[lkml]   [2006]   [Aug]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Unnecessary Relocation Hiding?
Sorry for perhaps extending the specific question to a more generic
one. In which cases shall we, in current or future development,
prevent gcc from knowing a pointer-addition in the way RELOC_HIDE? And
in what cases shall we just write pure C point addition?

After all, we are writing an OS in C not in pure assembly, so I am
just trying to learn some generial rules to mimize the raw assembly in


2006/8/25, Paul Mackerras <>:
> Christoph Lameter writes:
> No, RELOC_HIDE came from ppc originally. The reason for it is that
> gcc assumes that if you add something on to the address of a symbol,
> the resulting address is still inside the bounds of the symbol, and do
> optimizations based on that. The RELOC_HIDE macro is designed to
> prevent gcc knowing that the resulting pointer is obtained by adding
> an offset to the address of a symbol. As far as gcc knows, the
> resulting pointer could point to anything.
> It has nothing to do with linker relocations.
> Paul.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2006-08-25 03:35    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean