[PATCH v5 3/8] x86: re-work insn/suffix recognition

[Jan Beulich]

On 27.10.2022 19:21, H.J. Lu wrote:
> On Tue, Oct 25, 2022 at 12:26 AM Jan Beulich <jbeulich@suse.com> wrote:
>> @@ -989,13 +976,13 @@ emms, 0xf77, None, CpuMMX, No_bSuf|No_wS
>>  // copying between Reg64/Mem64 and RegXMM/RegMMX, as is mandated by Intel's
>>  // spec). AMD's spec, having been in existence for much longer, failed to
>>  // recognize that and specified movd for 32- and 64-bit operations.
>> -movd, 0x666e, None, CpuAVX, D|Modrm|Vex128|Space0F|VexW0|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX, { Reg32|Unspecified|BaseIndex, RegXMM }
>> +movd, 0x666e, None, CpuAVX, D|Modrm|Vex128|Space0F|VexW0|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX|Pass2, { Reg32|Unspecified|BaseIndex, RegXMM }
>>  movd, 0x666e, None, CpuAVX|Cpu64, D|Modrm|Vex=1|Space0F|VexW1|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Size64|SSE2AVX, { Reg64|BaseIndex, RegXMM }
>>  movd, 0x660f6e, None, CpuSSE2, D|Modrm|IgnoreSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg32|Unspecified|BaseIndex, RegXMM }
>>  movd, 0x660f6e, None, CpuSSE2|Cpu64, D|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Size64, { Reg64|BaseIndex, RegXMM }
>>  movd, 0xf6e, None, CpuMMX, D|Modrm|IgnoreSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Reg32|Unspecified|BaseIndex, RegMMX }
>>  movd, 0xf6e, None, CpuMMX|Cpu64, D|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Size64, { Reg64|BaseIndex, RegMMX }
>> -movq, 0xf37e, None, CpuAVX, Load|Modrm|Vex=1|Space0F|VexWIG|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX, { Qword|Unspecified|BaseIndex|RegXMM, RegXMM }
>> +movq, 0xf37e, None, CpuAVX, Load|Modrm|Vex=1|Space0F|VexWIG|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX|Pass2, { Qword|Unspecified|BaseIndex|RegXMM, RegXMM }
>>  movq, 0x66d6, None, CpuAVX, Modrm|Vex=1|Space0F|VexWIG|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX, { RegXMM, Qword|Unspecified|BaseIndex|RegXMM }
>>  movq, 0x666e, None, CpuAVX|Cpu64, D|Modrm|Vex=1|Space0F|VexW1|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Size64|SSE2AVX, { Reg64|Unspecified|BaseIndex, RegXMM }
>>  movq, 0xf30f7e, None, CpuSSE2, Load|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Unspecified|Qword|BaseIndex|RegXMM, RegXMM }
>> @@ -1159,7 +1146,7 @@ andpd<sse2>, 0x660f54, None, <sse2:cpu>,
>>  cmp<frel>pd<sse2>, 0x660fc2, <frel:imm>, <sse2:cpu>, Modrm|<sse2:attr>|<sse2:vvvv>|<frel:comm>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ImmExt, { RegXMM|Unspecified|BaseIndex, RegXMM }
>>  cmp<frel>sd<sse2>, 0xf20fc2, <frel:imm>, <sse2:cpu>, Modrm|<sse2:scal>|<sse2:vvvv>|<frel:comm>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ImmExt, { RegXMM|Qword|Unspecified|BaseIndex, RegXMM }
>>  cmppd<sse2>, 0x660fc2, None, <sse2:cpu>, Modrm|<sse2:attr>|<sse2:vvvv>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, RegXMM|Unspecified|BaseIndex, RegXMM }
>> -cmpsd<sse2>, 0xf20fc2, None, <sse2:cpu>, Modrm|<sse2:scal>|<sse2:vvvv>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Imm8, Qword|Unspecified|BaseIndex|RegXMM, RegXMM }
>> +cmpsd<sse2>, 0xf20fc2, None, <sse2:cpu>, Modrm|<sse2:scal>|<sse2:vvvv>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|Pass2, { Imm8, Qword|Unspecified|BaseIndex|RegXMM, RegXMM }
>>  comisd<sse2>, 0x660f2f, None, <sse2:cpu>, Modrm|<sse2:scal>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Qword|Unspecified|BaseIndex|RegXMM, RegXMM }
>>  cvtpi2pd, 0x660f2a, None, CpuSSE2, Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { RegMMX, RegXMM }
>>  cvtpi2pd, 0xf3e6, None, CpuAVX, Modrm|Vex|Space0F|VexW0|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX, { Qword|Unspecified|BaseIndex, RegXMM }
>> @@ -1184,7 +1171,7 @@ movlpd, 0x6613, None, CpuAVX, Modrm|Vex|
>>  movlpd, 0x660f12, None, CpuSSE2, D|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Qword|Unspecified|BaseIndex, RegXMM }
>>  movmskpd<sse2>, 0x660f50, None, <sse2:cpu>, Modrm|<sse2:attr>|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|No_ldSuf|NoRex64, { RegXMM, Reg32|Reg64 }
>>  movntpd<sse2>, 0x660f2b, None, <sse2:cpu>, Modrm|<sse2:attr>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { RegXMM, Xmmword|Unspecified|BaseIndex }
>> -movsd, 0xf210, None, CpuAVX, D|Modrm|VexLIG|Space0F|VexW0|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX, { Qword|Unspecified|BaseIndex, RegXMM }
>> +movsd, 0xf210, None, CpuAVX, D|Modrm|VexLIG|Space0F|VexW0|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX|Pass2, { Qword|Unspecified|BaseIndex, RegXMM }
>>  movsd, 0xf210, None, CpuAVX, D|Modrm|Vex=3|Space0F|VexVVVV=1|VexW=1|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|SSE2AVX, { RegXMM, RegXMM }
>>  movsd, 0xf20f10, None, CpuSSE2, D|Modrm|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { Qword|Unspecified|BaseIndex|RegXMM, RegXMM }
>>  movupd<sse2>, 0x660f10, None, <sse2:cpu>, D|Modrm|<sse2:attr>|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { RegXMM|Unspecified|BaseIndex, RegXMM }
>>
> 
> All these instructions with Pass2 have a vector register operand.  Can you
> use it instead?

I probably could, but that would go against your request of limiting as
much as possible the allocation of a copy of the input line: Far more
insns would then also undergo this setup for a possible 2nd parsing pass.
It may be possible to limit the set some by taking into account further
attributes (like, leaving aside move-with-sign-extend which you object
to being corrected, SSE2AVX), but the collection of those checks would
likely be clumsy and harder to maintain than the new attribute. For
example the consistency check in i386-gen would then not be possible
anymore, and hence the whole thing would become _silently_ dependent on
the ordering of templates in the file.

Furthermore keying this condition to insn attributes would be less
future proof. While it may not be very likely for new colliding
mnemonics to appear, if one would which then doesn't fit the chosen
pattern, the tweaking of the conditional would be more fragile than
the mere adding of Pass2 in the appropriate template. (Even if you
continue to object to it, simply consider the last patch of this series
an example.)

Jan