9][0-9]*[  ]+movsw %eax, %cx
>  [      ]*[1-9][0-9]*[  ]*
>  [      ]*[1-9][0-9]*[  ]+movsw %al, %ecx
> -[      ]*[1-9][0-9]*[  ]+movsw %ax, %ecx
> +[      ]*[1-9][0-9]* \?\?\?\? 660FBFC8[        ]+movsw %ax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsw %eax, %ecx
>  [      ]*[1-9][0-9]*[  ]*
>  [      ]*[1-9][0-9]*[  ]+movswl        %al, %cl
> --- a/gas/testsuite/gas/i386/movx32.l
> +++ b/gas/testsuite/gas/i386/movx32.l
> @@ -41,11 +41,11 @@
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %cl
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %cl
>  [      ]*[1-9][0-9]*[  ]*
> -[      ]*[1-9][0-9]*[  ]+movsb %al, %cx
> +[      ]*[1-9][0-9]* \?\?\?\? 660FBEC8[        ]+movsb %al, %cx
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %cx
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %cx
>  [      ]*[1-9][0-9]*[  ]*
> -[      ]*[1-9][0-9]*[  ]+movsb %al, %ecx
> +[      ]*[1-9][0-9]* \?\?\?\? 0FBEC8[  ]+movsb %al, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %ecx
>  [      ]*[1-9][0-9]*[  ]*
> @@ -82,7 +82,7 @@
>  [      ]*[1-9][0-9]*[  ]+movsw %eax, %cx
>  [      ]*[1-9][0-9]*[  ]*
>  [      ]*[1-9][0-9]*[  ]+movsw %al, %ecx
> -[      ]*[1-9][0-9]*[  ]+movsw %ax, %ecx
> +[      ]*[1-9][0-9]* \?\?\?\? 0FBFC8[  ]+movsw %ax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsw %eax, %ecx
>  [      ]*[1-9][0-9]*[  ]*
>  [      ]*[1-9][0-9]*[  ]+movswl        %al, %cl
> --- a/gas/testsuite/gas/i386/movx64.l
> +++ b/gas/testsuite/gas/i386/movx64.l
> @@ -106,17 +106,17 @@
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %cl
>  [      ]*[1-9][0-9]*[  ]+movsb %rax, %cl
>  [      ]*[1-9][0-9]*[  ]*
> -[      ]*[1-9][0-9]*[  ]+movsb %al, %cx
> +[      ]*[1-9][0-9]* \?\?\?\? 660FBEC8[        ]+movsb %al, %cx
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %cx
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %cx
>  [      ]*[1-9][0-9]*[  ]+movsb %rax, %cx
>  [      ]*[1-9][0-9]*[  ]*
> -[      ]*[1-9][0-9]*[  ]+movsb %al, %ecx
> +[      ]*[1-9][0-9]* \?\?\?\? 0FBEC8[  ]+movsb %al, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsb %rax, %ecx
>  [      ]*[1-9][0-9]*[  ]*
> -[      ]*[1-9][0-9]*[  ]+movsb %al, %rcx
> +[      ]*[1-9][0-9]* \?\?\?\? 480FBEC8[        ]+movsb %al, %rcx
>  [      ]*[1-9][0-9]*[  ]+movsb %ax, %rcx
>  [      ]*[1-9][0-9]*[  ]+movsb %eax, %rcx
>  [      ]*[1-9][0-9]*[  ]+movsb %rax, %rcx
> @@ -192,12 +192,12 @@
>  [      ]*[1-9][0-9]*[  ]+movsw %rax, %cx
>  [      ]*[1-9][0-9]*[  ]*
>  [      ]*[1-9][0-9]*[  ]+movsw %al, %ecx
> -[      ]*[1-9][0-9]*[  ]+movsw %ax, %ecx
> +[      ]*[1-9][0-9]* \?\?\?\? 0FBFC8[  ]+movsw %ax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsw %eax, %ecx
>  [      ]*[1-9][0-9]*[  ]+movsw %rax, %ecx
>  [      ]*[1-9][0-9]*[  ]*
>  [      ]*[1-9][0-9]*[  ]+movsw %al, %rcx
> -[      ]*[1-9][0-9]*[  ]+movsw %ax, %rcx
> +[      ]*[1-9][0-9]* \?\?\?\? 480FBFC8[        ]+movsw %ax, %rcx
>  [      ]*[1-9][0-9]*[  ]+movsw %eax, %rcx
>  [      ]*[1-9][0-9]*[  ]+movsw %rax, %rcx
>  [      ]*[1-9][0-9]*[  ]*
> --- a/opcodes/i386-opc.tbl
> +++ b/opcodes/i386-opc.tbl
> @@ -135,47 +135,37 @@
>  mov, 0xa0, None, CpuNo64, D|W|No_sSuf|No_qSuf|No_ldSuf, { Disp16|Disp32|Unspecified|Byte|Word|Dword, Acc|Byte|Word|Dword }
>  mov, 0xa0, None, Cpu64, D|W|No_sSuf|No_ldSuf, { Disp64|Unspecified|Byte|Word|Dword|Qword, Acc|Byte|Word|Dword|Qword }
>  movabs, 0xa0, None, Cpu64, D|W|No_sSuf|No_ldSuf, { Disp64|Unspecified|Byte|Word|Dword|Qword, Acc|Byte|Word|Dword|Qword }
> -movq, 0xa1, None, Cpu64, D|Size64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Disp64|Unspecified|Qword, Acc|Qword }
>  mov, 0x88, None, 0, D|W|CheckRegSize|Modrm|No_sSuf|No_ldSuf|HLEPrefixRelease, { Reg8|Reg16|Reg32|Reg64, Reg8|Reg16|Reg32|Reg64|Byte|Word|Dword|Qword|Unspecified|BaseIndex }
> -movq, 0x89, None, Cpu64, D|Modrm|Size64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|HLEPrefixRelease, { Reg64, Reg64|Unspecified|Qword|BaseIndex }
>  // In the 64bit mode the short form mov immediate is redefined to have
>  // 64bit value.
