Re: [PATCH 03/10] Support Intel AVX-NE-CONVERT

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

On Sun, Oct 23, 2022 at 10:59 PM Kong, Lingling <lingling.kong@intel.com> wrote:
>
>
> Hi Jan,
>
> Thanks you so much for reviewing this patch.  I really appreciate it. For these review comments, I have made some changes.
> Sorry, Forgot to delete i386-init.h and  i386-tbl.h in last email attachment.
>
> > -----Original Message-----
> > From: Jan Beulich <jbeulich@suse.com>
> > Sent: Friday, October 14, 2022 8:59 PM
> > To: Jiang, Haochen <haochen.jiang@intel.com>
> > Cc: hjl.tools@gmail.com; Kong, Lingling <lingling.kong@intel.com>;
> > binutils@sourceware.org
> > Subject: Re: [PATCH 03/10] Support Intel AVX-NE-CONVERT
> >
> > On 14.10.2022 11:12, Haochen Jiang wrote:
> > > --- a/opcodes/i386-dis.c
> > > +++ b/opcodes/i386-dis.c
> > > @@ -937,6 +937,8 @@ enum
> > >    MOD_VEX_0F385E_X86_64_P_3_W_0,
> > >    MOD_VEX_0F388C,
> > >    MOD_VEX_0F388E,
> > > +  MOD_VEX_0F38B0,
> > > +  MOD_VEX_0F38B1,
> > >    MOD_VEX_0F3A30_L_0,
> > >    MOD_VEX_0F3A31_L_0,
> > >    MOD_VEX_0F3A32_L_0,
> > > @@ -1132,6 +1134,9 @@ enum
> > >    PREFIX_VEX_0F3851_W_0,
> > >    PREFIX_VEX_0F385C_X86_64,
> > >    PREFIX_VEX_0F385E_X86_64,
> > > +  PREFIX_VEX_0F3872,
> > > +  PREFIX_VEX_0F38B0,
> > > +  PREFIX_VEX_0F38B1,
> >
> > PREFIX_VEX_0F38B0_M_1_W_0 and PREFIX_VEX_0F38B1_M_1_W_0
> > respectively, please. These enumerators are supposed to show the already
> > decoded components. Plus they need to be unambiguous if insns appear which
> > vary in (here) permitted ModR/M forms or the VEX.W bit.
>
> Yes, I changed it to PREFIX_VEX_0F38B0_M_1_W_0 and PREFIX_VEX_0F38B1_M_1_W_0.
>
> > > @@ -1526,8 +1531,11 @@ enum
> > >    VEX_W_0F385E_X86_64_P_1,
> > >    VEX_W_0F385E_X86_64_P_2,
> > >    VEX_W_0F385E_X86_64_P_3,
> > > +  VEX_W_0F3872_P_1,
> > >    VEX_W_0F3878,
> > >    VEX_W_0F3879,
> > > +  VEX_W_0F38B0,
> > > +  VEX_W_0F38B1,
> >
> > VEX_W_0F38B0_M_1 and VEX_W_0F38B1_M_1 respectively, please.
> >
> > > @@ -7618,6 +7654,14 @@ static const struct dis386 vex_w_table[][2] = {
> > >      /* VEX_W_0F3879 */
> > >      { "vpbroadcastw",      { XM, EXw }, PREFIX_DATA },
> > >    },
> > > +  {
> > > +  /* VEX_W_0F38B0 */
> >
> > Nit: Indentation.
>
>  Fixed.
>
> > > @@ -8428,6 +8472,14 @@ static const struct dis386 mod_table[][2] = {
> > >      /* MOD_VEX_0F388E */
> > >      { "vpmaskmov%DQ",      { Mx, Vex, XM }, PREFIX_DATA },
> > >    },
> > > +  {
> > > +    /* MOD_VEX_0F38B0*/
> > > +    { VEX_W_TABLE (VEX_W_0F38B0) },
> > > +  },
> > > +  {
> > > +    /* MOD_VEX_0F38B1*/
> > > +    { VEX_W_TABLE (VEX_W_0F38B1) },
> > > +  },
> >
> > Nit: Blanks missing in both of the comments.
