Hello,
In the discussion:
"Question about merging two instructions"
http://gcc.gnu.org/ml/gcc/2005-08/msg00563.html
You showed me that it might be dangerous to replace rtx on the LHS
of a SET using simplify_replace_rtx ().
simplify_rtx () seems safer, is there a good reason why it doesn't
work wi
Hello,
While reading the function pre_edge_insert () in gcse.c, something
didn't make sense to me:
According to the documentation:
/* Where PRE_INSERT_MAP is nonzero, we add the expression on that edge
if it reaches any of the deleted expressions. */
I understand that before inserting an expr
> > Why not just maintain it in a local tree and post refined
> > versions every now and then, until stage 1 for GCC 4.2 opens?
> > Branches are for major work and a new pass is not that major.
>
> It's also fine to create a new branch for this work. That let's other
> people see what you're wor
Hello,
Is it true that in a SET, a search for a _use_ of a register
in the LHS should be done only inside a memory address?
Like in this SET:
(set (mem:SI (plus:DI (reg:DI 159)
(reg/v/f:DI 150 )))
(subreg/s:SI (reg/v:DI 142 [ j ]) 4)) -1 (nil)
Registers 142, 159 and 150 are
Paolo Bonzini <[EMAIL PROTECTED]> wrote on 22/08/2005 10:10:40:
> > > I tried to use simplify_replace_rtx to replace any use of (reg r)
with[in]
> > > the right-hand-side of the extension and simplify the result.
>
> If he want to replace uses within the RHS of the extension, he should
> pass SE
> > 1. Can you please give me an example of something bad that can happen
to
> > the LHS. Maybe I'm missing something here.
>
> In this case nothing, but if NEW were a subreg, it can change a lot.
Why?
Do I always need to recognize the result?
If the answer is yes, than I suppose that if som
Hello,
I would like to know if someone knows a suitable branch for the sign
extension optimization pass.
This pass stands for itself. There are not many changes to the other
parts of the gcc.
For details see:
http://gcc.gnu.org/ml/gcc-patches/2005-08/msg01087.html
Thanks,
Leehod.
>>(insn 1 0 2 0 (set (reg/v:Xmode r)
>>(sign_extend:Xmode (op:Ymode (...
>>(insn 2 1 3 0 (set (lhs) (rhs)))
> To summarise, the change above is not unreasonable and I'd be
> happy to allow this change to simplify-rtx.c, but I'd be more
> cautious about where and why it was used. For e
Hello,
I'm working on a the sign extension elimination pass.
(see http://gcc.gnu.org/ml/gcc-patches/2005-08/msg01087.html for details)
I would like to merge these two instructions:
(insn 1 0 2 0 (set (reg/v:Xmode r)
(sign_extend:Xmode (op:Ymode (...
(insn 2 1 3 0 (set (lhs) (rhs)))
w
