2.10.91: A problem with R_MIPS_CALL relocations within gas

[Josh Scheid]

On Fri, Nov 17, 2000 at 10:40:18AM -0800, Josh Scheid wrote:
> >    Date: Fri, 17 Nov 2000 18:11:21 +0100 (MET)
> >    From: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>
> > 
> >    Gcc however prefers to
> >    generate code like the following:
> > 
> >    la $25,<symbol>
> >    jalr $25
> > 
> >    possibly because there are problems with other MIPS assemblers.
> 
> On Fri, Nov 17, 2000 at 09:16:52AM -0800, Ian Lance Taylor wrote:
> > FYI, gcc does this to permit better instruction scheduling.  Splitting
> > up the instructions permits, e.g., putting the la instruction in a
> > delay slot.  Other MIPS toolchains do extensive instruction scheduling
> > in the assembler, but in the GNU toolchain gcc can do a better job of
> > that.
> 
> What "LA" instruction?
> 
> I guess if all your symbols are under 0x00010000, LA 

Oops, didn't complete my thought.  LA is not an actual MIPS instruction, but 
an assembler tool that may become replaced with multiple instructions.  The
following won't work for all cases if you expect the LA to be complete when
execution gets to LabelFoo.

  beq   $0, $0, LabelFoo
  la    $1, <LabelBar>

-Josh

-- 
Josh Scheid		jscheid@sandcraft.com
Sandcraft, Inc.		408.490.3236