tree 873a77cf0b47c92fbdc5cb8dd8baa7583c26bbfd
parent 115b2ce1c3b974e43e45fa6c9e20cd7271a01dff
author Anton Blanchard <anton@samba.org> 1136877680 +1100
committer Linus Torvalds <torvalds@g5.osdl.org> 1136910755 -0800

[PATCH] Work around ppc64 compiler bug

In the process of optimising our per cpu data code, I found a ppc64
compiler bug that has been around forever. Basically the current
RELOC_HIDE can end up trashing r30. Details of the bug can be found at

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25572

This bug is present in all compilers before 4.1. It is masked by the
fact that our current per cpu data code is inefficient and causes
other loads that end up marking r30 as used.

A workaround identified by Alan Modra is to use the =r asm constraint
instead of =g.

Signed-off-by: Anton Blanchard <anton@samba.org>
[ Verified that this makes no real difference on x86[-64] */
Signed-off-by: Linus Torvalds <torvalds@osdl.org>