This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Question about Machine Description


Is it any way that we can chat?
I'm working on my thesis project and a paper. I appreciate it if you would
cooperate in this project.
I have gmail Id "amir.yazdanbakhsh"
and also skype "amir.yazdanbakhsh"

best regards,

yazdanbakhsh wrote:
> 
> Hi,
> 
> Please assume I'm working with the MIPS. There is a little difference
> between the MIPS and what I'm actually working on it. How can I remove
> immediate logical shift right/left from the compiler?
> I mean If I want the programmer writes an immediate shift, It is compiled
> to the two instructions:
> 
> sll %2,%2,5
> 
> changed to:
> 
> addi %3,%0,5
> sllv %2,%2,%3
> 
> thanks in advance
> 
> Ian Lance Taylor-3 wrote:
>> 
>> yazdanbakhsh <amir.yazdanbakhsh@gmail.com> writes:
>> 
>>> I'm working on my a gcc compiler for my own written processor with the
>>> help
>>> of SimpleScalar.
>>> I want to remove "srav/slav" (immediate arithmetic shift) from the
>>> instruction set. I explore ss.md file but I didn't see any define_ins
>>> for
>>> the mentioned instructions, but they are used in other instruction
>>> definitions.
>>> It is also exist for addi/addui. Where I can find the definitions of
>>> these
>>> instructions? I want to force gcc to just use register shift and
>>> register
>>> add.
>> 
>> There is no ss.md file in the standard gcc distribution.  If
>> SimpleScalar has a gcc port, I don't know anything about it.  So it's
>> hard to answer to your question precisely.
>> 
>> Instructions can come from either a .md file or a .c file in the
>> config/CPU directory used for your CPU.  If those instructions are
>> appearing in the generated assembler, then they must be in there
>> somewhere.
>> 
>> Ian
>> 
>> 
> 
> 

-- 
View this message in context: http://old.nabble.com/Question-about-Machine-Description-tp1026428p28439854.html
Sent from the gcc - Dev mailing list archive at Nabble.com.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]