Messages in this thread | | | From | Andi Kleen <> | Subject | Re: [Bugme-new] [Bug 7602] New: Failure on compilation: include/asm/bitops.h:122: error: inconsistent operand constraints in an `asm' in nfs_access_add_cache() | Date | Thu, 30 Nov 2006 23:49:12 +0100 |
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On Thursday 30 November 2006 23:32, Andrew Morton wrote: > On Thu, 30 Nov 2006 23:22:00 +0100 > Andi Kleen <ak@suse.de> wrote: > > > > > > > static __inline__ int __test_and_set_bit(int nr, volatile void * addr) > > > { > > > int oldbit; > > > > > > __asm__( > > > "btsl %2,%1\n\tsbbl %0,%0" > > > :"=r" (oldbit),"+m" (ADDR) > > > :"dIr" (nr)); > > > return oldbit; > > > } > > > > > > explodes with gcc-3.4.4. > > > > Known issue. The new form is correct and needed, but the old gcc doesn't accept > > it. I haven't gotten a form that is both and correct and works on the old compiler > > out of the gcc hackers I asked. > > Oh, thanks. > > What does "d" do, btw? My gcc info page only covers "x86" and says only "`d' register"
Hmm, normally edx (aka Extended D register eXtended :) or rdx
But you're right it doesn't make sense here because 'd' is already included in 'r'. Probably should be dropped.
> > (And, more importantly, where is the best description of gcc asm constraints?)
Either info pages or gcc source. There was also a web page somewhere with a tutorial, but i don't think it was a full reference.
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