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[PATCH v8 1/2] x86: replace adhoc (partly wrong) ambiguous operand checking for MOVSX/MOVZX

Jan Beulich jbeulich@suse.com
Fri Feb 14 12:42:00 GMT 2020 
On 14.02.2020 13:34, H.J. Lu wrote:
> On Fri, Feb 14, 2020 at 4:26 AM Jan Beulich <jbeulich@suse.com> wrote:
>> --- a/opcodes/i386-opc.tbl
>> +++ b/opcodes/i386-opc.tbl
>> @@ -132,13 +132,9 @@ movswl, 2, 0xfbf, None, 2, Cpu386, Modrm
>>  movsbq, 2, 0xfbe, None, 2, Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Rex64, { Reg8|Byte|Unspecified|BaseIndex, Reg64 }
>>  movswq, 2, 0xfbf, None, 2, Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Rex64, { Reg16|Word|Unspecified|BaseIndex, Reg64 }
>>  movslq, 2, 0x63, None, 1, Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Rex64, { Reg32|Dword|Unspecified|BaseIndex, Reg64 }
>> -// Intel Syntax next 3 insns
>> -movsx, 2, 0xfbe, None, 2, Cpu386, Modrm|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Reg8|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
>> -movsx, 2, 0xfbf, None, 2, Cpu386, Modrm|No_bSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Reg16|Unspecified|BaseIndex, Reg32|Reg64 }
>> -movsx, 2, 0x63, None, 1, Cpu64, Modrm|No_bSuf|No_wSuf|No_sSuf|No_qSuf|No_ldSuf|Rex64|ATTSyntax, { Reg32|Unspecified|BaseIndex, Reg64 }
>> -movsx, 2, 0xfbe, None, 2, Cpu386, Modrm|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IntelSyntax, { Reg8|Byte|BaseIndex, Reg16|Reg32|Reg64 }
>> -movsx, 2, 0xfbf, None, 2, Cpu386, Modrm|No_bSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IntelSyntax, { Reg16|Word|BaseIndex, Reg32|Reg64 }
>> -movsx, 2, 0x63, None, 1, Cpu64, Modrm|No_bSuf|No_wSuf|No_sSuf|No_qSuf|No_ldSuf|Rex64|IntelSyntax, { Reg32|Dword|BaseIndex, Reg64 }
>> +// Intel Syntax next 2 insns
> ^^^^^^^^^^^^^^^^ Is this comment correct?

Yes. MOVSX isn't AT&T syntax, it's just that we permit it to be used
there too (because people actually use it, albeit strictly speaking in
error).

>> +movsx, 2, 0xfbe, None, 2, Cpu386, W|Modrm|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg8|Reg16|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
>> +movsx, 2, 0x63, None, 1, Cpu64, Modrm|No_bSuf|No_wSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg32|Unspecified|BaseIndex, Reg32|Reg64 }
>>  movsxd, 2, 0x63, None, 1, Cpu64, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg32|Unspecified|BaseIndex, Reg32|Reg64 }
>>  movsxd, 2, 0x63, None, 1, Cpu64, Amd64|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg32|Unspecified|BaseIndex, Reg16 }
>>  movsxd, 2, 0x63, None, 1, Cpu64, Intel64|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg16|Unspecified|BaseIndex, Reg16 }
>> @@ -146,12 +142,9 @@ movsxd, 2, 0x63, None, 1, Cpu64, Intel64
>>  // Move with zero extend.
>>  movzb, 2, 0xfb6, None, 2, Cpu386, Modrm|No_bSuf|No_sSuf|No_ldSuf, { Reg8|Byte|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
>>  movzw, 2, 0xfb7, None, 2, Cpu386, Modrm|No_bSuf|No_wSuf|No_sSuf|No_ldSuf, { Reg16|Word|Unspecified|BaseIndex, Reg32|Reg64 }
>> -// Intel Syntax next 2 insns (the 64-bit variants are not particulary
>> +// Intel Syntax next insn (the 64-bit variant is not particulary
> ^^^^^^^^^^^^^^^^ Is this comment correct?

Same for MOVZX.

Jan

>>  // useful since the zero extend 32->64 is implicit, but we can encode them).
>> -movzx, 2, 0xfb6, None, 2, Cpu386, Modrm|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Reg8|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
>> -movzx, 2, 0xfb7, None, 2, Cpu386, Modrm|No_bSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax, { Reg16|Unspecified|BaseIndex, Reg32|Reg64 }
>> -movzx, 2, 0xfb6, None, 2, Cpu386, Modrm|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IntelSyntax, { Reg8|Byte|BaseIndex, Reg16|Reg32|Reg64 }
>> -movzx, 2, 0xfb7, None, 2, Cpu386, Modrm|No_bSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|IntelSyntax, { Reg16|Word|BaseIndex, Reg32|Reg64 }
>> +movzx, 2, 0xfb6, None, 2, Cpu386, W|Modrm|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg8|Reg16|Unspecified|BaseIndex, Reg16|Reg32|Reg64 }
>>
>>  // Push instructions.
>>  push, 1, 0x50, None, 1, CpuNo64, No_bSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg16|Reg32 }
>>
> 
>
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