Re: [PATCH] setup.c: introduce __pa_symbol() and get ride of CPHYSADDR()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Oct 10, 2006 at 06:04:53PM +0200, Franck Bui-Huu wrote:

> ok, and does the trick on KSEG0/XKPHYS really worth ? I mean what is
> the size code gain ?

Gcc / gas generate a 6 instruction sequence to load something from a
64-bit address, basically lui, add, dsll16, add, dsll16, add.  It's
just 2 instructions for 32-bit addresses.  This boils down to space
savings in the hundred of kilobytes for a kernel.

Of course there are more intelligent way to load an address via global
pointer optimization but that's the two choices we got today.

  Ralf


[Index of Archives]     [Linux MIPS Home]     [LKML Archive]     [Linux ARM Kernel]     [Linux ARM]     [Linux]     [Git]     [Yosemite News]     [Linux SCSI]     [Linux Hams]

  Powered by Linux