[Bug sanitizer/55975] asan does not work with 46 bit address space on PowerPC64

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55975

--- Comment #33 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-23 13:40:57 UTC ---
(In reply to comment #31)
> I've committed an upstream change
> http://llvm.org/viewvc/llvm-project?view=rev&revision=173260 that makes
> kHighMemEnd dynamic. 
> Hopefully, it will simplify further changes. 
> 
> I'd appreciate if someone who has access to a 46-bit AS machine 
> propose a patch that works for both 44 and 46 AS w/ and w/o unlimited stack.

Do you really want to make kHighMemEnd dynamic always?  Shouldn't it be dynamic
only when needed (i.e. for configurations like ppc64 which now require it)?
Otherwise it will slow down many of the inlines that use this heavily.
Furthermore, in configurations where kHighMemEnd is dynamic, also IMHO all
asan_mapping.h defines that are based on it should also be global variables
to avoid unnecessary runtime computations everywhere.
I mean kHighMemBeg, kHighShadowBeg, kHighShadowEnd, kShadowGapEnd.