PATCH: Turn mips relaxation if appropriate (Re: MIPS gas relaxation still doesn't work)

["H. J. Lu" <hjl at lucon dot org>]

On Sat, Oct 12, 2002 at 03:51:51PM -0700, H. J. Lu wrote:
> On Sat, Oct 12, 2002 at 11:34:23AM -0700, H. J. Lu wrote:
> > Hi Alexandre,
> > 
> > I don't think your MIPS gas relaxation works. I got
> > 
> > # mipsel-linux-gcc /export/gnu/src/gcc-3.2/gcc/gcc/testsuite/g++.dg/opt/longbranch1.C
> > /tmp/cc0rrnMz.s: Assembler messages:
> > /tmp/cc0rrnMz.s:33733: Error: Branch out of range
> > /tmp/cc0rrnMz.s:33740: Error: Branch out of range
> > 
> > Could you please verify it?
> > 
> 
> I see there are 2 problems:
> 
> 1. -relax-branch is not on by default.
> 2. I got
> 
> Warning: relaxed out-of-range branch into a jump
> 
> If I understand it correctly, -relax-branch is off by default since
> it may generate correct, but worse, code under certain conditions.
> My question is which ABI will generate code like
> 
> 	la	$3,l2-l3
> 
> If only EMBEDDED_PIC does it, why not turn it on for other ABIs?
> 
> Is the warning really necessary? Do other gas targets issue a warning
> for branch/jump relaxation? Does the native mips assembler issuse a
> warning? I changed the mips gas to get rid of some warnings:
> 
> http://sources.redhat.com/ml/binutils/2001-06/msg00101.html
> 
> I hate to see the new ones added for no very good reasons.
> 
> 

I am enclosing a patch to turn on branch relaxation if EMBEDDED_PIC is
not used. Also it won't give a warning if relaxation is on by default.


H.J.

Attachment: gas-mips-relax.patch
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