>
> Fixed.
>
> > > --- a/opcodes/i386-gen.c
> > > +++ b/opcodes/i386-gen.c
> > > @@ -249,6 +249,8 @@ static initializer cpu_flag_init[] =
> > >      "CPU_AVX2_FLAGS|CpuAVX_IFMA" },
> > >    { "CPU_AVX_VNNI_INT8_FLAGS",
> > >      "CPU_AVX2_FLAGS|CpuAVX_VNNI_INT8" },
> > > +  { "CPU_AVX_NE_CONVERT_FLAGS",
> > > +    "CPU_AVX2_FLAGS|CpuAVX_NE_CONVERT" },
> > >    { "CPU_IAMCU_FLAGS",
> > >      "Cpu186|Cpu286|Cpu386|Cpu486|Cpu586|CpuIAMCU" },
> > >    { "CPU_ADX_FLAGS",
> > > @@ -447,6 +449,8 @@ static initializer cpu_flag_init[] =
> > >      "CpuAVX_IFMA" },
> > >    { "CPU_ANY_AVX_VNNI_INT8_FLAGS",
> > >      "CpuAVX_VNNI_INT8" },
> > > +  { "CPU_ANY_AVX_NE_CONVERT_FLAGS",
> > > +    "CpuAVX_NE_CONVERT" },
> > >  };
> >
> > Like for patches 1 and 2 - CPU_ANY_AVX2_FLAGS also need adjusting.
>
> Fixed.
>
> > > --- a/opcodes/i386-opc.tbl
> > > +++ b/opcodes/i386-opc.tbl
> > > @@ -3027,6 +3027,21 @@ movdir64b, 0x660f38f8, None, CpuMOVDIR64B,
> > > Modrm|AddrPrefixOpReg, { Unspecified|
> > >
> > >  // MOVEDIR instructions end.
> > >
> > > +// AVX_NE_CONVERT instructions.
> > > +
> > > +vbcstnebf162ps, 0xf3b1, None, CpuAVX_NE_CONVERT,
> > Modrm|Vex|Space0F38|VexW0|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No
> > _sSuf|No_qSuf|No_ldSuf, {Word|Unspecified|BaseIndex, RegXMM|RegYMM}
> > > +vbcstnesh2ps,   0x66b1, None, CpuAVX_NE_CONVERT,
> > Modrm|Vex|Space0F38|VexW0|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No
> > _sSuf|No_qSuf|No_ldSuf, {Word|Unspecified|BaseIndex, RegXMM|RegYMM}
> >
> > Why CheckRegSize?
>
> Removed the CheckRegSize.
>
> > > +vcvtneoph2ps,   0xb0,   None,   CpuAVX_NE_CONVERT,
> > Modrm|Vex|Space0F38|VexW0|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No
> > _sSuf|No_qSuf|No_ldSuf, {Xmmword|Ymmword|Unspecified|BaseIndex,
> > RegXMM|RegYMM}
> > > +vcvtneebf162ps, 0xf3b0, None,   CpuAVX_NE_CONVERT,
> > Modrm|Vex|Space0F38|VexW0|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No
> > _sSuf|No_qSuf|No_ldSuf, {Xmmword|Ymmword|Unspecified|BaseIndex,
> > RegXMM|RegYMM}
> > > +vcvtneeph2ps,   0x66b0, None,   CpuAVX_NE_CONVERT,
> > Modrm|Vex|Space0F38|VexW0|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No
> > _sSuf|No_qSuf|No_ldSuf, {Xmmword|Ymmword|Unspecified|BaseIndex,
> > RegXMM|RegYMM}
> > > +vcvtneobf162ps, 0xf2b0, None,   CpuAVX_NE_CONVERT,
> > Modrm|Vex|Space0F38|VexW0|CheckRegSize|No_bSuf|No_wSuf|No_lSuf|No
> > _sSuf|No_qSuf|No_ldSuf, {Xmmword|Ymmword|Unspecified|BaseIndex,
> > RegXMM|RegYMM}
> > > +vcvtneps2bf16,  0xf372, None,   CpuAVX_NE_CONVERT,
> > Modrm|PseudoVexPrefix|Vex128|Space0F38|VexW0|CheckRegSize|No_bSuf|
> > No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf,
