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

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

On Fri, Feb 14, 2020 at 4:42 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> 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).

I am checking in a patch to document different mnemonics of movsx,
movsxd and movzx in AT&T syntax:

https://sourceware.org/ml/binutils/2020-02/msg00332.html

> >> +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.
>

-- 
H.J.