Messages in this thread | | | Date | Tue, 03 Jul 2007 16:10:31 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [patch 06/10] Immediate Value - i386 Optimization |
| |
Chuck Ebbert wrote: > On 07/03/2007 04:18 PM, H. Peter Anvin wrote: > >> One could, though, use an indirect jump to achieve, if not as good, at >> least most of the effect: >> >> movl $<patchable>,<reg> >> jmp *<reg> >> >> > > Yeah, but there's this GCC bug: > > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22448 > > You can't even dereference labels in an ASM statement.
I was told in absolute terms that any use of &&label other than to pass it to goto was not supported, and would not be supported.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29305
Seems that passing to an asm() falls into the same class of problem I had. I think the underlying problem is that if the code containing the label is in an inlined function or unrolled loop, the reference can't be resolved properly anyway.
J - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |