RE: [PATCH 1/2] Reorder APX insns in i386.tbl

["Hu, Lin1" <lin1.hu@intel.com>]

> -----Original Message-----
> From: Jan Beulich <jbeulich@suse.com>
> Sent: Tuesday, November 14, 2023 7:21 PM
> To: Hu, Lin1 <lin1.hu@intel.com>
> Cc: Lu, Hongjiu <hongjiu.lu@intel.com>; binutils@sourceware.org
> Subject: Re: [PATCH 1/2] Reorder APX insns in i386.tbl
> 
> On 14.11.2023 03:58, Hu, Lin1 wrote:
> > ---
> >  gas/config/tc-i386.c |     4 +-
> >  opcodes/i386-opc.tbl |   156 +-
> >  5 files changed, 13189 insertions(+), 10771 deletions(-)
> 
> What was the goal of sending this patch to the list, without any further
> comments or explanations? It quite clearly doesn't apply to the present code
> base.
> 
> The diffstat is pretty odd, too: There clearly aren't as many files/lines changed.

This patch is just to show you the changes I would need to make if I reorder .tbl, the big difference in lines is because I removed the changes to mnem.h, init.h, etc. in the email.

> 
> > @@ -2124,12 +2126,12 @@ xcryptofb, 0xf30fa7e8, PadLock,
> > NoSuf|RepPrefixOk, {}  xstore, 0xfa7c0, PadLock, NoSuf|RepPrefixOk, {}
> >
> >  // Multy-precision Add Carry, rdseed instructions.
> > +adcx, 0x6666, ADX|APX_F,
> >
> +C|Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|VexVVV
> VDe
> > +st|EVex128|EVexMap4, { Reg32|Reg64|Unspecified|BaseIndex,
> > +Reg32|Reg64, Reg32|Reg64 }
> >  adcx, 0x660f38f6, ADX,
> > Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf, {
> > Reg32|Reg64|Unspecified|BaseIndex, Reg32|Reg64 }  adcx, 0x6666,
> > ADX|APX_F,
> >
> Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|EVex128|E
> Vex
> > Map4, { Reg32|Reg64|Unspecified|BaseIndex, Reg32|Reg64 } -adcx,
> > 0x6666, ADX|APX_F,
> >
> Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|VexVVVVD
> est|
> > EVex128|EVexMap4, { Reg32|Reg64|Unspecified|BaseIndex, Reg32|Reg64,
> > Reg32|Reg64 }
> > +adox, 0xf366, ADX|APX_F,
> >
> +C|Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|VexVVV
> VDe
> > +st|EVex128|EVexMap4, { Reg32|Reg64|Unspecified|BaseIndex,
> > +Reg32|Reg64, Reg32|Reg64 }
> >  adox, 0xf30f38f6, ADX,
> > Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf, {
> > Reg32|Reg64|Unspecified|BaseIndex, Reg32|Reg64 }  adox, 0xf366,
> > ADX|APX_F,
> >
> Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|EVex128|E
> Vex
> > Map4, { Reg32|Reg64|Unspecified|BaseIndex, Reg32|Reg64 } -adox,
> > 0xf366, ADX|APX_F,
> >
> Modrm|CheckOperandSize|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|VexVVVVD
> est|
> > EVex128|EVexMap4, { Reg32|Reg64|Unspecified|BaseIndex, Reg32|Reg64,
> > Reg32|Reg64 }
> 
> What is this part about? I thought we agreed that ADCX/ADOX aren't suitable for
> NDD->REX2 optimization, at which point the ordering of templates here could as
> well be left alone.
>
      62 54 bd 18 66 c7       adcx   %r15,%r8,%r8
      66 4d 0f  38 f6  c7       adcx   %r15,%r8
      
The code can optimize adcx/adox from NDD to legacy, currently. Do you mean we don't consider the optimization If the code length remain the same?

BRs,
Lin