> > {Xmmword|RegXMM|Unspecified|BaseIndex, RegXMM}
> > > +vcvtneps2bf16,  0xf372, None,   CpuAVX_NE_CONVERT,
> > Modrm|PseudoVexPrefix|Vex256|Space0F38|VexW0|CheckRegSize|No_bSuf|
> > No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf,
> > {Ymmword|RegYMM|Unspecified|BaseIndex, RegXMM}
> > > +vcvtneps2bf16x, 0xf372, None,   CpuAVX_NE_CONVERT,
> > Modrm|PseudoVexPrefix|Vex128|Space0F38|VexW0|CheckRegSize|No_bSuf|
> > No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax,
> > {Xmmword|RegXMM|Unspecified|BaseIndex, RegXMM}
> > > +vcvtneps2bf16y,  0xf372, None,   CpuAVX_NE_CONVERT,
> > Modrm|PseudoVexPrefix|Vex256|Space0F38|VexW0|CheckRegSize|No_bSuf|
> > No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf|ATTSyntax,
> > {Ymmword|RegYMM|Unspecified|BaseIndex, RegXMM}
> >
> > Nit: Excess blank after the first comma on the last of the above lines, and excess
> > blanks on all vcvt* lines before CpuAVX_NE_CONVERT.
>
> Fixed.
>
> > Unnecessary Xmmword / Ymmword on the last four lines. And there again - why
> > CheckRegSize? But these would anyway benefit from using the AVX instance of
> > the <xy> template - then AT&T syntax handling for the suffix-less variant would
> > automatically be correct (it isn't in your code). Problem is that it wasn't clear
> > that there'll be a need to re-use xy's AVX instance this late in the file, so the
> > overloading of the name (commit e07ae9a3efee) will need undoing. To keep
> > names short (see commit 390ddd6f6812) I'd recommend using Vxy and Exy (for
> > the VEX and EVEX variants respectively).
> >
> > Like for the earlier patches I disagree with the uses of PseudoVexPrefix here (as
> > said - the attribute should really go away again, and I have a patch doing so), but
> > then ...
>
> Removed the CheckRegSize, Xmmword / Ymmword and PseudoVexPrefix.
> And added <Vxy> and <Exy>.
>
> > > +
> > > +// AVX_NE_CONVERT instructions end.
> > > +
> > >  // AVX512_BF16 instructions.
> > >
> > >  vcvtne2ps2bf16, 0xf272, None, CpuAVX512_BF16,
> > >
> > Modrm|Space0F38|VexVVVV|Masking=3|VexW0|Broadcast|Disp8ShiftVL|Chec
> > kRe
> > > gSize|No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, {
> > > RegXMM|RegYMM|RegZMM|Dword|Unspecified|BaseIndex,
> > > RegXMM|RegYMM|RegZMM, RegXMM|RegYMM|RegZMM }
> >
> > ... the new insns (at least the ones having AVX512 counterparts) need to be
> > placed after the AVX512 ones (which you'll note use the <xy> template.
> >
> > Jan
>
> Yes, Now placed after the AVX512 ones.
>
> Thanks,
> Lingling

Please add some comments to explain how <Exy> and <Vxy> are
used, something like <Vxy> is used on VEX instructions with x/y
suffixes and <Exy> is used on EVEX instructions with x/y suffixes.

Thanks.

-- 
H.J.