llvm dev - May 2013 - [LLVMdev] bug report on MC asm parser evaluating expressions

Hi, developers,

I notice following asm symbol definitions are eveluated improperly:

A = 9
B = 3*A - 2 * A + 1

the value of B should be 10 instead of 8.

It seems asm parser treat "B = 3*A - 2 * A + 1" as "B = 3*A - (2
* A + 1)"
because the second "*" has higher precedence than "-", and
evaluation just
performs simple recursion within AsmParser::ParseBinOpRHS (which resides in
file lib/MC/MCParser/AsmParser.cpp).

Can some one make a fixup?

Regard.
-- 
杨勇勇 (Yang Yong-Yong)
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On 3 May 2013 01:37, 杨勇勇 <triple.yang at gmail.com>
wrote:
> Hi, developers,
>
> I notice following asm symbol definitions are eveluated improperly:
>
> A = 9
> B = 3*A - 2 * A + 1
>
> the value of B should be 10 instead of 8.
>
> It seems asm parser treat "B = 3*A - 2 * A + 1" as "B = 3*A
- (2 * A + 1)"
> because the second "*" has higher precedence than "-",
and evaluation just
> performs simple recursion within AsmParser::ParseBinOpRHS (which resides in
> file lib/MC/MCParser/AsmParser.cpp).
>
> Can some one make a fixup?
This is a horrible bug :-(

Can you please report it in llvm.org/bugs?

Thanks,
Rafael

I just fixed this with r181366.
URL: http://llvm.org/viewvc/llvm-project?rev=181366&view=rev

Kev

On May 3, 2013, at 5:23 AM, Rafael Espíndola <rafael.espindola at
gmail.com> wrote:
> On 3 May 2013 01:37, 杨勇勇 <triple.yang at gmail.com> wrote:
>> Hi, developers,
>> 
>> I notice following asm symbol definitions are eveluated improperly:
>> 
>> A = 9
>> B = 3*A - 2 * A + 1
>> 
>> the value of B should be 10 instead of 8.
>> 
>> It seems asm parser treat "B = 3*A - 2 * A + 1" as "B =
3*A - (2 * A + 1)"
>> because the second "*" has higher precedence than
"-", and evaluation just
>> performs simple recursion within AsmParser::ParseBinOpRHS (which
resides in
>> file lib/MC/MCParser/AsmParser.cpp).
>> 
>> Can some one make a fixup?
> 
> This is a horrible bug :-(
> 
> Can you please report it in llvm.org/bugs?
> 
> Thanks,
> Rafael
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
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