Re: [PATCH 07/10] Support Intel WRMSRNS

[Jan Beulich <jbeulich@suse.com>]

On 14.10.2022 11:12, Haochen Jiang wrote:
> --- a/gas/config/tc-i386.c
> +++ b/gas/config/tc-i386.c
> @@ -1099,6 +1099,7 @@ static const arch_entry cpu_arch[] =
>    SUBARCH (avx_ne_convert, AVX_NE_CONVERT, ANY_AVX_NE_CONVERT, false),
>    SUBARCH (cmpccxadd, CMPCCXADD, ANY_CMPCCXADD, false),
>    SUBARCH (raoint, RAOINT, ANY_RAOINT, false),
> +  SUBARCH (wrmsrns, WRMSRNS, ANY_WRMSRNS, false),

As for some of the earlier patches - no need for ANY_WRMSRNS afaics.

> --- /dev/null
> +++ b/gas/testsuite/gas/i386/wrmsrns.s
> @@ -0,0 +1,9 @@
> +# Check WRMSRNS instructions
> +
> +	.allow_index_reg

Nit: Why?

> --- a/gas/testsuite/gas/i386/x86-64-lockbad-1.l
> +++ b/gas/testsuite/gas/i386/x86-64-lockbad-1.l
> @@ -36,9 +36,9 @@
>  .*:41: Error: .*
>  .*:42: Error: .*
>  .*:43: Error: .*
> -.*:46: Error: .*
> +.*:44: Error: .*
>  .*:47: Error: .*
> -.*:49: Error: .*
> +.*:48: Error: .*
>  .*:50: Error: .*
>  .*:51: Error: .*
>  .*:52: Error: .*
> @@ -66,13 +66,15 @@
>  .*:74: Error: .*
>  .*:75: Error: .*
>  .*:76: Error: .*
> -.*:78: Error: .*
> +.*:77: Error: .*
>  .*:79: Error: .*
>  .*:80: Error: .*
>  .*:81: Error: .*
>  .*:82: Error: .*
>  .*:83: Error: .*
>  .*:84: Error: .*
> +.*:85: Error: .*
> +.*:86: Error: .*
>  GAS LISTING .*

While for the diagnostics line numbers matter, ...

> @@ -119,47 +121,49 @@ GAS LISTING .*
>  [ 	]*41[ 	]+lock sbb \(%rbx\), %eax
>  [ 	]*42[ 	]+lock sub \(%rbx\), %eax
>  [ 	]*43[ 	]+lock xor \(%rbx\), %eax
> -[ 	]*44[ 	]+
> -[ 	]*45[ 	]+\.intel_syntax noprefix
> -[ 	]*46[ 	]+lock mov eax,ebx
> -[ 	]*47[ 	]+lock mov eax,DWORD PTR \[rbx\]
> -[ 	]*48[ 	]+
> -[ 	]*49[ 	]+lock add eax,ebx
> -[ 	]*50[ 	]+lock add ebx,0x64
> -[ 	]*51[ 	]+lock adc eax,ebx
> -[ 	]*52[ 	]+lock adc ebx,0x64
> -[ 	]*53[ 	]+lock and eax,ebx
> -[ 	]*54[ 	]+lock and ebx,0x64
> -[ 	]*55[ 	]+lock btc ebx,eax
> -[ 	]*56[ 	]+lock btc ebx,0x64
> -[ 	]*57[ 	]+lock btr ebx,eax
> +[ 	]*44[ 	]+lock wrmsrns
> +[ 	]*45[ 	]+
> +[ 	]*46[ 	]+\.intel_syntax noprefix
> +[ 	]*47[ 	]+lock mov eax,ebx
> +[ 	]*48[ 	]+lock mov eax,DWORD PTR \[rbx\]
> +[ 	]*49[ 	]+
> +[ 	]*50[ 	]+lock add eax,ebx
> +[ 	]*51[ 	]+lock add ebx,0x64
> +[ 	]*52[ 	]+lock adc eax,ebx
> +[ 	]*53[ 	]+lock adc ebx,0x64
> +[ 	]*54[ 	]+lock and eax,ebx
> +[ 	]*55[ 	]+lock and ebx,0x64
> +[ 	]*56[ 	]+lock btc ebx,eax
> +[ 	]*57[ 	]+lock btc ebx,0x64
>  \fGAS LISTING .*

.. please abstract away line numbers (see many other testcases) rather
than updating them here.

> --- a/gas/testsuite/gas/i386/x86-64-lockbad-1.s
> +++ b/gas/testsuite/gas/i386/x86-64-lockbad-1.s
> @@ -41,6 +41,7 @@ foo:
>  	lock sbb (%rbx), %eax
>  	lock sub (%rbx), %eax
>  	lock xor (%rbx), %eax
> +	lock wrmsrns

I wonder whether this is really necessary. If you limited yourself to ...

>  	.intel_syntax noprefix
>  	lock mov eax,ebx
> @@ -82,3 +83,4 @@ foo:
>  	lock sbb eax,DWORD PTR [rbx]
>  	lock sub eax,DWORD PTR [rbx]
>  	lock xor eax,DWORD PTR [rbx]
> +	lock wrmsrns

... this addition (which already seems excessive, as we don't test
the majority of insns here anyway), the overall diff to the testcase
would end up much smaller.

> --- /dev/null
> +++ b/gas/testsuite/gas/i386/x86-64-wrmsrns-intel.d
> @@ -0,0 +1,12 @@
> +#as:
> +#objdump: -dw -Mintel
> +#name: x86_64 WRMSRNS insns (Intel disassembly)
> +#source: wrmsrns.s

It's not just the source which can be shared here, but also the output
expectations.

> --- a/opcodes/i386-opc.tbl
> +++ b/opcodes/i386-opc.tbl
> @@ -3326,3 +3326,9 @@ aor, 0xf20f38fc, None, CpuRAOINT, Modrm|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|No_ld
>  axor, 0xf30f38fc, None, CpuRAOINT, Modrm|IgnoreSize|No_bSuf|No_wSuf|No_sSuf|No_ldSuf,{ Reg32|Reg64, Dword|Qword|Unspecified|BaseIndex}
>  
>  // RAOINT instructions end.
> +
> +// WRMSRNS instructions.
> +
> +wrmsrns, 0x0f01c6, None, CpuWRMSRNS, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, {}
> +
> +// WRMSRNS instructions end.

Nit: Use singular in the comments?

Jan