[LLVMdev] Some bugs in x86 disasm (llvm-mc)

[Craig Topper]

I started trying to fix this tonight but it's pretty nasty to fix. I'll try
to make another go at it later this week.


On Tue, Jan 14, 2014 at 5:47 AM, Jun Koi <junkoi2004 at gmail.com> wrote:

>
>
>
> On Thu, Nov 28, 2013 at 1:03 AM, Kay Tiong Khoo <kkhoo at perfwizard.com>wrote:
>
>> Hi Jun,
>>
>> I'm not sure how to fix this yet, but this looks incorrectly defined in
>> lib/Target/X86/X86InstrInfo.td:
>>
>> def MOV32o32a : Ii32 <0xA1, RawFrm, (outs), (ins offset32:$src),
>>                       "mov{l}\t{$src, %eax|eax, $src}", [], IIC_MOV_MEM>,
>>                      Requires<[In32BitMode]>;
>>
>> This instruction can be REX-prefixed for a 64-bit move, and that also
>> doesn't appear to be defined anywhere.
>>
>> I would file a bugzilla in the x86 component and cc Craig Topper, the x86
>> disasm/codegen expert.
>>
>>
>>
>> On Wed, Nov 27, 2013 at 8:56 AM, Jun Koi <junkoi2004 at gmail.com> wrote:
>>
>>> Hi,
>>>
>>> With objdump, i have this (Intel syntax)
>>>
>>>          64 a1 00 00 00 00        mov    eax,fs:0x0
>>>
>>>
>>> However, if I pass above string to llvm-mc, I would have:
>>>
>>> $ echo "0x64 0xa1 0x00 0x00 0x00 0x00"|./Release+Asserts/bin/llvm-mc
>>> -disassemble -arch=x86 --output-asm-variant=1
>>>     .text
>>>     mov    eax, dword ptr [0]
>>>
>>>
>>> You can see a big difference. This is on the latest code. Any idea how
>>> to fix this bug?
>>>
>>>
> Any plan to fix this bug?
>
> Thanks.
>
>
>
>


-- 
~Craig
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140114/0c4d3cb1/attachment.html>