>  mov, 0xb0, None, 0, W|No_sSuf|No_qSuf|No_ldSuf, { Imm8|Imm16|Imm32|Imm32S, Reg8|Reg16|Reg32 }
>  mov, 0xc6, 0, 0, W|Modrm|No_sSuf|No_ldSuf|HLEPrefixRelease|Optimize, { Imm8|Imm16|Imm32|Imm32S, Reg8|Reg16|Reg32|Reg64|Byte|Word|Dword|Qword|Unspecified|BaseIndex }
> -movq, 0xc7, 0, Cpu64, Modrm|Size64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|HLEPrefixRelease|Optimize, { Imm32S, Reg64|Qword|Unspecified|BaseIndex }
>  mov, 0xb8, None, Cpu64, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|Optimize, { Imm64, Reg64 }
>  movabs, 0xb8, None, Cpu64, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf, { Imm64, Reg64 }
> -movq, 0xb8, None, Cpu64, Size64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Optimize, { Imm64, Reg64 }
>  // The segment register moves accept WordReg so that a segment register
>  // can be copied to a 32 bit register, and vice versa, without using a
>  // size prefix.  When moving to a 32 bit register, the upper 16 bits
>  // are set to an implementation defined value (on the Pentium Pro, the
>  // implementation defined value is zero).
> -mov, 0x8c, None, 0, RegMem|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { SReg, Reg16|Reg32|Reg64 }
> +mov, 0x8c, None, 0, RegMem|No_bSuf|No_sSuf|No_ldSuf|NoRex64, { SReg, Reg16|Reg32|Reg64 }
>  mov, 0x8c, None, 0, D|Modrm|IgnoreSize|No_bSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { SReg, Word|Unspecified|BaseIndex }
> -movq, 0x8c, None, Cpu64, D|RegMem|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { SReg, Reg64 }
> -mov, 0x8e, None, 0, Modrm|IgnoreSize|No_bSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { Reg16|Reg32|Reg64, SReg }
> +mov, 0x8e, None, 0, Modrm|IgnoreSize|No_bSuf|No_sSuf|No_ldSuf|NoRex64, { Reg16|Reg32|Reg64, SReg }
>  // Move to/from control debug registers.  In the 16 or 32bit modes
>  // they are 32bit.  In the 64bit mode they are 64bit.
>  mov, 0xf20, None, Cpu386|CpuNo64, D|RegMem|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|No_qSuf|No_ldSuf, { Control, Reg32 }
>  mov, 0xf20, None, Cpu64, D|RegMem|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64, { Control, Reg64 }
> -movq, 0xf20, None, Cpu64, D|RegMem|Size64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { Control, Reg64 }
>  mov, 0xf21, None, Cpu386|CpuNo64, D|RegMem|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|No_qSuf|No_ldSuf, { Debug, Reg32 }
>  mov, 0xf21, None, Cpu64, D|RegMem|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_ldSuf|NoRex64, { Debug, Reg64 }
> -movq, 0xf21, None, Cpu64, D|RegMem|Size64|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|NoRex64, { Debug, Reg64 }
>  mov, 0xf24, None, Cpu386|CpuNo64, D|RegMem|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|No_qSuf|No_ldSuf, { Test, Reg32 }
>
>  // Move after swapping the bytes
>  movbe, 0x0f38f0, None, CpuMovbe, D|Modrm|No_bSuf|No_sSuf|No_ldSuf, { Word|Dword|Qword|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
>
>  // Move with sign extend.
