Hello, Dr. Uday Khedker:
I just found that emit_move_insn function can't be used in define_expand
pattern in the spim gcc4.0.2 platform. It will cause the Segmentation Fault.
Something like recursion happened.
I changed the define_expand "movsi" from:
(define_expand "movsi"
[(set (match_operand:SI 0 "nonimmediate_operand" "")
(match_operand:SI 1 "general_operand" "")
)]
""
{
if(GET_CODE(operands[0])==MEM && GET_CODE(operands[1])!=REG)
{
if(!no_new_pseudos)
{
operands[1]=force_reg(SImode,operands[1]);
}
}
}
)
to :
(define_expand "movsi"
[(set (match_operand:SI 0 "nonimmediate_operand" "")
(match_operand:SI 1 "general_operand" "")
)]
""
{
if(GET_CODE(operands[0])==MEM && GET_CODE(operands[1])!=REG)
{
if(!no_new_pseudos)
{
operands[1]=force_reg(SImode,operands[1]);
}
}
printf("Here1\n");
emit_move_insn (operands[0], operands[1]);
printf("Here2\n");
DONE;
}
)
The string 'Here2' nerver come out. Before Segmentation fault occurred, cc1
prints lots of the 'Here1'. So I guess the function emit_move_insn caused the
recursion. But I checked the mips md files. Mips also used the emit_move_insn
function in define_expand "movsi" pattern. So I guess whether I missed
something in md file. Can you give me any advices?
Thank you very much.
Best Wishes.
Tian Xiaonan
--- On Tue, 12/9/08, Uday P. Khedker <[email protected]> wrote:
> From: Uday P. Khedker <[email protected]>
> Subject: Re: redundancy code
> To: [email protected]
> Date: Tuesday, December 9, 2008, 12:25 PM
> Hi Tian,
>
> The goal of our machine descriptions has been to identify
> the
> minimal and hence essential parts of machine descriptions
> in
> order to generate correct code. Improving the code quality
> has
> not been addressed in these descriptions. In due course of
> time,
> we should be able to devise methodology for developing
> machine
> descriptions that address optimizations also.
>
> If you are interested in pursuing this idea, I will be
> happy to
> interact with you.
>
> With best regards,
>
> Uday Khedker.
> ----------------------------------------------------------------------
> Dr. Uday Khedker
> Associate Professor
> Department of Computer Science & Engg.
> IIT Bombay, Powai, Mumbai 400 076, India.
> email : [email protected]
> homepage: http://www.cse.iitb.ac.in/~uday
> phone : Office - 91 (22) 2576 7717
> Res. - 91 (22) 2576 8717, 91 (22) 2572 0288
> ----------------------------------------------------------------------
>
>
> > Hello,
> > I used the spim5 gcc 4.0.2 to study gcc port. but I
> found there are
> > lots of the 'move' insns redundancy code. For
> example, the C code like
> > this:
> > i=1;
> > i = i + 5;
> > the Spim compiler will generate the code like the
> following(PS:RX is the
> > register) .
> > li R0, #1
> > SW R0, 0(MEM)
> > LW R0, 0(MEM)
> > Addi R0, R0, #5
> > SW R0, 0(MEM)
> >
> > Obviously, there are two insn redundancy. What
> confused me is how it
> > generated. Is problem in the 'define_insn mov'
> pattern or the
> > define_peephole insn?
> >
> > spim5 porting backend code
> >
> here:http://www.cse.iitb.ac.in/~uday/gcc-workshop/downloads/IITB-Incremental-Machine-Descriptions/
> > Thank you.
> >
> Tian Xiaonan
> >
> >
> >
> >
> >
> ___________________________________________________________
> >
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> >
