Hi Sam,
I have tried to use __attribute__((section("xxx")), but it seems there
are no linker options to force a particular alignment for a section
for ELF. All those nice alignment options refers to Windows:
--section-alignment
Sets the section alignment. Sections in memory will
always begin at addresses which are a multiple of this number.
Defaults to 0x1000. [This option is specific to the i386 PE targeted
port of the linker]
I can only force the section to start on a particular address when
loaded. Then it works. But this is not what as I have no idea what the
address should be.
Have I missed something?
Regards, Igor
On 27/02/2008, Sam Ravnborg <sam@xxxxxxxxxxxx> wrote:
> On Wed, Feb 27, 2008 at 01:51:10PM +0100, Igor Bukanov wrote:
> > Hi,
> >
> > is it possible with GCC 4.1 to align one single function on a CPU page
> > boundary for ELF targets? This is very desired since the function in
> > question is an interpreter loop . It has 50K of code and is executed
> > very often. Aligning it on the page boundary should reduce TLB misses.
> >
> > It seems the forthcoming GCC 4.3 allows that as it supports the align
> > attribute for functions, but it would be nice to do that with GCC
> > 4.1.
>
>
> One way is to use the section attribute to tell gcc to put the
> function in a specific section and then in the linker script
> page align said section.
> This is used extensively in the linux kernel.
>
>
> Sam
>