> -// "movsbl" & "movsbw" must not be unified into "movsb" to avoid
> -// conflict with the "movs" string move instruction.
> -movsbl, 0xfbe, None, Cpu386, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg8|Byte|Unspecified|BaseIndex, Reg32 }
> -movsbw, 0xfbe, None, Cpu386, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg8|Byte|Unspecified|BaseIndex, Reg16 }
> -movswl, 0xfbf, None, Cpu386, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg16|Word|Unspecified|BaseIndex, Reg32 }
> -movsbq, 0xfbe, None, Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Size64, { Reg8|Byte|Unspecified|BaseIndex, Reg64 }
> -movswq, 0xfbf, None, Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Size64, { Reg16|Word|Unspecified|BaseIndex, Reg64 }
> +movsb, 0xfbe, None, Cpu386, Modrm|No_bSuf|No_sSuf|No_ldSuf, { Reg8|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
> +movsw, 0xfbf, None, Cpu386, Modrm|No_bSuf|No_wSuf|No_sSuf|No_ldSuf, { Reg16|Unspecified|BaseIndex, Reg32|Reg64 }
> +// "movslq" must not be converted into "movsl" to avoid conflict with the
> +// "movsl" string move instruction.
>  movslq, 0x63, None, Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Size64, { Reg32|Dword|Unspecified|BaseIndex, Reg64 }
>  movsx, 0xfbe, None, Cpu386, W|Modrm|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg8|Reg16|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
>  movsx, 0x63, None, Cpu64, Modrm|No_bSuf|No_wSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg32|Unspecified|BaseIndex, Reg32|Reg64 }
> @@ -492,9 +482,6 @@ set<cc>, 0xf9<cc:opc>, 0, Cpu386, Modrm|
>  // String manipulation.
>  cmps, 0xa6, None, 0, W|No_sSuf|No_ldSuf|IsString|RepPrefixOk, {}
>  cmps, 0xa6, None, 0, W|No_sSuf|No_ldSuf|IsStringEsOp0|RepPrefixOk, { Byte|Word|Dword|Qword|Unspecified|BaseIndex, Byte|Word|Dword|Qword|Unspecified|BaseIndex }
> -// Intel mode string compare.
> -cmpsd, 0xa7, None, Cpu386, Size32|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IsString|RepPrefixOk, {}
> -cmpsd, 0xa7, None, Cpu386, Size32|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IsStringEsOp0|RepPrefixOk, { Dword|Unspecified|BaseIndex, Dword|Unspecified|BaseIndex }
>  scmp, 0xa6, None, 0, W|No_sSuf|No_ldSuf|IsString|RepPrefixOk, {}
>  scmp, 0xa6, None, 0, W|No_sSuf|No_ldSuf|IsStringEsOp0|RepPrefixOk, { Byte|Word|Dword|Qword|Unspecified|BaseIndex, Byte|Word|Dword|Qword|Unspecified|BaseIndex }
>  ins, 0x6c, None, Cpu186, W|No_sSuf|No_qSuf|No_ldSuf|IsString|RepPrefixOk, {}
> @@ -509,9 +496,6 @@ slod, 0xac, None, 0, W|No_sSuf|No_ldSuf|
>  slod, 0xac, None, 0, W|No_sSuf|No_ldSuf|IsString|RepPrefixOk, { Byte|Word|Dword|Qword|Unspecified|BaseIndex, Acc|Byte|Word|Dword|Qword }
>  movs, 0xa4, None, 0, W|No_sSuf|No_ldSuf|IsString|RepPrefixOk, {}
>  movs, 0xa4, None, 0, W|No_sSuf|No_ldSuf|IsStringEsOp1|RepPrefixOk, { Byte|Word|Dword|Qword|Unspecified|BaseIndex, Byte|Word|Dword|Qword|Unspecified|BaseIndex }
> -// Intel mode string move.
> -movsd, 0xa5, None, Cpu386, Size32|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IsString|RepPrefixOk, {}
> -movsd, 0xa5, None, Cpu386, Size32|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IsStringEsOp1|RepPrefixOk, { Dword|Unspecified|BaseIndex, Dword|Unspecified|BaseIndex }
>  smov, 0xa4, None, 0, W|No_sSuf|No_ldSuf|IsString|RepPrefixOk, {}
>  smov, 0xa4, None, 0, W|No_sSuf|No_ldSuf|IsStringEsOp1|RepPrefixOk, { Byte|Word|Dword|Qword|Unspecified|BaseIndex, Byte|Word|Dword|Qword|Unspecified|BaseIndex }
>  scas, 0xae, None, 0, W|No_sSuf|No_ldSuf|IsString|RepPrefixOk, {}
>


-- 
H.J.