Re: [PATCH] X86: Disassemble primary opcode map's group 2 ModRM.reg == 6 aliases correctly

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

On Tue, May 30, 2017 at 7:41 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>> On 30.05.17 at 16:35, <hjl.tools@gmail.com> wrote:
>> On Tue, May 30, 2017 at 1:37 AM, Borislav Petkov <bp@suse.de> wrote:
>>> On Tue, May 30, 2017 at 02:34:28AM -0600, Jan Beulich wrote:
>>>> which I think should read
>>>>
>>>> "The CF flag contains the value of the last bit shifted out of the
>>>>  destination operand; for instructions other than SAR it is undefined
>>>>  when the count is greater than or equal to the size (in bits) of
>>>>  the destination operand."
>>>
>>> Makes sense.
>>
>> I look another look.  Disassembler always display "shl".  Please
>> don't use "sal" now.
>
> Which disassembler are you talking about, as you can't mean
> objdump or anything else that's libopcode-based?

[hjl@gnu-6 tmp]$ cat x.s
shl %cl, %eax
sal %cl, %eax
shl $1, %eax
sal $1, %eax
[hjl@gnu-6 tmp]$ gcc -c x.s
[hjl@gnu-6 tmp]$ objdump -dw x.o

x.o:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <.text>:
   0: d3 e0                 shl    %cl,%eax
   2: d3 e0                 shl    %cl,%eax
   4: d1 e0                 shl    %eax
   6: d1 e0                 shl    %eax
[hjl@gnu-6 tmp]$ objdump -dw -Mintel x.o

x.o:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <.text>:
   0: d3 e0                 shl    eax,cl
   2: d3 e0                 shl    eax,cl
   4: d1 e0                 shl    eax,1
   6: d1 e0                 shl    eax,1
[hjl@gnu-6 tmp]$



-- 
H.J.