mips5kc - cpu registers

mips5kc - cpu registers

[Amit.Lubovsky]

Hi,
is there a possibility to use cpu registers in the code (temporarily)
instead of allocating 
automatic variables something like:
	func a()
	{
		FAST int, i, tmp;
		tmp = ...
		...
	}

as in vxWorks ?

Thanks,
Amit.

Re: mips5kc - cpu registers

[Juan Quintela]

>>>>> "amit" == Amit Lubovsky <Amit.Lubovsky@infineon.com> writes:

amit> Hi,
amit> is there a possibility to use cpu registers in the code (temporarily)
amit> instead of allocating 
amit> automatic variables something like:
amit> func a()
amit> {
amit> FAST int, i, tmp;
amit> tmp = ...
amit> ...
amit> }

theorically, 
             register int i, tmp;

should de that, but I think that no modern compiler will honour the
register keyword.  Anyways, you should be doing something really
strange for the  compiler not to choose a register for a local
variable when it should automagically.

Later, Juan.


-- 
In theory, practice and theory are the same, but in practice they 
are different -- Larry McVoy

Re: mips5kc - cpu registers

[Kevin D. Kissell]

In general, gcc (and most other compilers)
will do this for you automatically if you enable
any reasonable level of optimization.  There
is no need to designate the variable as "FAST",
one simply needs to avoid having it be global,
static, or volatile.

----- Original Message ----- 
From: <Amit.Lubovsky@infineon.com>
To: <linux-mips@linux-mips.org>
Sent: Monday, March 31, 2003 6:45 PM
Subject: mips5kc - cpu registers


> Hi,
> is there a possibility to use cpu registers in the code (temporarily)
> instead of allocating 
> automatic variables something like:
> func a()
> {
> FAST int, i, tmp;
> tmp = ...
> ...
> }
> 
> as in vxWorks ?
> 
> Thanks,
> Amit.
> 
> 

Re: mips5kc - cpu registers

[Kevin D. Kissell]

In general, gcc (and most other compilers)
will do this for you automatically if you enable
any reasonable level of optimization.  There
is no need to designate the variable as "FAST",
one simply needs to avoid having it be global,
static, or volatile.

----- Original Message ----- 
From: <Amit.Lubovsky@infineon.com>
To: <linux-mips@linux-mips.org>
Sent: Monday, March 31, 2003 6:45 PM
Subject: mips5kc - cpu registers


> Hi,
> is there a possibility to use cpu registers in the code (temporarily)
> instead of allocating 
> automatic variables something like:
> func a()
> {
> FAST int, i, tmp;
> tmp = ...
> ...
> }
> 
> as in vxWorks ?
> 
> Thanks,
> Amit.
> 
> 

Re: mips5kc - cpu registers

[Muthukumar Ratty]

> In general, gcc (and most other compilers)
> will do this for you automatically if you enable
> any reasonable level of optimization.  There
> is no need to designate the variable as "FAST",
> one simply needs to avoid having it be global,
> static, or volatile.

just to add to that... you shouldnt have referred to the address of the
variable. Even if you do, say &tmp, and never assigned it to any ptr,
gcc will not use register for that var.







>
> ----- Original Message -----
> From: <Amit.Lubovsky@infineon.com>
> To: <linux-mips@linux-mips.org>
> Sent: Monday, March 31, 2003 6:45 PM
> Subject: mips5kc - cpu registers
>
>
> > Hi,
> > is there a possibility to use cpu registers in the code (temporarily)
> > instead of allocating
> > automatic variables something like:
> > func a()
> > {
> > FAST int, i, tmp;
> > tmp = ...
> > ...
> > }
> >
> > as in vxWorks ?
> >
> > Thanks,
> > Amit.
> >
> >
>

Re: mips5kc - cpu registers

[Muthukumar Ratty]

> In general, gcc (and most other compilers)
> will do this for you automatically if you enable
> any reasonable level of optimization.  There
> is no need to designate the variable as "FAST",
> one simply needs to avoid having it be global,
> static, or volatile.

just to add to that... you shouldnt have referred to the address of the
variable. Even if you do, say &tmp, and never assigned it to any ptr,
gcc will not use register for that var.







>
> ----- Original Message -----
> From: <Amit.Lubovsky@infineon.com>
> To: <linux-mips@linux-mips.org>
> Sent: Monday, March 31, 2003 6:45 PM
> Subject: mips5kc - cpu registers
>
>
> > Hi,
> > is there a possibility to use cpu registers in the code (temporarily)
> > instead of allocating
> > automatic variables something like:
> > func a()
> > {
> > FAST int, i, tmp;
> > tmp = ...
> > ...
> > }
> >
> > as in vxWorks ?
> >
> > Thanks,
> > Amit.
> >
> >
>